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Posted at 06:15 PM ET, 03/24/2011

Image of day: Sunday snow summary

Left panels indicate snow amounts forecast by SREF (15z) and NAM (18z) models. Right panels indicate the probability (in percent) of at least 1”, 2”, and 4”. (Top left, and right images courtesy NOAA. Bottom left image from
We’ve been talking about the chance of snow Sunday morning since Tuesday, but just today started to mention amounts. Generally speaking, we’re thinking a dusting to an inch is the best bet around the region. However, some of the model data and NOAA assessments indicate more is possible. So I thought I’d share them so everyone can understand the full array of possibilities.

To summarize what’s in the pictures:

*The top left image from the SREF model indicates potential for about 1” of snow around the metro region with 2” to the west and southwest.

* The bottom left image from the NAM model indicates potential for 2-4” of snow from District and south, and less than 2” north of town. (I think this is overdone, especially south)

*The right panels from NOAA’s Hydrometeorological Prediction Center indicate the probability of at least 1”, 2” and 4”of snow. Its probability of at least 1” around D.C. is 70 percent, 50 percent for 2”, and 20 percent for 4”.

We think all of these forecasts may be a little aggressive given temperatures, time of year, and the limited moisture associated with this storm system coupled with dry air to the north. What the system has going for it in terms of snow is an impressive cold air supply for the time of year and that steady precipitation may occur early in the morning before the sun comes up when temperatures are at their coldest.

We’ll re-evaluate accumulation potential tomorrow and may post a Snow Lover’s Crystal Ball.

By  |  06:15 PM ET, 03/24/2011

Categories:  Winter Storms

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