Monday 9 a.m.
A cold front moved through the Northeast during the weekend and has continued to drift south toward the Carolinas. This front has terminated the extreme heat for the time being. Through yesterday, Chicago's July has run more than 12 degrees above average and is only 3 degrees away from what is typical, in San Antonio, Texas.
While the Northeast and Great Lakes face more dry weather, there may be a tendency for moisture to creep northward through the Middle Atlantic states later this week. You can see some hints of that in this video.
Much of the uncertainty later this week is caused by the weakness of the predicted upper air flow. Weak flow means little should change. This means wherever it is raining when the weak flow regime starts could get a lot of rain, but other places won't have any rain at all.
This map shows the weakness of the flow predicted to be over the East (except for northern New England) later this week.
This map shows expected accumulations.
Check AccuWeather.com's latest info as the forecast ideas mature. This is a draft of the Thursday morning snow accumulation idea.
Here is one snapshot from this morning's NAM run, depicting the precipitation it predicts for Saturday between 1 and 7 p.m. ET. The rain/snow line should be close to the Pennsylvania-Maryland border.
it appears a storm will form the Southeast and trek toward eastern New England this weekend. Current models suggest this will turn into a mostly rain event in the I-95 corridor...
This map shows a draft of our starting time lines and expected accumulation from tomorrow's quick-moving East Coast storm.
A storm that has brought hardship and danger to parts of Texas and Arkansas with an assortment of ice and snow will send a swath of snow northeastward today and tonight. Here is a map showing our overall estimates as of 10 a.m. ET: