Here is today's morning forecast video:
There were numerous thunderstorms yesterday. This is the lightning stroke map covering the period from 8 ET yesterday morning to 7:30 ET this morning. Thunderstorms will be less numerous today, but any that do form can cause briefly strong and gusty winds.
Aloft, winds have been stronger than usual for early July. When thunderstorms boil and bubble skyward, some of that high speed can be transferred down to where all the people, buildings and crops are. Also, as rain descends into drier air, there is evaporative cooling. The cooled air is more dense than the hot, humid air outside the storm, and so it rushes down then spreads out at the ground. Unfortunately, the storms yesterday and last night turned deadly and destructive. Yesterday's report included a map showing the areas that the NWS Storm Prediction Center believed were most vulnerable to high winds. The forecast was very good in most areas, but the high winds persisted farther east.
This map shows the GFS forecast for Monday at 2 p.m. ET. If correct, rain will hold off for the Boston Marathon. However, you can see that any speedup of the rain would prove that idea to be wrong.
Another high pressure area will build over the Northeast during the weekend, so sunshine with mild afternoons can be expected. However, this forecast map for next Monday evening shows how extensive and wide ranging the next storm may be.
These maps show how the US model handles the disturbance now causing rain in Tennessee. On the 1st map (for tomorrow), it is embedded in a southwesterly flow. However the 2nd map (for late tomorrow night) shows it turning more toward the course that would take it out to sea.
In the middle of Pennsylvania, rain ended before daybreak, but rolls of sullen clouds presided during the first hours of daylight. A robin takes in the scene.
... map shows this morning's surface pressure pattern, including a southerly flow of warm air in the East and a northwesterly flow of cooler air behind a cold front that is drawn in blue. Showers accompany and precede the cold front marking the boundary between the two air masses.
Rainfall between today and Friday night will be highly variable between the Midwest and East Coast. Parts of the Ohio Valley, where it has been wet recently, will get more heavy rain; places along the East Coast will generally get less. From New York City to D.C., this weekend may be the nicest so far this year!