Jun 18, 2010 1630 UTC Day 1 Convective Outlook
Updated: Fri Jun 18 16:30:46 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the upper ms valley and upper great lakes this afternoon and evening....   Please read the latest public statement about this event.

Categorical Graphic
20100618 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100618 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100618 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100618 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 181625
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1125 AM CDT FRI JUN 18 2010
   
   VALID 181630Z - 191200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS PORTIONS OF SRN AND ERN IA...NRN
   MO...NRN AND WRN IL AND SRN AND ERN WI...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA
   FROM THE LWR MO AND MID MS VLYS INTO THE UPR GRT LKS...
   
   ...SYNOPSIS...
   RATHER DEEP VERTICALLY STACKED LOW OVER SRN MANITOBA WILL SHIFT EWD
   AND FILL WHILE THE STRONG MID/UPR WIND MAX NOW NRN PLAINS ROTATES
   EWD ACROSS NRN  MS VALLEY/UPR GREAT LAKES BY THIS EVENING.  THE
   ASSOCIATED COLD FRONT FROM THE MN ARROWHEAD SWWD TO CENTRAL NEB IS
   PRECEDED BY SEVERE MCS NOW OVER WRN IA.
   
   SINCE THE IA MCS WAS NOT ANTICIPATED BY ANY MODELS...WILL NEED TO
   MOVE UP THE TIMING OF THE PRIMARY SEVERE THUNDERSTORM THREAT ACROSS
   PORTIONS OF THE EARLIER OUTLOOK.
   
   ...UPPER GREAT LAKES TO MID MS VALLEY...
   WITH 850MB WINDS BACKING AND INCREASING AHEAD OF THE IA MCS AND THE
   COLD FRONT...A RAPIDLY MOISTENING AND DESTABILIZING AIR MASS WILL
   SPREAD NEWD ACROSS WI/NRN IL THIS AFTERNOON.
   
   EXPECT THE SEVERE MCS TO CONTINUE EWD ACROSS ERN IA/NRN IL THIS
   AFTERNOON WITH A CONTINUED THREAT OF DAMAGING WINDS AS WARM SECTOR
   BECOMES VERY MOIST AND UNSTABLE WITH MLCAPES AOA 3000 J/KG.
   
   MUCH OF WI WILL ALSO BECOME VERY UNSTABLE WITH THE STRONG HEATING
   AND THETAE E ADVECTION.  WITH THE APPROACHING MID/UPR WIND
   MAX...SHEAR PROFILES BECOME VERY FAVORABLE FOR SUPERCELLS ACROSS
   PARTICULARLY THE ERN HALF OF WI WHERE THE MLCAPES WILL RANGE UPWARDS
   FROM 2000 J/KG IN THE N TO NEAR 3000 J/KG SERN WI.
   
   SEVERE THUNDERSTORMS WILL DEVELOP IN ADVANCE OF BOTH THE COLD FRONT
   AND THE LEADING EDGE OF THE MCS WITH NOT ONLY DAMAGING WINDS BUT THE
   POTENTIAL FOR TORNADIC SUPERCELLS AS WELL...GIVEN THE 40-50KT OF
   SHEAR...PARTICULARLY ERN WI INTO WRN UPR MI.
   
   ADDITIONAL MCS DEVELOPMENT BY THIS EVENING IN THE WAKE OF THE
   CURRENT IA MCS IS LIKELY BUT THE TRACK AND INTENSITY IS HIGHLY
   DEPENDENT ON WHERE BOUNDARIES  WILL BE FROM CURRENT ACTIVITY.
   
   ...LWR MO VLY TO MID MS VLY THROUGH LATE TONIGHT...
   OUTFLOW BOUNDARY FROM IA MCS AND/OR EXISTING COLD FRONTAL 
   CONVERGENCE SHOULD SERVE AS FOCI FOR ADDITIONAL...INTENSE STORM
   DEVELOPMENT THIS AFTN AS SBCAPE INCREASES TO AROUND 4000 J/KG OVER
   PARTS OF  WRN IA/NRN MO/NE KS.  ALTHOUGH DEEP SHEAR WILL BE MODEST
   RELATIVE TO THAT FARTHER N...GIVEN DEGREE OF INSTABILITY ON EDGE OF
   EML AND RICH MOISTURE AVAILABILITY /SFC DEWPOINTS AROUND 70 F/ WILL
   BE AMPLE FOR SUSTAINED STORMS AND A FEW SUPERCELLS BEFORE ACTIVITY
   CONGEALS INTO ONE OR MORE LARGE CLUSTERS. SOME VERY LARGE HAIL COULD
   OCCUR OVER WRN PORTIONS OF THIS REGION DURING THE EARLY STAGES OF
   STORM DEVELOPMENT.
   
   ...SRN NEB/NRN KS LATE IN PERIOD...
   INCREASING WAA/MOISTURE INFLOW ATOP SHALLOW FRONTAL ZONE MAY SUPPORT
   DEVELOPMENT OF SCTD ELEVATED STORMS WITH HAIL LATE TONIGHT/EARLY SAT
   ALONG NERN FRINGE OF EML IN NRN KS/SRN NEB.
   
   ..HALES/STOPPKOTTE.. 06/18/2010
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z