Severe Weather Threat May 7-10, 2024

[jiharris0220]

The SPC made the right call with not issuing a 15% moderate tornado risk.

This is one of those conditional situations where the floor is no tornadoes to a ceiling of multiple significant/violent tornadoes could happen.

And it all depends on random chance storm mode, and mesoscale interactions along any established boundaries.

 

[Kds86z]

Yeah, it's an ensemble, so the HRRR, SREF, etc. all have to average their members to get 30%, so that's saying something. We'll have to see what happens.

Super interesting

 

[warneagle]

HREF rarely shows 30% probs. Surprised to see it not only show 30% but over such a large area, especially considering the uncertainties today.

Yeah it’s very weird to me given that there are significant uncertainties about storm mode etc. Way less confidence than the other day (even though that didn’t materialize).

 

[wx_guy]

Yeah it’s very weird to me given that there are significant uncertainties about storm mode etc. Way less confidence than the other day (even though that didn’t materialize).

Yeah, truly. The 30% area is elongated and covers a lengthy area, but it's relatively narrow vertically. Makes me wonder if the ensemble is seeing evidence of 1-2 monster long-lived supercells propagating across that area.

 

[Clancy]

Yeah, truly. The 30% area is elongated and covers a lengthy area, but it's relatively narrow vertically. Makes me wonder if the ensemble is seeing evidence of 1-2 monster long-lived supercells propagating across that area.

I mean, there is definitely the potential for a pretty nasty day, but yeah I'm just surprised because it's usually very shy about throwing out 15%+ numbers.

 

[Clancy]

Large D2 ENH, including 5% risk for tornadoes in parts of GA and AL.

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 PM CDT Wed May 08 2024

Valid 091200Z - 101200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS
TO CENTRAL/SOUTHERN GEORGIA AND FAR SOUTHERN SOUTH CAROLINA...

...SUMMARY...
Very large hail with multiple supercells appears probable across
parts of central Texas into the ArkLaTex vicinity Thursday afternoon
and evening. A broader corridor of severe hail and damaging wind
potential will extend from east Texas into the lower Mississippi
Valley and Southeast.

...East TX to South Carolina...

Most guidance is in agreement that an MCS will be ongoing Thursday
morning in the vicinity of northeast AL into northern GA. The
expectation is that this MCS will develop southeast toward southeast
GA/far southern SC through the day. Maintenance of this system
should be supported by a shortwave impulse migrating across the
region with 40 kt of 850-700 mb southwesterly flow overspreading a
very moist airmass. Downstream destabilization ahead of the MCS
across central/southern GA and perhaps portions of eastern AL is
forecast, with MLCAPE to near 2500 J/kg expected. Both GFS and NAM
forecast soundings indicate steep low-level lapse rates develop amid
strong heating into the 80s F. Furthermore, midlevel lapse rates
around 7 C/km and elongated hodographs are present. Severe/damaging
wind potential will be the main concern given expected bowing
convective mode. However, should any more discrete convection
develop, a risk for large hail and a tornadoes also will be present
given an environment capable of supporting supercells.

Further east, a cluster of supercells is expected to develop across
north TX southward toward the Hill Country in the vicinity of the
intersecting dryline and cold front. Strong to extreme instability
(3500+ MLCAPE) is anticipated amid a plume of very steep midlevel
lapse rates. This will support intense updraft development amid 40+
kt effective shear magnitudes and elongated/straight hodographs.
Very large hail (2-3 inch diameter) will be possible with these
storms. Steep low-level lapse rates, large CAPE and water-loaded
downdrafts also will support damaging wind potential.

With time, the damaging wind risk will increase as clustering
occurs. Most guidance generates an eastward propagating MCS from
the east TX cluster, moving across northern LA into MS/AL during the
evening/nighttime hours. This activity is expected to move along the
gradient of strong to extreme instability across this region ahead
of the southeastward progressing cold front. Some potential will
exist for significant gusts (to near 75 mph).

