Mid-Evening Update on Alabama’s Weather

Tonight, a frontal system extends all the way from Maine through the Great Lakes and Midwest to a surface low near Little Rock and on into Texas.

At about 5,000 feet, a low level jet was developing tonight from eastern Texas into southern Arkansas to the southeast of the front. Showers and storms were increasing in coverage and intensity tonight from Northeast Texas through Arkansas. The Storm Prediction Center contemplated a severe weather watch for these areas earlier but so far has not had to issue anything. There was a confirmed tornado

In the upper atmosphere, a deep trough was over the west, extending from the Dakotas to Arizona. Very strong winds are developing around the trough.

You notice a common thread here: strong wind fields. The strong wind fields are going to be a problem tonight and Saturday to our west and moving into Alabama tomorrow afternoon, tomorrow night and early Sunday.

Dewpoints have come up 25-30 degrees in the past twenty four hours across Central Alabama as moisture levels are rising dramatically. The Gulf of Mexico is open for business as strong high pressure well off the East Coast has resulted in a broad southerly flow of warm, moist air into the Southeast. The dewpoint is already at 60F at Tuscaloosa, with middle 50s at Birmingham and lower 50s over eastern Alabama.

Temperatures are in the 60s in the I-20 corridor. Lows won’t fall very far overnight, with middle 60s over western Alabama and middle 50s over eastern Alabama.

Highs tomorrow will rise in to the lower and middle 70s. We are calling for 73F at Birmingham, which would tie the record for the date.

Mid level clouds are thick across the state and additional low clouds will develop overnight as the moist air continues to be lifted. A few light showers were moving across Northwest and East Central Alabama, moving to the northeast in the southwesterly flow. Clouds will be a staple for much of the weekend. Except for some temporary clearing Sunday, skies will be mostly cloudy until Monday.

There will be a couple of rounds of light rounds during the across Central Alabama tomorrow, but rainfall amounts will be light. Additional showers and storms could develop during the afternoon across western Alabama if there is enough heating to break the cap. Instability values may approach 1,000 j/kg during the afternoon. Bulk wind shear values will be in excess of 60 knots, so storms that do develop will develop rotating updrafts. So if storms can develop, they could be supercells and these would have the potential to produce a couple of tornadoes as well as damaging winds. We will be watching for that possibility.

It looks like a solid line of intense thunderstorms will reach northwestern Alabama around 4-5 p.m. on Saturday. The line will make only slow progress eastward Saturday evening, so any storms ahead of it will be a concern with the strong wind fields.

A surface low will be near Little Rock again by sunset and it will pass over the Missouri Bootheel around midnight. This will put us in a favorable position for backed, southeasterly surface winds and increased low level helicity that could produce an isolated tornado in any isolated supercells or supercells embedded in the squall line. And with 60-70 knot winds just off the surface at 5,000 feet, it will be easy for any thunderstorms to bring high winds to the ground, so damaging winds will be possible.

The SPC has areas west of a line from Centre to Talladega to Montgomery to Evergreen in its Day Two Severe Weather Outlook in a slight risk category, their standard severe weather risk. There is an enhanced, or Moderate Risk, to the west of Alabama from Memphis to near Lake Charles LA.

The line of storms should reach I-59 between 3-5 a.m. and move across southern and eastern portions of the area before mid-morning. There could be some redevelopment over Central Alabama in areas mainly south and southeast of Birmingham Sunday afternoon if the front hangs up again for a few hours.

We will be watching the weather all weekend right here on the AlabamaWX.com blog with frequent updates and any watches and warnings that are issued.

Category: Alabama's Weather, Severe Weather