The Weather Authority | Alberto Almost Out Of Alabama; Moist Air Remains
From James Spann and the ABC 33/40 Weather Blog:
ALBERTO OVER NORTHWEST ALABAMA: The center of former Subtropical Storm Alberto is near Moulton this afternoon, moving northward. It will be in Tennessee tonight, but it has left a deep layer of tropical moisture over Alabama with very high precipitable water values.
WEST SIDE??? Traditionally, with landfalling tropical systems on the Gulf Coast, the big rains and main impact is along and to the right (east) of the circulation center. All forecasts were drawn with that in mind yesterday, but Alberto seems to have a mind of his own. Turned out the heaviest rain today was along and west of the center, on the “good” side with a north flow.
At first glance, it seems like Alberto entrained lots of dry air into the circulation over the northern Gulf of Mexico as it neared the coast yesterday (remember, this was a “subtropical storm” with mid latitude characteristics), and that dry slot held on the east side, setting up the odd and lopsided rain pattern today. High resolution models caught on to this late last night, and forecasts were adjusted during the pre-dawn hours… when counties in West Alabama were added to the flood watch.
Rain amounts of 3-4 inches were reported across much of Central, and parts of West Alabama since midnight, and gradient winds knocked down a few trees and power lines. At one point Alabama power reported 28,000 customers without service… most of them in the Birmingham metro (Jefferson and Shelby Counties).
RADAR CHECK: The most widespread rain is over Northwest Alabama this afternoon; a flash flood warning is in effect for parts of Colbert, Franklin, and Lauderdale counties until 6pm.
In the wake of Alberto’s passage, a number of scattered showers and storms are on radar across Alabama, moving northeast. There is still a very low end threat of an isolated, small tornado over far East Alabama this evening, but so far we have had no issues with rotating showers. We will still watch radar trends closely.
Showers and storm will diminish late tonight as the air becomes more stable.
REST OF THE WEEK: Very high precipitable water values will remain over Alabama tomorrow; we expect a mix of sun and clouds with scattered to numerous showers and thunderstorms, mostly during the afternoon hours. The high will be in the mid 80s. Then, the weather trends drier Thursday and Friday. Look for a decent amount of sunshine both days with just a few scattered showers and storms during the peak of the daytime heating process. Heat levels rise with highs in the 89-92 degree range.
THE ALABAMA WEEKEND: Not much change. About 7 to 9 hours of sunshine Saturday and Sunday with a few scattered, mostly afternoon and evening showers and thunderstorms. Chance of any one spot getting wet both days is about one in three, and we now project highs up in the low 90s.
A northerly flow next week should bring highs back down into the 80s; showers and storms for at least the first half of the week will be widely spaced. And, no sign of any tropical issues for the Gulf Coast for the next 7-10 days. See the Weather Xtreme video for maps, graphics, and more details…
BEACH FORECAST: Click here to see the AlabamaWx Beach Forecast Center page.
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