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ACUS01 KWNS 240539

SWODY1

SPC AC 240538



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

1238 AM CDT Wed Apr 24 2024



Valid 241200Z - 251200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF

WEST TEXAS THIS EVENING...



...SUMMARY...

Strong to severe thunderstorms will be possible today across parts

of Oklahoma and west Texas. Large hail and severe gusts will be the

primary hazards.



...Synopsis...



An upper ridge over the Rockies will shift east into the Plains

through tonight. However, guidance suggests subtle shortwave

impulses will migrate through the ridge during the late afternoon

into the evening/overnight. At the surface, strengthening lee

troughing is forecast across eastern NM near the TX border.

Meanwhile, a stationary boundary is forecast to extend across the TX

South Plains vicinity into southern/central OK, while a dryline

extends southward along the NM/TX border into southwest TX. Several

forecast models suggest a bulge in the dryline is possible across

far west TX where a weak surface low may develop. Overnight, the

stationary boundary is expected to lift northward as a warm front,

becoming located across the TX Panhandle into northern OK.



Further east, an upper trough will move across the Northeast states.

Boundary-layer moisture will remain limited, though midlevel

moisture will be plentiful. Cool temperatures aloft and modest

westerly flow will support isolated to scattered thunderstorms ahead

of an eastward-progressing cold front.



...OK - This Morning...



Thunderstorms are expected to develop early this morning across

central OK north of the stationary boundary in a warm advection

regime along the north edge of returning low-level moisture. This

activity is expected to be elevated. However, steep midlevel lapse

rates and increasing westerly mid/upper flow should be sufficient

for organized cells. Large hail will be possible with storms that

develop. However, coverage remains in question given expected height

rises through the morning hours as the upper ridge slowly shifts

east.



...West TX toward SW OK - This evening...



Capping will preclude convection for most of the day. However,

low-level moisture will increase with northwest extent on

southeasterly low-level flow, and low 60s F dewpoints are expected

into the Permian Basin and South Plains vicinity. Steep midlevel

lapse rates atop this moistening boundary-layer will foster moderate

instability from 1500-2500 J/kg. By late afternoon/early evening,

convection should begin to develop as inhibition weakens due to

increasing moisture and some indication of a weak impulse ejecting

east across the southern Rockies. Veering low-level wind profiles

become west/southwesterly aloft will result in favorable shear

profiles supporting supercells. Large hail to 2 inches in diameter

and gusts to 70 mph will be possible with storms that develop. 



...Northern OK - Late Tonight...



As the stationary boundary lifts northward as a warm front

overnight, another round of warm advection thunderstorms will be

possible, this time from the eastern TX Panhandle into northern OK.

Forecast guidance varies considerably regarding coverage and

location of potential development, though the overall environment

(moderate elevated instability and modest shear) conditionally will

support hail.



...Northeast...



While boundary-layer moisture will remain poor today, cold

temperatures aloft will support weak instability. Deep-layer

westerly flow around 20-30 kt may support transient organized

cells/clusters by early afternoon. Meanwhile, heating ahead of the

cold front will allow for steepening low-level lapse rates. Gusty

winds to 40 mph will be possible with afternoon thunderstorms, but

overall severe potential appears too low for severe probabilities.



..Leitman/Weinman.. 04/24/2024



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