Severe Weather Threat May 7-10, 2024

[tennessee storm chaser]

By reading MEG's discussion, it sounds like most of the activity will be overnight.

Lower level jet need watch that … only increase the threat

 

[Clancy]

Modelling continues to show strong indicators for severe during this time period. SREF shows a potent threat from AR-MO all the way through the OH Valley down into AL/GA, well into the evening Thursday.

 

[Gail]

Wednesday is my daughter’s birthday too. I guess we’re going to have a camp out in the shelter. It was such a nice spring too.

 

[Kds86z]

10% hatch for tomorrow. in/oh

 

[cincywx]

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1228 PM CDT MON MAY 06 2024

VALID 071200Z - 081200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHEAST
INDIANA INTO NORTHWEST AND CENTRAL OHIO...

..SUMMARY

SCATTERED SEVERE THUNDERSTORMS WILL BE POSSIBLE TUESDAY FROM THE
MID-SOUTH NORTHEASTWARD INTO THE OHIO VALLEY. A FEW TORNADOES, LARGE
TO VERY LARGE HAIL, AND SEVERE/DAMAGING WINDS ALL APPEAR POSSIBLE,
PARTICULARLY FROM NORTHEAST INDIANA INTO NORTHWEST AND CENTRAL OHIO.

..SYNOPSIS

A MID/UPPER CYCLONE IS FORECAST TO REMAIN LARGELY IN PLACE OVER THE
WESTERN DAKOTAS WHILE CONTINUING TO OCCLUDE. A CONVECTIVELY
AUGMENTED SHORTWAVE TROUGH WILL LIKELY MOVE THROUGH THE BASE OF THIS
CYCLONE, PROGRESSING FROM THE MID MS VALLEY QUICKLY NORTHEASTWARD
INTO THE UPPER MIDWEST AND UPPER GREAT LAKES DURING THE DAY. PRIMARY
SURFACE LOW WILL OCCLUDE BENEATH THE PARENT CYCLONE, BUT A SECONDARY
LOW WILL LIKELY DEVELOP AT THE TRIPLE POINT, MOVING FROM THE MN/IA
BORDER VICINITY EAST-NORTHEASTWARD ACROSS CENTRAL/SOUTHERN MN INTO
LOWER MI. THE COLD FRONT EXTENDING SOUTHWARD FROM THIS SECONDARY LOW
IS FORECAST TO PUSH EASTWARD ACROSS THE MID MS AND OH VALLEYS, WHILE
THE WARM FRONT SHIFTS NORTHEASTWARD INTO LOWER MI AND THE UPPER OH
VALLEY.

..MID-SOUTH/MID MISSISSIPPI VALLEY INTO THE OHIO VALLEY

A DECAYING CONVECTIVE LINE WILL LIKELY EXTEND FROM SOUTHERN WI
THROUGH WESTERN IL AND INTO WESTERN PORTIONS OF THE MID-SOUTH EARLY
TUESDAY MORNING. BUOYANCY WILL BE MODEST AHEAD OF THIS LINE, WHICH
WILL LIKELY LIMIT THE SEVERE POTENTIAL. EVEN SO, THERE IS STILL A
LOW-PROBABILITY CHANCE FOR A FEW INSTANCES OF HAIL AND/OR DAMAGING
GUSTS, PARTICULARLY ALONG THE SOUTHERN END OF THE CONVECTIVE LINE IN
THE MID-SOUTH VICINITY WHERE BUOYANCY IS GREATEST.

THE CONVECTIVE LINE IS EXPECTED TO MAKE QUICK NORTHEASTWARD
PROGRESS, CLEARING THE THROUGH THE LOWER OH VALLEY BY THE LATE
MORNING AND MUCH OF THE MIDDLE OH VALLEY BY THE EARLY AFTERNOON. THE
AIR MASS IS EXPECTED TO RECOVER QUICKLY IN ITS WAKE, WITH MID TO
UPPER 60S DEWPOINTS ADVECTING IN FROM THE SOUTHWEST. ADDITIONAL
THUNDERSTORM DEVELOPMENT IS EXPECTED AROUND 17-18Z ACROSS IL,
SUPPORTED BY BOTH WARM-AIR ADVECTION AND INCREASING LARGE-SCALE
ASCENT ATTENDANT TO THE APPROACHING SHORTWAVE TROUGH. THIS INITIAL
ACTIVITY WILL LIKELY BE ELEVATED, BUT SHEAR IS STRONG ENOUGH TO
SUPPORT SOME MORE ORGANIZED STRUCTURES CAPABLE OF HAIL. AS THE
DOWNSTREAM AIRMASS ACROSS OH AND IN DESTABILIZES, THESE INITIAL
STORMS WILL LIKELY TREND TOWARDS BECOMING MORE SURFACE-BASED. GIVEN
THE STRONG VERTICAL SHEAR IN PLACE, THE POTENTIAL FOR SUPERCELLS
WILL INCREASE AS STORMS BECOME SURFACE BASED. ALL SEVERE HAZARDS
WILL BE POSSIBLE WITH THESE SUPERCELLS, INCLUDING LARGE HAIL AND
TORNADOES. THE TORNADO THREAT IS EXPECTED TO MAXIMIZE FROM NORTHEAST
IN INTO WESTERN AND CENTRAL OH DURING THE LATE AFTERNOON/EARLY
EVENING, WHERE THE PROXIMITY TO THE WARM FRONT WILL CONTRIBUTE TO
BETTER LOW-LEVEL SHEAR.

