Wednesday 7 a.m.
As a storm develops in the middle of the country (and threatens to cause severe thunderstorms and even tornadoes from eastern Nebraska through the middle of Texas), a southwesterly flow of unseasonably warm air will extend from the Gulf States to New England.
As the warm air approaches and climbs over the cool air ahead of it, clouds and pockets of precipitation have broken out from the Ohio Valley to parts of New England today. I use the term precipitation rather than rain because light snow has been seen along the northern edge of the moist area. This video suggests how weather features will progress during the next several days.
One issue along in the I95 corridor will be whether the rain holds off until after trick-or-treat time tomorrow evening. As of this morning (Wednesday), it appears that the rain will hold off... but it looks like a close call. From Skull Run, W.Va., up to Lake Eerie and over to Gouldsboro, Pa., a thick of clouds will cause rain.
I will be out of the office tomorrow, but expect to be back Friday. In the meantime, I have an announcement that is pretty standard at this time of year: Turn your clocks back one hour by 2 a.m. Sunday. With 25 hours, Sunday is truly the longest day of the year,
There's a west to northwesterly flow of basically dry air from south-central Canada to the northern part of the Middle Atlantic states. The flow changes orientation farther south. A light northerly flow is helping slightly less humid air to seep southward.
In parts of the Northeast, a sky looking as blue and clear as the one in the picture will be quite a departure from the look of the rainy skies that were much more common earlier in the summer.
The steering winds aloft are changing, and the next phase looks like it will feature a northwesterly flow of cooler air this weekend and much of next week.
It's going to be hot hazy and humid in the much of the Northeast today through Thursday. The recalescent, sudorific, canicular, pyrogenic frying heat gains our attention.
A line of persistent showers and thunderstorms stretched from Long Island Sound to Cape Cod. Some areas in this zone had more than 3 inches of rain this morning, and there can be highway flooding in localized heavy showers this afternoon and evening. This radar shows the rain zone just after 10 a.m. ET.
This map shows the predicted upper-air flow for tomorrow night. Our timing estimates suggest showers and some thunderstorms could affect the I-95 corridor from Portland and Boston to New York City (and perhaps Philadelphia) on Sunday.