With the first severe threat of the spring tornado season here, time to make a few important points about severe weather safety:

*Most people who die in tornadoes in Alabama are in mobile homes and vehicles. It is very important for all people who live in mobile homes to have a shelter identified and available 24 hours a day, seven days a week. This might be the basement of a friends site built home, a mobile home park community shelter, or some type of business. We can provide good warnings, but they do no good if people do not have a safe place to go.

*Needless to say, you also have to do everything possible to avoid driving during tornado warnings. And, we occasionally have derecho events that produce widespread straight line wind damage. Nobody needs to be driving during that type of situation, so you also have to pay attention to severe thunderstorm warnings.

*Generally speaking, Alabama school systems do a great job with severe weather safety. Parents, you have to do your part as well. Do not pick up your child during a tornado warning; if you do that you are moving them from the safest place (an interior part of the school building) and putting them in a potential death trap (a car, van, or truck).

*Have a way of getting warnings. A NOAA Weather Radio receiver should be in every Alabama home and business. And, don’t forget you can get warnings on your cell phone or pager with ABC 33/40’s E-Warn service. You sign up on our web site by county, and there is no charge (but your cellular provider might charge for text messages; check with them about your plan).

You can sign up for E-Warn here:

http://beta.abc3340.com/weather/ewarnmain.hrb

Let’s pray nothing bad happens tonight, but we must be ready just in case!

* 100 was the high temperature in Laredo today...I believe it is the first 100 of the year in the USA

* 10 below zero was the Lower 48 States low in Saranac Lake, New York

* 0 is how many Tornado Warnings have been issued in the USA as of 9 o'clock tonight

* 38 is the number of Severe Thunderstorm Warnings needed so far, mostly in the Plains and Midwest

* 4 is the number of Severe Thunderstorm or Tornado Watches in effect now, stretching from North Texas to Southeast Iowa

* 17 is the number of hail reports so far today clustered over North Arkansas and Southeast Iowa

* 3 is the number of high wind reports...all in West Texas

* 60 mph is a wind gust recorded at Silverton, Texas tonight with NO thunderstorms around

* 62 mph is a wind gust in Lubbock (West Texas) with a thunderstorm

* 55 was the highest dewpoint in Alabama at 9

* 30 was the lowest dew point at Fort Payne. Rich moisture not here yet

* 0 was the number of showers in Alabama at 9 pm

* 3 is now many miles I walked today due to a certain little 9-pound animal

* 0 is how many naps I expect to get tomorrow

The Wednesday afternoon map discussion video is on the server:

http://beta.abc3340.com/weather/video.hrb

We will focus on the severe weather potential for Alabama.

As I write this, Birmingham's dewpoint is only 36... the low levels are very dry. The return of low level moisture and high dewpoints will be the key to this coming event.

As I wrote this morning, I really like to see a dewpoint of 65 or higher for a major "red letter" type spring even here. I don't think we will get there. In fact, the models keep our dewpoints in the 50s tomorrow. That will lessen the threat to some degree.

BUT... the dynamic forcing is amazing. Wind fields in the lower 5,000 feet will be very strong tomorrow, and even with no thunderstorms involved winds could easily gust to 40 mph by afternoon. This in itself might lead to some scattered power outages.

Strong to severe thunderstorms should form over Mississippi during the day tomorrow. Our friend Jeff Craven at the Jackson NWS office is very bullish on this event; he expects widespread wind damage and a few strong/violent, long track tornadoes over Central Mississippi. SPC has a moderate risk of severe weather in place for most of Mississippi and the western half of Alabama. The probabilities are really amazing; the SPC outlook shows a 45 percent chance of severe weather (damaging winds or a tornado in this case) within 25 miles of a specific point in the moderate risk.

I think a few isolated supercell storms could form over West Alabama from 3:00 until 6:00 p.m. tomorrow, and those could produce a few isolated tornadoes. But, as I have written here for several days, I still think our main threat will be from damaging winds along a squall line that should race through the state from 6:00 p.m. until 12:00 midnight. The 12Z NAM shows 850 mb winds (about 5,000 feet off the ground) in the 60 to 65 knot range. Based on the strength of the upper trough and the wind fields, it sure looks like a case where wind damage could be widespread along the line, especially over the western half of the state.

CALL TO ACTION: Once again, you need to review your severe weather plan at your home and business. Be sure you have a NOAA Weather Radio or E-Warn so you can get the warnings, and be sure everyone in the family knows the safe place in your home. If you live in a mobile home, you need to have a place to go at any hour of the day or night! Once again, the main threat tomorrow will come from 6:00 p.m. until midnight, but a few severe storms could break out over West Alabama between 3:00 and 6:00 p.m.

