Jul 28, 2014 1300 UTC Day 1 Convective Outlook
Updated: Mon Jul 28 12:25:34 UTC 2014 (20140728 1300Z Day 1 shapefile | 20140728 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140728 1300 UTC Day 1 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 82,320 6,662,077 Mobile, AL...Savannah, GA...Charleston, SC...Wilmington, NC...North Charleston, SC...
Probabilistic Tornado Graphic
20140728 1300 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 49,627 12,310,612 Boston, MA...Providence, RI...Worcester, MA...Springfield, MA...New Haven, CT...
Probabilistic Damaging Wind Graphic
20140728 1300 UTC Day 1 Damaging Wind Probabilities Graphic
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.
Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 82,132 6,649,188 Mobile, AL...Savannah, GA...Charleston, SC...Wilmington, NC...North Charleston, SC...
5 % 150,158 40,617,303 Philadelphia, PA...Jacksonville, FL...Norfolk, VA...Baton Rouge, LA...Chesapeake, VA...
Probabilistic Large Hail Graphic
20140728 1300 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
5 % 67,200 16,755,231 Providence, RI...Worcester, MA...Springfield, MA...Bridgeport, CT...Savannah, GA...
   SPC AC 281225

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0725 AM CDT MON JUL 28 2014

   VALID 281300Z - 291200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FROM THE
   COASTAL CAROLINAS TO THE N CENTRAL GULF COAST...

   ...SUMMARY...
   A FEW STRONG TO SEVERE STORMS CAPABLE OF PRODUCING DAMAGING WINDS
   WILL BE POSSIBLE THIS AFTERNOON AND EVENING FROM THE COASTAL
   CAROLINAS EXTENDING WEST SOUTHWESTWARD INTO THE NORTH CENTRAL GULF
   COAST STATES.  ISOLATED STRONG TO SEVERE STORMS MAY ALSO OCCUR TODAY
   OVER PORTIONS OF NEW ENGLAND.

   ...COASTAL CAROLINAS TO THE N CENTRAL GULF COAST THIS AFTERNOON...
   A SURFACE COLD FRONT WILL REACH THE NC COAST BY ABOUT MID
   AFTERNOON...AND WILL CONTINUE SWD TO THE I-10 CORRIDOR ALONG THE
   GULF COAST TONIGHT.  LOW-LEVEL ASCENT ALONG THE FRONT...POTENTIALLY
   AUGMENTED BY LOCAL SEA BREEZE CIRCULATIONS...WILL SUPPORT SCATTERED
   THUNDERSTORM DEVELOPMENT IN A BROKEN BAND ALONG THE FRONT THIS
   AFTERNOON/EVENING.  MODERATE-STRONG BUOYANCY IS EXPECTED IN ADVANCE
   OF THE FRONT...WHILE DEEP-LAYER FLOW AND VERTICAL SHEAR WILL WEAKEN
   QUICKLY WITH SWD EXTENT FROM NC.  FORECAST SOUNDINGS SHOW THE
   POTENTIAL FOR DAMAGING OUTFLOW WINDS WITH DOWNBURSTS...GIVEN BOTH
   LARGE BUOYANCY AND HIGH PW VALUES TO SUPPORT PRECIPITATION
   LOADING...AND LARGE DCAPE FOR STRONG RAIN-COOLED DOWNDRAFTS.  THE
   GREATER RISK FOR MORE ORGANIZED STORM CLUSTERS AND DOWNWARD MOMENTUM
   TRANSFER WILL BE ACROSS COASTAL NC WHERE MIDLEVEL FLOW WILL APPROACH
   50 KT.  

   ...NEW ENGLAND TODAY...
   INITIAL CLUSTERS OF THUNDERSTORMS WILL SPREAD NWD/NEWD OVER NEW
   ENGLAND THIS MORNING IN ASSOCIATION WITH LOW-LEVEL WAA AND A LEAD
   SHORTWAVE TROUGH.  THOUGH BUOYANCY IS LIMITED...VERTICAL SHEAR AND
   MOIST PROFILES COULD SUPPORT WEAKLY ROTATING STORMS THIS MORNING. 
   BY THIS AFTERNOON...THE PRIMARY SHORTWAVE TROUGH WILL PIVOT EWD OVER
   PA/NY...AS THE ASSOCIATED SURFACE CYCLONE DEVELOPS SLOWLY NEWD FROM
   NY TO NRN NEW ENGLAND...AND A TRAILING COLD FRONT LIKEWISE
   PROGRESSES EWD.  ADDITIONAL BANDS OF THUNDERSTORMS SHOULD DEVELOP BY
   EARLY AFTERNOON NEAR THE SURFACE LOW AND COLD FRONT WHERE ASCENT
   WILL BE FOCUSED.  A FEW CLOUD BREAKS WILL BE POSSIBLE ON THE EDGE OF
   THE MIDLEVEL DRY SLOT...SUCH THAT SOME SURFACE HEATING COULD BOOST
   MLCAPE TO 750-1500 J/KG.  MEANWHILE...VERTICAL SHEAR WILL BE AT
   LEAST MARGINALLY FAVORABLE FOR ORGANIZED STORMS/SUPERCELLS WITH
   EFFECTIVE BULK SHEAR OF 30-40 KT.  SINCE THE STRONGER LOW-LEVEL
   SHEAR WILL REMAIN REMOVED TO THE N OF THE STRONGER BUOYANCY AND
   LAPSE RATES WILL NOT BE STEEP...THE OVERALL SEVERE STORM RISK SHOULD
   REMAIN MARGINAL.

   ..THOMPSON/BOTHWELL.. 07/28/2014

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z