905 ACUS01 KWNS 050057 SWODY1 SPC AC 050055 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0655 PM CST MON MAR 04 2013 VALID 050100Z - 051200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... LOW-TOPPED CONVECTION IS INCREASING IN COVERAGE ACROSS SERN CO/NERN NM AS THE LOBE OF ASCENT ACCOMPANYING AN AMPLIFYING MID-LEVEL SHORTWAVE TROUGH BECOMES SUPERIMPOSED WITH A SWD-SURGING COLD FRONT OVER THE CNTRL HIGH PLAINS. ISOLATED THUNDERSTORMS WILL CONTINUE TO EVOLVE FROM THIS ACTIVITY PRIOR TO 04Z FROM SERN CO SEWD INTO THE CNTRL TX PANHANDLE INVOF THE FRONT WHILE THE SHORTWAVE TROUGH SHIFTS EWD. NOCTURNAL STABILIZATION WILL LIKELY MINIMIZE BUOYANCY SUCH THAT STORM COVERAGE WILL REMAIN BELOW 10 PERCENT AS THE TROUGH CROSSES PARTS OF OK. HOWEVER...A STRONG LOW-LEVEL JET MAXIMUM LEADING THE TROUGH WILL MAINTAIN AN INFLUX OF PARTIALLY MODIFIED MOISTURE FROM PARTS OF THE LOWER MS VALLEY INTO NRN KY. IN THIS AREA...THE COMBINATION OF ISENTROPIC ASCENT WITHIN A WAA REGIME...FRONTAL ASCENT...AND LIFT AT THE TERMINUS OF THE LOW-LEVEL JET MAXIMUM WILL SUPPORT ISOLATED THUNDERSTORMS LATE THIS EVENING AND ESPECIALLY OVERNIGHT TONIGHT. ANY STORMS ARE EXPECTED TO REMAIN ROOTED ABOVE THE STABLE BOUNDARY LAYER...AND SEVERE WEATHER IS NOT EXPECTED. ..COHEN/BROYLES.. 03/05/2013  188 ACUS02 KWNS 050519 SWODY2 SPC AC 050517 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1117 PM CST MON MAR 04 2013 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...WRN U.S... MULTIFACETED UPPER LOW WILL DIG SEWD ALONG THE PACIFIC COAST INTO THE DAY2 PERIOD. ONE SIGNIFICANT LEAD SHORT-WAVE TROUGH IS EXPECTED TO EJECT INLAND ACROSS THE GREAT BASIN DURING THE AFTERNOON WITH A CORRIDOR OF ASCENT FORECAST INTO ERN ID/NRN UT BY PEAK HEATING. FAVORABLY MOIST AND DEEP SWLY FLOW SHOULD ENHANCE ISOLATED TSTM THREAT ACROSS THIS REGION AS LAPSE RATES WILL BE SUFFICIENTLY STEEP TO SUPPORT UPRIGHT CONVECTION...ESPECIALLY ALONG WEST FACING SLOPES OF HIGHER TERRAIN. BENEATH THE UPPER TROUGH...VERY COLD MID LEVEL TEMPERATURES WILL SAG SWD ALONG THE ORE/NRN CA COAST WITH 500MB READINGS EXPECTED TO DROP BELOW MINUS 30C. ONSHORE FLOW COMBINED WITH MARINE INFLUENCES MAY LEAD TO A FEW TSTMS ALONG THE COAST. ADDITIONALLY...ISOLATED TSTMS MAY ALSO DEVELOP WITHIN WARM ADVECTION REGIME ACROSS THE SACRAMENTO VALLEY. FORECAST SOUNDINGS SUGGEST WEAK SFC-BASED BUOYANCY WILL DEVELOP AS TEMPERATURES WARM INTO THE UPPER 40S. ALTHOUGH SHEAR PROFILES WOULD SUPPORT ROTATING UPDRAFTS IT APPEARS INSTABILITY WILL BE TOO WEAK TO WARRANT ANY MEANINGFUL THREAT FOR SEVERE THUNDERSTORMS ACROSS THE VALLEY. ..DARROW.. 03/05/2013  508 ACUS01 KWNS 050602 SWODY1 SPC AC 050600 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1200 AM CST TUE MAR 05 2013 VALID 051200Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF FAR ERN AL AND WCNTRL GA... ...ERN AL/GA/WRN SC... AN UPPER-LEVEL LOW WILL DIG SEWD INTO THE LOWER OH VALLEY TODAY AS AN ASSOCIATED UPPER-LEVEL TROUGH MOVES EWD ACROSS THE TN VALLEY AND CNTRL GULF COAST STATES. AT THE SFC...A LOW WILL MOVE ENEWD ACROSS THE OH VALLEY AND DEEPEN TO ABOUT 1000 MB BY 00Z. A COLD FRONT EXTENDING SWD FROM THE SFC LOW WILL ADVANCE QUICKLY EWD ACROSS TN...MS AND AL THIS AFTERNOON. THUNDERSTORM DEVELOPMENT WILL BE LIKELY ALONG THE BOUNDARY LATE THIS AFTERNOON FROM ERN AL AND WRN GA EWD TO WRN SC WITH MODEL FORECASTS MOVING THE CONVECTION EWD TO THE COASTS OF THE CAROLINAS BY LATE THIS EVENING. FORECAST SOUNDINGS IN CNTRL GA JUST AHEAD OF THE FRONT THIS AFTERNOON GRADUALLY WEAKEN A CAPPING INVERSION AS A MID-LEVEL JET NOSES INTO THE REGION FROM THE NORTHWEST. SFC DEWPOINTS IN MACON GA ARE FORECAST TO REACH THE MID 50S F BY 21Z AS A 50 