058 ACUS01 KWNS 150048 SWODY1 SPC AC 150046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 PM CDT THU MAR 14 2013 VALID 150100Z - 151200Z ...NO TSTM AREAS FORECAST... ...DISCUSSION... A LARGE AREA OF CP HIGH PRESSURE EXISTS OVER THE SERN STATES WITH STABLE CONDITIONS AND MINIMAL CHANCE FOR THUNDERSTORMS OVER THE U.S. THE REST OF TONIGHT. SOME OF THE PRECIPITATION DROPPING SEWD THROUGH THE TN VALLEY IN ASSOCIATION WITH A PROGRESSIVE VORT MAX APPEARS CONVECTIVE IN NATURE. THE 00Z RAOB FROM NASHVILLE SHOWS A SHALLOW LAYER OF VERY WEAK CAPE BETWEEN 750 AND 600 MB...BUT THIS CONVECTIVE LAYER IS NOT EXPECTED TO BECOME SUFFICIENT FOR LIGHTNING PRODUCTION. ..DIAL.. 03/15/2013  766 ACUS01 KWNS 150436 SWODY1 SPC AC 150434 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1134 PM CDT THU MAR 14 2013 VALID 151200Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... MODEL CONSENSUS IS THAT UPPER PATTERN WILL UNDERGO DEAMPLIFICATION DURING THE DAY FRIDAY...BECOMING QUASI-ZONAL WITH TIME. SHORTWAVE TROUGH NOW ENTERING THE PACIFIC NW WILL TURN SEWD AFTER CRESTING UPPER RIDGE AND CONTINUE ESEWD THROUGH THE UPPER MS VALLEY AND GREAT LAKES REGION. AT THE SFC A COLD FRONT WILL SETTLE SWD THROUGH THE NRN/CNTRL PLAINS AND GREAT LAKES...WHILE A WARM FRONT SHIFTS EWD THROUGH THE OH VALLEY. ...OH VALLEY... FLOW OVER THE WRN GULF HAS RETURNED TO SLY. AS THE LARGE AREA OF HIGH PRESSURE OVER THE NRN GULF SHIFTS EWD...AXIS OF MODIFIED CP AIR WITH UPPER 40S TO NEAR 50 LOW-LEVEL DEWPOINTS WILL ADVECT THROUGH THE LOW-MID MS VALLEYS. THIS MOISTURE WILL REACH THE OH VALLEY BY FRIDAY NIGHT SUPPORTED BY A STRENGTHENING WSWLY LLJ. A PLUME OF STEEPER MID-LEVEL LAPSE RATES IS EXPECTED TO ADVECT EWD ABOVE THE AXIS OF MODEST LOW-LEVEL MOISTURE...CONTRIBUTING TO A CORRIDOR OF MARGINAL ELEVATED INSTABILITY OVER A PORTION OF THE MID MS THROUGH OH VALLEY FRIDAY NIGHT. INCREASING THETA-E ADVECTION AND ISENTROPIC ASCENT WILL SUPPORT THE DEVELOPMENT OF A FEW THUNDERSTORMS OVERNIGHT AS THE ATMOSPHERE DESTABILIZES. STEEPENING MID-LEVEL LAPSE RATES...COLD TEMPERATURES ALOFT AND UP TO 40 KT UNIDIRECTIONAL SHEAR THROUGH THE CONVECTIVE LAYER MIGHT SUPPORT SOME THREAT FOR MARGINALLY SEVERE HAIL. MODEST INSTABILITY RESULTING FROM LIMITED MOISTURE RETURN SHOULD SERVE AS AN OVERALL LIMITING FACTOR. ..DIAL/MOSIER.. 