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ACUS02 KWNS 031731

SWODY2

SPC AC 031729



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1229 PM CDT Fri May 03 2024



Valid 041200Z - 051200Z



...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN THE PERMIAN

BASIN OF WEST TX...



...SUMMARY...

Scattered severe thunderstorms are expected across parts of west

Texas from late afternoon through the evening on Saturday. Several

storms may produce very large to giant hail, and a couple strong

tornadoes are possible.



...Synopsis...

A shortwave trough over the Upper Midwest will progress largely into

northern Ontario, while a deep closed mid/upper low moves inland of

the West Coast and reaches the CA/NV/OR border vicinity by early

Sunday. A near 100-kt southern-stream upper jet will shift east from

Baja/Gulf of CA across parts of northwest and north-central Mexico. 



At the surface, a weak cyclone over the Upper MS Valley will move

northeast. A trailing cold front will arc southwestward and push

southeastward, likely from the Ozark Plateau to west TX by Saturday

afternoon. This boundary should stall for a time in the Permian

Basin/South Plains vicinity before being reinforced by convective

outflows Saturday evening. 



...West TX vicinity...

A weak, lee surface cyclone will diurnally deepen in the Trans-Pecos

vicinity, within the left-exit region of the aforementioned upper

jet impinging eastward. As the cold front settles south and stalls

in vicinity of this low, a very rich western Gulf airmass to its

south will become strongly unstable with MLCAPE of 3000-3500 J/kg

expected by late afternoon. Convective initiation appears likely

north of the cold front in southeast NM to the South Plains and

farther south in the lee of the higher terrain of the Trans-Pecos.

Several, largely elevated, supercells should become established

north of the surface front. An elongated and nearly straight-line

hodograph within the buoyancy profile should foster splitting cells

with a threat for very large hail. Farther south, a few supercells

along and south of the front across parts of the Permian Basin will

also pose a threat for potentially giant hail as well while

low-level shear is initially modest. But shear will strengthen into

early evening, posing an increasing threat for a strong tornado or

two. 12Z HREF members are nearly unanimous in suggesting very high

updraft helicity values in at least one simulated warm-sector

supercell during this time frame. 



Deeper into the evening, convection should increasingly consolidate

and become more widespread as low-level jet mass response continues.

This should favor a mix of severe wind gusts with embedded large

hail and tornado threats. These hazards will subside overnight, but

should linger on an isolated basis towards parts of central TX.



...Mid-MS Valley to the Ozarks/Ark-La-Tex...

A line of strong thunderstorms should be ongoing at 12Z Saturday,

just ahead of the aforementioned cold front, from northwest MO into

southeast KS. This activity should largely wane through the morning,

but locally damaging winds and marginal hail will be possible until

it decays. 



Renewed thunderstorm development is expected during the afternoon,

especially late along parts of the cold front where adequate

boundary-layer destabilization occurs in the wake of the morning

activity. With the Upper Midwest shortwave trough progressing

northeast, strong mid-level southwesterlies will be displaced north

of the destabilizing warm sector. Deep-layer shear will be modest,

largely from 20-30 kts. This would be adequate for some small,

multicell clusters. Overall severe threat will probably remain

isolated and marginal with a mix of damaging winds and hail, largely

peaking in the late afternoon to early evening.



..Grams.. 05/03/2024



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