Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Virginia Beach, VA...Minneapolis, MN...St. Paul, MN...Norfolk, VA...Chesapeake, VA...
SPC AC 120539
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1239 AM CDT SUN JUN 12 2016
VALID 121200Z - 131200Z
...THERE IS A SLGT RISK OF SVR TSTMS FOR THE ERN DAKOTAS AND
WRN/CNTRL MN...
...THERE IS A MRGL RISK OF SVR TSTMS FOR PORTIONS OF THE UPPER MS
VALLEY...CNTRL HIGH PLAINS...AND CNTRL PLAINS...
...THERE IS A MRGL RISK OF SVR TSTMS FOR SE VA AND NE NC...
...SUMMARY...
A FEW SEVERE THUNDERSTORMS ARE POSSIBLE SUNDAY AFTERNOON AND EVENING
ACROSS THE EASTERN DAKOTAS INTO WESTERN AND CENTRAL MINNESOTA.
STRONG THUNDERSTORMS ARE ALSO POSSIBLE ACROSS PARTS OF THE CENTRAL
PLAINS...CENTRAL HIGH PLAINS...AND MID-ATLANTIC.
...SYNOPSIS...
CONVECTIVELY INDUCED SHORTWAVE TROUGH CURRENTLY MOVING THROUGH MT IS
EXPECTED TO CONTINUE NEWD...EVENTUALLY MOVING THROUGH SRN MANITOBA
EARLY IN THE PERIOD AND ACTING TO DAMPEN THE UPPER RIDGE EXTENDING
ACROSS MUCH OF THE CNTRL CONUS. ASSOCIATED SURFACE LOW WILL TRACK
ACROSS ND AND NRN MD WHILE THE ATTENDANT COLD FRONT MOVES ACROSS THE
NRN PLAINS AND UPPER MS VALLEY.
FARTHER E...A STRONG SHORTWAVE TROUGH WILL MOVE THROUGH NEW ENGLAND
WHILE STRONG MID/UPPER LEVEL WINDS ACCOMPANYING THE SYSTEM SPREAD
OVER THE NORTHEAST AND MID-ATLANTIC. OCCLUDED SURFACE LOW ASSOCIATED
WITH THIS SYSTEM WILL MOVE ACROSS ME WHILE A RELATED COLD FRONT
SWEEPS ACROSS THE OH VALLEY AND MID-ATLANTIC. WRN PORTION OF THIS
FRONT WILL TRANSITION TO A WARM FRONT THAT INTERSECTS THE ND SURFACE
LOW.
...NRN PLAINS/UPPER MS VALLEY...
WHILE SOME ELEVATED TSTMS WILL LIKELY BE ONGOING AT THE BEGINNING OF
THE PERIOD...PRIMARY SVR THREAT IS EXPECTED TO EVOLVE DURING THE
AFTERNOON WITHIN THE WARM SECTOR AHEAD OF THE COLD FRONT. AIRMASS
THERE WILL LIKELY BE CHARACTERIZED BY DEWPOINTS IN THE MID 60S AND
TEMPERATURES NEAR 90. SLIGHTLY HIGHER DEWPOINTS MAY BE REALIZED
ALONG THE WARM FRONT BUT CLOUDS WILL LIMIT HEATING AND MIXING. THESE
SURFACE CONDITIONS WILL RESULT IN MODERATE INSTABILITY. DESPITE THE
LACK OF ANY LARGE-SCALE FORCING FOR ASCENT...CONVERGENCE ALONG THE
FRONT COUPLED WITH THE WARM AND MOIST AIRMASS IS EXPECTED TO RESULT
IN A LINE OF STORMS ALONG THE FRONT BY MID-AFTERNOON. MID-LEVEL FLOW
AND ASSOCIATED VERTICAL SHEAR WEAKENS WITH SRN EXTENT...WITH THE
BEST CHANCE OF SVR NEAR THE TRIPLE POINT. PRIMARY SVR HAZARD IS WIND
WITH SOME ISOLATED LARGE HAIL AS A SECONDARY THREAT. LOW TORNADO
THREAT ALSO EXISTS NEAR THE WARM FRONT WHERE WINDS WILL BE BACKED
BUT WEAK VERTICAL SHEAR SUGGEST MOST OF THE STORMS WILL BE WEAKLY
ORGANIZED AND OUTFLOW DOMINANT.
...CNTRL PLAINS/CNTRL HIGH PLAINS...
BOUNDARY LAYER MOISTURE HERE IS EXPECTED TO BE LESS THAN AREAS NW
BUT MID-LEVEL LAPSE RATES WILL BE STEEPER AND...AS A RESULT...THE
AIRMASS WILL LIKELY BE MODERATELY UNSTABLE BY MID-AFTERNOON. UPSLOPE
FLOW AND CONVERGENCE ALONG THE FRONT AMIDST THIS MODERATELY UNSTABLE
AIRMASS IS EXPECTED TO RESULT IN SCATTERED TSTM COVERAGE ALONG THE
FRONT DURING THE AFTERNOON. WEAK SHEAR SHOULD LIMIT STORM
ORGANIZATION BUT A DEEPLY MIXED BOUNDARY LAYER WILL LIKELY SUPPORT
SOME GUSTY WINDS AND/OR HAIL WITH THE STRONGEST STORMS. GUSTY
CONVECTIVE WINDS ARE ALSO POSSIBLE WITH ISOLATED STORMS IN WY WHERE
BETTER DEEP-LAYER FLOW EXISTS.
...MID-ATLANTIC WWD INTO THE OH VALLEY...
TEMPERATURES IN THE LOW TO MID 90S AND DEWPOINTS IN THE LOW TO MID
60S ARE EXPECTED AHEAD OF THE COLD FRONT PROGRESSING THROUGH THE
AREA. HOWEVER...WARM TEMPERATURES ALOFT WILL LIMIT MID-LEVEL LAPSE
RATES AND ASSOCIATED CONVECTIVE INHIBITION IS EXPECTED TO TEMPER THE
OVERALL CONVECTIVE COVERAGE. VERTICAL SHEAR WILL BE VERY WEAK ALONG
MUCH OF THE FRONT...SO ANY STORMS THAT DO DEVELOP WILL LIKELY BE
OUTFLOW DOMINANT MULTICELLS. THE ONLY EXCEPTION WILL BE AROUND THE
SERN VA/NERN NC WHERE SOME OVERLAP BETWEEN INSTABILITY AND STRONGER
DEEP-LAYER FLOW EXISTS. HERE...SOME GUSTY WINDS AND HAIL ARE
POSSIBLE WITH ANY MORE PERSISTENT STORMS DURING THE AFTERNOON.
..MOSIER/GLEASON.. 06/12/2016
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
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