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.
SPC AC 151250
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0750 AM CDT TUE MAR 15 2016
VALID 151300Z - 161200Z
...THERE IS AN ENH RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR NE
MO...EXTREME SE IA...AND W CENTRAL IL...
...THERE IS A SLGT RISK OF SVR TSTMS THROUGH TONIGHT FROM NRN MO TO
SW LOWER MI...
...THERE IS A MRGL RISK OF SVR TSTMS THROUGH TONIGHT FROM THE MID MS
VALLEY TO PARTS OF THE OH VALLEY AND GREAT LAKES...
...SUMMARY...
SEVERE THUNDERSTORMS WILL FORM LATE THIS AFTERNOON ACROSS NORTH
CENTRAL AND NORTHEAST MISSOURI...AND STORMS WILL SUBSEQUENTLY SPREAD
NORTHEASTWARD ACROSS SOUTHEAST IOWA AND NORTHERN ILLINOIS TO
SOUTHWEST LOWER MICHIGAN TONIGHT. A FEW TORNADOES AND LARGE HAIL
WILL BE THE MAIN THREATS THIS AFTERNOON AND EVENING...WHILE THE
LARGE HAIL AND DAMAGING WIND RISK WILL PERSIST OVERNIGHT.
...MID MS VALLEY THIS AFTERNOON TO LOWER MI/INDIANA TONIGHT...
A SURFACE CYCLONE IN SE KS WILL DEVELOP NEWD TO THE MO/IA/IL BORDER
INTERSECTION BY THIS EVENING...AND THE LOW WILL CONTINUE NWD
OVERNIGHT INTO SRN WI. SUBSTANTIAL DEEPENING OF THE CYCLONE WILL BE
SUPPORTED BY FOCUSED ASCENT IN THE LEFT EXIT REGION OF A 90-120 KT
MID-UPPER JET THAT WILL TRANSLATE ENEWD FROM THE CO/NM BORDER TO THE
MID MS VALLEY. LOW-LEVEL MASS RESPONSE TO THE DEEPENING CYCLONE
WILL ALSO LEAD TO INCREASING VERTICAL SHEAR IN THE WARM SECTOR THIS
AFTERNOON/EVENING...WHICH WILL FAVOR SUPERCELLS WITH THE INITIAL
CONVECTIVE DEVELOPMENT NEAR AND E-NE OF THE SURFACE CYCLONE BY
MID-LATE AFTERNOON.
THE PRIMARY UNCERTAINTY THIS FORECAST PERIOD IS THE DEGREE OF
LOW-LEVEL MOISTURE AND RESULTANT BUOYANCY IN THE WARM SECTOR.
NAM/RAP FORECASTS SHOW BOUNDARY LAYER DEWPOINTS INCREASING INTO THE
LOW-MID 60S...WHILE THE ECMWF IS MORE MUTED WITH UPPER 50S
DEWPOINTS. THE DRIER SCENARIO APPEARS TO BE A LITTLE MORE REALISTIC
WHEN CONSIDERING THAT ONLY A SHALLOW LAYER OF 60+ DEWPOINTS IS STILL
NEAR AND S OF I-20 IN TX/LA BASED ON 12Z SOUNDINGS. THE MOISTURE
DIFFERENCES CONTRIBUTE TO RELATIVELY LARGE DIFFERENCES IN MLCAPE
/2500 J PER KG IN THE MOIST SCENARIO TO AOB 1500 J PER KG IN THE
DRIER SCENARIO/. REGARDLESS...BUOYANCY AND VERTICAL SHEAR WILL BE
FAVORABLE FOR A FOCUSED CLUSTER OF SUPERCELLS THIS AFTERNOON/EVENING
NEAR THE SURFACE LOW. THE MORE DISCRETE STORMS IN THE 21-01Z TIME
FRAME WILL BE CAPABLE OF PRODUCING A FEW TORNADOES AND LARGE HAIL AS
THE PRIMARY RISKS.
A COMMA-SHAPED ARC OF CONVECTION WILL SPREAD QUICKLY NEWD TONIGHT
TOWARD SRN LAKE MI AND VICINITY...WITH SOME TENDENCY FOR SWD
DEVELOPMENT ALONG THE SURGING COLD FRONT ACROSS IL/INDIANA.
ISOLATED LARGE HAIL AND DAMAGING GUSTS WILL BE THE MAIN THREAT
TONIGHT.
..THOMPSON/GLEASON.. 03/15/2016
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z
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