Two Day Severe Weather Threat Ahead

An all new edition of the ABC 33/40 Weather Xtreme video is available in the player on the right sidebar of the blog. You can subscribe to the Weather Xtreme video on iTunes by clicking here.

STORMS OF APRIL: I was a child of the 1970s… living through those remarkable spring tornado seasons is one of the reasons I do this for a living today. It has been a long time since we have really had an active spring season here, so we were simply overdue. And, we now have a two day severe weather threat to deal with. While the biggest concern is clearly tomorrow, let’s pay close attention to the weather today.

THE NEXT 24 HOURS: As expected, the storms that entered Northwest Alabama early this morning weakened and we have no severe weather issues at this early hour. Rain and storms are in progress over the northwest counties of the state, with heavy rain in spots.

We expect storms to become more numerous later today, possibly becoming severe. Seems like the main threat this afternoon and tonight will come from hail and damaging winds, but with the boundaries left over from the early morning convection, there could be a few spots where surface winds back around to the southeast, providing sufficient low level helicity for rotating updrafts and isolated tornadoes.

We should also mention that the rain will be heavy at times with the stronger storms; the NWS in Huntsville has their County Warning Area under a flash flood watch.

In terms of timing, severe weather will be possible today anytime after the late morning hours, through the afternoon and well into the night. Of course, we will also watch developments to the west closely, where SPC has a moderate risk of severe weather in place from near Paris, Texas to east of Memphis. Most of North Alabama is in the standard slight risk today and tonight.

RED LETTER DAY TOMORROW? Possible. Long time readers here know the ultimate severity of a tornado outbreak is determined by mesoscale features that really can’t be identified far in advance, but clearly on the synoptic scale, all of the players are on the field for a very significant outbreak here across the northern half of Alabama.

Aloft, we have a very deep, slightly negative tilt upper trough moving in with a strongly diffluent flow, adding to the upward parcel velocities. At the surface, strong winds out of the southeast will feed the storms, with a very high degree of veering wind direction with height. Steep lapse rates will be in place, and a capping inversion will prevent morning convection from stabilizing the atmosphere early in the day. All in all a classic severe weather setup.

TIMING: The main window for severe storms will begin tomorrow in the 11:00 a.m. to 1:00 p.m. time frame. The afternoon storms will become severe quickly where they develop, and all modes of severe weather will be possible, including large hail, damaging winds, and tornadoes. Forecast parameters suggest a few violent, long track tornadoes are possible.

The storms will evolve into a long squall line tomorrow night with potential for damaging winds, and they should exit the state soon after midnight, in the 1:00 to 3:00 a.m. time frame early Thursday.

REMEMBER: With potential for some severe weather today, and a red letter kind of severe weather day possible tomorrow, be sure you are in a position to hear severe weather warnings (never rely on a siren!), and have a good plan of action when warnings are issued. No need to panic; even large tornadoes are small compared to a large county. But, we must be prepared.

SCHOOLS: For school systems that do decide to dismiss early tomorrow, please consider giving students that live in mobile homes the option of staying in school buildings. In many rural parts of the state those school buildings are absolutely the safest place.

RESOURCES: As we get ready for more active weather… let me list some resources that will help.

ABC 33/40 WEATHER CALL: The service that will send you a phone call if you are within a tornado warning polygon. Works very well and is very reliable.

ABC 33/40 LIVE RADAR STREAM: This is also the stream we use for long form tornado coverage when warnings begin to fly.

APPS: The ABC 33/40 Weather app for your iPhone or Android phone lets you watch our live coverage anytime, anywhere.

STORM CHASER STREAM: Ride along with the ABC 33/40 StormChaser on this stream. The team will be out in the field later as the severe weather event unfolds.

THURSDAY/FRIDAY: Beautiful weather on these days in the wake of the storms; lots of sun with cooler temperatures. Highs in the low 70s Thursday, followed by upper 70s Friday. We have a chance of reaching the upper 40s early Friday morning.

THE WEEKEND: Saturday will be dry with a high in the low 80s, but a cold front will bring some risk of showers and storms on Sunday. The front is expected to become nearly stationary over the Tennessee Valley, which should prolong the chance of storms into Monday. For now the severe weather risk looks low with this system.

WEATHER BRAINS: Don’t forget you can listen to our weekly 90 minute netcast anytime on the web, or on iTunes. This is the show all about weather featuring many familiar voices, including our meteorologists here at ABC 33/40. Scroll down for the show notes on this week’s new episode.

FOLLOW ALONG: Here are our weather team Twitter accounts….

I have a weather program scheduled for Calera Elementary today… hopefully I will be able to make it, but if severe weather breaks out I will have to postpone to another day. Stay tuned to the blog for running updates through this entire event!

Tags: severe storms

Category: Alabama's Weather