| 
)| Categorical Graphic | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
|||||||||
| Probabilistic Tornado 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. |
|||||||||
| Probabilistic Damaging Wind 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. |
|||||||||
| Probabilistic Large Hail 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. |
|||||||||
| |||||||||
SPC AC 271627 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1127 AM CDT FRI SEP 27 2013 VALID 271630Z - 281200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL NEB TO THE TX PANHANDLE... ...CENTRAL NEB TO TX PANHANDLE THIS AFTERNOON INTO EARLY TONIGHT... A MIDLEVEL SHORTWAVE TROUGH OVER THE GREAT BASIN WILL EJECT ENEWD OVER THE CENTRAL ROCKIES TODAY...REACHING THE CENTRAL/NRN PLAINS BY EARLY SATURDAY. LEE CYCLOGENESIS IS EXPECTED ACROSS THE CENTRAL HIGH PLAINS TODAY IN ADVANCE OF THE MIDLEVEL TROUGH...AND ONLY SLOWLY EWD/SEWD MOTION OF A COLD FRONT IS EXPECTED THROUGH THIS EVENING ACROSS NEB/WRN KS/TX AND OK PANHANDLES/ERN NM. MEANWHILE...A MARITIME TROPICAL AIR MASS IS SPREADING NWD INTO CENTRAL/NW TX AS OF MID MORNING...WITH LOW 60S DEWPOINTS EXPECTED TO REACH WRN KS/S CENTRAL NEB BY MID-LATE THIS AFTERNOON. THE MOISTENING WILL OCCUR BENEATH THE REMNANTS OF A RELATIVELY SHALLOW EML PLUME /STEEPEST LAPSE RATES CONFINED TO 800-600 MB LAYER/...AND COMBINED WITH DAYTIME HEATING...WILL RESULT IN A NARROW CORRIDOR OF 500-1250 J/KG MLCAPE. THUNDERSTORM DEVELOPMENT IS EXPECTED BY MID AFTERNOON ALONG THE LEE TROUGH/PACIFIC COLD FRONT...IN CONJUNCTION WITH THE BAND OF ASCENT DENOTED BY THE WEAK MIDLEVEL CONVECTION NOW EXTENDING FROM THE TX/NM BORDER TO WRN KS. THE INITIAL STORMS WILL FORM A LITTLE W/NW OF THE RICHER BOUNDARY LAYER MOISTURE...WHERE VERTICAL MIXING WILL BE GREATER AND TEMP-DEWPOINT SPREADS WILL LIKELY EXCEED 25 F. VERTICAL SHEAR PROFILES WILL BE MORE FAVORABLE FOR SUPERCELLS WITH NWD EXTENT FROM THE TX PANHANDLE INTO WRN KS...THOUGH LARGELY BOUNDARY-PARALLEL DEEP-LAYER SHEAR VECTORS AND LINEAR FORCING FOR ASCENT SUGGEST A FAIRLY QUICK TRANSITION TO A LINEAR CONVECTIVE MODE BY THIS EVENING. THUS...DAMAGING GUSTS AND MARGINALLY SEVERE HAIL APPEAR TO BE THE MAIN SEVERE WEATHER THREATS. THE TORNADO THREAT IS MORE UNCERTAIN GIVEN THE EXPECTED LARGER TEMP-DEWPOINT SPREADS WITH THE INITIAL STORMS...AS WELL AS THE TENDENCY FOR MORE LINEAR CONVECTION AND GRADUAL STABILIZATION OF THE BOUNDARY LAYER PRIOR TO AN INCREASE IN LOW-LEVEL SHEAR BY EARLY TONIGHT. ..THOMPSON/COHEN.. 09/27/2013 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z |