Severe WX April 12-15th, 2018 Severe Potential

[warneagle]

This thing is also gonna drop some serious snow in the upper midwest. I definitely got out of Michigan just in the nick of time.

 

[Richardjacks]

Looking at the NAM and now CAMS, which are coming into range, looks to me like the storms are going to stay well west of I65 until the afternoon...the anticyclonic curvature over Al is really hanging on.

 

[Bamamuscle]

I bet most of you all follow him already but if not he’s a wealth of knowledge on severe weather.




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[Taylor Campbell]

Except for the one supercell, the slight risk verified rather fine. Also have to remember this was before the introduction of the ENH, and a hatched 10% would've been a slight.

In today's perspective it was a busted forecast because it warranted a 10% hatched tornado threat. It's a good example of why enhanced is needed as a categorical risk. By no means was that a slight risk day based on reports.

 

[SilentShadow87]

My crappy old computer is having trouble again and no images or graphics are loading, so...
What time tomorrow is the supercell potential going to be highest and when should it fully transition to QLCS?

 

[Austin Dawg]

Like warneagle said - it is by no means limited to Alabama.

I doubt it is limited to the south, in spite of preconceptions.

How many urban dwellers leave the city?

 

[Kory]

HRRRX still knocks out the northern 1/3 of AL with the initial outflow of the morning storms. Untapped atmosphere to the South of that outflow. One thing of note, lots of pre QLCS convection into the midday across eastern and Southern MS...and the QLCS isn't fully congealed. I think the tornado threat is ticking upward for places that don't get shunted by outflow.

 

[MichelleH]

Well, it changed again...most of AL now in the enhanced risk for Saturday per SPC.

http://www.spc.noaa.gov/products/outlook/day2otlk.html

 

[warneagle]

This is weird. There's a moderate area showing on the map on the SPC homepage but the banner and the actual outlook haven't been updated to reflect it.

 

[South AL Wx]

BMX's forecast for Saturday... a little different than SPC's:

 

[Kory]

The CAPE, which appeared to be the most questionable factor, is really ticking up on the models. Places that avoid the outflow would likely see CAPE in excess of 2,000 J/KG, which is a healthy amount. We likely won't know which places will be affected by outflow until overnight and early tomorrow. As you can see, the NAM is more bullish with the northern extent given it doesn't progress the morning convection as far east. It appears to be a broken line as well...reflecting little disruption from a cold pool.

HRRRX Convective Available Potential Energy: https://rapidrefresh.noaa.gov/hrrr/...maxFcstLen=48&fcstStrLen=-1&domain=t6&adtfn=1

NAM CAPE products: http://www.pivotalweather.com/model.php?m=nam4km&p=sbcape&rh=2018041306&fh=39&r=us_se&dpdt=

 

[South AL Wx]

This is weird. There's a moderate area showing on the map on the SPC homepage but the banner and the actual outlook haven't been updated to reflect it.

It looks like the outlook on the SPC page is a little behind. The College of DuPage site has the updated outlook:

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS
CENTRAL/SOUTHWEST AR...FAR NORTHEAST TX...FAR NORTHWEST LA...

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHERN IA TO
NORTHEAST TX AND THE LOWER MS VALLEY...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE
CENTRAL STATES...

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE
CENTRAL STATES...

..SUMMARY

NUMEROUS TO WIDESPREAD SEVERE STORMS ARE EXPECTED FROM THE
MID-MISSOURI VALLEY SOUTH INTO THE ARK-LA-TEX STATES AND LOWER
MISSISSIPPI VALLEY THIS AFTERNOON INTO TONIGHT. SEVERAL TORNADOES
(SOME STRONG), VERY LARGE HAIL, AND DAMAGING WINDS WILL BE POSSIBLE.

HAVE UPGRADED TO A TORNADO-DRIVEN MODERATE RISK CENTERED ON THE
ARK-LA-TEX TO CENTRAL AR WITH THE POTENTIAL FOR SEVERAL TORNADOES TO
OCCUR WITHIN THIS REGION LATE TODAY THROUGH TONIGHT.

http://kamala.cod.edu/spc/

 

[warneagle]

can we get live mode enabled on this thread? I have a feeling we're gonna need it in a few hours.

 

[Daryl]

 

[MichelleH]

Does anyone else feel like today's outlook is flipping them off or is it just me? LOL

 

[SilentShadow87]

Looks like the SPC is having some technical difficulties...

Several tornadoes %28some strong%29, very large hail, and damaging winds will be possible.

 

[HazardousWx]

I bet most of you all follow him already but if not he’s a wealth of knowledge on severe weather.




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Never heard of him. Who is he?

 

[Richardjacks]

Never heard of him. Who is he?

Good, I don't feel so bad, never heard of him either.

 

[Richardjacks]

The bmx office said their forecasts were suffering by aligning with the SPC. They told media partners to expect these differences to continue.

 

[Bamamuscle]

Never heard of him. Who is he?

He’s one of the main researchers working on Vortex SE at UAH. Jason Simpson refers to him during coverage a lot. Very smart dude.


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