...North Carolina to the Mid-Atlantic vicinity...

Some showers and thunderstorms may be ongoing across the Chesapeake
Bay vicinity southward to far eastern NC. Nevertheless, weak
destabilization/airmass recovery is forecast by afternoon. Isolated
to scattered thunderstorms are expected to develop from the Upper
Ohio Valley eastward across parts of VA/NC ahead of the
south/southeastward-advancing cold front. Locally strong gusts and
small hail will be possible with this activity.

..Leitman.. 05/08/2024

 

[tennessee storm chaser]

The SPC made the right call with not issuing a 15% moderate tornado risk.

This is one of those conditional situations where the floor is no tornadoes to a ceiling of multiple significant/violent tornadoes could happen.

And it all depends on random chance storm mode, and mesoscale interactions along any established boundaries.

Thin there some
Gun shy also after this week lol

 

[South AL Wx]

Large D2 ENH, including 5% risk for tornadoes in parts of GA and AL.
View attachment 26797View attachment 26798

30% hatched wind area for much of the enhanced, with the text mentioning potential gusts to 75 mph.

 

[wx_guy]

Large D2 ENH, including 5% risk for tornadoes in parts of GA and AL.
View attachment 26797View attachment 26798

A rather big expansion.

 

[warneagle]

Large D2 ENH, including 5% risk for tornadoes in parts of GA and AL.
View attachment 26797View attachment 26798

I think that’s our first tornado probability of the year up here. All we’ve really had so far was one severe thunderstorm with some small hail.

 

[buckeye05]

My concerns from this morning remain the same. If this is one of those “really high CAPE and boundaries will compensate for weak low level shear and messy storm mode” situations, I just want to say I’ve seen similar setups, and the scenario of boundaries/CAPE actually compensating for those limiting factors rarely seem to play out. I can remember a lot of messy wind/hail days with a low shear, high CAPE setup where people were banking on that to come into play, but it didn’t. So yeah I’m skeptical, but could also completely eat my words later too.

 

[warneagle]

My concerns from this morning remain the same. If this is one of those “really high CAPE and boundaries will compensate for weak low level shear and messy storm mode” situations, I just want to say I’ve seen similar setups, and the scenario of boundaries/CAPE actually compensating for those limiting factors rarely seem to play out. I can remember a lot of messy wind/hail days with a low shear, high CAPE setup where people were banking on that to come into play, but it didn’t. So yeah I’m skeptical, but could also completely eat my words later too.

A classic case of low confidence but high ceiling. Why we need that 5# probability.

 

[wx_guy]

A classic case of low confidence but high ceiling. Why we need that 5# probability.

Or instead of hatches, a bunch of question marks lol EDIT: And when you click on the ? marks on the map, it comes up with a Suggestion Box where you get to tell the SPC what it's going to do lol

 

[JBishopwx]

Past the caffine.

Bump.

 

[warneagle]

TOR warned supercell in S KY doesn’t look like anything special on velocity but it’s going to pass very close to Bowling Green so it definitely merits close attention.

 

[Tanner]

If I'm not mistaken the Brimfield tornado occurred on a low risk day

5%. The scariest day of my life.

 

[Tanner]

My concerns from this morning remain the same. If this is one of those “really high CAPE and boundaries will compensate for weak low level shear and messy storm mode” situations, I just want to say I’ve seen similar setups, and the scenario of boundaries/CAPE actually compensating for those limiting factors rarely seem to play out. I can remember a lot of messy wind/hail days with a low shear, high CAPE setup where people were banking on that to come into play, but it didn’t. So yeah I’m skeptical, but could also completely eat my words later too.

Exactly my concern. Overall, 10% is the correct play.

 

[UncleJuJu98]

Hrrr looks crazy for north Tennessee.

 

[TheSuckZone]

 

[Kds86z]

Wouldn’t sleep on this area..