| Categorical Graphic |
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| Probabilistic Tornado Graphic |
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| 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 |
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| 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 |
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| 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 260609 DAY 1 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 0109 AM CDT TUE APR 26 2011 VALID 261200Z - 271200Z ...THERE IS A MDT RISK OF SVR TSTMS FROM NERN TX/SERN OK ACROSS MUCH OF AR AND INTO WRN TN/NRN MS... ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN TX/ERN OK NEWD ACROSS MUCH OF THE TN/OH VALLEYS AND INTO PA AND NY... CORRECTED FOR WORDING ...SYNOPSIS... A STRONG UPPER JET WILL DIVE SEWD ACROSS THE SRN ROCKIES...NOSING INTO THE SRN PLAINS BY 00Z WED. AT THE SURFACE...LOW PRESSURE IS FORECAST TO DEEPEN OVER NWRN TX DURING THE DAYTIME...WITH A TRAILING DRYLINE MOVING EWD TO AROUND I-35 IN TX BY 00Z. E OF THE DRYLINE...A RELATIVELY WIDE WARM SECTOR WILL EXIST WITH DEWPOINTS MAINLY IN THE MID TO UPPER 60S F EWD TO THE MS RIVER. STRONG SHEAR PROFILES WILL EXIST ACROSS THE REGION AS THE UPPER TROUGH NEARS...WITH AMPLE INSTABILITY DUE TO DAYTIME HEATING AND MOISTURE ADVECTION. THE AFOREMENTIONED SURFACE LOW SHOULD MOVE EWD FROM NWRN TX AT 00Z INTO AR BY 12Z WED...AND THIS IS WHERE FORCING/LIFT WILL BE FOCUSED. THE PRIMARY ZONE FOR SIGNIFICANT SEVERE WEATHER INCLUDING STRONG TORNADOES WILL COMMENCE BY LATE AFTERNOON ACROSS NERN TX/SERN OK...AND WILL EXPAND EWD ACROSS MUCH OF SRN AR...EXTREME NRN LA...AND INTO NRN MS/WRN TN BY WED MORNING. A SEPARATE AREA OF SEVERE POTENTIAL WILL EXIST FROM THE MID MS VALLEY NEWD INTO THE OH VALLEY...AS A LEAD UPPER SHORTWAVE TROUGH EJECTS NEWD. ...A FEW STRONG TO VIOLENT TORNADOES WILL BE POSSIBLE FROM NERN TX/SERN OK EWD ACROSS AR LATE TODAY/TONIGHT... ...NERN TX/SERN OK EWD INTO AR...LA...MS...WRN TN... STRONG INSTABILITY WILL DEVELOP ACROSS THE WARM SECTOR WITH MUCAPE 2000-3000 J/KG E OF THE DRYLINE ACROSS TX/OK BENEATH STEEP MID LEVEL LAPSE RATES. SHEAR WILL INCREASE THROUGH THE DAY...AND WILL BE QUITE FAVORABLE FOR SIGNIFICANT SEVERE WEATHER. CAPPING WILL BE BREACHED BY LATE AFTERNOON/EARLY EVENING OVER NERN TX/SERN OK...WITH SUPERCELLS CAPABLE OF STRONG TORNADOES AND VERY LARGE HAIL. THESE STORMS SHOULD CONTINUE IN SOME FORM EWD WITH THE SURFACE LOW ACROSS MUCH OF AR...FAR NRN LA AND INTO NWRN MS AND WRN TN. INITIALLY...SUPERCELLS ARE THE PREFERRED STORM MODE...BUT WITH TIME...EXTREMELY STRONG BOWS CAPABLE OF DESTRUCTIVE STRAIGHT LINE WINDS MAY MATERIALIZE AS WELL..ESPECIALLY LATE NIGHT. HIGH RESOLUTION WRF MODELS DEPICT THIS SCENARIO. THERE ARE QUESTIONS ABOUT POTENTIAL STRONG/VIOLENT TORNADO COVERAGE SINCE LATE INITIATION WILL BE A POSSIBILITY...AND CAPPING WILL PLAY A ROLE WITH SWD EXTENT. WILL DEFER ANY POSSIBLE UPGRADE TO HIGH RISK TO LATER OUTLOOKS. ...AR/NRN MS/WRN TN EARLY/MIDDAY... WARM ADVECTION NWD INTO AR/MS/TN...ATOP RESIDUAL COOL OUTFLOW FROM EARLIER CONVECTION...MAY HELP INITIATE AREAS OF STORMS BY EARLY AFTERNOON. SHEAR PROFILES...ALTHOUGH NOT AS STRONG AS THEY WILL BE LATER...WILL STILL BE SUFFICIENT FOR SUPERCELLS...CAPABLE OF A FEW TORNADOES AND LARGE HAIL. ...TN/OH VALLEYS INTO LOWER GREAT LAKES... LEAD UPPER SHORTWAVE AND WARM MOIST AIR STREAMING NWD WILL HELP FUELS STORMS IN THIS REGION WITH HAIL AND WIND LIKELY. SHEAR APPEARS SUFFICIENT FOR A FEW SUPERCELLS...AND ISOLATED TORNADOES MAY OCCUR AS WELL. ..JEWELL.. 04/26/2011 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z