Pilots Peak Winter Weather: Assessing conditions …...Adiabatic Cooling & Orographic Precip In english units… Dry = 5.5 F/1,000 ft Wet = 3.0 F/1,000 ft Generally unless an inversion
39
Winter Weather: Assessing conditions before the trailhead Jeff Anderson Hydrologist NRCS Snow Survey Boise, ID [email protected]Pilots Peak January 22, 2011
Winter Weather Assessing conditions before the trailhead
Jeff Anderson
Hydrologist
NRCS Snow Survey
Boise ID
jeffandersonidusdagov
Pilots Peak
January 22 2011
Presenter
Presentation Notes
Large avalanches can occur in the Boise backcountry
What are Red Flag conditions
bull Observations
bull Precipitation
bull Wind
bull Temperature
Presenter
Presentation Notes
Observations 13Recent natural slides whumpfs cracks13Precipitation 13Snowfall greater than 1rdquohr or 10rdquoday13Rain on snow13Wind13Sustained wind greater than 15 mph 13Temperature13Rapid warming that goes above freezing13Springtime ndash no freeze only thaw13Snowfall after hoar frost (cold clear)
What Happened SNOTEL Products
What Going to Happen
Weather Service
Pre-trip Weather Assessment
Now
Snow depth sensor
Precipitation gage
Snow pillow
Trinity Mountain SNOTEL
Temp Sensor SNOTEL
stands for SNOw
TELemetry
Presenter
Presentation Notes
Typical snotel site13SNOTEL snow telemetry13Items measured ndash snow water snow depth temp sensor precip some have wind too13Run by solar and batteries13
This gage is 16ft tall
Trinity Mountain SNOTEL March 2006
March 2006
Presenter
Presentation Notes
Site in winter
Weight of frozen water (Snow amp Ice)
Weight of liquid water
Snow Water Equivalent (SWE or WTEQ)
7800ft
7800ft
Ideal SNOTEL Location
North Aspect Mid-Elevation
Sheltered Summer road
access
Mores Ck Summit SNOTEL (6100ft)
Presenter
Presentation Notes
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Observations 13Recent natural slides whumpfs cracks13Precipitation 13Snowfall greater than 1rdquohr or 10rdquoday13Rain on snow13Wind13Sustained wind greater than 15 mph 13Temperature13Rapid warming that goes above freezing13Springtime ndash no freeze only thaw13Snowfall after hoar frost (cold clear)
What Happened SNOTEL Products
What Going to Happen
Weather Service
Pre-trip Weather Assessment
Now
Snow depth sensor
Precipitation gage
Snow pillow
Trinity Mountain SNOTEL
Temp Sensor SNOTEL
stands for SNOw
TELemetry
Presenter
Presentation Notes
Typical snotel site13SNOTEL snow telemetry13Items measured ndash snow water snow depth temp sensor precip some have wind too13Run by solar and batteries13
This gage is 16ft tall
Trinity Mountain SNOTEL March 2006
March 2006
Presenter
Presentation Notes
Site in winter
Weight of frozen water (Snow amp Ice)
Weight of liquid water
Snow Water Equivalent (SWE or WTEQ)
7800ft
7800ft
Ideal SNOTEL Location
North Aspect Mid-Elevation
Sheltered Summer road
access
Mores Ck Summit SNOTEL (6100ft)
Presenter
Presentation Notes
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Typical snotel site13SNOTEL snow telemetry13Items measured ndash snow water snow depth temp sensor precip some have wind too13Run by solar and batteries13
This gage is 16ft tall
Trinity Mountain SNOTEL March 2006
March 2006
Presenter
Presentation Notes
Site in winter
Weight of frozen water (Snow amp Ice)
Weight of liquid water
Snow Water Equivalent (SWE or WTEQ)
7800ft
7800ft
Ideal SNOTEL Location
North Aspect Mid-Elevation
Sheltered Summer road
access
Mores Ck Summit SNOTEL (6100ft)
Presenter
Presentation Notes
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Typical snotel site13SNOTEL snow telemetry13Items measured ndash snow water snow depth temp sensor precip some have wind too13Run by solar and batteries13
This gage is 16ft tall
Trinity Mountain SNOTEL March 2006
March 2006
Presenter
Presentation Notes
Site in winter
Weight of frozen water (Snow amp Ice)
Weight of liquid water
Snow Water Equivalent (SWE or WTEQ)
7800ft
7800ft
Ideal SNOTEL Location
North Aspect Mid-Elevation
Sheltered Summer road
access
Mores Ck Summit SNOTEL (6100ft)
Presenter
Presentation Notes
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Compare avy weather location with SNOTEL13Mores Ck represents worse possible conditions (low elev) 13To get insight into what happened higher on mtn you can 13 rely on some properties of atmosphere13 look at data from a nearby site with a higher elev13
