Winter Weather to impact the East Coast

Winter Weather Advisories have been put into effect from Louisiana through parts of Northern Georgia.   This system is going to head toward the coast and move up the Eastern Seaboard with minor to moderate impacts.

Matt and Chris already have good coverage for the forecast for the Southern Plains and the Southeast, so my focus will be from the Delmarva Peninsula northward into New England.   A cold front associated with a system that moved up into Canada, has pushed well into the Gulf and off the east coast, spanning from near Greenland back to Mexico.  The cold air is well established with snow as far south as the Texas and Mexico border and advisories to nearly the Gulf Coast.

One of the challenges with this system will be the usual early season marine influence.   Sea surface temperatures are still warm and any easterly winds will impact surface temperatures over the land.  This will be a major impact along the coast down in Virginia and for Cape Cod as well as the islands.  Coastal areas should expect to see a heavier wetter snow once the snow starts to fall.  This set up may also trigger a few ocean effect bands, which could make for small areas of higher snow totals right next to areas of lower totals.

The NAM model is being for more aggressive with snowfall accumulations across the region than other modelling, though this is common for the NAM.   The expected snowfall accumulations occur for most locations later on Saturday into Saturday night.  The GFS shows a far lower area of accumulation as well as lower overall totals.

Figure 1: NAM model snowfall accumulation forecast through Sunday afternoon. Source: Tropical Tidbits

Figure 2: GFS model snowfall accumulation forecast through Sunday afternoon. Source: Tropical Tidbits

Despite the differences, both models show plowable snows into the I-95 corridor with some higher snowfall total further east where the rain/mix doesn’t hold totals down.   I’ll be doing some follow ups on this as the track and actual conditions get closer.   There is another chance for a storm early next week that we’ll also be keeping an eye on as cold and windy conditions are expected to take hold in the Eastern United States, but we’ll get through this first storm first and focus on the longer term risks as they get closer.

Rob