Notice the NAO is going negative next week; in fact, we have been in a negative NAO most of the summer. Some studies have shown that a negative NAO during the summer means heat in the Northeast, while a negative NAO in the winter means colder, stormy weather. So one can surmise that as the jet starts to migrate south in September that a negative NAO would mean stormy weather for the Northeast which looks to be the case next week.
The system coming out of Texas and the Gulf Coast will bring a lot of rain north late in the weekend and early next week. You can see on the GFS model total rainfall that some areas can pick up 1-3 inches of rain which may cause some minor flooding problems.
Also, the pattern across the Great Lakes and Northeast will feature several pushes of chilly air the next 14 days. I would not be surprise to see snowflakes over the Upper Peninsula of Michigan in the cold pushes.
Storms in the mid-Atlantic can be severe today. Pattern changes to a cooler one later this week.
A stormy time across the southern Plains today into Saturday. Flooding rains will be the main issue during the period.
Storms will be severe in the southern mid-Atlantic and in the Southern Plains. Tornadoes possible in the Plains Friday.
The focus of the severe weather will be across southern Iowa into western Illnois where storms should develop around the upper-level low.
Storm coming out of the Rockies will bring tornadoes and severe winds to the Plains and Mississippi. Mid-Atlantic has big storms too.
Severe weather will occur this week as a series of storms move across the country.