Wednesday January 18, 2017
Forecaster: James Spann
ACTIVE JANUARY WEATHER: We will have two different opportunities for strong to severe storms across Alabama over the next five days, but today will be relatively quiet. The sky will be mostly cloudy, and a little light rain is possible in spots, but most of the day will be dry and the high will be in the mid 60s, about ten degrees cooler than yesterday thanks to a weak surface front that slipped through last night.
TOMORROW: We have a "marginal" risk of severe storms for a decent part of Alabama tomorrow afternoon and tomorrow night as defined by SPC.
An upper trough will approach from the west tomorrow; the current surface front over Central Alabama will lift northward during the day, putting the state in an unstable airmass. Forecast soundings are fairly saturated; you usually need dry air in the mid levels for a big severe weather threat (the best convective instability occurs when dry mid-level air advects over warm and moist air in the lower troposphere).
Here are the details..
TIMING: The main window for strong to severe storms will come from about 4:00 p.m. tomorrow through 2:00 a.m. Friday.
THREATS: The main threats will come from damaging straight line winds and small hail, although an isolated, brief tornado can't be ruled out.
RAIN: Rain amounts of around one inch are likely; some minor flooding issues are possible, but major flash flooding is not expected.
As always, be sure you have a way of getting severe weather warnings in the event they are needed tomorrow night.
FRIDAY: Rain moves out during the pre-dawn hours, and the sky should become partly sunny during the day with a high in the low 70s.
WEEKEND SEVERE WEATHER THREAT: A robust system will impact Alabama over the weekend. A deep upper low will set up west of the state with strong wind fields, and unstable air will build across the Deep South.
On Saturday, surface based CAPE values will rise to nearly 2,000 j/kg, very high for January, and during the afternoon and evening hours a few severe storms are possible. However the "main event" will most likely come late Saturday night into Sunday as the best dynamic support arrives. A deepening surface low will be over Arkansas, supported by a strong upper trough. Alabama will be in the "warm sector" of the storm with unstable air and severe storm potential.
Understand it is simply too early to be specific concerning timing and the magnitude of this event; we need to get past the round of storms tomorrow night before we can do this. We will get a good look at the state of the atmosphere Friday morning and give you some detailed forecast information then. For now, just understand we will have the risk of strong to severe storms over the weekend... no need to be alarmed, just be aware of the potential.
BENEFICIAL RAIN: Rain amounts could easily exceed three inches over much of the state by early next week from the multiple rounds of storms.... more good drought relief.
NEXT WEEK: Monday will be cloudy and much cooler with periods of light rain; the high will be in the 50-55 degree range. And, toward the end of the week, even colder air arrives with highs dropping into the 40s.See a detailed seven day forecast here.
See the latest forecast for the Alabama Gulf Coast here.
Today's Record Temperatures