a climate study of above and below normal temperatures along with longevity (is there a pattern?)...
TRANSCRIPT
A CLIMATE STUDY of ABOVE and BELOW
NORMAL TEMPERATURESALONG with LONGEVITY
(Is there a Pattern?)
Matthew Masek
(WFO North Platte, NE)
OUTLINE• Data Set• Above and Below Normal Average Temps
– A look at the numbers– Patterns/Signals??
• Consecutive Days – Above/Below Normal Average Temps– 20+ Days, 25+ Days, 30+ Days
• By Years (pattern/signal??)• By Time of Year - Months (pattern/signal??)
• Final Thoughts
DATA SET
• North Platte (LBF) – (used exclusively)
• Existing Data Set– Sept 18, 1874 to Present
• Used– Jan 1, 1875 to June 30, 2006* (131.5 Years)
• Ignored Site and Equipment Changes
• Allowed Average T to have .5
DATA SET
• 30 Year Normal for Average T – 1970 to 2000– Assumed representative
• 1870s & 2000s (decades)– Estimated based on partial record
INSIDE THE NUMBERS
• Total Days in the Study– 48,028 Days
• Average T Above Normal– 25,650 Days (53.4%)
• Average T Below Normal– 21,381 Days (44.5%)
• Average T Equal Normal– 997 Days (2.1%)
53.4%
44.5%
2.1%
INSIDE THE NUMBERS
• Difference between Above and Below– 4,269 Days– Over 11.5 Years– Remember ONLY 131.5 Years in Set
That’s 9% more Above Days than
Below Days
How Can That Be?
• Departure of Average T from Normal CAN be More Significant when Below than Above
• February 11, 1899 – High -13, Low -29– Average T = -21 degrees (normal 28 degrees)– Departure from normal 49 degrees
• December 23, 1964– High 74, Low 34 – Average T = 54 degrees (normal 24 degrees)– Departure from normal 30 Degrees
• 279 days with departure below normal 30+279 days with departure below normal 30+˚̊
TOTAL DAYS - BELOW AVERAGE TEMPERATURE
0
50
100
150
200
250
300
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
TOTAL DAYS - BELOW AVERAGE TEMPERATURE
0
50
100
150
200
250
300
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
TOTAL DAYS - ABOVE AVERAGE TEMPERATURE
0
50
100
150
200
250
300
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
TOTAL DAYS - ABOVE AVERAGE TEMPERATURE
0
50
100
150
200
250
300
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
TOTAL DAYS - NORMAL AVERAGE TEMPERATURE
0
5
10
15
20
25
30
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
TOTAL DAYS - ABOVE/NORMAL/BELOW AVERAGE TEMPERATURE
0
50
100
150
200
250
300
350
400
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
YEAR
DA
YS
Below Ave T Above Ave T
• 5 years with most 1978 - 222 (60.8%) 1996 - 216 1967 - 212 1993 - 211 1951 - 206
• 5 years with least 1934 - 86 (23.5%) 1931 - 107 1900 - 108 1939 - 109 1938 - 110
• 5 years with most 1934 - 276 (75.6%) 1931 - 253 1933 - 251 1938 - 250 1939 - 248 (tied with 1900)
• 5 years with least 1978 - 131 (35.8%) 1996 - 139 1967 - 141 1993 - 144 1951 - 148
TOTAL DAYS - BELOW AVERAGE TEMPERATURE
0
500
1000
1500
2000
2500
1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
DECADE
DA
YS
TOTAL DAYS - ABOVE AVERAGE TEMPERATURE
0
500
1000
1500
2000
2500
1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
DECADE
DA
YS
TOTAL DAYS - NORMAL AVERAGE TEMPERATURE
0
50
100
150
200
250
1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
DECADE
DA
YS
TOTAL DAYS - ABOVE/NORMAL/BELOW AVERAGE TEMPERATURE
0
500
1000
1500
2000
2500
3000
3500
4000
1870s 1880s 1890s 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s
DECADE
DA
YS
Trends
• 30s were definitely HOT
• Fairly constant last 10 years
• Signs of Global Warming (not really)– Remember this is not looking at magnitude
just number of days
Consecutive Days
• Allowed for crossover Jan 1
• Based on above or below the normal average T – NOT based on Magnitude– 2 degrees or 30 degrees above (don’t care)
• Winter 2005-2006 set new record for consecutive days with average temp above normal (49 days)
• 20+ days, 25+ days, 30+ days (trend???)
20+ Consecutive Above/Below Average T
-100
-50
0
50
100
150
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
Year
Da
ys
25+ Consecutive Days Above/Below Average T
-80
-60
-40
-20
0
20
40
60
80
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
Year
Da
ys
30+ Consecutive Days Above/Below Average T
-60
-40
-20
0
20
40
60
80
1875 1885 1895 1905 1915 1925 1935 1945 1955 1965 1975 1985 1995 2005
Year
Da
ys
Time of Year
• Winter months are when long consecutive streaks have been set
• For 30+ day events - all but one during the months from November-April– Ended July 14 1933 (31 Days)
30+ Day Events by Month
0
1
2
3
4
5
6
7
January February March April May June July August September October November December
Month
Ev
en
ts
30+ Days Below 30+ Days Above
25+ Day Events by Month
0
2
4
6
8
10
12
January February March April May June July August September October November December
Month
Ev
en
ts
25+ Days Below 25+ Days Above
20+ Day Events by Month
0
5
10
15
20
25
30
January February March April May June July August September October November December
Month
Ev
en
ts
20+ Days Below 20+ Days Above
Final Thoughts
• Wish there was 200 - 300 Years of Data• Limited Patterns/Signals• Causes - Unknown• History Repeats –
– Doubt a 30+ days event of below normal ave T – 20-29 days event possible
• Next– Look at magnitude overall and during streaks
• Average High and Average Low
– Add more sites to see if pattern is widespread
THE END
????