A weak area of low pressure appears like it will move into the D.C. area on Christmas Eve and there is still an outside chance that at least parts of the region may receive some snow. Model guidance depicts a disturbance that is currently out over the Pacific Ocean moving into the western states and eventually getting to the D.C. area by Monday evening. With high temperatures only forecast to be in the low to mid 40s through the afternoon hours, it may be cold enough for snow by Monday evening and night.
Surely with the recent snowfall across the country, the D.C. area should get in on the action too right? Below is a look at the snow analysis across the U.S. with the heaviest snowfall totals across the mountains in the western U.S. but also some heavy snow through parts of Iowa, Wisconsin and Michigan.
- Snow Analysis as of 12/21/12
For now, the best chance for snow would be at the onset of precipitation Monday evening, as this is when the atmosphere needs to moisten and the temperature will drop to reach saturation as precipitation moves in. This may give the area some snowflakes for a few hours before a changeover to light rain.
- Global Ensemble Forecast System Spaghetti Plot
There is another scenario though, that would be better for snowlovers, as the area of low pressure could actually be located a bit farther to the south. This would help allow for more cold air in the region and a better possibility for snowfall. Currently the guidance has a bit of a spread in the exact location of the low but a fair number of the models keep the are of low pressure a bit farther north. This would mean warmer air for the D.C. area and a better chance for rain. If you look in the red circle in the above image, you can see there isn't much of a consensus as to where this low will move, so there's still hope.
There is just one more thing you can do to try and help... Give a little Christmas spirit and sing!