According to radar estimates of the storm total precipitation, much of Central and West Alabama received between one half and one inch of rain during the morning hours today. Some spots may have seen amounts between one and two inches. Seems from my quick look that one of the most common amounts is around three-quarters of an inch.
The big question is what will happen now? Will storms redevelop? There are reasons to believe that showers may redevelop and reasons to think they might not.
Here are some of the observations as to why showers might reform.
1. The upper trough, 500 millibar level, is still well west of us. In fact, at 12Z (7 am) today, the trough ran roughly from St. Louis to Tyler, Texas. The trough won’t actually get here until about 00Z of 7 pm.
2. Surface dewpoints remain in the lower 60s from East Mississippi eastward across Alabama.
3. The cold front, based on wind and dewpoint analysis at 11 am, ran from about Nashville to Tupelo to Monroe.
4. Clearing has occurred between the rain band and the trough axis which will allow heating of the surface and the lower portion of the atmosphere which could help to destabilize the atmosphere and allow storms to regenerate.
Here are some reasons why shower won’t redevelop.
1. The atmosphere got worked over pretty hard with the squall line, so it should be pretty stable. The storm wrung out a good deal of water.
2. There appears to be little if any warm air advection in the lower part of the atmosphere, from 850 millibars down. Plus the wind at 850 is roughly westerly.
3. Surface low is a long way north of Central Alabama.
4. Cooling of the lowest 100 millibars of the atmosphere as seen on the Jackson sounding seems fairly significant.
5. Convergence along the front is weak with a generally southwest wind in the band between the ongoing convection and the drier air with a west wind.
So there you have it. All good reasons but in different directions. And there’s a funny thing about forecasting. You can’t say both! Either you think there will be redevelopment or you think there won’t. I’m cautiously optimistic that the rest of the day will be dry. But I’ll be watching just in case.
-Brian-
