438  
ACUS48 KWNS 270916  
SWOD48  
SPC AC 270914  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0414 AM CDT SUN SEP 27 2026  
 
VALID 301200Z - 051200Z  
   
..DISCUSSION
 
   
..WEDNESDAY/DAY 4 TO FRIDAY/DAY 6
 
 
DURING THE MID-WEEK, AN UPPER-LEVEL LOW IS FORECAST TO MOVE SLOWLY  
EASTWARD FROM THE SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. AS THE  
SYSTEM APPROACHES, LOW-LEVEL MOISTURE WILL ADVECT NORTHWARD INTO THE  
SOUTHERN AND CENTRAL PLAINS. A POCKET OF MODERATE INSTABILITY MAY  
DEVELOP OVER THE SOUTHERN HIGH PLAINS BY WEDNESDAY AFTERNOON. AS  
SURFACE HEATING IS MAXIMIZED WEDNESDAY AFTERNOON, THUNDERSTORMS ARE  
EXPECTED TO FORM ALONG AND NEAR THE INSTABILITY AXIS. A MID-LEVEL  
JET, ASSOCIATED WITH THE APPROACHING SYSTEM, IS FORECAST TO MOVE  
INTO THE SOUTHERN HIGH PLAINS IN THE AFTERNOON. THIS FEATURE WILL  
INCREASE DEEP-LAYER SHEAR. THE TIMING OF THE MID-LEVEL JET IS STILL  
IN QUESTION, BUT IF THE MID-LEVEL JET CAN MOVE INTO THE SOUTHERN  
PLAINS SOON ENOUGH, THEN A SEVERE THREAT COULD DEVELOP. UNDER THIS  
SCENARIO, ISOLATED SUPERCELLS WITH LARGE HAIL AND SEVERE WIND GUSTS  
WILL BE POSSIBLE.  
 
FROM THURSDAY INTO FRIDAY, THE UPPER-LEVEL TROUGH IS FORECAST TO  
REMAIN OVER THE SOUTHERN HIGH PLAINS. AHEAD OF THE SLOW-MOVING  
SYSTEM, A MOIST AND SOMEWHAT UNSTABLE AIRMASS IS FORECAST TO BE IN  
PLACE BOTH THURSDAY AND FRIDAY OVER PARTS OF EAST-CENTRAL TEXAS. ON  
THESE TWO DAYS, DEEP-LAYER SHEAR MAY BE STRONG ENOUGH FOR AN  
ISOLATED SEVERE THREAT, MAINLY WITH STORMS THAT FORM NEAR THE  
INSTABILITY AXIS.  
   
..SATURDAY/DAY 7 AND SUNDAY/DAY 8
 
 
OVER THE WEEKEND, AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE ACROSS  
THE CENTRAL U.S. AHEAD OF THE TROUGH, A MOIST AND SOMEWHAT UNSTABLE  
AIRMASS IS FORECAST TO BE IN PLACE OVER MUCH OF THE SOUTHEAST, WHERE  
SCATTERED TO NUMEROUS THUNDERSTORMS WILL BE POSSIBLE EACH DAY. OF  
THE TWO DAYS, THE STRONGEST INSTABILITY IS FORECAST TO BE ON SUNDAY,  
WHEN AN ISOLATED SEVERE THREAT WILL BE POSSIBLE. UNCERTAINTY  
REGARDING THE SPATIAL EXTENT AND MAGNITUDE IS SUBSTANTIAL AT THIS  
RANGE.  
 
..BROYLES.. 09/27/2026  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SPC Page Main Text Page