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Posted at 10:27 AM ET, 03/11/2013

February was colder than average in Washington, D.C., March tending that way too


Of the meteorological winter months (December-February), February was our coldest, but only slightly below normal (-0.7F). The month was also drier-than-normal, with a deficit of 0.95 inches. But it sure seemed like a wetter month than that.

The data are interesting, because Reagan National Airport reported precipitation on over half of the days of the month (15 of them!). And eight of those days had snow reported too. You wouldn’t know it, however, given our snow drought. The various snow “events” produced totals ranging from a trace to, on our biggest snow days, a mere 0.2 inches (Feb. 1 and Feb. 2).

The numbers were not impressive enough to rank in the top ten category of the long-term historical dataset.


Here is the side-by-side comparison of 2013 compared to last year. We didn’t hit 70+ this year and barely hit 60F. Also, we managed one morning in the upper teens at National vs. zero incidences last year.

While last February was wetter than this year, it wouldn’t have been if not for Leap Year. Feb 29 was the wettest day last year with 1.44 inches. Without that, 2013 would’ve easily been wetter than 2012.

With regard to daily details, the colder-than-normal (blue) days did indeed outnumber the warm (red) days, but it was close with only three more cold vs. warm days over the course of the four weeks. You can see the tracking of temperatures and precipitation here:


Daily temperatures compared to normal in February at Reagan National Airport


Days with precipitation in February at Reagan National Airport


The upper level pattern for February was a strange one.

Normally, when you have warm upper level high pressure (“ridging”) over Greenland, you tend to have a colder pattern over the Eastern U.S. However, when you have a cold upper level low pressure (“troughing”) over Alaska, you tend to see a warmer pattern over the eastern half of the U.S. more often than not. I believe this conflict of influences was responsible for our very volatile back-and-forth month with regard to temperatures and prevailing weather patterns. The North Atlantic ridge won out, but only barely with our marginal net colder-than-normal result.

February marks the end of the meteorological winter (December-February). That period turned out to be the third warmest of the 2000s and 13th warmest of all-time. For precipitation, it was the sixth driest of the 2000s and 40th driest of all-time.

From a snow standpoint, the three-month core winter period saw the least amount of snow (only 1.5”) since 1997-98’s very minuscule 0.1 inch meteorological winter. The graphics below show how the meteorological winter has been tracking through the 2000s. There is a more noticeable uptrend in temperatures and precipitation.


Winters have generally been trending warmer and slightly wetter in D.C. since 2000

A look ahead

Will March also lean to the colder side and give us a last-minute chance for some more snow? At the current glance, a lot of the upper level features that complicated February look to complicate March too with a cold and sometimes snow-supporting North Atlantic pattern and a warmer non-supportive snow pattern from the North Pacific. This pattern type suggests this March should be *much different* from last year’s warmest-on-record result with more temperature variability and perhaps like February, a marginal cooler-than-normal result but with near normal precipitation. This idea is already bearing out, as the month is averaging slightly cooler than normal (-1.4F).

The National Weather Service is having a tricky time on this issue as they originally issued a warm forecast for us two weeks ago and then removed it. They replaced it with that inconclusive “EC” option they employ, which means equal chances of anything happening for temperatures. However, they do have our area on the edge of the higher probability for a wetter-than-normal month. Many folks should be happy about that prognostication given our dryness issues last year.

Link: National Weather Service 30-day outlook

Further information

The National Weather Service publishes nice monthly assessments usually within a week of the close of each month (should be available shortly):

You can click on your closest airport location here:

Reagan National (DCA)

Dulles Airport (IAD)

Baltimore-Washington (BWI)

By  |  10:27 AM ET, 03/11/2013

Categories:  Latest, Local Climate

 
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