Adiabatic Cooling amp Orographic Precip
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
In english unitshellip Dry = 55degF1000 ft Wet = 30degF1000 ft
Presenter
Presentation Notes
Generally unless an inversion is present the atmosphere cools with elevation at a steady rate13Rate depends on atmospherersquos degree of saturation1313If the atmosphere is dry it cools at a rate of 3C or 55F degrees per 1000F13If the atmosphere is saturated (storming) it cools at a rate of 15C or 3F per 1000F1313As a storm system moves over mountains it is orographically lifted The adiabatic cooling causes orographic precipitation 13This lifting is the main reason the mountains get more precipitation than valley locations 13 13The windier a storm the more rapid the lifting and the greater the amount of precipitation that will fall
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
What is the magic temp for Boise during a storm that will produce snow at Bogus
6100ft 32 F
2700ft F
3400ft difference
Dry lapse rate = 55degF1000 ft Wet late rate = 30degF1000 ft
httpwwwwccnrcsusdagovsnow
Dai
ly D
ata
Presenter
Presentation Notes
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Did it snow How do you know13Total snow depth not snowfall ndash VERY IMPORTANT13How many inches of new snow fell in this 7 day period13 8rdquo increase between 119 and 1114 10rdquo from 119-1113 11rdquo total 12rdquo if you include the extra tenth on 111513What happened between 119 and 1111 did it really snow 13 Yes 2 inches of snowfall followed by a high of 43F and 2rdquo of settling 01rdquo gain in SWE and 2rdquo gain in depth = 5 snow13Talk about -999
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Wind new light powder falling or blowing snow fog rime or snow build-up on sensor can prevent the sound pulse from making a return trip from sensor to snow and back No measurement = -999
-999 = itrsquos probably snowing
Hou
rly
Dat
a
Presenter
Presentation Notes
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
How much did it snow 7 inches (not 12 inches) remember total snow depth not snowfall13How good was the snow Calc 10 density Look at observed temperature relatively cold but not really cold Getting colder13Can you estimate how many inches of new snow were present at 200 9 inches because two tenths of new swe 01rdquoswe=1rdquosnowfall13
Mores Ck Summit ndash 6100 ft January 2012
48rdquo
Presenter
Presentation Notes
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Good graph to track trends in the hourly data1313Lets think back to our red flag conditions and see which ones we can see in this graph1313Snowfall = Notice 48rdquo of new snowdepth added in 3 day period (average 16rdquo per day)13Temp = What happened with temp as snowfell that would alert you to an upside down snowpack13Warmed from 5F to above freezing Snow density increasing13What kind of conditions existed prior to storm13Clear (no precip) and cold couple days of temps lt15F
Trinity Mtn - 7770ft Jan 2012
54rdquo
Presenter
Presentation Notes
Compare to higher site orographics produced 6rdquo more inches of snow13Temp barely got to freezing at 7800ft
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Jet Stream is influenced by ocean conditions in the central Pacific13Cold Ocean temps = La Nina Warm = El Nino13During El Nino the storm tracks are typically pushed south the PNW is warm and dry13During La Nina the Polar Jet and Pacific Jet tend to converge on PNW bring coldstormy weather
36
Nov 2010 ndash Strong La Nina
Nov 2011 ndash Weak La Nina
November 2012 - Neutral
Presenter
Presentation Notes
LaNina = cold
Presenter
Presentation Notes
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
This graphs ranks each winter from low to high for Boise basin Pink are el nino winters blue la nina and white neutral13Slightly more neutral ENSO winters have been above normal than below but its no gaurantee
In 2006 Bogus opened 122
Presenter
Presentation Notes
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
Out of the last 10 years all three neutral winters have been above average132006 was my first winter in Idaho and Bogus opened right after Thanksgiving
Winter WeatherAssessing conditions before the trailhead
