| Sep 1, 2012 1300 UTC Day 1 Convective Outlook | |
| Updated: Sat Sep 1 12:39:27 UTC 2012 | |
| Probabilistic to Categorical Outlook Conversion Table | |
| 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 011235 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0735 AM CDT SAT SEP 01 2012 VALID 011300Z - 021200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF AR NEWD INTO SRN IL... ...SYNOPSIS... REMNANT ISAAC CIRCULATION WILL GRADUALLY COME UNDER THE INFLUENCE OF THE LARGER SCALE WLYS THIS PERIOD AS THE LOW CENTER CEASES ITS WWD/NWWD MOTION AND BEGINS TO MOVE EAST ACROSS MO AND INTO WRN IL THROUGH EARLY SUNDAY. WHILE UPPER RIDGING DOMINATES THE CNTRL AND SRN U.S...MODEST MID LEVEL FLOW AND TRANSIENT SHORTWAVE DISTURBANCES WILL CROSS PARTS OF THE GREAT BASIN/NRN ROCKIES AND NRN PLAINS...AS WELL AS PORTIONS OF THE NORTHEAST/MID-ATLANTIC. ...AR TO SRN IL... MODELS ARE FORECASTING AN AXIS OF STRONGER DESTABILIZATION WITHIN THE SRN/SERN FLANK OF REMNANT ISAAC CIRCULATION LATER TODAY. DRY SLOT WRAPPING INTO THE CIRCULATION FROM OK/KS INTO AR/MO PER MORNING SATELLITE IMAGERY APPEARS TO COINCIDE WITH THE CORRIDOR OF GREATER POTENTIAL DESTABILIZATION LATER TODAY FROM AR NEWD INTO SRN IL. GIVEN PLUME OF RICH TROPICAL MOISTURE AND TEMPERATURES CLIMBING INTO THE 90S IN THOSE AREAS WITH GREATER SFC HEATING...MLCAPE OF 1500-2000 J/KG AND WEAK INHIBITION SHOULD RESULT. PERSISTENT ASCENT AROUND THE LOW CIRCULATION WILL AID/SUSTAIN TSTMS MOVING INTO THE INSTABILITY AXIS WHERE THE COMBINATION OF LOW LEVEL CAPE AND HODOGRAPH CURVATURE WILL CONTRIBUTE TO STRONGER UPDRAFT ROTATION AND THE CHANCE FOR A COUPLE OF TORNADOES AND/OR DAMAGING DOWNBURST WIND EVENTS. ...NRN GREAT BASIN... A SERIES OF RELATIVELY FAST-MOVING SHORTWAVE TROUGHS WILL SPREAD NEWD FROM THE GREAT BASIN TO THE NRN PLAINS THROUGH TONIGHT. ONE OF THESE FEATURES WAS TRACKING ACROSS NRN UT THIS MORNING ACCOMPANIED BY RELATIVELY WIDESPREAD CONVECTION. WHILE SOME CONVECTIVE CLOUD COVER AND GENERALLY DRY BOUNDARY LAYER AWAY FROM THE CONVECTION WILL LIMIT DESTABILIZATION...SOME LOCATIONS WILL EXPERIENCE INSOLATION SUFFICIENT TO BOOST MLCAPE INTO THE 500-1000 J/KG RANGE. DYNAMIC LIFT...TERRAIN INFLUENCES...AND RELATIVELY FAST MID LEVEL SWLY FLOW ON THE ORDER OF 40KT...SHOULD SUPPORT CLUSTERS OF MORE ORGANIZED/PERSISTENT STORMS POSING BOTH HAIL AND WIND HAZARDS THROUGH THE AFTERNOON. THE FOCUS FOR MORE SUBSTANTIAL SEVERE STORM COVERAGE CURRENTLY REMAINS MASKED BY EARLY DAY STORMS AND ILL-DEFINED SFC FEATURES. HOWEVER...SOME OF THIS REGION MAY REQUIRE GREATER SEVERE WEATHER PROBABILITIES IN LATER OUTLOOKS IF STORM CHARACTER AND EVOLUTION BECOME CLEARER. ...MID ATLANTIC... BACKDOOR FRONT WILL LIKELY REMAIN NORTH OF THE PA/MD BORDER WITH AREAS OF STRONGER DIURNAL DESTABILIZATION DEVELOPING ALONG/SOUTH OF THE FRONT FROM SRN PA ACROSS THE DELMARVA REGION AND INTO THE CAROLINAS. WHILE MID LEVEL FLOW ACROSS THE REGION IS FORECAST TO REMAIN MEAGER...WEAK HEIGHT FALLS TRAILING THE SHORT WAVE TROUGH MOVING OFF THE NEW ENGLAND COAST MAY PROMOTE TSTMS ACROSS THE WARM SECTOR ALONG AND EAST OF THE APPALACHIAN HIGHLANDS. A COUPLE OF STORMS MAY PRODUCE GUSTY WINDS CAPABLE OF TOPPLING TREES. ..CARBIN/ROGERS.. 09/01/2012 CLICK TO GET WUUS01 PTSDY1 PRODUCT NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z