It's typical during fall and spring for us to see long stretches of nice weather in the South and that's just what we have underway in the Southeast. Of course, the nights are going to be rather cool to chilly. As this week wears on, it will turn a little warmer though, so even the nights will be for the most part comfortable. It looks as though the nice weather will last through Friday in most places.
West of the Mississippi, it's a somewhat different story. With high pressure over the Southeast, y'all in SEC West/Big 12 South (I have taken to calling that the "Big Whatever's Left Conference") territory will be stuck in a persistent southerly to southeasterly flow pulling moisture and warmth northward from the tropics. So, it looks persistently breezy, very warm, and humid back there. Perhaps "very warm" won't cut it in some places. Frederick, OK got to at least 96 today. Morning clouds will be fairly widespread but afternoons look mainly sunny. However, I'm still watching for the little upper level low spinning over northwestern Mexico now (see the water vapor image at left to show where it is this evening) to shoot northeastward through tomorrow and it will cause some thunderstorms along the way. They will hit mainly in the Transpecos and Permian Basin tonight and then across Oklahoma and perhaps far north Texas tomorrow. Enough shear will be present for a tornado concern. The problem will be those morning clouds that could be fairly extensive. If they hold down temperatures enough, then we might not be able to get many storms going. So, this doesn't look to be a major threat, though we really won't know for sure how bad it can get until we see what cloud cover and temperatures look like around midday tomorrow.
Really, though, the main concerns for now remain in the long range and they involve two different storm systems. I'll start by talking about what we know. First, we expect that low pressure now forming in the central Caribbean will eventually become a tropical system of some sort and head north out of the Caribbean. Sandy is the next name on the list, by the way. The storm should start to wind up down in the Caribbean by Wednesday. Meanwhile, the second of a 1-2 punch of storms to hit the western states this week will pull some rather cold air southward out of Canada. That should arrive in the southern Plains by Friday, perhaps sooner. That front should cause some some rain and thunderstorms, by the way, but probably not much severe weather since it looks like a situation where cold air will undercut warm air in place ... usually not much severe weather comes out of such a setup unless there's large hail with the "elevated" thunderstorms.
The computer models have differing suggestions as to where they think the Sandy-to-be will eventually go, but they have one thing in common, they all have trended farther west with their track over the last few days. Y'all remember from yesterday I was getting concerned that might happen. Of course, this raises the concern of potential direct impacts somewhere in the U. S. down the road. There's still plenty of reason to hope that the front and the developing upper trough supporting it will steer the storm off the East Coast but I'm less confident in saying that will happen at this point ... my gut feeling is that it will stay off the Southeast at least but it's probably going to be close. And try not to laugh too much the European model's very entertaining model solution. While I don't think it will happen that way, with the storm getting completely phased in with the trough and causing a wild blast of high wind and flooding rain across a lot of the Mid-Atlantic, it is plausible.
Basically, the slower that front moves and the longer the upper trough with it takes to dig in over the eastern part of the country, the farther west any Sandy-to-be can get. Often the models, especially the GFS, tend to be too fast with such features. On the other hand, it seems to have done a decent job with timing lately. Either way, there's plenty of reason for worry here. The GFS is one of the models that keeps the potential Sandy offshore (that's what it has for a week from today at left) but if it's too fast with the front/upper trough ... well then we instead have problems along the East Coast. The 0Z Canadian run illustrated the probably worst-case scenario ... nobody wants to see a 954 millibar storm over Washington next Sunday evening that sort of sits and spins slowly northward through Halloween. Well, maybe I can think of a few people who do, but I won't go there.
So, while we expect mostly quiet weather for the next few days, those near the East Coast need to carefully watch the way this situation plays out over the next several days and prepare accordingly. One more thing today, no matter the timing and whether or not some huge storm hits, behind whatever does come to pass next weekend will come some rather chilly air, probably sending temperatures for most of the South as far below normal as they will be above normal over the next 3-5 days.
While the East Coast remains cool and rainy for a while, Texas and Oklahoma will dry out and heat up. One source of moisture down the road for the middle of the nation could be the tropical systems in the East Pacific.
A slow moving upper low and a steamy air mass beneath it will keep drenching thunderstorms near the East Coast the next several days while areas farther west largely dry out. There's plenty of tropical stuff to watch as well.
The southern Plains will see less rain, maybe very little the next several days, hooray! Meanwhile, the Southeast will see wetter weather, hooray!
In the southern Plains the threat for flooding rain continues into the weekend before finally shifting east. The Southeast could use the rain but let's hope it's not too much of a good thing.
The weather pattern will remain favorable for wet but maybe not as wet weather in the Southern Plains while the Southeast gradually moistens up. Time to take a peek a the tropics again, too.
A minor change in the upper level pattern will give the southern Plains a brief respite from the heavy rains, which will shift to the east somewhat. Eventually, we'll moisten up much of the Southeast as a result.