The temperature forecast

Warmer-than-normal temperatures look very likely, but the big question is how warm? An average temperature of 49 to 51 degrees is favored at this time. The 30-year normal at Washington, DC is 46.8 degrees, so our forecast translates to temperatures two to four degrees warmer than normal. If we’re wrong, we think chances are it could even be warmer.

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The rain forecast

We favor above normal precipitation for March. Normal is 3.48 inches, and we predict between 3.75 and 4.25 inches. History shows El Niño March periods, like this one, tend wet (1998- the last big El Niñ0- delivered 5.4 inches) and we wouldn’t be surprised if rainfall exceeds our forecast.

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The snow forecast

Below normal March snow is favored. The normal is only 1.3 inches so if Friday’s storm takes a colder track, we’ll easily flip to an above normal March. Right now, the set up does not look ideal for significant snow (high pressure that supplies the cold is not in the right spot). After Friday, the balance of month looks too warm for snow and we may end up with 0.0 inches.

Here is how March snowfall has worked out in the 2000s. It is interesting to note that the 2000s mean is snowier than the 30-year normal in Washington D.C. and that we’ve had above normal snow the past two Marches.

March forecast rationale

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New round of warming ahead



We’ve got three days of cold weather coming up later this week into the front half of the weekend, but this colder period is sandwiched by very mild conditions tomorrow into early Wednesday and then a massive warm-up next week.

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The medium range modeling we examine- from the European guidance to the Canadian (Environment Canada) outputs to the U.S. National Weather Service modeling all agree on a powerful warm pattern evolving by next week for much of the eastern two-thirds of the U.S. I’m not prepared to say this will be super-warm March 2012 (we had an average temperature that was ten degrees above normal), but it is a definitely something to watch.

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El Niño

This new surge of bigger warmth appears to be a driven by our continued El Niño pattern which has been quite effective this winter at preventing colder patterns from locking in place. This is still classified as a super El Niño (sea surface temperatures more than two degrees warmer than normal in the central tropical Pacific Ocean).

The pattern seems prime to open the storm floodgates for the West Coast, potentially offering them their wettest month of this winter, while sending lots of warm, moist, westerly flow our way.

Here is how the high altitude weather pattern is looking based on the European ensemble for later next week:

Long-range models

While the medium-range models are offering lots of warmth over the next two weeks, the long-range guidance is essentially on the same page. The National Weather Service CFS model shows a very warm month ahead with above normal precipitation. Other long-lead products we monitor concur.

National Weather Service

The National Weather Service agrees with a warm and wet month favored. They are going to update their maps late this afternoon and I suspect they will increase their confidence on the warm and wet forecast based on all the latest guidance and pattern trends. You can read the Weather Service’s March forecast discussion here.

February forecast review

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February average temperature forecast verification

We had forecast near normal (39 degrees) to above normal (40-41 degrees) temperatures for the monthly average and the result is just slightly warmer than 39 degrees thanks to our last-minute super-warming Sunday and today (thank you Leap Year!). It’s a win.

February precipitation forecast verification



We predicted a range of 2.5 to 3.5 inches (a lean to the wetter side) with the result coming in at 3.79 inches. It was the correct direction, but the answer came in slightly wetter than we expected. Getting the direction right gives us a marginal win.

February snow forecast verification

We said near to below normal snow fall for Washington D.C. for February and the result of 3.1 inches was indeed below the normal 5.7″. A win!

Summary review

All three forecasts were in the correct direction, but rain got ahead of us a bit…

Grade: A