Here is today's video forecast:
As a storm strengthens off the New England coast and a high pressure area inches eastward from the Great Lakes, gusty and chilly northwest winds have developed from Ontario to Virginia. Lake-effect showers affected lower elevations of western and central New York this morning, and snow showers were common over the mountains of northwestern Pennsylvania.
The northwesterly flow will be strong over New England tomorrow but will weaken farther west. Warmer air will spread through the Mississippi Valley and western Great Lakes tomorrow. The warmth will extend into the Middle Atlantic region for Friday and Saturday, but chillier air will hold its ground farther north.
Yesterday, we talked about the blocking pattern that may be prevalent next week. This could lead to wet weather from the Midwest to the East Coast. The placement and movement of individual low pressure area will help determine where showers and thunderstorms will be most prevalent. On the north side the storm tracks, it will be quite chilly far late April, and some areas could face unusual late season snows. No, I don't have a handle on exactly where that may be, so keep those screens focused on AccuWeather.com.
Thunderstorms accompanied the cold front across parts of the Middle Atlantic region yesterday. We had the first thunder of the season at our house in the middle of Pennsylvania. Sam the Dog, now a 15-year-old American Eskimo dog, lost his hearing several months ago but is otherwise alert and always ready to eat as if he had never been fed before. In the past, thunder terrified him, so I am glad he didn't hear the thunder. In recent years, however, he learned that lightning was somehow connected with the thunder, so he got agitated when lightning would flash at night. I'd like to think that my explanations of what was going on enlightened him, but we all know better! This map shows the distribution of lightning from around daybreak yesterday to the wee hours of the morning today.
Thunderstorms broke out in eastern New England this morning. Here is a lightning map showing strikes between 8 a.m. and 10:30 ET:
The cold front is accompanied and preceded by a band of showers, some heavy. As the front continues SE today, some thunderstorms should develop.
Yesterday, there was a sharp boundary between air that was cool and dry enough to suppress thunderstorms and air that was warm and humid enough to support them. This map shows the lightning strikes from 8 a.m. ET yesterday to (almost) the same time today.
As the second low pressure area develops off the East coast, it will work in concert with a high pressure area from Canada to orchestrate cooler-than-usual conditions with showers in the Middle and North Atlantic states Thursday.
Looking ahead to <strong>next</strong> weekend, the Mothers Day Weekend, we see quite a difference between the GFS model and European models on where cold Canadian air is heading at 2 a.m. Sunday.
Rain is spreading across the Middle Atlantic states today. Dampness will linger from southern New York state to Virginia tomorrow even as the main rain area moves offshore.
For the rest of the week and this weekend, the upper-air "steering winds" will be arranged in two separate streams. The northern branch will send air from central Canada toward New England.