Aug 3, 2015 0600 UTC Day 1 Convective Outlook
Updated: Mon Aug 3 05:55:28 UTC 2015 (20150803 1200Z Day 1 shapefile | 20150803 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150803 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 167,148 24,878,726 Columbus, OH...Cleveland, OH...Pittsburgh, PA...Cincinnati, OH...Lexington-Fayette, KY...
MARGINAL 435,176 50,681,651 New York, NY...Detroit, MI...Indianapolis, IN...Denver, CO...Nashville, TN...
Probabilistic Tornado Graphic
20150803 1200 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.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 601,022 74,461,925 New York, NY...Detroit, MI...Indianapolis, IN...Columbus, OH...Denver, CO...
Probabilistic Damaging Wind Graphic
20150803 1200 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.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 167,158 24,887,053 Columbus, OH...Cleveland, OH...Pittsburgh, PA...Cincinnati, OH...Lexington-Fayette, KY...
5 % 433,607 49,376,750 New York, NY...Detroit, MI...Indianapolis, IN...Denver, CO...Nashville, TN...
Probabilistic Large Hail Graphic
20150803 1200 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.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 167,095 24,866,174 Columbus, OH...Cleveland, OH...Pittsburgh, PA...Cincinnati, OH...Lexington-Fayette, KY...
5 % 433,904 49,606,081 New York, NY...Detroit, MI...Indianapolis, IN...Denver, CO...Nashville, TN...
   SPC AC 030555

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1255 AM CDT MON AUG 03 2015

   VALID 031200Z - 041200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE
   NORTHEAST AND OH VALLEY VICINITY...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM NEW ENGLAND SWWD ACROSS
   THE OH VALLEY...AND THEN WWD ACROSS MO/KS INTO THE CENTRAL AND SRN
   HIGH PLAINS...

   ...SUMMARY...
   A FEW SEVERE STORMS ARE EXPECTED FROM THE NORTHEAST INTO THE OHIO
   VALLEY...ACCOMPANIED BY ISOLATED OCCURRENCES OF SEVERE WIND AND/OR
   HAIL DURING THE AFTERNOON. ISOLATED HAIL AND WIND ARE ALSO POSSIBLE
   ACROSS PORTIONS OF THE CENTRAL PLAINS AND INTO THE TEXAS PANHANDLE
   AREA.

   ...SYNOPSIS...
   A LARGE MID- AND UPPER-LEVEL VORTEX CENTERED INVOF JAMES BAY IS
   PROGGED TO DRIFT VERY GRADUALLY EWD THIS PERIOD...WITH ENHANCED
   CYCLONIC FLOW/TROUGHING TO RESIDE OVER MUCH OF THE ERN CONUS. 
   FARTHER W...NEGATIVELY TILTED SHORT-WAVE TROUGHING SHOULD SHIFT NEWD
   ACROSS THE ROCKIES/PLAINS THROUGH A BACKGROUND/LONGER-WAVELENGTH
   MEAN RIDGE.

   AT THE SURFACE...A WEAKENING COLD FRONT TRAILING SWD/SWWD FROM A WRN
   QUEBEC LOW IS FORECAST TO SHIFT EWD ACROSS THE NORTHEAST U.S. AND
   SEWD INTO THE OH VALLEY/MIDWEST REGION...AND THEN WWD ACROSS MO AND
   KS AND INTO THE CENTRAL HIGH PLAINS.  THIS FRONT WILL FOCUS
   CONVECTION/ISOLATED SEVERE RISK THROUGH THE PERIOD.

   ...PORTIONS OF NEW ENGLAND SWWD INTO THE OH VALLEY...
   AS A WEAKENING COLD FRONT MOVES SLOWLY EWD ACROSS THE NORTHEAST U.S.
   DURING THE DAY...GRADUAL DEVELOPMENT OF SCATTERED SHOWERS AND
   THUNDERSTORMS IS EXPECTED TO OCCUR...AS DIURNAL HEATING PUSHES
   MIXED-LAYER CAPE INTO THE 1000 TO 2000 J/KG RANGE ACROSS THE
   NORTHEAST/NEW ENGLAND...AND IN EXCESS OF 3000 J/KG INTO THE MID-OH
   VALLEY REGION.  

   WITH A BELT OF ENHANCED/CYCLONIC LOW- TO MID-LEVEL SWLYS PROGGED TO
   RESIDE ACROSS THE REGION...A FEW STRONGER STORMS ARE EXPECTED --
   THOUGH FLOW LARGELY PARALLEL TO THE FRONTAL ZONE AND UNIDIRECTIONAL
   WITH HEIGHT SHOULD TEND TO LIMIT THE OVERALL SEVERE POTENTIAL TO
   SOME DEGREE.  STILL...STRONGER CELLS ACROSS THE AREA WILL BE CAPABLE
   OF PRODUCING MARGINAL HAIL AND/OR DAMAGING GUSTS DURING THE
   AFTERNOON AND EARLY EVENING HOURS. 

   ...PORTIONS OF THE CENTRAL AND SRN PLAINS...
   SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST ACROSS PORTIONS OF
   THE CENTRAL AND SRN PLAINS...AS LARGE-SCALE ASCENT ASSOCIATED WITH A
   WEAK VORT MAX SHIFTING EWD OUT OF THE CENTRAL ROCKIES IS FOCUSED AT
   LOW LEVELS ALONG THE COLD FRONT PROGGED TO LIE W-E ACROSS THE NRN KS
   VICINITY AS WELL AS INVOF A LEE TROUGH OVER THE HIGH PLAINS.  WHILE
   FLOW ALOFT WILL REMAIN RELATIVELY WEAK ACROSS MOST OF THE AREA --
   AND THUS ONLY LIMITED SEVERE THREAT WITH LARGELY DISORGANIZED
   STORMS...SLIGHTLY GREATER SHEAR IS EXPECTED WHERE LOW-LEVEL FLOW IS
   BACKED -- I.E. JUST E OF THE HIGH-PLAINS LEE TROUGH...AND TO THE
   COOL SIDE OF THE SURFACE FRONT.  IN BOTH AREAS...MULTICELL
   ORGANIZATION POTENTIAL MAY SUPPORT EVOLUTION OF A FEW STRONGER STORM
   CLUSTERS -- ALONG WITH A FEW HAIL/WIND OCCURRENCES APPROACHING OR
   EXCEEDING SEVERE LEVELS.

   ..GOSS/MARSH.. 08/03/2015

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z