The SPC is forecasting ...severe thunderstorms expected over parts of the south-central plains this afternoon 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 141928 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0228 PM CDT THU APR 14 2011 VALID 142000Z - 151200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM SERN KS/SWRN MO SWD THRU ERN OK FAR WRN AR INTO PORTIONS OF NERN TX... ...THERE IS A SLGT RISK OF SVR TSTMS FROM PORTIONS OF THE CENTRAL AND SRN PLAINS INTO PARTS OF THE LOWER MS VALLEY... LITTLE CHANGE TO PREVIOUS OUTLOOK. LATEST VISIBLE IMAGERY SHOWS TCU DEVELOPING ALONG THE DRYLINE FROM S CNTRL KS SWD ALONG I-35 INTO N TX WHERE STRONG HEATING HAS ERODED CAP. MODIFIED 18Z OUN SOUNDING EXHIBITS STRONG INSTABILITY WITH SHEAR FAVORABLE FOR SUPERCELLS. EXTREMELY LARGE HAIL MAY OCCUR AS WELL AS AN INCREASING TORNADO THREAT TOWARDS EVENING AS SUPERCELLS MATURE AND MOVE INTO A MORE FAVORABLE LCL ENVIRONMENT. FOR MORE INFORMATION SEE MESOSCALE DISCUSSION 425. TO THE N...SEVERE STORMS WERE ERUPTING ALONG THE WARM FRONT FROM NRN KS INTO SRN NEB WITH MAINLY A HAIL THREAT CURRENTLY. HOWEVER...POCKETS OF HEATING AND FURTHER DESTABILIZATION MAY ALLOW FOR AN INCREASE IN EFFECTIVE LOW LEVEL SHEAR...WITH AN INCREASED THREAT OF ROTATION. EXPANDED TORNADO PROBS A BIT N TO THE NEB BORDER WHERE WARMING IS OCCURRING. FOR MORE INFORMATION SEE MESOSCALE DISCUSSION 424. ..JEWELL.. 04/14/2011 .PREV DISCUSSION... /ISSUED 1111 AM CDT THU APR 14 2011/ ...CENTRAL AND SRN PLAINS... ...SEVERE THUNDERSTORM AND TORNADO OUTBREAK EXPECTED LATER THIS AFTERNOON AND TONIGHT... DEVELOPING UPPER LOW OVER CO/NM WILL DEEPEN ENEWD INTO CENTRAL KS BY TONIGHT AS POWERFUL UPSTREAM JET AND COLD ADVECTION ROTATE SEWD ACROSS SRN ROCKIES AND OUT INTO THE SRN PLAINS. SURFACE LOW NWRN OK DEEPENS NNEWD INTO KS THIS AFTERNOON WHILE A SECONDARY LOW TAKES SHAPE BY THIS EVENING SRN OK/TX BORDER IN RESPONSE TO APPROACH OF THE UPSTREAM JET AND LARGE SCALE ASCENT. PARAMETERS FAVORABLE FOR THE INITIATION OF THE FORECAST OUTBREAK OF SEVERE THUNDERSTORMS WILL FOCUS ON THE DRY LINE BY MID/LATE AFTERNOON. FROM THE SURFACE LOW IN KS THE DRY LINE SHOULD MIX OUT TO A POSITION FROM NEAR RSL SSEWD TO ABOUT ICT AND THEN VICINITY I-35 INTO NRN TX. THE ONLY QUESTION WILL BE THE MOISTURE RETURN BUT GIVEN THE VERY STEEP LAPSE RATES AND STRONG HEATING...STRONG INSTABILITY WILL DEVELOP WITH MLCAPES AOA 2500 J/KG NWD AHEAD OF DRY LINE INTO CENTRAL/SERN KS. DISCRETE THUNDERSTORM DEVELOPMENT WILL TAKE PLACE BY MID/LATE AFTERNOON BENEATH STRONGLY DIFFLUENT UPPER JET SPREADING ACROSS THE DRYLINE. THE STRONG INSTABILITY COMBINED WITH STRONG DEEP LAYER VERTICAL WIND SHEAR /NEAR 70 KT IN THE 0-8 KM LAYER/ WILL FAVOR A FEW LONGER-LIVED SUPERCELLS. VERY LARGE HAIL WILL DEVELOP RATHER QUICKLY ONCE INITIATION OCCURS. LOW-LEVEL HODOGRAPH STRUCTURE ALSO FORECAST TO ENLARGE BY LATER THIS AFTERNOON AND EVENING AS LOW LEVEL JET BACKS AND INCREASES...WITH EFFECTIVE SRH VALUES INCREASING TO 200-400 M2 S-2. THIS SUPPORTS THE DEVELOPMENT OF TORNADIC SUPERCELLS...WITH POTENTIAL FOR STRONG TORNADOS. WITH THE SECONDARY LOW DEVELOPMENT NEAR THE RED RIVER THIS EVENING...HIGH RES MODELS SUPPORT A GREATER POTENTIAL FOR LONG LIVED TORNADIC SUPERCELLS THIS EVENING ACROSS SERN OK. DEEPER MOISTURE AND THE DIFFLUENCE OF THE APPROACHING 120KT UPPER JET MAX WILL BE FOCUSING ON THIS AREA BY THIS EVENING AND IT WILL BE MONITORED FOR A POSSIBLE UPGRADE IN THE AFTERNOON UPDATE IF THIS SCENARIO SEEMS LIKELY TO PLAY OUT. SURFACE COLD FRONT CURRENTLY NWRN OK SWWD INTO TX PANHANDLE IS FORECAST TO RAPIDLY MOVE ACROSS ERN OK INTO WRN AR AFTER 00Z. STRENGTHENING LOW-LEVEL LINEAR FORCING FOR ASCENT IS EXPECTED TO AID IN UPSCALE GROWTH TO A QLCS STRUCTURE. THIS ACTIVITY WILL LIKELY MOVE ACROSS AR AND SRN MO OVERNIGHT...POSING A THREAT FOR DAMAGING WINDS. THERE WILL CONTINUE TO BE TORNADO POTENTIAL WITH EMBEDDED SUPERCELL STRUCTURES. CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z