03/15/2013  931 ACUS02 KWNS 150557 SWODY2 SPC AC 150555 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1255 AM CDT FRI MAR 15 2013 VALID 161200Z - 171200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SRN VA AND NRN NC... ...CNTRL APPALACHIAN MTNS/NRN NC/SRN VA... A WEST TO WEST-NORTHWEST FLOW PATTERN WILL BE IN PLACE ACROSS THE CONUS ON SATURDAY WITH SEVERAL IMPULSES EMBEDDED IN THE FLOW. A MINOR SHORTWAVE TROUGH IS FORECAST TO MOVE ESEWD FROM THE MID MS VALLEY INTO THE CNTRL APPALACHIANS ON SATURDAY WITH ANOTHER SHORTWAVE TROUGH MOVING ACROSS VA. THUNDERSTORMS COULD BE ONGOING AHEAD OF THE LEADING SHORTWAVE TROUGH ACROSS THE CNTRL APPALACHIANS SATURDAY MORNING. THIS ACTIVITY SHOULD BE LOCATED NEAR A SFC LOW MOVING EWD ALONG A QUASI-STATIONARY FRONTAL BOUNDARY. THE MORNING CONVECTION COULD HAVE A HAIL THREAT DUE TO STEEP MID-LEVEL LAPSE RATES. HOWEVER...FORECAST SOUNDINGS BEFORE NOON SHOW A SFC INVERSION SUGGESTING THE CONVECTION WILL BE ELEVATED HELPING TO LIMIT THE WIND DAMAGE POTENTIAL. THE TRAILING SHORTWAVE TROUGH IS FORECAST TO MOVE EWD ACROSS THE OHIO VALLEY INTO THE CNTRL APPALACHIAN MTNS SATURDAY AFTERNOON. SFC HEATING ALONG THE FRONTAL BOUNDARY ALONG WITH INCREASING LARGE-SCALE ASCENT SHOULD ALLOW A CLUSTER OF SFC-BASED THUNDERSTORMS TO INITIATE AND INCREASE IN COVERAGE FROM ERN KY/ERN TN EWD ACROSS SRN VA AND NRN NC. FORECAST SOUNDINGS AT 21Z AT JACKSON KY AND RICHMOND VA SHOW ABOUT 1000 J/KG OF SBCAPE WITH 60 TO 65 KT OF DEEP LAYER SHEAR. THIS ENVIRONMENT SHOULD BE SUPPORTIVE OF AT LEAST AN ISOLATED SEVERE THREAT. IF STORMS CAN EXHIBIT ROTATION...THEN A THREAT FOR ISOLATED LARGE HAIL MAY DEVELOP. AS LOW-LEVEL LAPSE RATES STEEPEN...A WIND DAMAGE THREAT MAY ALSO DEVELOP ACROSS THE REGION. THE MAIN CONCERN IS INSTABILITY. SFC DEWPOINTS ARE FORECAST TO ONLY BE AROUND 50 F ALONG THE FRONTAL BOUNDARY. IN SPITE OF THIS FACTOR...A STRONG WIND FIELD WILL BE PRESENT AND LOW-LEVEL LAPSE RATES WILL BE STEEP DURING THE AFTERNOON. FOR THESE REASONS...WILL ADD A SMALL SLIGHT RISK AREA ACROSS SRN VA AND NRN NC. ..BROYLES.. 03/15/2013  047 ACUS03 KWNS 150722 SWODY3 SPC AC 150720 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0220 AM CDT FRI MAR 15 2013 VALID 171200Z - 181200Z ...NO SVR TSTM AREAS FORECAST... AN UPPER-LEVEL TROUGH IS FORECAST TO DIG ESEWD ACROSS THE NRN AND CNTRL ROCKIES ON SUNDAY. AHEAD OF THE SYSTEM...A LOW IS FORECAST TO QUICKLY DEEPEN ACROSS THE NRN HIGH PLAINS WITH A WELL-DEFINED LEE TROUGH EXTENDING SWD ACROSS ERN WY...ERN CO INTO NE NM. SFC TEMPS SHOULD WARM INTO THE UPPER 40S IN SE WY TO THE UPPER 60S IN SERN CO ALLOWING FOR INSTABILITY TO DEVELOP TO THE EAST OF THE FRONT RANGE OF ERN CO. AS LARGE-SCALE ASCENT MOVES INTO THE CNTRL HIGH PLAINS SUNDAY AFTERNOON...THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE ALONG THE SFC TROUGH WITH CONVECTION POSSIBLY MOVING EWD INTO THE WRN NEB...WRN KS AND INTO THE NRN TX PANHANDLE DURING THE EVENING. THIS ACTIVITY IS NOT EXPECTED TO REACH SEVERE LIMITS DUE TO THE WEAK