810  
ACUS03 KWNS 070732  
SWODY3  
SPC AC 070731  
 
DAY 3 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
0231 AM CDT TUE JUL 07 2020  
 
VALID 091200Z - 101200Z  
 
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE UPPER  
MIDWEST INTO THE CENTRAL PLAINS AND OZARK PLATEAU...  
   
..SUMMARY
 
 
ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE FROM THE UPPER MIDWEST  
INTO THE CENTRAL PLAINS AND OZARK PLATEAU ON THURSDAY.  
   
..UPPER MIDWEST INTO THE CENTRAL PLAINS/OZARKS
 
 
LOCATION OF THE GREATEST SEVERE WEATHER POTENTIAL ON THURSDAY WILL  
DEPEND LARGELY ON THE ORGANIZATION AND LONGEVITY OF ANTECEDENT  
THUNDERSTORMS. MODEL GUIDANCE IS IN GOOD AGREEMENT THAT AN ORGANIZED  
CONVECTIVE LINE WILL BE IN ITS DISSIPATION STAGE OVER THE LOWER MO  
VALLEY EARLY THURSDAY. OUTFLOW BOUNDARY ASSOCIATED WITH THIS SYSTEM  
WILL THEN SERVE AS THE PRIMARY LOCATION FOR CONVECTIVE DEVELOPMENT  
THURSDAY AFTERNOON AND EVENING. BASED ON CURRENT MODEL PROGS, THIS  
INITIATION WOULD OCCUR FROM CENTRAL KS EASTWARD INTO SOUTHERN MO.  
HOWEVER, MESOSCALE NATURE OF THIS SCENARIO INTRODUCES SIGNIFICANT  
UNCERTAINTY AT THIS FORECAST RANGE, RESULTING IN THE INTRODUCTION OF  
ONLY 5% SEVERE PROBABILITIES.  
 
THE OVERALL PATTERN, WITH A RIDGE BUILDING ACROSS THE SOUTHWEST AND  
A BELT OF ENHANCED UPPER FLOW FROM THE GREAT BASIN THROUGH THE MID  
MS VALLEY, SUGGESTS THE POTENTIAL EXISTS FOR A CONVECTIVE LINE TO  
INITIATE OVER THE CENTRAL HIGH PLAINS AND THEN MOVE  
EASTWARD/SOUTHEASTWARD OVERNIGHT. HOWEVER, AS WITH THE THREAT  
DISCUSSED IN THE PREVIOUS PARAGRAPH, PREDICTABILITY IS LIMITED BY  
THE NUMEROUS MESOSCALE FACTORS INVOLVED IN THE DEVELOPMENT OF SUCH A  
CONVECTIVE LINE. THIS LIMITED PREDICTABILITY IS EVIDENCED BY THE  
WIDE RUN-TO-RUN AND MODEL-TO-MODEL VARIABILITY IN THE DEVELOPMENT  
AND LOCATION OF THE LINE. GIVEN ALL OF THESE FACTORS, ELECTED TO  
INCLUDE A BROAD 5% PROBABILITY WITH THE EXPECTATION INCREASED  
PROBABILITIES WILL LIKELY BE NEEDED IN SUBSEQUENT OUTLOOKS AS THE  
PREDICTABILITY IMPROVES.  
 
LASTLY, A WEAK COLD FRONT IS EXPECTED OVER THE UPPER MIDWEST,  
CONTRIBUTING TO SCATTERED THUNDERSTORM DEVELOPMENT THURSDAY  
AFTERNOON. VERTICAL SHEAR WILL BE WEAK BUT MODERATE TO STRONG  
INSTABILITY IS STILL EXPECTED TO RESULT IN A FEW STRONGER STORMS.  
   
..CAROLINAS/VA TIDEWATER
 
 
A SURFACE LOW IS FORECAST TO BE JUST OFF THE CAROLINA COAST EARLY  
THURSDAY MORNING. SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS THE  
CAROLINAS AND INTO PORTIONS OF SOUTHEAST VA DURING THE DAY.  
STRENGTHEN/MATURING OF THIS LOW WILL RESULT IN ENHANCED LOW TO  
MID-LEVEL FLOW THROUGHOUT ITS EASTERN PERIPHERY. HOWEVER, ALL THE  
GUIDANCE CURRENTLY KEEPS THIS REGION OFFSHORE, LIMITING THE SEVERE  
POTENTIAL OVER LAND AREAS.  
 
..MOSIER.. 07/07/2020  
 

 
 
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