Wednesday, 11:30 a.m.
So far in the 2013 Atlantic Hurricane season, we have had two named storms, a relatively fast open to the season. There are no named storms in the basin now, and it's unlikely there will be one through Friday. However, that doesn't mean the tropics won't be able to make a significant contribution to the weather. If you look at the enhanced infrared image from late this morning, you can really see all of the convection flaring over the eastern Gulf, with a taproot in the northwest Caribbean:
All of this moisture had been streaming at the Florida Peninsula and up the Eastern Seaboard, but with the upper-level ridge over the western Atlantic flexing its muscles, so to speak, that corridor of tropical moisture is being nudged farther and farther west with time. It's now taking dead aim on the Florida Panhandle, and the radar is loaded up from Fort Walton Beach to Tallahassee. And this is just the beginning of this onslaught from the tropics.
Another tool we can look at to give us an idea of the rainfall potential is something called precipitable water. It's basically a measure of how much moisture there is in a column of air over a given location. The higher the number, the greater the rainfall potential. Here's what that looks like this evening from the 12z July 3 NAM model:
You can see that the precipitable water totals are quite high over the Gulf, nosing into the Florida Panhandle, southwestern Georgia and parts of Alabama. The whole region from the central and eastern Gulf up to the eastern Ohio Valley on east is more or less soaked, and it's no wonder why we've seen so much rain over the past several days in these areas, with much more to come for some.
With the axis of moisture now aimed farther west, it'll be the area from the Florida Panhandle northward through the Tennessee Valley into the Ohio Valley. And it will likely come in waves through tomorrow into Friday and probably through the weekend. While the QPF forecast is not necessarily to be trusted completely, it may be a pretty decent guide as to what one might see in the next few days. Here's the 6z July 3 GFS total precipitation forecast through Sunday evening:
Again, all of that will likely be accomplished without a tropical storm of any kind, maybe not even a tropical low. Nevertheless, there will be some flooding issues in the coming days, starting in Florida and working northward across portions of Alabama and Mississippi into Tennessee. There may also be some severe weather, particularly Sunday in parts of the Ohio Valley and mid-Atlantic, but the main attraction, unfortunately, will be the rain.
Two systems will delay the onset of warm weather in the Ohio Valley and the East over the next week or so, but then it should get warm all across the country heading into the Memorial Day weekend.
A turn to much colder air over the Northeast and mid-Atlantic states will set the stage for a rain and snow storm later this weekend before it turns much warmer later next week.
It's warm now, but will turn much colder this weekend, with a storm threat later Saturday into Sunday. Warmth will return by the second half of next week.
Though it is cold now east of the Mississippi, with a couple of opportunities for snow into the weekend, a blast of warmth is due for much of the country east of the Rockies next week.
Warm air will once again surge eastward from the Plains to the East Coast this weekend and early next week. A strong storm next Tuesday and Wednesday will then be followed by colder air later next week.
A storm in Southeast Texas will generate severe thunderstorms this afternoon and tonight, and some wet snow on its western flank as it heads into the Ohio Valley tomorrow.