..UPPER MIDWEST

DESPITE RELATIVELY COOL SURFACE TEMPERATURES, COOLING MID-LEVELS
COUPLED WITH MODEST LOW-LEVEL MOISTURE ARE EXPECTED TO RESULT IN
AIRMASS DESTABILIZATION AND MODEST BUOYANCY AHEAD OF THE TRIPLE
POINT AND ASSOCIATED SURFACE BOUNDARIES. THUNDERSTORM DEVELOPMENT IS
ANTICIPATED BOTH NEAR THE TRIPLE POINT, AS WELL AS ALONG AND
NORTH/NORTHEAST OF THE OCCLUDED FRONT. MUCH OF THE ACTIVITY IN THE
VICINITY OF THE OCCLUDED FRONT WILL LIKELY BE ELEVATED, BUT A FEW
STRONGER UPDRAFTS CAPABLE OF HAIL ARE STILL POSSIBLE. MORE
SURFACE-BASED STORMS ARE POSSIBLE NEAR THE TRIPLE POINT ACROSS
SOUTHERN WI. HERE, ISOLATED HAIL AND GUSTY WINDS MAY OCCUR WITH THE
MORE ROBUST CORES, AND A BRIEF TORNADO OR TWO ALSO APPEARS POSSIBLE.

..MID-ATLANTIC

ISOLATED TO PERHAPS WIDELY SCATTERED THUNDERSTORMS MAY DEVELOP
TUESDAY AFTERNOON ACROSS PARTS OF VA/NC, GENERALLY ALONG/EAST OF A
WEAK SURFACE LEE TROUGH. SUFFICIENT FORECAST INSTABILITY AND SHEAR
SHOULD BE PRESENT TO SUPPORT SOME THREAT FOR HAIL AND STRONG WINDS
WITH ANY THUNDERSTORMS THAT FORM. THE OVERALL SEVERE THREAT IS
EXPECTED TO REMAIN FAIRLY ISOLATED/MARGINAL.

..LOWER MISSISSIPPI VALLEY/DEEP SOUTH

THIS REGION WILL BE DISPLACED SOUTH OF THE STRONGER FORCING FOR
ASCENT, BUT MODERATE BUOYANCY AND VERTICAL SHEAR STILL SUGGEST THERE
IS ISOLATED SEVERE POTENTIAL WITH ANY STORMS THAT DO FORM. CURRENT
GUIDANCE SUGGESTS THE GREATEST PROBABILITY OF STORMS EXISTS ACROSS
MS AND AL WHERE THE LOW-LEVEL MOISTURE CONVERGENCE IS GREATEST.

..CENTRAL TEXAS

THE SEVERE THUNDERSTORM THREAT REMAINS HIGHLY CONDITIONAL ACROSS
PARTS OF CENTRAL TX TUESDAY AFTERNOON ALONG/NEAR A LOW-LEVEL
MOISTURE GRADIENT/SHARPENING DRYLINE. LARGE-SCALE ASCENT WILL BE
NEGLIGIBLE, WITH THUNDERSTORM INITIATION RELYING ON SURFACE
CONVERGENCE. IF ANY THUNDERSTORMS CAN FORM AND PERSIST, THEY
COULD BECOME SEVERE GIVEN A STRONGLY UNSTABLE AIRMASS. THIS SCENARIO
REMAIN TOO UNCERTAIN TO ADD LOW SEVERE PROBABILITIES WITH THIS
OUTLOOK.

..MOSIER.. 05/06/2024

Parts of tomorrow's threat area just got upgraded to an Enhanced risk. Could have two consecutive days of rough weather IMBY.

 

[Kds86z]

Parts of tomorrow's threat area just got upgraded to an Enhanced risk. Could have two consecutive days of rough weather IMBY.

View attachment 26412

March outbreak came to mind. Same area.

