Sep 10, 2014 1630 UTC Day 1 Convective Outlook
Updated: Wed Sep 10 16:28:29 UTC 2014 (20140910 1630Z Day 1 shapefile | 20140910 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140910 1630 UTC Day 1 Outlook Graphic
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 125,136 22,200,530 Detroit, MI...Indianapolis, IN...St. Louis, MO...Toledo, OH...Cincinnati, OH...
Probabilistic Tornado Graphic
20140910 1630 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 % 72,994 12,174,116 Indianapolis, IN...St. Louis, MO...Toledo, OH...Fort Wayne, IN...Dayton, OH...
Probabilistic Damaging Wind Graphic
20140910 1630 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
30 % 22,122 2,491,958 St. Louis, MO...Terre Haute, IN...Belleville, IL...University City, MO...Oakville, MO...
15 % 103,281 19,639,428 Detroit, MI...Indianapolis, IN...Toledo, OH...Fort Wayne, IN...Dayton, OH...
5 % 137,162 26,513,896 Chicago, IL...Columbus, OH...Cleveland, OH...Cincinnati, OH...Buffalo, NY...
Probabilistic Large Hail Graphic
20140910 1630 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 % 88,881 6,809,648 St. Louis, MO...Springfield, MO...Fort Smith, AR...Fayetteville, AR...St. Charles, MO...
   SPC AC 101628

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1128 AM CDT WED SEP 10 2014

   VALID 101630Z - 111200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM LWR MI AND THE LWR OH VLY
   SWWD INTO THE OZARKS...

   ...SUMMARY...
   THUNDERSTORMS...SOME SEVERE...ARE EXPECTED TO DEVELOP NEAR A COLD
   FRONT FROM THE SOUTHERN GREAT LAKES SOUTHWESTWARD THROUGH THE LOWER
   OHIO AND MID-MISSISSIPPI VALLEYS INTO THE OZARKS. DAMAGING WINDS
   WILL BE THE PRIMARY THREAT THIS AFTERNOON THROUGH EARLY TONIGHT.

   ...SYNOPTIC SETUP...
   SEASONABLY STRONG WSW FLOW WILL PREVAIL FROM THE SRN PLNS TO THE LWR
   GRT LKS THROUGH THU...DOWNSTREAM FROM POTENT SHORTWAVE TROUGH
   AMPLIFYING SE FROM BC/AB INTO THE NRN RCKYS. WITHIN THE WSW
   FLOW...SHORTWAVE IMPULSE NOW OVER THE MID MS VLY SHOULD SHEAR NE
   ACROSS MI LATER TODAY...AND INTO WRN QUE EARLY THU...WHILE TRAILING
   DISTURBANCE NOW OVER ERN CO REACHES IA THIS EVE AND SRN MI/NW OH
   EARLY THU.

   AT THE SFC...LOW NOW OVER CNTRL WI SHOULD FURTHER DEEPEN AS IT
   CONTINUES ENE TO NRN LWR MI THIS EVE AND INTO SW QUE BY 12Z THU.
   COLD FRONT TRAILING SW FROM THE LOW WILL ACCELERATE S/SE ACROSS THE
   SRN PLNS/OZARKS/MID-MS VLY/LWR OH VLYS...EVENTUALLY OVERTAKING
   OUTFLOW FROM PRE-FRONTAL CONVECTION/SQLN. 

   ...SRN GRT LKS SW INTO OZARKS/SRN PLNS...
   LEAD UPR MS VLY UPR IMPULSE WILL ENHANCE ASCENT OVER COLD FRONTAL
   ZONE CROSSING ERN IL/IND/LWR MI/WRN-NRN OH THROUGH EARLY-MID AFTN.
   MID-LVL LAPSE RATES ACROSS REGION WILL REMAIN WEAK PER MORNING 500
   MB ANALYSIS. BUT GIVEN EXPECTED GRADUAL WARMING OF INCREASINGLY
   MOIST BOUNDARY LAYER /REF MCD 1707/...SETUP COULD PROMOTE SOME
   INTENSIFICATION OF SCTD STRONGER UPDRAFTS WITHIN EXISTING
   BROKEN...PRE-FRONTAL CONVECTIVE BANDS. 700-500 MB WSW FLOW WILL
   REMAIN AROUND 50 KTS...WITH LOW-LVL HODOGRAPHS ENLARGED BY BELT OF
   ENHANCED 925-850 MB FLOW ASSOCIATED WITH DEEPENING SFC LOW.
   THUS...SOME RISK WILL EXIST FOR ISOLD TORNADOES IN ADDITION TO
   LOCALLY DMGG WIND THROUGH LATE AFTN FROM ERN IL ENE INTO PARTS OF
   OH/LWR MI.

   LATER TODAY...ADDITIONAL STORM DEVELOPMENT APPEARS POSSIBLE FROM
   CNTRL/SRN IL SWWD THROUGH ERN/SRN MO INTO NRN AR AS SFC HEATING
   DESTABILIZES LWR LVLS ALONG IMMEDIATE COLD FRONT. PRE-FRONTAL
   CONVECTION IS INCREASINGLY LIMITED WITH SW EXTENT ALONG THIS
   CORRIDOR...ALLOWING FOR MORE SUBSTANTIAL LOW-LVL WARMING IN WAKE OF
   MORNING STORMS RELATIVE TO POINTS FARTHER NE. ALTHOUGH MID-LVL LAPSE
   RATES WILL REMAIN WEAK...SOME INCREASE IN FORCING FOR ASCENT LIKELY
   WILL OCCUR AS CO UPR IMPULSE CROSSES THE CNTRL PLNS. HIGH PW /AOA 2
   INCHES/ COUPLED WITH 30-40 UNIDIRECTIONAL WSWLY 700-500 MB FLOW
   COULD YIELD SHORT LINES/SMALL CLUSTERS OF STORMS WITH A RISK FOR
   LOCALLY DMGG WIND AND PERHAPS A SPOT OR TWO OF HAIL. A TORNADO
   CANNOT BE RULED OUT IN IL/ERN MO GIVEN GREATER PROXIMITY TO FASTER
   FLOW ALOFT AND STRONGER FORCING FOR ASCENT.  

   ...SRN PLNS LATE THIS AFTN/EVE...  
   CAPPING ASSOCIATED WITH RESIDUAL EML SHOULD DELAY DIURNAL CONVECTIVE
   DEVELOPMENT...DESPITE STRONG SFC HEATING...ALONG COLD FRONT AND
   EWD-DISPLACED LEE TROUGH OVER SRN/ERN OK AND N TX LATER TODAY.
   COMBINATION OF WEAK CONVERGENCE ALONG THE FRONT/TROUGH AND
   DEEPLY-MIXED ENVIRONMENT MAY YIELD SCTD LATE AFTN/EVE STORMS WITH
   LOCALLY DMGG GUSTS.

   ..CORFIDI/MOSIER.. 09/10/2014

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