Multiple Days Of Severe Weather Possible 5/7 & 5/8

Key Points:

• Strong to severe storms are expected on Tuesday afternoon, with the primary concern being damaging winds.
• The likelihood of severe weather escalates from Wednesday night into Thursday.
• Potential threats from Wednesday into Thursday include damaging winds, large hail, and the possibility of tornadoes.

Tuesday (5/7)

..LOWER MISSISSIPPI VALLEY/DEEP SOUTH  
  
THIS REGION WILL BE DISPLACED SOUTH OF THE STRONGER FORCING FOR  
ASCENT, BUT MODERATE BUOYANCY AND VERTICAL SHEAR STILL SUGGEST THERE  
IS ISOLATED SEVERE POTENTIAL WITH ANY STORMS THAT DO FORM. CURRENT  
GUIDANCE SUGGESTS THE GREATEST PROBABILITY OF STORMS EXISTS ACROSS  
MS AND AL WHERE THE LOW-LEVEL MOISTURE CONVERGENCE IS GREATEST.

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Wednesday (5/8) into Thursday (5-9)

..SUMMARY  
  
SCATTERED TO NUMEROUS SEVERE THUNDERSTORMS APPEAR LIKELY WEDNESDAY  
ACROSS FROM PARTS OF THE SOUTHERN PLAINS INTO THE MID MISSISSIPPI,  
OHIO, AND TENNESSEE VALLEYS. ALL SEVERE HAZARDS, INCLUDING  
TORNADOES, VERY LARGE HAIL, AND SEVERE/DAMAGING WINDS SHOULD OCCUR.  
SOME OF THE TORNADOES MAY BE STRONG.  
  
...SOUTHERN PLAINS INTO THE MID-SOUTH/MID MISSISSIPPI VALLEY AND  
OHIO/TENNESSEE VALLEYS...  
AN UPPER LOW WILL REMAIN OVER THE NORTHERN PLAINS AND UPPER MIDWEST  
ON WEDNESDAY. AN EMBEDDED SHORTWAVE TROUGH WILL EJECT EASTWARD  
ACROSS THE MID MS VALLEY INTO THE OH VALLEY THROUGH THE PERIOD. THE  
PRIMARY SURFACE LOW OF INTEREST WILL MOVE ACROSS MO INTO IL/IN  
THROUGH THE DAY, WITH A WARM FRONT EXTENDING EASTWARD FROM THIS LOW  
ACROSS THE OH VALLEY. AN ATTENDANT COLD FRONT SHOULD ALSO MAKE SOME  
SOUTHEASTWARD PROGRESS ACROSS THE SOUTHERN PLAINS INTO THE MID MS  
VALLEY.  
  
A VOLATILE SETUP FROM SEVERE THUNDERSTORMS HAS BECOME MORE APPARENT  
FROM NORTHEAST TX INTO THE MID-SOUTH/MID MS VALLEY AND PARTS OF THE  
OH VALLEY, WHERE AND ENHANCED RISK HAS BEEN INTRODUCED. HERE, A VERY  
FAVORABLE COMBINATION OF STRONG INSTABILITY AND DEEP-LAYER SHEAR IS  
FORECAST TO DEVELOP, SUPPORTING A THREAT FOR SUPERCELLS AND INTENSE  
BOWING CLUSTERS/LINE SEGMENTS. CURRENT EXPECTATIONS ARE FOR SEVERE  
CONVECTION TO ERUPT FAIRLY EARLY IN THE DAY, PERHAPS BY LATE  
WEDNESDAY MORNING, ALONG BOTH THE COLD FRONT AND WARM FRONT AS  
ASCENT WITH THE SHORTWAVE TROUGH OVERSPREADS THE RAPIDLY  
DESTABILIZING WARM SECTOR.  
  
ALTHOUGH CONVECTIVE EVOLUTION REMAINS SOMEWHAT UNCERTAIN, VERY LARGE  
HAIL WILL BE A THREAT WITH INITIAL SUPERCELLS, AND SEVERE/DAMAGING  
WINDS WILL LIKELY BECOME AN INCREASING CONCERN AS INTENSE CONVECTION  
SPREADS EAST-SOUTHEASTWARD THROUGH THE AFTERNOON AND EVENING. A  
MODERATE TO STRONG LOW-LEVEL JET SHOULD MIGRATE EASTWARD ACROSS THE  
MID MS AND OH VALLEYS THROUGH THE DAY, SUPPORTING ENHANCED LOW-LEVEL  
SHEAR, ESPECIALLY IN THE VICINITY OF THE WARM FRONT. TORNADOES WILL  
BE A CONCERN WITH ANY SUPERCELLS IN THIS FAVORABLE SHEAR  
ENVIRONMENT. SOME OF THESE TORNADOES COULD BE STRONG GIVEN THE  
FAVORABLE THERMODYNAMIC AND KINEMATIC ENVIRONMENT. THE SEVERE THREAT  
IS EXPECTED TO CONTINUE WITH SOUTHWARD AND EASTWARD EXTENT INTO THE  
LOWER MS VALLEY, TN VALLEY, AND CENTRAL/SOUTHERN APPALACHIANS  
THROUGH AT LEAST WEDNESDAY EVENING BEFORE EVENTUALLY WEAKENING.