445  
ACUS01 KWNS 160557  
SWODY1  
SPC AC 160556  
 
DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1256 AM CDT MON SEP 16 2024  
 
VALID 161200Z - 171200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF  
THE NORTHERN PLAINS...  
   
..SUMMARY
 
 
THUNDERSTORMS CAPABLE OF SEVERE GUSTS AND LARGE HAIL ARE EXPECTED  
TODAY IN PARTS OF THE NORTHERN PLAINS. AN ISOLATED TORNADO THREAT IS  
EXPECTED IN THE CAROLINAS. MARGINALLY SEVERE WIND AND HAIL MAY OCCUR  
IN PARTS OF THE FOUR CORNERS AND INTERMOUNTAIN WEST.  
   
..NORTHERN PLAINS
 
 
SOUTHWEST MID-LEVEL FLOW WILL BE IN PLACE ACROSS THE NORTH-CENTRAL  
U.S. TODAY. A SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS NORTH  
DAKOTA THIS AFTERNOON. AT THE SURFACE, A LOW WILL DEEPEN ACROSS  
SOUTHEAST MONTANA AS A WARM FRONT MOVES NORTHWARD ACROSS CENTRAL AND  
EASTERN NORTH DAKOTA. SURFACE DEWPOINTS NEAR THE FRONT WILL BE IN  
THE MID TO UPPER 60S F AND MODERATE INSTABILITY IS EXPECTED TO  
DEVELOP BY AFTERNOON. THE FRONT WILL BE A FOCUS FOR CONVECTIVE  
INITIATION FROM LATE THIS MORNING INTO THE AFTERNOON. RAP FORECAST  
SOUNDINGS NEAR THE FRONT IN EAST-CENTRAL NORTH DAKOTA HAVE 0-6 KM  
SHEAR IN THE 30 TO 35 KNOT RANGE WITH SOME DIRECTIONAL SHEAR IN THE  
BOUNDARY LAYER. MID-LEVEL LAPSE RATES ARE FORECAST TO BE BETWEEN 7.5  
AND 8 C/KM. THIS ENVIRONMENT SHOULD SUPPORT SUPERCELLS WITH SEVERE  
GUSTS AND LARGE HAIL. THE EVENT WILL BE DRIVEN BY MESOSCALE  
PROCESSES, AND THE GREATEST SEVERE THREAT COVERAGE WILL LIKELY BE  
LOCATED IN AREAS WHERE THE MAXIMA IN LOW-LEVEL CONVERGENCE,  
INSTABILITY AND DEEP-LAYER SHEAR BECOME JUXTAPOSED. THE SEVERE  
THREAT MAY RAMP UP DURING THE EARLY EVENING AS A 40 TO 50 KNOT  
LOW-LEVEL JET STRENGTHENS ACROSS THE NORTHERN PLAINS.  
   
..EASTERN NORTH CAROLINA/FAR EASTERN SOUTH CAROLINA
 
 
A LOW PRESSURE AREA OFF THE COAST OF THE CAROLINAS IS FORECAST TO  
BECOME A TROPICAL STORM BY THE NATIONAL HURRICANE CENTER AND MOVE  
NORTHWESTWARD INTO FAR EASTERN SOUTH CAROLINA THIS EVENING. RAP  
FORECAST SOUNDINGS TO THE RIGHT OF THE EXPECTED LANDFALL AT  
WILMINGTON, NORTH CAROLINA HAVE 0-3 KM STORM-RELATIVE HELICITY  
INCREASING TO AROUND 150 M2/S2 BY EARLY EVENING WITH 0-1 KM SHEAR  
REACHING THE 20 TO 25 KNOT RANGE. THIS SHOULD SUPPORT AN ISOLATED  
TORNADO THREAT AS THE TROPICAL STORM MOVES INLAND THIS EVENING. THIS  
THREAT MAY CONTINUE INTO THE LATE EVENING AND OVERNIGHT ALONG THE  
COAST OF NORTH CAROLINA, WHERE MODERATE INSTABILITY IS FORECAST.  
   
..FOUR CORNERS/INTERMOUNTAIN WEST
 
 
AN MID-LEVEL LOW WILL MOVE NORTHEASTWARD ACROSS THE INTERMOUNTAIN  
WEST TODAY. AHEAD OF THE SYSTEM, A BAND OF STRONG LARGE-SCALE ASCENT  
WILL AID THUNDERSTORM DEVELOPMENT FROM THE FOUR CORNERS REGION  
NORTHWESTWARD ACROSS PARTS OF UTAH. SCATTERED STORMS WILL LIKELY  
DEVELOP AND MOVE NORTHEASTWARD ACROSS THE REGION DURING THE  
AFTERNOON. ALTHOUGH INSTABILITY WILL REMAIN WEAK, VERY STEEP LAPSE  
RATES AND STRONG DEEP-LAYER SHEAR MAY SUPPORT AN ISOLATED SEVERE  
THREAT. MARGINALLY SEVERE WIND AND HAIL WILL BE POSSIBLE WITH THE  
STRONGER CELLS.  
 
..BROYLES/WEINMAN.. 09/16/2024  
 

 
 
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