Potential Severe Weather Threat May 1 - 4 2018

[JayF]

 

[warneagle]

Alright, SPC, you have my attention.

 

[JayF]

Time to start looking at models to see what dynamics are in play.

 

[JayF]

Nebraska, Kansas, and Oklahoma are going to really need to be watching the storm potential for Tuesday and Wednesday next week if the models are correct.

 

[Daryl]

SPC

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK

On Wednesday/D5
the greatest threat will be from the low
southward along the dryline, from KS into OK, where a few tornadic
supercells are expected, along with very large hail supported by
steep lapse rates aloft and robust boundary layer moisture. Some
tornadoes may be strong, although forecast hodographs do vary among
the models.

 

[warneagle]

Tomorrow doesn't look too exciting. Most of the warm sector is capped but there might be a narrow band right along the dry line in the Panhandle where a couple of storms can get going (plus whatever junky stuff up in Nebraska), and then we can turn on the chaser map and watch them converge like moths to a flame.

 

[bwalk]

Wednesday has been targeted as the big day but Reed Timmer says Tuesday, 5/1/18, may get things rolling, especially in Kansas.

 

[South AL Wx]

I was just looking at the SPC Day 2 Outlook, and noticed a new "Maximum Risk by Hazard" table at the bottom of the outlook. Evidently this was recently added by SPC to the text section of all Day 2 Outlooks. Here is an example for tomorrow from http://www.spc.noaa.gov/products/outlook/day2otlk.html:

...MAXIMUM RISK BY HAZARD...
Tornado: 10% SIG - Enhanced
Wind: 30% - Enhanced
Hail: 30% SIG - Enhanced

For more information on the change, see: http://www.nws.noaa.gov/os/notification/scn18-31spc_text_productaaa.htm

 

[warneagle]

Yeah I noticed that too. It's convenient.

 

[buckeye05]

Lots of excitement surrounding Wednesday's potential event, but i'm tempering my expectations. In a nutshell, this is shaping up to be one of those events where while the "big picture" looks impressive, but the best kinematics likely won't arrive until well after convective initiation has taken place. This means we will probably see a slow uptick in tornado potential throughout the day, potentially after storm mode starts to grow upscale and things go downhill. Anyone remember May 18 of last year? Yeah.

I prefer setups in which explosive supercell development occurs in a very high-CAPE environment, during the window of absolute best possible kinematic support, usually leading to a "string of pearls" of tornadic supercells. Anyone expecting that kind of thing for Wednesday may be disappointed. I could be totally wrong and we witness a full fledged outbreak, but I feel we'll see mostly see hail and wind producers throughout the day, before the potential for a handful of tornadoes (maybe a significant one or two) peaks around sunset.

 

[warneagle]

You know the day has busted when the chasers are this bored.



I guess if it were me I would just turn it into a birding trip.

 

[tennessee storm chaser]

Lots of excitement surrounding Wednesday's potential event, but i'm tempering my expectations. In a nutshell, this is shaping up to be one of those events where while the "big picture" looks impressive, but the best kinematics likely won't arrive until well after convective initiation has taken place. This means we will probably see a slow uptick in tornado potential throughout the day, potentially after storm mode starts to grow upscale and things go downhill. Anyone remember May 18 of last year? Yeah.

I prefer setups in which explosive supercell development occurs in a very high-CAPE environment, during the window of absolute best possible kinematic support, usually leading to a "string of pearls" of tornadic supercells. Anyone expecting that kind of thing for Wednesday may be disappointed. I could be totally wrong and we witness a full fledged outbreak, but I feel we'll see mostly see hail and wind producers throughout the day, before the potential for a handful of tornadoes (maybe a significant one or two) peaks around sunset.

models starting to pick up a pretty good cap also... could be a player. something to watch

 

[rolltide_130]

Lots of excitement surrounding Wednesday's potential event, but i'm tempering my expectations. In a nutshell, this is shaping up to be one of those events where while the "big picture" looks impressive, but the best kinematics likely won't arrive until well after convective initiation has taken place. This means we will probably see a slow uptick in tornado potential throughout the day, potentially after storm mode starts to grow upscale and things go downhill. Anyone remember May 18 of last year? Yeah.

I prefer setups in which explosive supercell development occurs in a very high-CAPE environment, during the window of absolute best possible kinematic support, usually leading to a "string of pearls" of tornadic supercells. Anyone expecting that kind of thing for Wednesday may be disappointed. I could be totally wrong and we witness a full fledged outbreak, but I feel we'll see mostly see hail and wind producers throughout the day, before the potential for a handful of tornadoes (maybe a significant one or two) peaks around sunset.

Maybe further north, but across OK I don't see this as a case where storms will fire too early and ruin everything. If anything, it wouldn't surprise me to not see storms initiate period until late in the afternoon to starting to get close to sunset.

 

[warneagle]

Upgraded to hail-driven moderate risk

 

[warneagle]

Day 2 upgraded to a wind-driven moderate as well.

 

[buckeye05]

Tomorrow has gone Moderate as well.

Edit: whoops, nice timing lol

 

[bwalk]

At 4:45pm, a line of semi-discreet cells have fired and are well in progress. Line of storms runs from central Kansas to southeastern Nebraska.

2 Tornado warnings right now near Aurora & Doniphan, Nebraska, per National Weather Service Hastings NE. Doniphan tornado is confirmed by NWS. Cells appear to be becoming a little less discreet in last 15 minutes as they move farther E/NE.

 

[SilentShadow87]

Weak rain-wrapped tornado in Barton County, Kansas just now coming out of an evil-looking bat-wing cell.

Image: Aaron Jayjack via Severe Studios

 

[Bama Ravens]

Small moderate risk for tomorrow. Interesting.

 

[warneagle]

WOW