Tuesday 9 a.m.
This morning's video describes where areas of thunderstorms were early this morning, then proceeds to a discussion of where and when showers or thunderstorms might be expected in parts of the Northeast during the next few days.
Some severe thunderstorms can break out today into tonight in parts of the Great Lakes and Ohio Valley regions as shown on the map.
Tonight, the thunderstorms may continue across the West Virginia mountains to reach the D.C. area and parts of Virginia.
In the worst-hit areas, plan for travel bans (for all non-emergency activities) because of impassable roads and extremely poor visibility. This map shows our projection for snow accumulations by early Wednesday. In many areas the heaviest snow should fall overnight and tomorrow morning.
In the worst-hit areas, plan for travel bans (for all non-emergency activities) because of impassable roads and extremely poor visibility. If you get stranded, rescue crews may not be able to reach you. Storms like this sometimes generate thunderstorms within the heaviest snow bands. The map shows predicted snow accumulations by early Wednesday.
It appears likely that many normal activities can go on through the day Monday, as long as the typical cautions for light to moderate snowfalls are observed. Tuesday will be an <strong>entirely different story</strong>. This map shows the GFS- predicted snowfall through 7 P.M. ET Monday:
The second storm we have been talking about will affect the Middle Atlantic region late Sunday and Sunday night. This GFS forecast map is for 7PM ET Sunday and shows precipitation amounts for the 6 hours up to that time.
This was our snow accumulation projection as of mid-morning. A storm that will develop in the Midwest on Sunday is likely to track to the Virginia-Maryland coastal area by Monday morning, then turn east. It will probably bring some to snow places that get mostly rain out out of the first storm.
Just a 1- or 2-degree temperature difference in the lowest 5,000 feet of the atmosphere can make the difference between heavy wet snow and heavy wet rain. Here is a draft of our snowfall map from mid-morning.