The SPC is forecasting ...severe thunderstorms expected over parts of the central and southern plains 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 261949 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0249 PM CDT MON MAY 26 2008 VALID 262000Z - 271200Z ...THERE IS A MDT RISK OF SVR TSTMS THIS AFTN/EVE ACROSS PARTS OF NE TX...NW OK AND SW/SC KANSAS.... ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTN AND TONIGHT...FROM PARTS OF THE SRN PLAINS EAST NORTHEASTWARD INTO THE LWR GREAT LAKES REGION.... ...THERE IS A SLGT RISK OF SVR TSTMS LATE THIS AFTN/EVE ACROSS PARTS OF THE CNTRL ROCKIES.... ...CNTRL ROCKIES INTO CNTRL/SRN PLAINS... A SIGNIFICANT IMPULSE EMBEDDED WITHIN THE LARGER SCALE EASTERN PACIFIC/WESTERN U.S. MID/UPPER TROUGH IS IN THE PROCESS OF LIFTING OUT OF THE SOUTHERN GREAT BASIN. MOTION IS MORE NORTH THAN EAST...WITH STRONGER MID-LEVEL COOLING AND SOUTHWESTERLY MID/UPPER FLOW FIELDS EXPECTED TO SPREAD ACROSS THE CENTRAL ROCKIES...AND NOT BE OF A SUBSTANTIAL INFLUENCE ON THE PLAINS. BUT...GUIDANCE IS SUGGESTIVE THAT LOWER/MID TROPOSPHERIC FORCING ON THE TAIL END OF THIS IMPULSE WILL IMPACT THE SOUTH CENTRAL HIGH PLAINS LATE THIS AFTERNOON. THIS IS EXPECTED TO CONTRIBUTE TO INCREASING/ INTENSIFYING CONVECTIVE DEVELOPMENT ALONG THE SHARPENING DRY LINE ACROSS THE EASTERN TEXAS PANHANDLE/WESTERN OKLAHOMA INTO THE VICINITY OF A SURFACE LOW OVER SOUTHWEST KANSAS...AND PERHAPS ALONG A REMNANT OUTFLOW BOUNDARY ACROSS NORTHEAST OKLAHOMA INTO SOUTH CENTRAL KANSAS. ADDITIONAL STORMS MAY INITIATE ALONG THE COLD FRONT NOSING SOUTHWARD ACROSS WESTERN KANSAS. A FEW SUPERCELLS APPEAR LIKELY IN THE PRESENCE OF MODERATE TO STRONG DEEP LAYER SHEAR BENEATH 30-50 KT FLOW ON THE SOUTHERN FRINGE OF THE STRONGER WESTERLIES. HOWEVER...BY THE EVENING HOURS...IF NOT A BIT BEFORE...INCREASINGLY FOCUSED LOW-LEVEL CONVERGENCE ON THE NOSE OF A STRENGTHENING SOUTHERLY LOW-LEVEL JET...AND NEAR CONVERGING BOUNDARIES...BENEATH AN INCREASINGLY DIFLUENT AND DIVERGENT UPPER FLOW...PROBABLY WILL SUPPORT THE CONSOLIDATION OF ACTIVITY INTO A LARGE MESOSCALE CONVECTIVE SYSTEM. WITH MIXED LAYER CAPE UP TO 3000 J/KG CONTRIBUTING TO INTENSE UPDRAFTS...VERY LARGE HAIL MAY ACCOMPANY THE STRONGEST STORMS. A COUPLE OF TORNADOES ARE ALSO POSSIBLE EARLY...BUT EVAPORATIVE COOLING IS EXPECTED TO EVENTUALLY CONTRIBUTE TO MORE OF A DAMAGING WIND THREAT WITH ISOLATED DOWNBURSTS AND SURFACE COLD POOL DEVELOPMENT. THE SEVERE THREAT MAY DIMINISH LATE THIS EVENING...BUT THE RISK FOR HEAVY RAIN MAY PERSIST OVERNIGHT...AS THE CONVECTIVE SYSTEM ONLY SLOW SPREADS EASTWARD ACROSS SOUTHERN KANSAS/NORTHERN OKLAHOMA...AND THE LOW-LEVEL JET MAINTAINS TRAINING NEW CONVECTIVE DEVELOPMENT ALONG ITS TRAILING OUTFLOW BOUNDARY. ...MIDDLE MISSISSIPPI VALLEY INTO CENTRAL APPALACHIANS... PRIMARY CONVECTIVE POTENTIAL NOW APPEARS TO EXIST ALONG A CONGLOMERATE OUTFLOW BOUNDARY ASSOCIATED WITH ONE RE-INTENSIFYING STORM CLUSTER NOW SPREADING TOWARD THE CENTRAL APPALACHIANS...AND ANOTHER WEAKENING STORM CLUSTER NEAR/WEST OF THE MISSOURI OZARKS. THE EFFECTIVE BOUNDARY GENERALLY EXTENDS ACROSS PARTS OF EASTERN OKLAHOMA/CENTRAL ARKANSAS INTO NORTHERN MISSISSIPPI...GENERALLY WITHIN WEAK DEEP LAYER SHEAR TO THE SOUTH OF THE STRONGER WESTERLIES. BUT...STEEPENING LOW-LEVEL LAPSE RATES AND MIXED LAYER CAPE IN EXCESS OF 2000 J/KG MAY CONTRIBUTE TO A FAVORABLE ENVIRONMENT FOR A FEW STRONG/SEVERE STORMS CAPABLE OF DAMAGING WINDS AND SOME HAIL. ...GREAT LAKES REGION... STRONGER PRE-FRONTAL DESTABILIZATION IS NOW OCCURRING ACROSS PARTS OF NORTHERN ILLINOIS INTO LOWER MICHIGAN. AND...THIS MAY BECOME SUFFICIENT TO SUPPORT VIGOROUS CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON/EARLY EVENING...AIDED BY FORCING ON THE TAIL END OF THE NORTHERN BRANCH TROUGH NOW BEGINNING TO DIG TO THE SOUTHEAST OF HUDSON BAY. MODERATE TO STRONG WESTERLY DEEP LAYER FLOW FIELDS AND SHEAR /30-50 KT/ WILL CONTRIBUTE TO DAMAGING WIND GUST/HAIL POTENTIAL IN STORMS...WHICH COULD SPREAD TO THE LEE OF THE LOWER GREAT LAKES LATE TONIGHT. ..KERR.. 05/26/2008 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z