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ACUS01 KWNS 092000

SWODY1

SPC AC 091958



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0258 PM CDT Tue Apr 09 2024



Valid 092000Z - 101200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF

CENTRAL AND EASTERN TEXAS INTO LOUISIANA...



...SUMMARY...

Scattered severe thunderstorms are likely through tonight across

much of Texas into the lower Mississippi River Valley.  A few

tornadoes and an isolated strong tornado or two, large to very large

hail up to 2.5 inches in diameter, and severe gusts of 60-75 mph

will be possible.



...TX into LA...

A very moist and unstable air mass exists south of an east-west

oriented front across central TX. An MCS will likely produce severe

weather as it moves from northeast TX into northern LA, along the

instability gradient and where shear remains favorable.



Farther south, continued heating as well as convergence near the

boundary will likely lead to additional development this afternoon,

with large hail and expected.



Overnight, as cooling aloft with the shortwave trough spreads across

central TX, an associated cold front is expected to support

additional storms which would travel quickly northeastward across

the unstable air mass. Such an overnight scenario would likely yield

damaging winds as well as hail.



..Jewell.. 04/09/2024



.PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Apr 09 2024/



...TX/LA through tonight...

A midlevel low over northern Mexico will move eastward toward west

TX later today into tonight, with exit regions of embedded jet

streaks persisting over central/east TX through tonight.  Only weak

surface cyclogenesis is expected across central/east TX along a

stalled front through tonight, while widespread ongoing convection

will persist through the period from central TX eastward into LA.



Regional 12z soundings revealed a broad area with rich low-level

moisture (boundary-layer dewpoints in the low 70s) beneath a

elevated mixed layer with midlevel lapse rates greater than 8 C/km. 

As a result, MLCAPE of 2000-3500 J/kg will continue along and south

of the rain-reinforced front through tonight from central into east

TX, with slightly lower buoyancy farther to the east in LA. 

Low-level mass response will not be particularly large given only

weak cyclogenesis in TX, though there could be some increase in

low-level shear later this evening into tonight from east TX into

LA.



Widespread convection and resultant messy convective modes will be

the main concern through the period.  Observed and forecast

hodographs will favor embedded supercells capable of producing a few

tornadoes, isolated very large hail up to 2.5 inches in diameter,

and damaging gusts of 60-75 mph.  Longer/straighter hodographs and

closer proximity to the steep lapse rate plume suggest that the hail

threat will be greatest across central TX with the more

isolated/cellular storm mode.  The wind threat will be greater this

evening into tonight from east TX into LA, based largely on upscale

growth of storms into bowing segments along the stalled front. 

There will also be some potential for additional storm development

tonight across south central TX along the west edge of the richer

low-level moisture and with the ejecting midlevel trough, with a

conditional threat for very large hail and damaging winds.



...Northern OH area this afternoon/evening...

The glancing influence of a midlevel trough moving over Lower MI and

a surface cold front could focus isolated thunderstorm development

this afternoon/evening across northern OH.  Surface heating, a

modest increase in low-level moisture and wind profiles with mainly

straight hodographs will support some potential for isolated large

hail/wind damage for a few hours later this afternoon/evening.



$$