878  
ACUS48 KWNS 310856  
SWOD48  
SPC AC 310854  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0354 AM CDT SAT MAY 31 2025  
 
VALID 031200Z - 081200Z  
   
..DISCUSSION  
 
SOMEWHAT GREATER CONFIDENCE EXISTS FOR A MORE SOUTH-SOUTHWEST TO  
NORTH-NORTHEAST ORIENTED SWATH OF SEVERE ON D4/TUESDAY. THIS APPEARS  
FOCUSED FROM THE SOUTHERN GREAT PLAINS TO THE MIDWEST FROM MIDDAY  
INTO EARLY EVENING. OVERALL PATTERN APPEARS LESS AMPLIFIED AFTER D4,  
WITH NEBULOUS SEVERE POTENTIAL IN THE CENTRAL TO EASTERN STATES.  
   
..D4/TUESDAY  
 
A LOW-AMPLITUDE SOUTHERN-STREAM SHORTWAVE IMPULSE MAY PHASE WITH A  
NORTHERN-STREAM SHORTWAVE TROUGH IN THE UPPER GREAT LAKES VICINITY  
BY LATE TUESDAY. THE ACCOMPANYING SURFACE WAVE OVER KS MAY SIMILARLY  
TRACK NORTHEASTWARD ALONG A COLD FRONT THROUGH THE UPPER MIDWEST.  
RICH LOW-LEVEL MOISTURE WILL BECOME MORE PREVALENT AHEAD OF THE  
FRONT AND SHOULD SPREAD INTO AT LEAST WI. EXTENSIVE CONVECTION MAY  
BE ONGOING AT 12Z WITHIN AN INCREASINGLY FAVORABLE DIFFLUENT  
UPPER-FLOW REGIME THAT IS COUPLED WITH A BROAD LOW-LEVEL JET. AMID  
RELATIVELY WARM 500-MB TEMPERATURES WITHIN THE SOUTHWEST FLOW REGIME  
ATTENDANT TO THE SOUTHERN-STREAM IMPULSE, MID-LEVEL LAPSE RATES WILL  
LIKELY BE WEAK IN THE WARM-MOIST SECTOR. WHERE APPRECIABLE  
BOUNDARY-LAYER HEATING CAN OCCUR AHEAD OF MORNING CONVECTION,  
SCATTERED SEVERE STORMS ARE POSSIBLE.  
   
..D5-8/WEDNESDAY-SATURDAY  
 
WEAK MID-LEVEL LAPSE RATES WILL BE PERVASIVE, SUGGESTING THAT ROBUST  
DIURNAL HEATING WILL LARGELY DRIVE DAILY BOUTS OF SEEMINGLY  
LOWER-PROBABILITY SEVERE. GUIDANCE CONSENSUS SUGGESTS A MORE ZONAL  
MID-LEVEL FLOW REGIME MAY EVOLVE TOWARDS D7/FRIDAY, WHICH WOULD AID  
IN THE DEVELOPMENT/EXPANSION OF THE ELEVATED MIXED LAYER AND A  
RETURN OF STEEP MID-LEVEL LAPSE RATES ACROSS THE HIGH PLAINS.  
 
..GRAMS.. 05/31/2025  
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