391
ACUS01 KWNS 280501
SWODY1
SPC AC 280500
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1100 PM CST THU NOV 27 2025
VALID 281200Z - 291200Z
..NO SEVERE THUNDERSTORM AREAS FORECAST
..SUMMARY
WEAK THUNDERSTORM ACTIVITY MAY BEGIN TO DEVELOP ACROSS PARTS OF
WESTERN TEXAS BY THIS AFTERNOON, BEFORE INCREASING WITHIN AN
EXPANDING AREA OF PRECIPITATION ACROSS PARTS OF THE CENTRAL AND
SOUTHERN GREAT PLAINS TOWARD LOWER MISSOURI AND MISSISSIPPI VALLEYS
TONIGHT.
..DISCUSSION
DOWNSTREAM OF AMPLIFYING FLOW, INCLUDING BUILDING MID/UPPER RIDGING
ACROSS THE MID-LATITUDE EASTERN PACIFIC, IT APPEARS THAT AT LEAST A
COUPLE OF SHORT WAVE PERTURBATIONS MAY CONSOLIDATE INTO LARGER-SCALE
DIGGING TROUGHING ACROSS AND EAST OF THE CANADIAN AND NORTHERN U.S.
ROCKIES LATER TODAY THROUGH TONIGHT. THERE IS NOTABLE SPREAD STILL
EVIDENT WITHIN/AMONG THE MODEL OUTPUT CONCERNING THIS EVOLUTION, BUT
MODELS GENERALLY INDICATE THAT THIS WILL BE ACCOMPANIED BY MODEST
SURFACE CYCLOGENESIS ACROSS PARTS OF EASTERN COLORADO INTO THE
ADJACENT CENTRAL GREAT PLAINS BY 12Z SATURDAY.
THIS IS CLOSE ON THE HEELS OF A COOL/DRY INTRUSION STILL ONGOING
ACROSS THE CENTRAL INTO SOUTHWESTERN GULF BASIN, IN THE WAKE OF
AMPLIFIED MID/UPPER TROUGHING APPROACHING THE ATLANTIC SEABOARD.
HOWEVER, THE MOST SIGNIFICANT SHORT WAVE PERTURBATION STILL DIGGING
WITHIN THIS REGIME IS FORECAST TO RAPIDLY ACCELERATE INTO THE
NORTHWESTERN ATLANTIC TODAY THROUGH TONIGHT, AND TRAILING SURFACE
RIDGING LIKELY WILL BEGIN SHIFTING EAST OF THE SOUTHERN GREAT
PLAINS/LOWER MISSISSIPPI VALLEY. MODELS SUGGEST THAT THIS WILL
OCCUR IN A MANNER ALLOWING FOR A STRENGTHENING SOUTHERLY RETURN FLOW
FROM THE TEXAS SOUTH PLAINS/LOWER RIO GRANDE VALLEY TOWARD THE LOWER
MISSOURI VALLEY BY LATE TONIGHT.
THIS MAY BE ACCOMPANIED BY RAPID NORTH-NORTHEASTWARD ADVECTION OF
MOISTURE NOW PRESENT ACROSS/EAST OF THE MEXICAN PLATEAU, AND INCLUDE
NEAR-SURFACE DEW POINTS INCREASING THROUGH THE MID 50S TO LOWER 60S
F ACROSS DEEP SOUTH TEXAS INTO PORTIONS OF WESTERN NORTH TEXAS BY
THE END OF THE PERIOD. HOWEVER, TO THE NORTH OF DEEP SOUTH TEXAS,
WHERE RELATIVELY WARM MID-LEVEL TEMPERATURES PROBABLY WILL INHIBIT
THUNDERSTORM DEVELOPMENT, THE MOISTURE RETURN IS GENERALLY FORECAST
ABOVE A RESIDUAL COOL/STABLE NEAR-SURFACE LAYER, WHICH WILL REMAIN
DEEPER WITH NORTHWARD/EASTWARD EXTENT INTO THE CENTRAL GREAT PLAINS
AND LOWER/MIDDLE MISSISSIPPI VALLEY.
STILL, FORECAST SOUNDINGS INDICATE THAT THIS MOISTENING, NEAR THE
BASE OF A LAYER OF STEEPENING LAPSE RATES AIDED BY
LOWER/MID-TROPOSPHERIC WARM ADVECTION, WILL PROVIDE SUPPORT FOR
CONVECTIVE DEVELOPMENT CAPABLE OF PRODUCING LIGHTNING. IT APPEARS
THAT THIS COULD INITIATE ACROSS THE PERMIAN BASIN VICINITY BY THIS
AFTERNOON, IF NOT PERHAPS EARLIER, BEFORE FORCING FOR ASCENT
SUPPORTS INCREASINGLY WIDESPREAD CONVECTION AND EMBEDDED WEAK
THUNDERSTORM ACTIVITY ACROSS PARTS OF THE SOUTHERN INTO CENTRAL
GREAT PLAINS AND LOWER MISSOURI VALLEY TONIGHT.
..KERR/WEINMAN.. 11/28/2025
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