MOISTURE AND INSTABILITY. FURTHER TO THE EAST FROM THE OZARKS NEWD INTO THE OH VALLEY...THUNDERSTORMS WILL ALSO BE POSSIBLE SUNDAY EVENING INTO THE OVERNIGHT PERIOD AS A LEAD SHORTWAVE TROUGH MOVES EWD ACROSS THE MID MS VALLEY. THE THUNDERSTORM ACTIVITY SHOULD BE CONCENTRATED ON THE WRN EDGE OF A 40 TO 55 KT LOW-LEVEL JET AND ALONG THE NRN EDGE OF THE MOIST SECTOR WHERE SFC DEWPOINTS ARE FORECAST TO BE IN THE 50S F. THIS ACTIVITY MAY BE ELEVATED IN NATURE AND IS ALSO NOT EXPECTED TO POSE A SEVERE THREAT. ..BROYLES.. 03/15/2013  177 ACUS48 KWNS 150859 SWOD48 SPC AC 150858 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0358 AM CDT FRI MAR 15 2013 VALID 181200Z - 231200Z ...DISCUSSION... THE MEDIUM RANGE MODELS BEGIN THE DAY 4 TO 8 PERIOD WITH AN UPPER-LEVEL TROUGH IN THE GREAT PLAINS AND MOVE THIS FEATURE EWD ACROSS THE MID TO UPPER MS VALLEY ON MONDAY/DAY 4. THE MODELS SHOW A CORRIDOR OF LOW-LEVEL MOISTURE EXTENDING NWD FROM THE CNTRL GULF COAST STATES INTO THE OH VALLEY WHERE THUNDERSTORMS COULD DEVELOP DURING THE DAY ON MONDAY. THE MODELS ARE IN DECENT AGREEMENT WITH THE MID-LEVEL JET FORECAST TO COUPLE WITH THE LOW-LEVEL JET ACROSS THE OH VALLEY. THIS SCENARIO WOULD RESULT IN STRONG SHEAR PROFILES WITH SEVERE THUNDERSTORMS POSSIBLE DURING THE AFTERNOON AND EVENING. THE SEVERE THREAT SHOULD EXTEND SWD FROM KY INTO TN AND NRN AL WHERE MODEL FORECASTS SHOW 60+ SFC DEWPOINTS AND MODERATE INSTABILITY. ON TUESDAY/DAY 5...THE MODELS MOVE THE UPPER-LEVEL TROUGH ACROSS THE ATLANTIC SEABOARD WITH A COLD FRONT MOVING OFFSHORE INTO THE ATLANTIC. ON WEDNESDAY/DAY 6...THE MODELS DEVELOP ZONAL FLOW ACROSS THE CONUS WITH THE MOIST SECTOR LOCATED FROM EAST TX EWD ACROSS LA. THUNDERSTORMS COULD OCCUR DURING THE DAY ON WEDNESDAY OR DURING THE OVERNIGHT PERIOD ALONG THE MOISTURE GRADIENT FROM NE TX EWD INTO THE CNTRL GULF COAST STATES. AT THIS POINT...ANY SHORTWAVE TROUGH THAT MOVES ACROSS THE SCNTRL U.S. ON WEDNESDAY WILL BE LOW-AMPLITUDE. FOR THIS REASON...THE MODELS DIFFER ON THE SCENARIO WITH THE GFS SHOWING A CONVECTIVE POTENTIAL MUCH FURTHER EAST THAN THE ECMWF. CONCERNING THE DAY 4 TO 8 PERIOD...A SEVERE THREAT WILL CERTAINLY BE POSSIBLE ACROSS THE OH AND TN VALLEYS ON MONDAY AFTERNOON AND EVENING. WILL ADD A 30 PERCENT SEVERE PROBABILITY AREA ACROSS PARTS OF THE SRN OH VALLEY AND TN VALLEY WHERE THE MODELS ARE IN DECENT AGREEMENT THAT THE COMBINATION OF INSTABILITY...SHEAR AND LIFT WILL SUPPORT AN ENHANCED SEVERE THREAT. ..BROYLES.. 