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State of the Climate across Southwest Nebraska
By Matt MasekMarch 22, 2012
OutlineReview of 2011 – 2012 Winter
Role of La Niña and Arctic OscillationSpring Outlook
One month (April) outlookThree month (April, May, June) outlook
Current Drought ConditionsDeveloping???
Quick look at the end of March Forecast
La Niña 2011-2012For southwestern Nebraska, closer proximity to cool temperatures and drier conditions.
La Niña - Typical Wintertime Pattern
What was 2011-2012 Winter? Temperatures were above normalPrecipitation (rain/snow) was above normalWhy - last year and this year both were La Niña years
La Niña was NOT the dominate player
So what was the dominate player? Arctic Oscillation
Based on 1000 mb height anomalies pole ward of 20° N
2011-2012 Positive Phase
Only major snowstorm for southwest Nebraska
2011-2012 WinterNorth Platte, NE
Facts for the 3 month period of December, January, & February (and the last 5 years).
2011-2012 Winter North Platte, NE
2011-2012 Winter North Platte, NE
Temperature Summary for North PlatteDec 1, 2011 to Feb 29, 2012
Smooth tan line is normalRed and blue lines are records
Precipitation Summary for North PlatteDec 1, 2011 to Feb 29, 2012 (dark blue)
Dec 1 2010 to Feb 28, 2011 (magenta)Smooth red line is normal
2011-2012 Winter Imperial, NE
Temperature Summary for ImperialDec 1, 2011 to Feb 29, 2012
Smooth tan line is normalRed and blue lines are records
Precipitation Summary for ImperialDec 1, 2011 to Feb 29, 2012 (dark blue)
Dec 1 2010 to Feb 28, 2011 (magenta)Smooth red line is normal
2011-2012 Winter Haigler, NE
Temperature Summary for HaiglerDec 1, 2011 to Feb 29, 2012
Smooth tan line is normalRed and blue lines are records
Precipitation Summary for HaiglerDec 1, 2011 to Feb 29, 2012 (dark blue)
Dec 1 2010 to Feb 28, 2011 (magenta)Smooth red line is normal
Spring OutlookStill have a La Niña pattern (although it is weakening)Lingering effects from wintertime pattern and the positive AO
Polar Jet Stream – promotes more clipper systems or fast moving cold frontsFast moving fronts have limited time to produce significant moisture over the
high plainsDrier overall atmospheric conditions favor a wide swing of temperatures
from day to dayDue to warm winter over the Northern Plains there is a lack of snow cover –
this will help to modify (warm) cold arctic outbreaks
Climate Prediction CenterForecast - April
Higher confidence in southwest Nebraska to experience below normal precipitation while equal chances for above, below or near normal precipitation for the rest of Nebraska. Higher confidence for above normal temperatures to continue over Nebraska and much of the lower 48 states.
Climate Prediction CenterForecast - April, May, June
The forecast for April, May and June are higher chance for below normal precipitation over Western Nebraska, with equal chances for above, below or near normal precipitation over central and eastern Nebraska. There is higher confidence the desert southwest and much of the south and eastern U.S. will see above normal temperatures. However over Nebraska no strong signals results in equal chances for above, below or near normal temperatures.
Climate Prediction CenterSummer Forecast – June, July, August
The ENSO (El Niño Southern Oscillation) phase is expected to trend toward neutral this summer. This pushes the long range forecast to have more uncertainty for the summer across the central plains. Thus western and north central Nebraska see a forecast of equal chances for above, below or near normal precipitation and temperatures. Although recent trends for warm conditions over the desert southwest have a chance of expanding over the high plains.
Current Drought State
Current Drought State
Drought Developing??
Drought Developing??Areas to the southwest of Nebraska are being
monitored for developing drought conditions over the next several months.
Due to the uncertainty of precipitation for May and June, southwest Nebraska is not expected to see the development of the drought yet.
Below normal precipitation is expected over the next month or so. April is when this area begins to receive more significant rainfall from thunderstorms.
May and June are the wettest months of the year.
Climate Prediction Center8 to 14 Day Outlook (Mar 29-Apr 4)
March to end and April begins with continued warm conditions. Low pressure system tracks across the southern plains. Western Nebraska likely to miss out on the moisture with this system.
National Weather Service Online
Final Thoughts for the Spring• Weakening La Niña to create tricky forecast for Nebraska• Higher confidence April will be warm• Higher confidence areas to the southwest – dry• Drought conditions may expand into southwest Nebraska, (May and June?) however uncertainty exists at this time.
Questions – [email protected]
The End – Questions???
