225  
ACUS03 KWNS 231831  
SWODY3  
SPC AC 231831  
 
DAY 3 CONVECTIVE OUTLOOK AMEND 1  
NWS STORM PREDICTION CENTER NORMAN OK  
0131 PM CDT TUE APR 23 2024  
 
VALID 251200Z - 261200Z  
 
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE  
EASTERN TX PANHANDLE AND WESTERN OK INTO SOUTHWEST/SOUTH-CENTRAL  
KS...  
 
AMENDED TO UPDATE FORECAST  
   
..SUMMARY
 
 
SEVERE THUNDERSTORMS ARE LIKELY FROM LATE THURSDAY AFTERNOON INTO  
THURSDAY NIGHT ACROSS PARTS OF THE CENTRAL AND SOUTHERN GREAT  
PLAINS. VERY LARGE HAIL, SEVERE WIND GUSTS, AND STRONG TORNADOES  
WILL ALL BE POSSIBLE.  
 
GUIDANCE CONTINUES TO SUGGEST STRONG BUOYANCY WILL BE IN PLACE AHEAD  
OF A NEGATIVELY TILTED SHORTWAVE TROUGH EJECTING ACROSS THE SOUTHERN  
HIGH PLAINS. GENERAL FORECAST EXPRESSED IN THE PREVIOUS OUTLOOK  
REMAINS VALID, BUT CONFIDENCE IN AN AREA OF GREATER SEVERE-WEATHER  
POTENTIAL HAS BECOME MORE APPARENT WITH THE MOST RECENT GUIDANCE.  
LATE AFTERNOON DEVELOPMENT IS ANTICIPATED ACROSS THE TX PANHANDLE,  
WITH THESE STORMS QUICKLY BECOMING SEVERE AND CAPABLE OF LARGE TO  
VERY LARGE HAIL UP TO 3" IN DIAMETER. LOW-LEVEL MOISTURE MAY BE  
LATER TO ARRIVE IN WEST-CENTRAL/SOUTHWEST KS, DELAYING CONVECTIVE  
INITIATION TO A FEW HOURS LATER THAN FARTHER SOUTH. LARGE TO VERY  
LARGE HAIL IS ANTICIPATED WITH INITIAL DEVELOPMENT ACROSS  
WEST-CENTRAL/SOUTHWEST KS AS WELL.  
 
IN BOTH OF THESE AREAS, STORMS ARE EXPECTED TO MOVE  
EAST-NORTHEASTWARD OFF THE DRYLINE, ENCOUNTERING STRENGTHENING  
LOW-LEVEL SOUTHERLY FLOW AND ENVIRONMENT THAT IS INCREASINGLY  
FAVORABLE FOR TORNADOES. LOW-LEVEL SHEAR WILL CONTINUE TO  
STRENGTHENING INTO THE EARLY EVENING, AND THE OVERALL ENVIRONMENT  
SUPPORTS THE POTENTIAL FOR STRONG TO INTENSE TORNADOES IF A DISCRETE  
MODE CAN BE MAINTAINED.  
 
--- PREVIOUS DISCUSSION ISSUED AT 0230 AM CDT TUE APR 23 2024 ---  
   
..SYNOPSIS
 
 
A SHORTWAVE TROUGH INITIALLY OVER THE SOUTHWEST IS FORECAST TO TAKE  
ON AN INCREASINGLY NEGATIVE TILT AS IT MOVES EASTWARD TOWARDS THE  
CENTRAL/SOUTHERN PLAINS BY THURSDAY NIGHT INTO FRIDAY MORNING. IN  
RESPONSE, A SURFACE LOW WILL CONSOLIDATE AND DEEPEN ACROSS THE  
CENTRAL HIGH PLAINS THROUGH THE DAY, BEFORE MOVING NORTHEASTWARD  
TOWARD NORTHWEST KS/SOUTHWEST NE BY FRIDAY MORNING. AN INITIALLY  
STATIONARY SURFACE BOUNDARY WILL MOVE NORTHWARD AS A WARM FRONT  
ACROSS THE CENTRAL PLAINS THROUGH THE DAY. ALONG/SOUTH OF THE WARM  
FRONT, RELATIVELY RICH LOW-LEVEL MOISTURE WILL STREAM NORTHWARD TO  
THE EAST OF A DRYLINE THAT WILL BECOME ESTABLISHED FROM THE EASTERN  
TX PANHANDLE INTO WESTERN KS AND EASTERN CO.  
   
