135  
ACUS48 KWNS 150900  
SWOD48  
SPC AC 150858  
 
DAY 4-8 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0358 AM CDT TUE APR 15 2025  
 
VALID 181200Z - 231200Z  
   
..DISCUSSION
 
 
AN ACTIVE SEVERE WEATHER PATTERN EXPECTED THROUGH AT LEAST THIS  
WEEKEND, BEFORE PREDICTABILITY DIMINISHES EARLY NEXT WEEK.  
   
..D4/FRIDAY
 
 
GUIDANCE REMAINS CONSISTENT WITH A BROAD SWATH OF STRONG MID-LEVEL  
SOUTHWESTERLIES FROM THE SOUTHERN HIGH PLAINS TO THE GREAT LAKES,  
DOWNSTREAM OF A LONGWAVE TROUGH FROM NORTHERN ON TO THE LOWER CO  
VALLEY. THIS WILL OVERLAP A SIMILARLY ORIENTED SURFACE FRONT. IN  
RESPONSE TO INCREASING MID-LEVEL HEIGHT FALLS, A SURFACE CYCLONE  
SHOULD TRACK ACROSS THE CENTRAL GREAT LAKES PORTION OF THE  
BAROCLINIC ZONE DURING THE DAY. AFTERNOON SEVERE MAY BE FOCUSED IN  
THIS REGION WITH STRONGER LOW-LEVEL SHEAR. PARTS OF THIS REGION MAY  
WARRANT HIGHER PROBABILITIES IN LATER OUTLOOKS.  
 
FARTHER SOUTHWEST, A PRONOUNCED EML MAY DELAY THE BULK OF STORM  
DEVELOPMENT ALONG THE FRONT UNTIL EVENING. BUT GIVEN THE STRONG  
DEEP-LAYER SHEAR AND MODERATE BUOYANCY, SCATTERED SEVERE STORMS  
APPEAR POSSIBLE.  
   
..D5/SATURDAY
 
 
AMPLIFICATION OF AN EMBEDDED NORTHERN-STREAM SHORTWAVE IMPULSE OVER  
ON/QC SHOULD SUSTAIN AN EXPANSIVE SWATH OF STRONG MID-LEVEL FLOW  
FROM THE OH VALLEY NORTHEASTWARD. THE NORTHEAST EXTENT OF  
APPRECIABLE INSTABILITY OVERLAPPING WITH THIS REGIME BECOMES  
NEBULOUS EAST OF THE APPALACHIANS, BUT SCATTERED SEVERE STORMS SEEM  
POSSIBLE FROM THE CUMBERLAND PLATEAU INTO THE MID-SOUTH ON SATURDAY  
AFTERNOON TO EVENING.  
 
OVER THE SOUTHERN GREAT PLAINS, LINGERING CONVECTION SATURDAY  
MORNING RENDERS UNCERTAINTY ALONG THE LARGELY STALLING BAROCLINIC  
ZONE THAT WILL UNDOUBTEDLY BE MODIFIED BY CONVECTIVE OUTFLOW. BUT  
WITH GREATER CONSISTENCY IN GUIDANCE HANDLING THE PIVOT OF THE BASAL  
SHORTWAVE IMPULSE ACROSS THE SOUTHWEST, MULTIPLE ROUNDS OF STRONG TO  
SEVERE CONVECTION ARE PLAUSIBLE THROUGH SATURDAY NIGHT.  
   
..D6/SUNDAY
 
 
PREDICTABILITY LESSENS BY THIS PERIOD WITH THE EVOLUTION OF COMPACT  
SHORTWAVE TROUGH EJECTING ONTO THE SOUTHERN GREAT PLAINS. THIS  
YIELDS SUBSTANTIAL SPREAD IN THE ATTENDANT SYNOPTIC CYCLONE. IN  
ADDITION, POTENTIALLY EXTENSIVE ONGOING CONVECTION SUNDAY MORNING  
FURTHER LESSENS CONFIDENCE IN MESOSCALE DETAILS. BUT A BELT OF  
POTENTIALLY VERY STRONG MID-LEVEL SOUTHWESTERLIES OVERLAPPING RICH  
WESTERN GULF MOISTURE SUPPORTS INCLUSION OF A SEVERE-AREA HIGHLIGHT  
IN THE SOUTH-CENTRAL STATES.  
 
..GRAMS.. 04/15/2025  
 
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