03/15/2013  651 ACUS01 KWNS 151241 SWODY1 SPC AC 151239 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0739 AM CDT FRI MAR 15 2013 VALID 151300Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... THE UPPER FLOW REGIME WILL BECOME INCREASINGLY QUASI-ZONAL AS A TROUGH MOVES OFFSHORE THE SERN ATLANTIC COAST AND A RIDGE DAMPENS OVER THE WRN CONUS. A LOW-AMPLITUDE SHORTWAVE UPPER TROUGH CURRENTLY OVER THE NRN ROCKIES IS FORECAST TO REACH THE GREAT LAKES BY EARLY SAT MORNING. AN ACCOMPANYING INCREASE IN LOW-LEVEL FLOW AND ENEWD THETA-E ADVECTION OVER THE OH VALLEY WILL AID IN THUNDERSTORM DEVELOPMENT LATE IN THE PERIOD. ...OH VALLEY... MODEST ADVECTION OF MOISTURE NEWD WILL OCCUR TODAY ACROSS THE OH VALLEY...AS THIS AREA IS DOWNSTREAM FROM A RESERVOIR OF MID-40S F DEWPOINTS OVER THE SRN PLAINS/MID-SOUTH. A PLUME OF STEEP MIDLEVEL LAPSE RATES WILL SPREAD EWD OUT OF THE CNTRL PLAINS IN ASSOCIATION WITH THE AFOREMENTIONED SHORTWAVE UPPER TROUGH. ALTHOUGH SOME MODEL FORECAST SOUNDINGS APPEAR TO BE TOO AGGRESSIVE IN LOW-LEVEL MOISTENING THIS AFTERNOON /E.G. 06Z NAM/ DEPICTING WIDESPREAD MID-50S DEWPOINTS OVER THE LOWER OH VALLEY...CONSENSUS SUGGESTS MUCAPE VALUES OF 200-600 J/KG WILL BECOME COMMON AFTER 16/01Z...SUPPORTIVE FOR THUNDERSTORM DEVELOPMENT WITHIN A WEAK LOW-LEVEL WAA REGIME. MODERATELY STRONG DEEP-LAYER SHEAR COULD SUPPORT ORGANIZED ELEVATED THUNDERSTORMS WITH THE POTENTIAL TO PRODUCE MARGINALLY SVR HAIL...BUT A MORE SIGNIFICANT/WIDESPREAD THREAT APPEARS TO BE LIMITED BY WEAK INSTABILITY. ..ROGERS/EDWARDS.. 03/15/2013  619 ACUS01 KWNS 151622 SWODY1 SPC AC 151620 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1120 AM CDT FRI MAR 15 2013 VALID 151630Z - 161200Z ...NO SVR TSTM AREAS FORECAST... ...OH VALLEY... UPPER RIDGE HAS DIMINISHED OVER THE INTERMOUNTAIN REGION AS A LOW AMPLITUDE SHORT WAVE TROUGH MOVES ACROSS MT THIS MORNING. THIS SYSTEM IS EXPECTED TO MOVE ESEWD TOWARD THE UPPER MS VALLEY AND GREAT LAKES LATER THIS AFTERNOON AND TONIGHT...RESULTING IN A WEAKLY CYCLONIC WNWLY FLOW ALOFT ACROSS MUCH OF THE CONUS. AT THE SURFACE...A LOW OVER ERN NEB/WRN IA IS FORECAST TO MOVE/REDEVELOP EWD INTO THE MID MS VALLEY THIS EVENING CONTINUING EWD INTO THE OH VALLEY TONIGHT. THE NWLY FLOW PATTERN ALOFT COUPLED WITH PREVIOUS COLD FRONTAL INTRUSION DEEP INTO THE GULF OF MEXICO WILL STRONGLY LIMIT THE MAGNITUDE OF MOISTURE RETURN NEWD INTO THE MID MS AND OH VALLEYS IN ADVANCE OF THE SURFACE LOW. 12Z RAOB AND SATELLITE DATA INDICATE PW GENERALLY AOB 0.75 INCH WILL BE AVAILABLE FOR POTENTIAL CONVECTIVE DEVELOPMENT WITH THIS SYSTEM...WITH MID/UPPER 40S SURFACE DEW POINTS CURRENTLY MOVING NEWD ACROSS AR TOWARD THE OH VALLEY. HOWEVER...A PLUME OF STEEPER MID LEVEL LAPSE RATES IS FORECAST TO SPREAD EWD TOWARD THE MID MS AND UPPER OH VALLEY WHICH WILL CONTRIBUTE TO INCREASING ELEVATED INSTABILITY /MUCAPE OF 500-800 J PER KG/ ABOVE 850 MB TONIGHT. SOME MODEL GUIDANCE INCLUDING 09Z SREF WRF-NMM AND WRF-ARW MEMBERS APPEAR TO BE OVERPREDICTING A RAPID INCREASE IN LOW LEVEL MOISTURE THIS AFTERNOON AND EVENING INTO THE LOWER OH VALLEY...AND THIS IN TURN MAY RESULT IN SOME MODEL FORECASTS INDICATING EXCESSIVELY LARGE CAPE VALUES. MODEL CONSENSUS INCLUDING CONVECTION-ALLOWING MODELS AND SPC SSEO DEVELOP ELEVATED STORMS BY THIS EVENING OVER PARTS OF CENTRAL IL WITH ACTIVITY SPREADING EWD/ESEWD INTO THE OH VALLEY TONIGHT. THERE MAY BE SUFFICIENT INSTABILITY COUPLED WITH STRONG EFFECTIVE BULK SHEAR WITHIN THE CLOUD-BEARING LAYER FOR ISOLATED ELEVATED SUPERCELLS TO DEVELOP...WITH STRONGER CELLS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL. CURRENT OUTLOOK WILL MAINTAIN 5% NOCTURNAL HAIL PROBABILITY GIVEN UNCERTAINTY ABOUT THE MAGNITUDE OF INSTABILITY THAT WILL BE PRESENT TONIGHT. ..WEISS/GRAMS.. 03/15/2013  361 ACUS02 KWNS 151709 SWODY2 SPC AC 151707 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1207 PM CDT FRI MAR 15 2013 VALID 161200Z - 171200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A RELATIVELY ZONAL PATTERN WILL BE IN PLACE ACROSS THE ERN CONUS WITH NWLY FLOW OVER THE W. A WEAK SFC LOW IS FORECAST TO MOVE FROM OH EWD TO THE DELMARVA BY 00Z ASSOCIATED WITH A WLY SURGE OF THETA-E JUST OFF THE SURFACE. HEATING AND STRONG FLOW ALOFT COULD SUPPORT ISOLATED SEVERE STORMS FROM ERN KY/TN INTO VA DURING THE AFTERNOON. ELSEWHERE...A LOW AMPLITUDE SHORTWAVE TROUGH IS FORECAST TO EMERGE ACROSS THE CNTRL/SRN HIGH PLAINS OVERNIGHT...WHICH WILL HELP INDUCE WARM ADVECTION ATOP THE SURFACE FRONT WHICH WILL EXTEND FROM NW TX INTO NRN AR AT 06Z. ISOLATED WEAK CONVECTION WILL RESULT ACROSS NRN OK. ...SRN VA...NRN NC...ERN KY AND TN... CLOUDS AND RAIN WILL BE ONGOING EARLY IN THE DAY ACROSS MUCH OF THE DELMARVA AND VA...PERHAPS INTO NERN NC. THIS ACTIVITY WILL BE DRIVEN BY WARM ADVECTION ATOP THE SYNOPTIC FRONT ACROSS CNTRL VA. BEHIND THIS ACTIVITY...HEATING WILL OCCUR AND WILL HELP TO CREATE MARGINAL INSTABILITY. WHILE THE NAM SUGGESTS MUCAPE OF 300-500 J/KG...GFS SOUNDINGS SHOW ONLY 100 J/KG OR LESS. MODERATE UNIDIRECTIONAL WIND PROFILES WILL BE IN PLACE CAPABLE OF SUPPORTING ORGANIZED CONVECTION...BUT AT THIS TIME IT APPEARS STORMS MAY BE TOO MARGINAL AND ISOLATED FOR A SLIGHT RISK. HOWEVER...40 KT FLOW JUST OFF THE SURFACE AND ANY MIXING FROM PRECIPITATION COULD RESULT IN STRONG WIND GUSTS OVER A RELATIVELY LARGE AREA EVEN AWAY FROM THE STRONGER CONVECTION. ..JEWELL.. 