Wednesday, 11:40 a.m.
Another day of heavy rain occurred in the Gulf Coast area, with Louisiana over to the Florida Panhandle bearing the brunt of the heaviest rains over the past 24 hours. Parts of Louisiana picked up 2-4 inches of rain, but they were hardly alone in the wetness. The main low pressure area tracking from Oklahoma toward Illinois brought heavy rain to northern Illinois, resulting in minor flooding overnight and early this morning.
If you examine the upper levels of the atmosphere, it's a pretty weak upper-level low raising this ruckus:
The low levels of the atmosphere, however, are rich in moisture with an unabated flow from the Gulf of Mexico right into the Ohio Valley and mid-Atlantic states. Dew points are at least in the mid-60s in most of these places, and that's helping to fuel showers and thunderstorms at the drop of a hat. As we saw in parts of Maryland and Pennsylvania yesterday and again early this morning, that can also lead to some sporadic downpours well removed from the parent storm or upper trough!
This will go on with this particular feature for a couple of days yet. For the most part, areas of the the Ohio and Tennessee valleys will be out of the heavy action after this evening. There will still be some localized downpours through tomorrow in the East, but less so on Friday. Most of the heftier rains after that will be relegated to New England.
We can't forget about the hard charging cold front coming out of the northern Plains, as it's raining pretty hard across parts of North Dakota this morning, and this is spreading into northern Minnesota. As the front itself charges southeastward tonight and tomorrow, more strong to locally severe thunderstorms will erupt in Kansas and Oklahoma, thunderstorms that will also contain heavy rains. Once formed, the thunderstorms will likely advance into parts of North Texas, Arkansas and southern Missouri.
While this front will have no trouble gliding off the New England and mid-Atlantic coast Friday night, it will stall in the South, leaving the region warm and humid, a perfect incubating ground for some thunderstorms. With that same feature coming out of the Ozarks on Friday, it will lead to more showers and thunderstorms across of the South to end the workweek.
Even as that is taking place, yet another disturbance will come through the Northwest tomorrow. Initially, it won't have a lot of active weather with it, but as it comes over the northern Rockies Friday, low pressure will redevelop over the Dakotas, and that will help ignite more showers and thunderstorms across the northern Plains Friday night into Saturday, and some of these could well be severe as the march into Minnesota.
And that's just getting into the start of the weekend! The atmosphere as a rule right now is just not warm enough aloft to handle all of the low-level moisture that is now in place over such a widespread area. It's as if the low levels now fully realize it's summer, but the upper level still thinks it's the middle of spring. It's a combination that means there is still no shortage of active weather around the country.
A snow storm affecting the central Plains and Midwest into the Great Lakes this afternoon into tomorrow night will be followed by the first of two arctic outbreaks around the country before Thanksgiving.
Winter is six weeks away, and there will be a couple of signs this week of the approaching season as a storm develops on the western Plains and heads through the Great Lakes.
A warm pattern is setting up for much of the nation next week.
Tropical moisture associated with the one-time Hurricane Patricia will bring heavy rains to many areas east of the Mississippi Valley between now and Wednesday night.
Patricia, the strongest hurricane on record in the eastern Pacific, will make landfall this evening in Mexico. It will spread torrential rains into East Texas, and impact the weather all the way to the Northeast next week.