..SOUTHERN/CENTRAL GREAT PLAINS
 
 
COVERAGE OF THE SEVERE-THUNDERSTORM THREAT REMAINS SOMEWHAT  
UNCERTAIN, BUT A COUPLE INTENSE SUPERCELLS ARE POSSIBLE BY THURSDAY  
EVENING NEAR THE DRYLINE FROM WESTERN KS INTO WESTERN OK AND THE  
TX/OK PANHANDLES. ANOTHER ROUND OF OVERNIGHT CONVECTION WILL  
POTENTIALLY BRING THE SEVERE THREAT EASTWARD INTO A LARGER PORTION  
OF THE CENTRAL/SOUTHERN PLAINS.  
 
THE WARM SECTOR OF THE DEEPENING CYCLONE WILL LIKELY REMAIN CAPPED  
FOR MUCH OF THE DAY, THOUGH ELEVATED CONVECTION MAY PERSIST FROM  
PARTS OF CENTRAL/EASTERN KS INTO EASTERN OK, TO THE NORTH OF THE  
EFFECTIVE WARM FRONT. INCREASING MOISTURE BENEATH STEEP MIDLEVEL  
LAPSE RATES WILL SUPPORT MLCAPE IN EXCESS OF 2000 J/KG ALONG/EAST OF  
THE DRYLINE, AS DEEP-LAYER SHEAR STRENGTHENS ACROSS THE REGION  
THROUGH THE DAY.  
 
ASCENT ATTENDANT TO THE APPROACHING SHORTWAVE TROUGH WILL BEGIN TO  
IMPINGE UPON THE WARM SECTOR BY LATE AFTERNOON, WITH ISOLATED  
SUPERCELL DEVELOPMENT POSSIBLE NEAR THE SURFACE LOW ACROSS SOUTHWEST  
KS AND SOUTHWARD DOWN THE DRYLINE INTO THE TX PANHANDLE. VERY LARGE  
HAIL (POTENTIALLY 2-3 INCHES IN DIAMETER) WILL LIKELY BE THE PRIMARY  
INITIAL HAZARD. A NOTABLE INCREASE IN LOW-LEVEL FLOW/SHEAR NEAR AND  
AFTER 00Z WILL ALSO SUPPORT A TORNADO THREAT WITH ANY SUPERCELLS  
THAT CAN PERSIST INTO THE EVENING ACROSS PARTS OF WESTERN KS/OK.  
 
WHILE ANY INITIAL DRYLINE STORMS MAY WEAKEN BY MID/LATE EVENING DUE  
TO INCREASING MLCINH WITH EASTWARD EXTENT, RENEWED STORM DEVELOPMENT  
IS POSSIBLE OVERNIGHT ALONG THE PACIFIC COLD FRONT FROM SOUTHWEST TX  
INTO WESTERN/CENTRAL KS/OK AS STRONGER LARGE-SCALE ASCENT  
OVERSPREADS THE REGION. STEEP MIDLEVEL LAPSE RATES, MODERATE  
BUOYANCY, AND STRONG LOW-LEVEL AND DEEP-LAYER SHEAR WILL  
CONDITIONALLY SUPPORT A SEVERE THREAT WITH OVERNIGHT CONVECTION  
ACROSS THE WARM SECTOR, THOUGH STORM MODE MAY BECOME COMPLEX AND  
TEND TOWARD A LINEAR EVOLUTION WITH TIME. SEVERE WIND GUSTS MAY  
BECOME AN INCREASING THREAT WITH THE NOCTURNAL CONVECTION, THOUGH  
HAIL AND A COUPLE TORNADOES WILL ALSO BE POSSIBLE IF SEMI-DISCRETE  
OR EMBEDDED SUPERCELLS CAN BE MAINTAINED.  
   
..NE/WY BORDER REGION INTO NORTHEAST CO
 
 
LOW-LEVEL SOUTHEASTERLY FLOW WILL SUPPORT MODEST MOISTURE RETURN  
INTO PARTS OF NORTHEAST CO, SOUTHEAST WY, AND WESTERN NE, TO THE  
NORTH OF THE DEEPENING CYCLONE. THUNDERSTORM DEVELOPMENT WILL BE  
POSSIBLE NEAR AND TO THE COOL SIDE OF THE EFFECTIVE WARM FRONT  
DURING THE AFTERNOON. WHILE DEEP-LAYER SHEAR WILL BE WEAKER COMPARED  
TO AREAS FARTHER SOUTHEAST, STEEP MIDLEVEL LAPSE RATES WILL SUPPORT  
AN ISOLATED HAIL THREAT. A TORNADO ALSO CANNOT BE RULED OUT, IF  
SURFACE-BASED STORMS CAN BE MAINTAINED WITHIN THIS REGIME.  
 
..MOSIER.. 04/23/2024  
 

 
 
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