THE WEEKEND: I really think most of the weekend will be dry and warm, but we will maintain the risk of widely scattered showers or storms with the southwest flow aloft. Temperatures will be close to 80 both Saturday and Sunday.

NEXT WEEK: Another severe weather threat is likely early next week... the latest GFS suggests the big threat will come from midnight Monday night to noon on Tuesday, but that could change. Lets get through the event tomorrow night and then we can be more accurate on next week's situation.

I enjoyed speaking to the juniors and seniors at Thompson High School today in Alabaster...

Keep an eye on the blog for updates as we get closer to tomorrow's event!

SPC has upgraded the severe weather risk for the Deep South tomorrow:



I will have much more on our afternoon discussion post coming by 3:30...

This week's WeatherBrains podcast (30 minute show) is available now via iTunes, RSS, or on the web...

http://www.weatherbrains.com/

Severe weather is the big topic this week, as you might imagine....

The Wednesday morning map discussion video is on the server:

http://beta.abc3340.com/weather/video.hrb

Let the storms of spring begin.

A very dynamic storm system is on the way. Can the thermodynamics be in place for a big severe weather event?

TODAY: Nice today... partly sunny with the mercury reaching the low 70s this afternoon. We will be watching for severe storms as they form in a band from Texas to Missouri this afternoon.

SEVERE WEATHER DISCUSSION: The sharp upper trough comes out of the southwest U.S. tomorrow and goes negative tilt across the southern plains. SPC has a slight risk in place for much of Louisiana, Arkansas, Mississippi, Alabama, Tennessee, and Kentucky.

We need to note up front winds will really increase across Alabama tomorrow, and by afternoon south winds could gust as high as 40 mph, especially on the ridge tops.

Thunderstorms will begin to form as the cap breaks over Mississippi during the day tomorrow. A squall line will form tomorrow afternoon over Mississippi, but any storms out ahead of the line could become a supercell and produce a tornado. The guys over at the Jackson NWS office seem pretty impressed with their severe weather potential.

Here in Alabama, I still think much of the day tomorrow will be dry. However, between 3:00 and 6:00 p.m. there is potential for thunderstorms to creep into the western part of the state, and some of those storms could be severe with the potential for isolated tornadoes.

But, the main threat for us will be a long squall line racing through here between 6:00 p.m. and midnight. The potential for damaging straight line winds along the line will be high. I guess we might have the potential for a few QLCS (quasi linear squall line) tornadoes, but damaging straight line winds will be the big issue.

Here are some severe weather parameters from the NAM valid for 9:00 tomorrow night:

Surface based CAPE: 608
Lifted index: -2.3
0 to 3 km helicity: 550
SWEAT index: 422
Total totals: 49.8
850 mb winds: 67 knots

For additional information on these parameters, go here:

http://www.crh.noaa.gov/lmk/soo/docu/indices.php

I know this is a little "old fashioned", but I really like to see a dewpoint of 65 or higher for a big time spring tornado/severe weather event. That, of course, is involved in the evolution of instability, or the ability of a parcel of air to rise. I don't think we can get dewpoints of 65 in here tomorrow night, but they should be in the 60 to 65 range. I will be keeping an eye on that.

CALL TO ACTION: This is a great time to review your severe weather safety plan since the spring severe weather season is upon us. Of course, we hoped you did this last month, but be sure you have a good way of getting warnings (NOAA Weather Radio, E-Warn, etc), and know the safe place in your home. With some potential for a damaging wind event tomorrow night, it is also very important for people in mobile homes to have a place to go at any hour of the day or night. Talk with your children about this as well. Lets hope we just have some routine thunderstorms tomorrow night, but we have to be ready.

WEEKEND WEATHER: This should be the warmest weekend so far this year with the mercury approaching 80 degrees both Saturday and Sunday. There will be sunny periods, but I think we still need to mention a chance of scattered showers and storms since the air will be pretty unstable.

NEXT WEEK: The 06Z GFS shows the southwest trough coming out early next week. The latest run would suggest some potential for strong to severe storms Monday afternoon and Monday night, and a quick shot of colder air on Tuesday. Then, milder for the latter half of the week.

Like football coaches, I like to take weather events one at a time. Lets get through the event tomorrow night and then we can be more confident about next week.

RADAR: Scroll down to the post below this one about the NEXRAD radar in Birmingham being out; our radar system atop Double Oak Mountain is available to you as always.

TODAY: I will be speaking at Thompson High School in Alabaster, but will be in the office for the next map discussion video, which should be ready by 3:30 p.m!