risc brief jun 2015 final
TRANSCRIPT
FEMA RIX RISC BRIEF – JUNE 2015
DR
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MID APR-MID JUN PRECIPITATION
• Several northern storms brought beneficial rains to northern/western NV, the Sierra & northeast CA• 8-10 inches in the Sierra!• 100-150% of normal
• Rest of CA saw lighter rainfall amounts
• Storms in southern stream brought beneficial rains to much of AZ & southeast CA
• 150-200% of normal
Total Precipitation 4/15/15 – 6/14/15
DROUGHT UPDATE• Late spring storms
• Beneficial storms – short term• Not widespread enough and/or amounts
were not significant enough• Resulted in little change in severity of
drought conditions
• Long-term severe or greater drought continues
• Some level of drought continuesin 74% of the west and 97% of CONUS FR9
HAWAII DROUGHT UPDATE
• Overall dry pattern has developed in recent weeks (except Kauai)
• Dry pattern is forecast to continue over all islands
• Some drought development on Hawaii and Maui
ENSO OUTLOOK
• CPC continues an El Niño Advisory• A >90% chance that El Niño
conditions/impacts will continue through the Northern Hemisphere fall 2015
• Around an 85% chance that it will last through the 2015-16 winter
• Models are more robust this month vs. last month for the upcoming winter
• Supported by:• Increased SST anomalies• Increased subsurface temperatures• Enhanced convection over the Date
Line• Increased persistence of low-level
westerly winds
Weak
ModerateStrong
30/90/180 DAY OUTLOOK
• Above normal temperatures are favored throughout the far west thru Sep 2015
• Especially northern CA/western NV
• Above normal precipitation is favored over parts of eastern NV/NE AZ…an extension of the wet weather expected over the Rockies this summer
• Above normal precipitation is favored over all of AZ, southern CA, and extreme southern NV in the fall/early winter• In association with an expected active
eastern Pacific TC season• Expected influence from a moderate
to possibly strong El Niño condition
Jun 2015 Jun 2015
JAS 2015 JAS 2015
OND 2015 OND 2015
DROUGHT OUTLOOK
• Drought is forecast to persistor worsen through Aug 2015• Essentially all of CA & NV
• Potential drought impacts• Continued stress on water
resources• Water rationing• Water quality• Greater number of dust storms
negative impacts on air quality• Crop damages• Livestock sell off• Widespread fire season
• Influence/improvements from the developing El Niño not expected until fall/winter
Jul-Aug-Sep El Nino Precipitation Distribution (in) for Arizona
Median
KEY
Middle 1/3 cases
Upper1/3 cases
Lower1/3 cases
90%tile
67%tile
33%tile
10%tile
Climate Division 95 Climate Division 96
Climate Division 98Climate Division 97
EL NIÑO & THE NORTH AMERICAN MONSOON
• Previous 5 established or emerging El Niño years were examined
• Trend toward a delayed onset• Trend is towards lower than
normal rainfall totals during these El Niño seasons• Certainly not every year
• Even in a typical monsoon season• Rainfall distribution can be
extremely disparate• Making a seasonal forecast based
on El Niño for any given location carries very limited skill
Rainfall totals for AZ WFO locations
http://www.atmo.arizona.edu/~castro/Reviewedpubs/R-1.pdf
http://www.nhc.noaa.gov/climo/
-Agency change in 1970
-Better satellite images and analysis techniques
Long-term average:• 15 NS
• 8 H• 4 MH
http://www.nhc.noaa.gov/climo/
Eastern Pacific Tropical Cyclones by Date
1971 - 2009
Several peaks evident in the season• Related to the ITCZ
http://www.nhc.noaa.gov/climo/
Frequency of Eastern Pacific Tropical Cyclone Formation by Location
1971 - 2009
2015 EP Season Outlook
15-22 Named Storms7-12 Hurricanes
5-8 Major Hurricanes
“El Niño is the main climate factor expected to enhancethe 2015 eastern Pacific hurricane season”
http://www.nhc.noaa.gov
CP Tropical Weather Climatology• Central Pacific (Avg/Yr)
– 4-5 Tropical Cyclones
• 1970 to 2014– 186 Tropical Cyclones
www.weather.gov/cphc
• Three Direct Hits(since 1950)
– Dot (1959), Iwa (1982), Iniki (1992)
– Total damage more than $3.25 billion
•
Januar
y
Febru
ary
Mar
chApril
May
June
July
August
Septe
mber
October
Novem
ber
Decem
ber0
10
20
30
40
50
60
70
80
20 1 1 0 1
46
76
36
18
3 2
Central Pacific Tropical Cyclones by Month1970 - 2014
www.weather.gov/cphc
CP TC Climate Factors• El Niño conditions
typically mean a more active TC season in the Central Pacific. (6-7/yr since 1970)
• La Niña conditions typically mean a less active TC season in the Central Pacific. (3/yr since 1970)
www.weather.gov/cphc
La Niña
El Niño
Neutral
2015 CP Season Outlook
5-8 Tropical Cyclones
70% Above Normal Season25% Normal Season (4-5 TCs)
5% Below Normal Season
El Niño conditions expected to strengthen during the season
PACIFIC TROPICAL CYCLONE SUMMARY/OUTLOOK
• Eastern Pacific• 15-22 Named Storms• 7-12 Hurricanes• 5-8 Major Hurricanes
• Central Pacific• 5-8 Tropical Cyclones
• Western Pacific• Five named TCs already!• 1CAT5, 1CAT3, 1CAT1• Higher than normal• >/= to 30 named TCs
• Southern Pacific• Off Season
2014 tracks
Pacific Typhoon Tracks 1980-2005
SUMMARY• Spring storms brought beneficial rains in the short-term to portions of northern
CA/NV, the Sierra, and much of AZ and southeast CA• Resulted in little change in severity of drought conditions• Long-term severe or greater drought continues
• 97% of CONUS FR9• Drought is forecast to persist or worsen through Aug 2015
• Nearly all of CONUS FR9• Numerous potential impacts continue
• An El Niño Advisory continues• >90% chance it will continue through the NH fall 2015 and likely through the
upcoming 2015-16 winter• While intensity is difficult to forecast, a weak to moderate El Niño winter is likely and
a moderate to strong El Niño winter is possible• Above normal temperatures are favored throughout much of the far west through
summer 2015• A delayed start to the summer monsoon is favored• A trend exists toward lower summer monsoon seasonal rainfall but this skill is very
limited• Above normal precipitation is favored over all of AZ, southern CA, and extreme
southern NV for the fall/early winter in association with the developing El Niño
Questions and Contacts
WR Duty Officer 801-524-7907 [email protected]
Bill Ward 808-532-6415 [email protected]
www.weather.gov "Climate is what you expect,
Weather is what you get". ~ R. Heinlein