633  
ACUS03 KWNS 220742  
SWODY3  
SPC AC 220742  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0242 AM CDT WED MAY 22 2019  
 
VALID 241200Z - 251200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM A PORTION OF  
THE CENTRAL PLAINS INTO THE UPPER MISSISSIPPI VALLEY REGION...  
   
..SUMMARY
 
 
A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE ON FRIDAY FROM A  
PORTION OF THE UPPER MISSISSIPPI VALLEY REGION INTO A PART OF THE  
CENTRAL AND SOUTHERN PLAINS.  
   
..SYNOPSIS
 
 
MODEL CONSENSUS IS THAT A SHORTWAVE TROUGH INITIALLY OVER THE  
CENTRAL/NORTHERN PLAINS EARLY FRIDAY WILL CONTINUE NORTHEAST INTO  
THE UPPER MS VALLEY REGION DURING THE DAY. ATTENDANT SURFACE LOW  
INITIALLY OVER SD WILL REACH MN BY MID-LATE AFTERNOON WITH TRAILING  
COLD FRONT EXTENDING SOUTHWEST THROUGH IA AND CENTRAL KS. A WARM  
FRONT WILL ADVANCE NORTHEAST THROUGH THE UPPER MS VALLEY AND BY  
EARLY EVENING SHOULD EXTEND FROM THE SURFACE LOW IN MN THROUGH THE  
SOUTHERN GREAT LAKES AND INTO THE OHIO VALLEY. DRYLINE WILL RESIDE  
ACROSS WEST TX DURING THE DAY, BUT SHOULD RETREAT INTO EASTERN NM  
DURING THE EVENING.  
   
..EASTERN KANSAS THROUGH THE UPPER MISSISSIPPI VALLEY REGION
 
 
RICHER LOW-LEVEL MOISTURE WITH MID-UPPER 60S F DEWPOINTS WILL ADVECT  
NORTHEAST THROUGH THE MID-UPPER MS VALLEY WARM SECTOR DURING THE DAY  
AND THIS SHOULD CONTRIBUTE TO A CORRIDOR OF MODERATE INSTABILITY  
(1500-2000 J/KG MLCAPE) AS THE BOUNDARY LAYER WARMS. SOME STORMS MAY  
BE ONGOING ON COOL SIDE OF THE WARM FRONT AS WELL AS FARTHER WEST  
ACROSS KS IN VICINITY OF THE COLD FRONT. ADDITIONAL STORMS WILL  
PROBABLY DEVELOP ALONG THE COLD FRONT OR RESIDUAL OUTFLOW BOUNDARIES  
DURING THE AFTERNOON. FLOW IN THE LOWEST 3 KM IS FORECAST TO WEAKEN  
AND THE STRONGEST MID-UPPER WINDS WILL LIKELY REMAIN NORTH OF THE  
WARM SECTOR WHICH COULD BE LIMITING FACTORS FOR A MORE ROBUST SEVERE  
THREAT. HOWEVER, WINDS ALOFT WILL SUPPORT 40-45 KT LARGELY  
UNIDIRECTIONAL EFFECTIVE BULK SHEAR. IT APPEARS THE PARAMETER SPACE  
WILL BE SUFFICIENT FOR A THREAT OF SOME STRONG TO SEVERE STORMS WITH  
LARGE HAIL AND DAMAGING WIND THE MAIN THREATS THROUGH EARLY EVENING.  
 
   
..SOUTHERN HIGH PLAINS AREA
 
 
STORMS MAY BE ONGOING FROM A PORTION OF WEST TX INTO OK WHICH  
COMPLICATES THE FORECAST TO SOME DEGREE. NEVERTHELESS, INITIAL  
ACTIVITY MAY WEAKEN, WITH POTENTIAL FOR BOUNDARY-LAYER RECOVERY  
DURING THE AFTERNOON, POTENTIALLY SUPPORTING STRONG INSTABILITY WITH  
2000-3000 J/KG MLCAPE. A BELT OF 40-50 KT MID-LEVEL WINDS WILL  
PERSIST OVER THIS REGION, THEREFORE THE PARAMETER SPACE WILL BE  
CONDITIONALLY SUPPORTIVE OF SEVERE STORMS. WHILE DRYLINE CONVERGENCE  
IS NOT EXPECTED TO BE PARTICULARLY STRONG AND FORCING ALOFT WILL BE  
WEAK, POTENTIAL STILL EXISTS FOR ISOLATED STORM DEVELOPMENT EITHER  
ALONG THE DRYLINE OR IN ASSOCIATION WITH RESIDUAL BOUNDARIES FROM  
EARLY CONVECTION. WILL INTRODUCE A MARGINAL RISK CATEGORY THIS  
UPDATE, BUT AN UPGRADE TO HIGHER PROBABILITIES MAY BE NEEDED IN  
FUTURE OUTLOOKS ONCE SOME OF THE MESOSCALE UNCERTAINTIES HAVE BEEN  
MITIGATED.  
 
..DIAL.. 05/22/2019  
 

 
 
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