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.
Cold air will rule the Southeast for a while with areas west of the Mississippi getting a glancing blow or outright warm. There is potential for a winter storm early next week.
The rest of the week will be cold and this weekend is looking very cold as arctic air moves in. With so much cold air available, there will be snow to talk about, too. West of the Mississippi, warmth will hold on in many areas.
Here's an update on the severe storm and tornado risk for the first part of the week. Behind the stormy weather, it will turn colder again.
A powerful storm will bring severe storms to parts of the South though the first part of the workweek, then much colder air arrives behind the storm. Opportunities for snow and ice will follow.
Warmer air will spread over the South this weekend and early next week while a powerful storm forms over the Southwest. This storm will cause a severe weather outbreak over a large part of the South next week, including tornadoes.
A storm and front converging on Florida will generate thunderstorms, some severe with lots of rain, through Thursday. Otherwise, we're heading into a quiet and warm spell that will last into early next week.