03/15/2013  832 ACUS01 KWNS 151931 SWODY1 SPC AC 151929 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0229 PM CDT FRI MAR 15 2013 VALID 152000Z - 161200Z ...NO SVR TSTM AREAS FORECAST... LITTLE CHANGE WAS MADE TO THE PREVIOUS OUTLOOK. HIGH RESOLUTION MODELS CONTINUE TO AGREE ON INITIATION OF ELEVATED THUNDERSTORMS AROUND 04Z ACROSS INDIANA THEN CONTINUING RAPIDLY ESEWD INTO WV BY SAT MORNING. ALTHOUGH MOISTURE WILL BE MARGINAL...COOL PROFILES ALOFT COMBINED WITH AMPLE DEEP LAYER SHEAR AND FORCING MAY RESULT IN HAIL AROUND 1 INCH DIAMETER. ADDITIONAL CONVECTION MAY OCCUR ALONG THE SYNOPTIC COLD FROM FARTHER W ACROSS MO AND IL...BUT THIS ACTIVITY IS LIKELY TO BE WEAKER WITH LOWER HAIL POTENTIAL. ..JEWELL.. 03/15/2013 .PREV DISCUSSION... /ISSUED 1120 AM CDT FRI MAR 15 2013/ ...OH VALLEY... UPPER RIDGE HAS DIMINISHED OVER THE INTERMOUNTAIN REGION AS A LOW AMPLITUDE SHORT WAVE TROUGH MOVES ACROSS MT THIS MORNING. THIS SYSTEM IS EXPECTED TO MOVE ESEWD TOWARD THE UPPER MS VALLEY AND GREAT LAKES LATER THIS AFTERNOON AND TONIGHT...RESULTING IN A WEAKLY CYCLONIC WNWLY FLOW ALOFT ACROSS MUCH OF THE CONUS. AT THE SURFACE...A LOW OVER ERN NEB/WRN IA IS FORECAST TO MOVE/REDEVELOP EWD INTO THE MID MS VALLEY THIS EVENING CONTINUING EWD INTO THE OH VALLEY TONIGHT. THE NWLY FLOW PATTERN ALOFT COUPLED WITH PREVIOUS COLD FRONTAL INTRUSION DEEP INTO THE GULF OF MEXICO WILL STRONGLY LIMIT THE MAGNITUDE OF MOISTURE RETURN NEWD INTO THE MID MS AND OH VALLEYS IN ADVANCE OF THE SURFACE LOW. 12Z RAOB AND SATELLITE DATA INDICATE PW GENERALLY AOB 0.75 INCH WILL BE AVAILABLE FOR POTENTIAL CONVECTIVE DEVELOPMENT WITH THIS SYSTEM...WITH MID/UPPER 40S SURFACE DEW POINTS CURRENTLY MOVING NEWD ACROSS AR TOWARD THE OH VALLEY. HOWEVER...A PLUME OF STEEPER MID LEVEL LAPSE RATES IS FORECAST TO SPREAD EWD TOWARD THE MID MS AND UPPER OH VALLEY WHICH WILL CONTRIBUTE TO INCREASING ELEVATED INSTABILITY /MUCAPE OF 500-800 J PER KG/ ABOVE 850 MB TONIGHT. SOME MODEL GUIDANCE INCLUDING 09Z SREF WRF-NMM AND WRF-ARW MEMBERS APPEAR TO BE OVERPREDICTING A RAPID INCREASE IN LOW LEVEL MOISTURE THIS AFTERNOON AND EVENING INTO THE LOWER OH VALLEY...AND THIS IN TURN MAY RESULT IN SOME MODEL FORECASTS INDICATING EXCESSIVELY LARGE CAPE VALUES. MODEL CONSENSUS INCLUDING CONVECTION-ALLOWING MODELS AND SPC SSEO DEVELOP ELEVATED STORMS BY THIS EVENING OVER PARTS OF CENTRAL IL WITH ACTIVITY SPREADING EWD/ESEWD INTO THE OH VALLEY TONIGHT. THERE MAY BE SUFFICIENT INSTABILITY COUPLED WITH STRONG EFFECTIVE BULK SHEAR WITHIN THE CLOUD-BEARING LAYER FOR ISOLATED ELEVATED SUPERCELLS TO DEVELOP...WITH STRONGER CELLS CAPABLE OF PRODUCING MARGINALLY SEVERE HAIL. CURRENT OUTLOOK WILL MAINTAIN 5% NOCTURNAL HAIL PROBABILITY GIVEN UNCERTAINTY ABOUT THE MAGNITUDE OF INSTABILITY THAT WILL BE PRESENT TONIGHT.