The SPC is forecasting ...severe thunderstorms expected over parts of the corn belt and mid-missouri river valley later today and tonight.... Please read the latest public statement about this event.
| Categorical Graphic |
|---|
|
| Probabilistic Tornado Graphic |
 |
 |
| Probabilistic Damaging Wind Graphic |
 |
 |
| Probabilistic Large Hail Graphic |
 |
 |
SPC AC 111256 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0756 AM CDT WED JUN 11 2008 VALID 111300Z - 121200Z ...THERE IS A MDT RISK OF SVR TSTMS WRN IA...SERN NEB...N-CNTRL KS...FAR SWRN MN... ...THERE IS A SLGT RISK OF SVR TSTMS UPPER MS RIVER VALLEY TO THE CNTRL PLAINS... ...SYNOPSIS... A VIGOROUS UPPER LEVEL LOW OVER THE NRN ROCKIES WILL TRANSLATE SLOWLY EWD INTO THE NRN HIGH PLAINS. EMBEDDED SHORT WAVE TROUGH /OVER THE ERN GREAT BASIN PER LATEST WATER VAPOR IMAGERY/ WILL EJECT E/NEWD INTO THE NRN/CNTRL PLAINS BY THIS EVENING. ASSOCIATED BELT OF INTENSE MID-LEVEL SWLYS FROM THE FOUR CORNERS TO THE NRN PLAINS WILL SHIFT TO THE CNTRL PLAINS THROUGH UPPER MS RIVER VALLEY. LOW-LEVEL JET WILL BE MAINTAINED ACROSS THE CNTRL CONUS THROUGH THE PERIOD...NOCTURNALLY INCREASING IN RESPONSE TO APPROACHING SHORT WAVE TROUGH. BY 12/00Z...SURFACE CYCLONE OVER N-CNTRL NEB/S-CNTRL SD SHOULD GRADUALLY DEVELOP NEWD REACHING MN/SD/ND BORDER AREA. WARM FRONT SHOULD LIFT NWD INTO CNTRL MN/SRN WI. COLD FRONT WILL BE ORIENTED MORE N/S ACROSS ERN SD INTO NERN NEB...THEN ARCING MORE SWWD TO A TRIPLE POINT LOW IN SWRN KS. ...UPPER MS RIVER VALLEY THROUGH THE CNTRL PLAINS... ONGOING ELEVATED CONVECTION EXTENDS FROM ERN SD INTO NERN KS ON LEADING EDGE OF STRONG LOW-LEVEL WARM/MOISTURE ADVECTION. ATTENDANT SEVERE WIND/HAIL THREATS SHOULD CONTINUE WITH THIS REGIME AS TSTMS LIKELY PROGRESS E/NEWD ACROSS THE UPPER MS RIVER VALLEY. SEE LATEST MCD/S AND WATCHES FOR ADDITIONAL SHORT-TERM DETAILS. IN THE WAKE OF THIS ACTIVITY...STOUT EML WITH VERY WARM LOW/MID-TROPOSPHERIC TEMPERATURES /FROM 12 TO 16 DEG C AT 700 MB PER 12Z LBF/DDC RAOBS/ WILL PROVIDE A SUBSTANTIAL CAPPING INVERSION...LIKELY HINDERING ADDITIONAL CONVECTIVE DEVELOPMENT WITHIN THE WARM SECTOR AND ALONG THE COLD FRONT THROUGH AT LEAST EARLY AFTERNOON. INCREASINGLY DIVERGENT UPPER-LEVEL FLOW...HEIGHT FALLS ATTENDANT TO EJECTING SHORT WAVE TROUGH ACROSS THE CNTRL ROCKIES AND CONVERGENCE ALONG THE COLD FRONT...SHOULD PROVIDE THE IMPETUS FOR RAPID TSTM DEVELOPMENT TOWARDS MID-AFTERNOON FROM SERN SD INTO N-CNTRL KS. WITH MORE ISOLATED DEVELOPMENT PROBABLE INTO SWRN KS AND POST-FRONTAL IN WRN/CNTRL NEB BY LATE AFTERNOON/EARLY EVENING. WITH THE WARM SECTOR CHARACTERIZED BY 60S SURFACE DEW POINTS AND PERHAPS INTO THE LOWER 70S ACROSS THE MID-MO RIVER VALLEY...THE AIR MASS WILL BECOME MODERATELY TO VERY UNSTABLE THROUGH INSOLATION AND GIVEN STEEP MID-LEVEL LAPSE RATES. STRONG LOW/MID-LEVEL FLOW WILL BE QUITE CONDUCIVE TO SUPERCELLS...WITH ATTENDANT THREATS FOR LARGE HAIL /SOME SIGNIFICANT/ AND TORNADOES. SLIGHTLY MORE BACKED AND STRONGER LOW-LEVEL FLOW OVER IA/ERN NEB...AND THE TENDENCY FOR MORE DISCRETE SUPERCELLS GIVEN THE ORIENTATION OF THE COLD FRONT SHOULD LEND TO THE GREATEST SIGNIFICANT TORNADO THREAT ALONG THE MID-MO RIVER VALLEY. FARTHER SWWD ACROSS MOST OF KS...MORE DEEPLY-MIXED THERMODYNAMIC PROFILES AND MORE PARALLEL ORIENTATION OF THE FRONTAL BOUNDARY TO AMBIENT STEERING FLOW SHOULD LEAD TO A QUICKER TRANSITION TO A LINEAR CONVECTIVE MODE. WITH TIME...UPSCALE GROWTH SHOULD RESULT IN ONE OR MORE QLCS/S WITH EMBEDDED BOWING STRUCTURES AND ATTENDANT DAMAGING WIND/ISOLATED TORNADO THREATS. ..GRAMS/THOMPSON.. 06/11/2008 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z