Aug 19, 2015 0600 UTC Day 1 Convective Outlook
Updated: Wed Aug 19 05:35:11 UTC 2015 (20150819 1200Z Day 1 shapefile | 20150819 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150819 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 42,703 3,872,625 Grand Rapids, MI...Lansing, MI...Flint, MI...Kalamazoo, MI...Wyoming, MI...
MARGINAL 416,825 50,434,186 Dallas, TX...Detroit, MI...Indianapolis, IN...Columbus, OH...Austin, TX...
Probabilistic Tornado Graphic
20150819 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 % 82,375 4,665,486 Grand Rapids, MI...Lansing, MI...Flint, MI...Kalamazoo, MI...Wyoming, MI...
Probabilistic Damaging Wind Graphic
20150819 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 % 43,851 3,936,155 Grand Rapids, MI...Lansing, MI...Flint, MI...Kalamazoo, MI...Wyoming, MI...
5 % 415,235 50,233,839 Dallas, TX...Detroit, MI...Indianapolis, IN...Columbus, OH...Austin, TX...
Probabilistic Large Hail Graphic
20150819 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
5 % 72,186 9,293,048 Dallas, TX...Austin, TX...Fort Worth, TX...Arlington, TX...Plano, TX...
   SPC AC 190535

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1235 AM CDT WED AUG 19 2015

   VALID 191200Z - 201200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS OVER A PORTION OF LOWER AND
   UPPER MI...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM A PORTION OF TX THROUGH
   THE LOWER MS...TN AND OH VALLEYS...

   ...SUMMARY...
   A FEW STRONG TO SEVERE STORMS REMAIN POSSIBLE WEDNESDAY OVER A
   PORTION OF THE GREAT LAKES...LOWER OHIO VALLEY...LOWER MISSISSIPPI
   AND TENNESSEE VALLEYS...AND NORTHEAST THROUGH SOUTHWEST TEXAS.
   LOCALLY STRONG TO DAMAGING WIND GUSTS WILL BE THE MAIN THREATS.

   ...SYNOPSIS...

   SYNOPTIC UPPER TROUGH NOW OVER THE CNTRL U.S. WILL ADVANCE SLOWLY
   EWD TOWARD THE WRN GREAT LAKES AND OH VALLEY WEDNESDAY. SEVERAL
   VORTICITY MAXIMA WILL ROTATE THROUGH THIS FEATURE INCLUDING A LEAD
   IMPULSE THAT WILL MOVE THROUGH THE NRN GREAT LAKES EARLY IN THE
   PERIOD. THIS FEATURE WILL BE FOLLOWED CLOSELY BY PRIMARY VORTICITY
   MAXIMUM THAT WILL MOVE THROUGH NRN WI AND THE WRN UPPER PENINSULA OF
   MI LATER WEDNESDAY MORNING AND EARLY AFTERNOON. PRIMARY SFC LOW WILL
   CONSOLIDATE OVER THE WRN GREAT LAKES AND LIKELY BE LOCATED OVER NRN
   WI BY MID DAY WITH TRAILING COLD FRONT EXTENDING SSWWD INTO NRN AND
   SWRN TX. THE LOW WILL ADVANCE NWD INTO SRN ONTARIO WITH COLD FRONT
   EXTENDING THROUGH THE OH VALLEY SWWD TO NEAR THE TX COAST BY THE END
   OF THE PERIOD.

   ...GREAT LAKES AREA...

   POOR MID-LEVEL LAPSE RATE AND AREAS OF CLOUDS WILL RESULT IN WEAK
   INSTABILITY /400-800 J/KG MLCAPE/ IN PRE-FRONTAL WARM SECTOR...AND
   THE MARGINAL THERMODYNAMIC ENVIRONMENT SHOULD SERVE AS A LIMITING
   FACTOR FOR A MORE ROBUST SEVERE THREAT. LOWER-TROPOSPHERIC WINDS
   WILL STRENGTHEN AS LLJ SHIFTS NEWD TO THE EAST OF CYCLONE.
   HOWEVER...0-2 KM HODOGRAPHS ARE NOT FORECAST TO BE PARTICULARLY
   LARGE OVER LOWER MI DUE TO THE UNIDIRECTIONAL NATURE OF THE WINDS.
   NEVERTHELESS...EFFECTIVE BULK SHEAR FROM 30-40 KT WILL CHARACTERIZE
   WARM SECTOR. SOME CLOUD BREAKS AND DIABATIC WARMING IS EXPECTED TO
   OCCUR DURING THE DAY...AND THUNDERSTORMS SHOULD REDEVELOP OVER LOWER
   MI ALONG WARM CONVEYOR BELT. PRIMARY THREAT WITH THIS ACTIVITY WILL
   BE A FEW STRONG TO DAMAGING WIND GUSTS SUPPORTED BY DOWNWARD
   TRANSFER OF MOMENTUM WHERE SUFFICIENT BOUNDARY LAYER DESTABILIZATION
   OCCURS.

   A SECONDARY AREA OF THUNDERSTORMS MAY DEVELOP OVER WRN THROUGH CNTRL
   UPPER MI IN DRY SLOT REGION AND WITHIN ZONE OF ASCENT ACCOMPANYING
   PRIMARY VORTICITY MAXIMUM. INSTABILITY WILL REMAIN MARGINAL IN THIS
   AREA...BUT LAPSE RATES MAY BECOME SLIGHTLY BETTER THAN ACROSS LOWER
   MI DUE TO COOLER MID-LEVEL TEMPERATURES IN CLOSER PROXIMITY TO UPPER
   LOW. POTENTIAL WILL EXIST FOR A COUPLE OF LOW TOPPED SUPERCELLS
   CAPABLE OF PRIMARILY STRONG WIND GUSTS AND A BRIEF TORNADO.

   ...SWRN TX THROUGH LOWER MS VALLEY...SERN STATES AND OH VALLEY...

   PRE-FRONTAL WARM SECTOR WILL BECOME MARGINALLY TO MODERATELY
   UNSTABLE FROM THE OH VALLEY SWWD THROUGH TX...WITH THE STRONGER
   INSTABILITY EXPECTED FROM TX INTO THE LOWER MS VALLEY AREA.
   THUNDERSTORMS WILL LIKELY REDEVELOP ALONG AND AHEAD OF SEWD
   ADVANCING COLD FRONT WITHIN THE WEAKLY CAPPED WARM SECTOR. THESE
   AREAS WILL REMAIN SOUTH AND EAST OF THE STRONGER WINDS ALOFT WITH
   WEAK VERTICAL SHEAR SUPPORTIVE OF MULTICELLS CAPABLE OF MAINLY A FEW
   STRONG TO DAMAGING WIND GUSTS.

   ..DIAL/LEITMAN.. 08/19/2015

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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