 

[JBishopwx]

MEG's discussion for Wednesday:

Confidence continues to increase severe weather potential on
Wednesday. A negatively tilted trough will interact with a surface
low under strong upper level divergence to allow convection to
commence. CIPS analogs are indicative of organized convection (70-
90%) generally along and north of Interstate 40. Our biggest concern
of this active pattern will be Wednesday night as deterministic
soundings continue to trend favorable for severe storms. GFS
soundings indicate MLCAPE values ~3500 J/kg, steep lapse rates, 40-
50 kts of effective shear, and a slight curvature to hodographs.
Another concerning aspect is as trends continue to paint this as a
nocturnal event, this means intensification of the LLJ. Nonetheless,
this potential severe weather event will be closely monitored over
the next couple of days. Stay tuned.

 

[JPWX]

I'll be honest. The first thing I thought of when NWS Memphis mentioned the overnight threat Wednesday was December 10th 2021

 

[tennessee storm chaser]

Storms firing south of Nashville. Got tight rotation Wilson county

 

[tennessee storm chaser]

I'll be honest. The first thing I thought of when NWS Memphis mentioned the overnight threat Wednesday was December 10th 2021

Yeah. The lower level jet is going enhance the tornado risk. Could we see two high risk days this week … tell u todays 12 z runs increasing the threat … moderate risk coming somewhere l within that large enhance area

 

[akt1985]

How is it looking Friday afternoon/evening for middle Tennessee? I’m flying out of Nashville then.

 

[MichelleH]

How is it looking Friday afternoon/evening for middle Tennessee? I’m flying out of Nashville then.

Pretty sure the cold front will already have gone through by then. So calm, but a lot cooler.

 

[JPWX]

How is it looking Friday afternoon/evening for middle Tennessee? I’m flying out of Nashville then.

You shouldn't have any problems on Friday.

 

[JPWX]

One thing that is really concerning about Wednesday night. Instability won't be a problem especially at this time of year. I don't like it.

 

[Fred Gossage]

The main thing we need to watch out for in the overnight of Wednesday night into predawn Thursday morning is how warm the temperatures stay up overnight. That will determine if the environment stays surface-based or if some nocturnal low-level inhibition builds in that makes the warm sector over TN/MS/AL/GA elevated. If surface temperatures stay closer to the 74+ range overnight, the instability profile would be surface-based. That would mean a tornado threat of some magnitude would be more likely to verify... elevated QLCS spin-up type tornado risk if things congeal more linear overnight... possibly even a nocturnal/predawn strong tornado risk as far southeast as southern TN, north MS, north AL, northwest GA if storms are more cellular or clustered (BIG IF, don't go trying to hang onto that being the likely outcome yet, y'all get somewhere and sit down lol).

 

[Clancy]

While it's not a classic tornado setup, we may be dealing with a fairly persistent severe threat for much of Thursday through at least Friday morning, if a solution like this were to verify. Will have to watch this carefully. Also wowzers at the CAPE values.

 

[tennessee storm chaser]

Thus far things not going as planned in th plains outbreak , but it’s early …. Things don’t get rough like modeled , wonder that will affect Wednesday threat in some fashion. Something ponder on

 

[atrainguy]

Thus far things not going as planned in th plains outbreak , but it’s early …. Things don’t get rough like modeled , wonder that will affect Wednesday threat in some fashion. Something ponder on

I'm not familiar with how one day of an event affects the next. If one day underperforms, does that usually result in the next day underperforming too? Or is there no reliable pattern?

Edit: not calling today a bust, it's still in progress and I don't know enough about this stuff to make rash judgment calls. Just curious about the what if scenario.

 

[Fred Gossage]

TUESDAY being affected by convective evolution from today would be a very normal thing. WEDNESDAY into early THURSDAY being affected by today's events when the lead wave from today lifts northeastward and it's a completely different shortwave in the overall trough that drives the Wednesday-Thursday threat, and storms from tonight won't even survive in existence to Wednesday morning in order to be able to have an effect later in the day? I'm sorry, but no, even if Wednesday underperforms too. It won't be because of today's evolution. It will be because of factors related to Wednesday in particular and maybe from Tuesday overnight (that will already be disconnected from tonight's convective evolution itself).

 

[atrainguy]

TUESDAY being affected by convective evolution from today would be a very normal thing. WEDNESDAY into early THURSDAY being affected by today's events when the lead wave from today lifts northeastward and it's a completely different shortwave in the overall trough that drives the Wednesday-Thursday threat, and storms from tonight won't even survive in existence to Wednesday morning in order to be able to have an effect later in the day? I'm sorry, but no, even if Wednesday underperforms too. It won't be because of today's evolution. It will be because of factors related to Wednesday in particular and maybe from Tuesday overnight (that will already be disconnected from tonight's convective evolution itself).

Interesting, thanks for the info! I'm particularly interested in what might happen Tuesday since I'm kind've in the threat area. Only the border of the 2% and 5% tornado threat, but still, keeping an eye on it. I believe the Grand Blanc EF2 (less than 10 minutes from me) happened in a marginal threat, IIRC.