SPC AC 191630

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CDT FRI JUN 19 2015

   VALID 191630Z - 201200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS ACROSS THE NORTHERN PLAINS...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE NORTHERN
   PLAINS/UPPER MIDWEST...

   ...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE NORTHERN
   PLAINS/UPPER MIDWEST...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM THE MID-SOUTH TO
   VA/CAROLINAS...

   ...SUMMARY...
   SCATTERED SEVERE STORMS INITIALLY WITH VERY LARGE HAIL AND A FEW
   TORNADOES ARE EXPECTED OVER PARTS OF THE NORTHERN HIGH PLAINS THIS
   AFTERNOON INTO EVENING. THIS ACTIVITY IS EXPECTED TO DEVELOP INTO A
   FAST-MOVING SQUALL LINE OVER PARTS OF THE DAKOTAS WITH INTENSE
   SEVERE WIND GUSTS TONIGHT.

   ...MT/NORTHERN HIGH PLAINS TO UPPER MIDWEST...
   LARGE-SCALE HEIGHT FALLS AND A STRENGTHENING OF MID/HIGH-LEVEL
   WESTERLIES WILL OCCUR ACROSS THE REGION TODAY AHEAD OF A SUBSTANTIAL
   TROUGH OVER BRITISH COLUMBIA AND THE ADJACENT PACIFIC NORTHWEST.
   WITH AID OF LEE-SIDE CYCLOGENESIS AND A SOUTHEASTWARD-MOVING
   FRONT/HIGHER TERRAIN...THE MAIN SCENARIO WILL BE FOR SURFACE-BASED
   STORMS TO INCREASE LATER THIS AFTERNOON/EARLY EVENING...INITIALLY
   ACROSS SOUTHEAST/EAST-CENTRAL MT AND FAR NORTHEAST WY...WITH OTHER
   STORMS POTENTIALLY MOVING EAST-SOUTHEASTWARD OUT OF SASKATCHEWAN.
   STRENGTHENING DEEP-LAYER SHEAR AND A MODERATELY UNSTABLE ENVIRONMENT
   WILL SUPPORT INITIAL SUPERCELLS CAPABLE OF LARGE HAIL AND A COUPLE
   OF TORNADOES. SUBSEQUENTLY...UPSCALE QUASI-LINEAR GROWTH INTO A
   FORWARD-PROPAGATING/ACCELERATING MCS SEEMS HIGHLY LIKELY BY
   EVENING...PARTICULARLY WITHIN A CORRIDOR FROM SOUTHEAST MT INTO
   PORTIONS OF SD WHERE A RELATIVE CONCENTRATION OF WIND
   DAMAGE/SEVERE-CALIBER WIND GUSTS IS POSSIBLE. ALTHOUGH OVERALL
   INTENSITY SHOULD DIMINISH LATE TONIGHT OWING TO INCREASINGLY
   ELEVATED INFLOW...SEVERE-CALIBER WIND GUSTS MAY BE POSSIBLE AS FAR
   EAST AS PORTIONS OF MN/NORTHERN IA IN ASSOCIATION WITH THE
   FAST-MOVING CONVECTIVE LINE.

   ...MID-SOUTH AND TN/LOWER OH RIVER VALLEYS...
   THE REMNANTS OF BILL...LOCATED OVER THE OZARKS/NEARING THE MIDDLE MS
   RIVER VALLEY LATE THIS MORNING...WILL CONTINUE A SLOW EASTWARD
   PROGRESSION TODAY WITH A MODERATELY STRONG LOW-LEVEL WIND FIELD
   REMAINING ON ITS EASTERN PERIPHERY. THIS ENHANCED LOW-LEVEL WIND
   FIELD WILL AT LEAST PARTIALLY INTERACT WITH A FRONTAL ZONE THAT
   EXTENDS WSW-ENE ACROSS THE OH RIVER VALLEY. A BRIEF TORNADO OR TWO
   COULD OCCUR THIS AFTERNOON/EARLY EVENING...WITH THE MAIN CORRIDOR OF
   ANY SUCH POTENTIAL EXPECTED TO BE LOCATED ACROSS PORTIONS OF FAR
   SOUTHERN IL/INDIANA AND WESTERN KY AND POSSIBLY WESTERN TN. BOUTS OF
   LOCALLY DAMAGING WINDS WILL OTHERWISE BE A CONCERN PRIMARILY THIS
   AFTERNOON/EARLY EVENING.

   ...CENTRAL/SOUTHERN APPALACHIANS INTO VA/CAROLINAS...
   HEATING OF THE ELEVATED TERRAIN COUPLED WITH CONVERGENCE ALONG A LEE
   TROUGH...RESIDUAL OUTFLOW BOUNDARIES AND THE DEVELOPING SEA BREEZE
   FRONT WILL CONTRIBUTE TO THE FORMATION OF SCATTERED STORMS THIS
   AFTERNOON. MODEST /25-30 KT/ DEEP-LAYER SHEAR ALIGNED WITH MLCAPE OF
   1000-2000 J/KG WILL PROMOTE THE DEVELOPMENT OF MULTICELL CLUSTERS
   CAPABLE OF MAINLY ISOLATED DAMAGING WIND GUSTS INTO EARLY EVENING.

   ..GUYER/COOK.. 06/19/2015

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z