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| Probability of severe weather within 25 miles of a point. Hatched Area: 10% or greater probability of significant severe within 25 miles of a point. |
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SPC AC 100543 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1243 AM CDT SAT MAY 10 2014 VALID 111200Z - 121200Z ...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY TO THE SRN PLAINS... ...SUMMARY... AT LEAST SCATTERED SEVERE STORMS APPEAR PROBABLE BEGINNING SUNDAY AFTERNOON FROM IOWA TO WESTERN OKLAHOMA. SEVERE TO VERY LARGE HAIL...DAMAGING WINDS...AND TORNADOES WILL BE POSSIBLE. ...SYNOPSIS... A VIGOROUS SHORTWAVE IMPULSE EMBEDDED WITHIN AN AMPLIFIED UPPER-LEVEL TROUGH WILL TRACK FROM THE SRN GREAT BASIN TO THE SRN ROCKIES. ATTENDANT MID-LEVEL SPEED MAX WILL BECOME CENTERED FROM THE SRN HIGH PLAINS TO THE CNTRL PLAINS EARLY MON. AT THE SURFACE...A CYCLONE WILL DIURNALLY DEEPEN IN THE LEE OF THE SRN ROCKIES WITH A DRYLINE MIXING TOWARDS THE ERN TX PANHANDLE/WRN OK BORDER S/SWWD ACROSS THE PERMIAN BASIN. GUIDANCE CONTINUES TO DIFFER ON THE ACCELERATION OF A S/SEWD-PROGRESSING COLD FRONT OVER THE CNTRL/SRN PLAINS. MODEST CYCLOGENESIS SHOULD OCCUR ALONG A PORTION OF THIS FRONT FROM THE CNTRL PLAINS TO UPPER MIDWEST ON SUN NIGHT. ....UPPER MS VALLEY TO CNTRL PLAINS... CONSIDERED A MODERATE RISK FOR PORTIONS OF KS TO IA WHERE SCATTERED TO NUMEROUS STORMS ARE EXPECTED WITHIN A STRONG COMBINATION OF INSTABILITY/SHEAR. BUT UNCERTAINTIES WITH REGARD TO FRONTAL PLACEMENT...DEEP-LAYER FLOW GENERALLY PARALLELING THE FRONT AND EFFECTS OF EARLY-DAY CONVECTION PRECLUDE AN UPGRADE THIS OUTLOOK. STRENGTHENING SWLYS AT 700 MB WILL RESULT IN AN EXPANDING EML PLUME AND ATTENDANT CAPPING INVERSION EARLY SUN...WITH INCREASINGLY RICH BOUNDARY LAYER MOISTURE AMIDST POLEWARD ADVECTION FROM THE WRN GULF. MIDDLE TO UPPER 60S SURFACE DEW POINTS SHOULD BECOME ESTABLISHED FROM AT LEAST THE LOWER MO VALLEY SWD...YIELDING A BROAD STRONGLY UNSTABLE AIR MASS WITH MLCAPE REACHING 2500-3500 J/KG IN THE AFTERNOON AHEAD OF THE COLD FRONT AND DRYLINE. LOW-LEVEL WAA ON THE LEADING EDGE OF THE RICHER MOISTURE RETURN/CAPPING INVERSION SHOULD AID IN REGENERATIVE CLUSTERS OF ELEVATED STORMS SUN MORNING INTO AFTERNOON FROM PARTS OF THE LOWER MO TO UPPER MS VALLEY. HOW EXACTLY THIS CONVECTION WILL PLAY OUT IS UNCLEAR...BUT THERE IS POTENTIAL FOR AN EFFECTIVE WARM FRONT/OUTFLOW BOUNDARY TO BECOME ESTABLISHED FROM PARTS OF IA TO IL. SHOULD THIS OCCUR...HODOGRAPHS DURING LATE AFTERNOON AND EVENING ALONG THIS W/E-ORIENTED BOUNDARY WOULD BECOME QUITE FAVORABLE FOR SUPERCELLS AS THE LLJ STRENGTHENS. THIS SUGGESTS A RISK FOR STRONG TORNADOES MAY DEVELOP IN IA. THE ECMWF/UKMET REMAIN CONSISTENTLY SLOWER WITH COLD FRONT PROGRESSION COMPARED TO THE NAM/GFS IN NEB/KS. EVEN SO...STRONG CONVERGENCE ALONG THIS FRONT WILL YIELD INCREASINGLY NUMEROUS STORMS LATE AFTERNOON INTO EVENING. LARGE HAIL /SOME SIGNIFICANT/ AND A FEW TORNADOES WILL BE POSSIBLE INITIALLY. THE POTENTIAL FOR UNDERCUTTING BY THE FRONT APPEARS MORE LIKELY IN KS WITH WEAK CYCLOGENESIS EXPECTED TO OCCUR TOWARDS THE MO VALLEY. WITH MID-LEVEL WINDS GENERALLY PARALLELING THE FRONT...CLUSTER/LINEAR MODES SHOULD BECOME DOMINANT AS CONVECTION SHOULD TEND TO ZIPPER S/SWWD ALONG THE FRONT. SEVERE HAIL/WIND HAZARDS SHOULD PERSIST INTO SUN NIGHT. ...SRN PLAINS... INTENSE SURFACE HEATING ALONG WITH STRENGTHENING CONVERGENCE NEAR THE LEE CYCLONE/DRYLINE INTERSECTION SHOULD YIELD ISOLATED STORMS DEVELOPING LATE AFTERNOON. ALTHOUGH HODOGRAPHS SHOULD NOT BE OVERLY LARGE INITIALLY...CROSS-BOUNDARY DEEP-LAYER FLOW WILL BE FAVORABLE FOR DISCRETE SUPERCELLS GIVEN STRONG INSTABILITY. VERY LARGE HAIL WILL LIKELY BE THE PRIMARY INITIAL HAZARD WITH CONVECTION PROBABLY FORMING AMIDST MODERATELY LARGE SURFACE TEMPERATURE/DEW POINT SPREADS. SPREADS WILL LOWER DURING THE EARLY EVENING AS A SLY LLJ STRENGTHENS...LIKELY MAXIMIZING POTENTIAL FOR A COUPLE TORNADOES DURING THIS TIME FRAME INVOF WRN OK. GREATER CONVECTIVE COVERAGE SHOULD OCCUR SUN NIGHT AS THE FRONT IMPINGES ON THE STILL STRONGLY BUOYANT AIR MASS...WITH ATTENDANT SEVERE HAIL/WIND HAZARDS. ..GRAMS.. 05/10/2014 CLICK TO GET WUUS02 PTSDY2 PRODUCT NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z |