635  
ACUS02 KWNS 181703  
SWODY2  
SPC AC 181703  
 
DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK  
1203 PM CDT MON JUN 18 2018  
 
VALID 191200Z - 201200Z  
 
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF  
THE CENTRAL PLAINS...  
   
..SUMMARY
 
 
SEVERE THUNDERSTORMS WITH LARGE HAIL AND WIND DAMAGE WILL BE  
POSSIBLE ACROSS PARTS OF THE CENTRAL PLAINS TUESDAY AFTERNOON AND  
EVENING. MARGINALLY SEVERE THUNDERSTORMS MAY ALSO AFFECT PARTS OF  
THE CENTRAL HIGH PLAINS AND MID TO UPPER MISSISSIPPI VALLEY  
EAST-SOUTHEASTWARD TO VIRGINIA.  
   
..CENTRAL PLAINS
 
 
AN UPPER-LEVEL LOW WILL REMAIN IN PLACE ACROSS THE NORTHERN ROCKIES  
AND GRADUALLY FILL ON TUESDAY AS AN UPPER-LEVEL TROUGH MOVES INTO  
THE CENTRAL ROCKIES. AT THE SURFACE, A COLD FRONT IS FORECAST TO  
MOVE SOUTHWARD ACROSS THE CENTRAL PLAINS WITH THE MOIST SECTOR  
LOCATED FROM THE LOWER TO MID MISSOURI VALLEY EXTENDING WESTWARD  
ACROSS SOUTHERN NEBRASKA. THUNDERSTORM DEVELOPMENT IS EXPECTED TO  
TAKE PLACE TUESDAY AFTERNOON ALONG THE FRONT FROM NORTHWEST KANSAS  
EXTENDING NORTHEASTWARD INTO SOUTHEAST NEBRASKA. CONVECTION IS ALSO  
FORECAST TO INITIATE IN THE HIGHER TERRAIN FROM NORTHEAST COLORADO  
NORTHWARD INTO EASTERN WYOMING WITH STORMS DEVELOPING AND MOVING  
EASTWARD INTO THE CENTRAL HIGH PLAINS. AS STORM COVERAGE INCREASES  
DURING THE LATE AFTERNOON AND EARLY EVENING, MCS FORMATION WILL BE  
POSSIBLE ACROSS PARTS OF KANSAS AND NEBRASKA.  
 
FORECAST SOUNDINGS FOR 00Z/WEDNESDAY ACROSS THE SLIGHT RISK AREA  
FROM NORTH PLATTE, NE EASTWARD TO GRAND ISLAND, NE AND SOUTHWARD TO  
DODGE CITY, KS GENERALLY SHOW IMPRESSIVE THERMODYNAMICS COINCIDING  
WITH SUPERCELL WIND PROFILES (0-6 KM SHEAR IN THE 35 TO 45 KT  
RANGE). THIS COMBINED WITH 700-500 MB LAPSE RATES AROUND 8 C/KM WILL  
SUPPORT LARGE HAIL WITH ANY SUPERCELL THAT CAN DEVELOP IN THE LATE  
AFTERNOON. CONDITIONS FOR SUPERCELLS MAY BE GREATEST IN THE WESTERN  
PART OF THE SLIGHT RISK AREA DUE TO THE CLOSER PROXIMITY TO THE  
UPPER-LEVEL TROUGH AND STRONGER DEEP-LAYER SHEAR. AS CONVECTIVE  
COVERAGE CONTINUES TO INCREASE IN THE EARLY TO MID EVENING,  
MULTICELL MAY BECOME THE MORE FAVORED MODE AS A LINE-SEGMENT  
ORGANIZES AND MOVES EAST-SOUTHEASTWARD ACROSS WEST-CENTRAL KANSAS  
AND SOUTHERN NEBRASKA. WIND DAMAGE WOULD BECOME THE FAVORED SEVERE  
THREAT IF A LINEAR MCS CAN ORGANIZE.  
   
..MID TO UPPER MISSISSIPPI VALLEY/OHIO VALLEY/MID-ATLANTIC
 
 
A BROAD REGION OF ANTICYCLONIC FLOW WILL BE IN PLACE ON TUESDAY FROM  
THE MID TO UPPER MISSISSIPPI AND OHIO VALLEYS EXTENDING INTO THE  
MID-ATLANTIC. AT THE SURFACE, A COLD FRONT IS FORECAST TO MOVE  
SOUTHWARD ACROSS THE MID TO UPPER MISSISSIPPI VALLEY, OHIO VALLEY  
AND MID-ATLANTIC. THUNDERSTORM DEVELOPMENT WILL LIKELY TAKE PLACE  
ALONG MUCH OF THE FRONT TUESDAY AFTERNOON AS SURFACE TEMPERATURES  
WARM. DUE TO THE PRESENCE OF THE UPPER-LEVEL RIDGE, DEEP-LAYER SHEAR  
IS FORECAST TO BE GENERALLY WEAK ACROSS MOST OF THE EAST-CENTRAL  
U.S. THIS WILL MAKE MULTICELL AND PULSE CONVECTION THE FAVORED STORM  
MODES. AREAS THAT LOCALLY HEAT UP THE MOST FROM NEAR AND TO THE  
SOUTH OF THE FRONT, MAY HAVE THE GREATEST THREAT FOR STRONG  
THUNDERSTORM DEVELOPMENT. ALTHOUGH SOME HAIL WILL BE POSSIBLE NEAR  
INSTABILITY MAXIMA, MARGINALLY SEVERE WIND GUSTS WOULD BE THE MOST  
LIKELY SEVERE THREAT. THE POTENTIAL FOR STRONG WIND GUSTS SHOULD BE  
MAXIMIZED DURING OR JUST AFTER PEAK HEATING WHEN LOW-LEVEL LAPSE  
RATES WILL BE STEEP.  
   
..MAXIMUM RISK BY HAZARD
 
 
TORNADO: 2% - MARGINAL  
WIND: 15% - SLIGHT  
HAIL: 15% - SLIGHT  
 
..BROYLES.. 06/18/2018  
 

 
 
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