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Severe WX Severe Weather Threat 4/5/17-4/6/17

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Areas affected...Portions of AL/GA/SC

Concerning...Outlook upgrade

Valid 051443Z - 051645Z

SUMMARY...Portions of the states of AL/GA/SC are being considered
for an Outlook upgrade -- though the details are still being
analyzed. A very notable dry bias is apparent in the latest model
guidance, and observational data and previous model runs are being
heavily referenced in Outlook preparation.

DISCUSSION...GPS PW data are exhibiting a low bias by at least 0.5
inch from parts of AL into GA, which has influenced initialization
of the latest numerical weather prediction guidance. Per
coordination with the Weather Prediction Center, it appears that
related initialization is causing substantial dry biases in model
guidance -- extended through the Day 1 forecast period. With an
inland influx of rich moisture feeding ongoing intense supercells in
southern AL (with dewpoints into the middle 70s), and the
around-16.6-g/kg mean mixing ratio per LIX 12Z sounding, and around
1.5-inch PW per Atlanta and Birmingham 12Z soundings, it is evident
that rich moisture and related strong buoyancy does indeed extend
inland. As such, observational data and previous model runs will
play a major role in the consideration for a High Risk upgrade, as
the dry bias has influenced the latest model guidance. While an
Outlook upgrade is possible, it is not certain.

..Cohen/Marsh/Hart.. 04/05/2017
 
JP Dice really seems to think areas in Alabama south of I-20 and east of I-65 is where the primary tornado threat is. Didn't say other areas couldn't see tornadoes, but says that really seems to be the bullseye.

Yeah, that's basically been the forecast for Alabama for the last 3 days.
 
In my unscientific opinion based on "feel", I would think it is going to really have to get sunny around this area (20 miles N of Bham) to destabilize enough to get really bad. This morning was a monsoon for 2 hours or so and it is still cloudy here. I guess if anything bad is going to fire here, it will have to be late in the afternoon, and by then, some ingredients may have pushed east ahead of the sunshine.
 
In my unscientific opinion based on "feel", I would think it is going to really have to get sunny around this area (20 miles N of Bham) to destabilize enough to get really bad. This morning was a monsoon for 2 hours or so and it is still cloudy here. I guess if anything bad is going to fire here, it will have to be late in the afternoon, and by then, some ingredients may have pushed east ahead of the sunshine.

Perhaps so, but you'll have the sun poking through within the next 30 minutes
 
Vis satellite shows clearing well underway. Dry slot in place it appears, sliding in on water vapor
 
Anyone else think the band of showers forming over western Alabama is the last of it? If it is, this will be a non-event west of 65. Certainly seems like east central Alabama and central Georgia are the areas of concern. I just don't see much happening in places like Birmingham and Tuscaloosa.
 
Dr. Tim Coleman has mentioned a possible cap around Birmingham. Says it could be an error from the balloon being launched in a thunderstorm, but if it is real, it would limit storm formation in the Birmingham area unless we got into the lower 80s and could break it.

http://birmingham.raycomweather.com/2017/04/severe-weather-update-928-am.html
I've discounted a lot of what Tim Coleman says after the "closed upper level lows don't produce tornadoes" comment right before 4/15/11.
 
It's gonna take some mesoscale boundaries today. Critical angles are not favorable as of NOW.
This.

I am not overly enthusiastic about events that rely entirely on mesoscale kinematics to verify. I've seen far too many potent setups that seem to have everything going for them end up underperforming due to other compensating factors simply not being enough to make up for a bad wind profile. For anyone expecting everything on the radar to be spinning like crazy once round 2 starts, I'd temper your expectations a bit. We may see a lot of cells that end up not doing too much, with just a few going nuts due to boundary interactions. Just my two cents.
 
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