Strong Thunderstorms Building Over Parts Of The Area – A Quick Check At 5:30 PM

Collaborative post by Scott Martin and Bill Murray

RADAR CHECK AT 5:25 PM

Showers and thunderstorms are continuing to fire up over the northern and the western parts of the state, especially in a zone west of I-65 from Athens in Limestone County, down to Sweet Water in southern Marengo County.

The strongest storms in the area at this point are located in the Tennessee Valley. One large cell located in southwestern Jackson and northeastern Marshall counties that is producing very heavy rainfall and copious amounts of cloud-to-ground lightning. A significant weather advisory is currently in effect on this storm as strong gusty winds capable of knocking down small tree limbs are possible, along with pea size hail. This cell is moving to the south at 25 MPH, and will affect the communities of New Hope, Grant, Langston, Paint Rock, Trenton, and Garth within the next 30 minutes.

UPDATE: Severe thunderstorm warning was just issued on this cell for Jackson and Marshall counties until 6:00 PM. Details are on the blog.

The other area of concern is a large cluster of storms that stretches over parts of Marion and Franklin counties eastward to Lawrence and Morgan Counties. These also have a significant weather advisory in effect as pea size hail and wind gusts of 40-50 MPH are possible, along with dangerous cloud-to-ground lightning and very heavy rainfall. These are moving to the east at 15 MPH, and will affect Somerville, Hartselle, Falkville, Flint City within the next 15-30 minutes.

More heavy thunderstorms are active in the southwestern parts of the area as well as multiple cells are currently dropping very heavy rain with plenty of lightning over Hale, Perry, Dallas, and Marengo counties. No active warnings or advisories are in effect for these storms at this point, but lightning is a big issue with these cells. These have really fired up within the past 15-25 minutes and are moving slowly southward. Newbern, Uniontown, Sweet Water, and Marion are in the path of these.

If you hear thunder, you are close enough to the parent thunderstorm to be struck by lightning. When thunder roars, go indoors.

MESOSCALE ANALYSIS

Instabilities have risen through the day across Central Alabama as a good supply of sunshine was maintained thanks to slightly warmer temperatures aloft and slightly drier air than that to the southeast and to the west.

A convergence zone seems to be setting up on either side of the I-65 Corridor between the outer band on the northwestern side of the low in the Gulf and a surface low near Memphis.

A large pocket of slightly colder temperatures aloft is across Northeast Mississippi and Northwest Alabama. It is coincident with an area of higher moisture as well. Storms are forming along the gradient on the front edge of this higher moisture and instability.

Mid-level lapse rates are mediocre, but low level lapse rates are high, so storms are forming quickly where they can get an updraft going.

There is very little wind shear, so storms are not very organized, but they will be able to produce a few reports of damaging wind gusts where there are stronger updrafts and downdrafts.

Convection is increasing this evening from Lawrence and Limestone Counties over North Alabama down through Winston, Walker, Tuscaloosa, Fayette, Hale and Marion Counties. Storms were beginning to bubble up in this zone and are becoming more widespread and stronger.

This trend is backed up by the HRRR model which depicts an area of storms slowly edging east through the evening hours into the I-65 corridor before weakening after midnight.

We will be monitoring the storms through the evening and will have warnings and significant weather advisories posted immediately to the blog along with frequent updates.

Category: Alabama's Weather, ALL POSTS