Wednesday, 9 a.m.
A southerly flow of increasingly moist air is spreading up the I95 corridor, where the dawn was greeted by dreary dullness and dim, drab drippiness from Maryland to Massachusetts. There are also some showers from western New York to Ohio along a cold front that will reach the East Coast this evening. When that cold front arrives, it will usher in a dry air mass that pulls back the curtain of clouds to reveal brilliant sunshine that plays off the multicolored leaves in the Northeast from tomorrow into the weekend.
In New York City and Philadelphia, typical afternoon temperatures are well up in the 60s at this time of year. Nights cool to about 50 in the cities, but well down in the 40s in many suburbs. The air masses in place from tomorrow through Saturday will bring temperatures that run about a half-dozen degrees below those long-term averages. Saturday morning is apt to be frosty in the colder suburbs from Washington, D.C., to New York City and below freezing in upstate New York and much of New England's interior. However, a strong southwesterly flow of warmer air could boost temperatures to 70 degrees in these areas on Sunday afternoon.
A strong storm is likely to cut through the Great Lakes Saturday night and Sunday, and its associated cold front will trigger showers and even thunderstorms. However, the air coming in behind that storm should not be as chilly as the air that follows this week's fronts. The reason: this week's upper air flow into the Northeast can be traced back to northwest Canada. Next week's main upper air current looks like it will be straight west to east. The video has more.
In yesterday's report I made an analogy about predicting snow amounts using our 16 year old American Eskimo dog Sam as an example. I told Sam about it before taking this picture, but he just looked at me.
This map shows the pressure pattern around the big storm that some people in Boston and Providence are comparing with the Blizzard of '78.
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.