TO 65 KT LOW-LEVEL JET BECOMES FOCUSED ACROSS THE REGION. THE LOW-LEVEL JET COUPLED WITH THE EXIT REGION OF THE MID-LEVEL JET WILL CREATE STRONG DEEP LAYER SHEAR AND ENHANCE LIFT. IN SPITE OF THE WEAK INSTABILITY...FORECAST SOUNDINGS IN WCNTRL GA AT 21Z SHOW 0-6 KM SHEAR AROUND 60 KT ALONG WITH 30 KT OF 0-1 KM SHEAR. THE STRONG SHEAR AND STEEP LAPSE RATES COULD BE ENOUGH FOR A SUPERCELL THREAT WITH HAIL AND DAMAGING WIND GUSTS POSSIBLE. IN ADDITION...A MARGINAL TORNADO THREAT COULD DEVELOP. THE GREATEST POTENTIAL FOR SEVERE STORMS SHOULD BE LOCATED FROM COLUMBUS GA NEWD TO JUST SOUTHWEST OF THE ATLANTA METRO AREA WHERE FORECAST SOUNDINGS MAXIMIZE THE COMBINATION OF INSTABILITY...SHEAR AND LIFT. FOR THIS REASON...HAVE ADDED A SMALL SLIGHT RISK AREA TO ACCOUNT FOR THE POSSIBILITY OF SUPERCELL DEVELOPMENT IN WCNTRL GA LATE THIS AFTERNOON. ..BROYLES/COHEN.. 03/05/2013  253 ACUS03 KWNS 050803 SWODY3 SPC AC 050801 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0201 AM CST TUE MAR 05 2013 VALID 071200Z - 081200Z ...NO SVR TSTM AREAS FORECAST... ...CA... COLD UPPER LOW IS EXPECTED TO DROP SSEWD ALONG THE CA COAST WITH A POSITION NEAR SFO BY THE END OF THE PERIOD. AN EXPANSIVE COLD POCKET OF 500MB TEMPERATURES LESS THAN MINUS 30C WILL CONTRIBUTE TO STEEP LAPSE RATES BENEATH THE UPPER LOW. WITH WEAK ONSHORE FLOW ALONG THE COAST IT APPEARS MARINE LAYER MOISTURE WILL CONTRIBUTE TO WEAK SFC-BASED INSTABILITY AND WITH SOME DIURNAL HEATING PERHAPS SBCAPE WILL APPROACH 150 J/KG. CONVECTION IS ALSO POSSIBLE OVER THE INTERIOR VALLEY REGION. DESPITE THE MEAGER INSTABILITY CLOUD TOPS MAY EXCEED 5KM AND THIS WILL BE MORE THAN ADEQUATE FOR LIGHTNING DISCHARGE WITHIN THE STRONGER UPDRAFTS. EVEN SO TSTMS SHOULD REMAIN ISOLATED. ..DARROW.. 03/05/2013  047 ACUS48 KWNS 050920 SWOD48 SPC AC 050919 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0319 AM CST TUE MAR 05 2013 VALID 081200Z - 131200Z ...DISCUSSION... ECMWF REMAINS A BIT MORE CONSISTENT THAN THE GFS REGARDING THE EVOLUTION OF UPPER LOW AS IT MOVES ACROSS THE SWRN U.S. THEN EJECTS INTO THE HIGH PLAINS THIS WEEKEND. WHILE THIS SYSTEM WILL INDUCE A LEE TROUGH AND ACCOMPANYING LLJ...BOUNDARY LAYER MOISTURE IS EXPECTED TO ONLY SLOWLY INCREASE ACROSS THE SRN PLAINS AHEAD OF WIND SHIFT. LATEST GUIDANCE SUGGESTS AIRMASS MODIFICATION ACROSS THE WRN GULF BASIN WILL BE SLOW AND A NARROW AXIS OF 50S SFC DEW POINTS IS EXPECTED BY PEAK HEATING SATURDAY AFTERNOON ACROSS NWRN TX/WRN OK. RESULTANT INSTABILITY SHOULD BE MORE THAN ADEQUATE FOR DRYLINE/FRONTAL CONVECTION GIVEN THE ACCOMPANYING LARGE SCALE FORCING...HOWEVER THE PROSPECT FOR ORGANIZED SEVERE THUNDERSTORMS REACHING 30 PERCENT CRITERIA IS UNCERTAIN GIVEN THE FORECAST INSTABILITY. NARROW SQUALL LINE COULD EMERGE ALONG THE ADVANCING COLD FRONT LATE DAY5 THAT SHOULD ADVANCE INTO THE MS VALLEY DAY6. ..DARROW.. 03/05/2013  666 ACUS01 KWNS 051249 SWODY1 SPC AC 051247 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0647 AM CST TUE MAR 05 2013 VALID 051300Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS OVER PART OF FAR ERN AL INTO PORTIONS OF NRN AND CNTRL GA... ...SYNOPSIS... A MIDLEVEL LOW OVER THE MID-MO VALLEY WILL DEVELOP SEWD TO VA/NC BY 06/12Z IN RESPONSE TO THE SLOW EWD PROGRESSION OF A DEEP-LAYER CYCLONE ONTO THE PACIFIC NW COAST. WITH RESPECT TO THE FORMER...A SUBSTANTIAL VORTICITY MAXIMUM AND DEVELOPING 100-120KT JET STREAK AT 500 MB WILL ROTATE THROUGH THE BASE OF THE PARENT LOW...CONTRIBUTING TO A MARKED INCREASE IN FORCING FOR ASCENT AND VERTICAL SHEAR FROM THE TN VALLEY AND CNTRL GULF STATES EWD TO THE SERN ATLANTIC COAST. IN THE LOW LEVELS...A SURFACE CYCLONE NEAR THE CONFLUENCE OF THE MS AND OH RIVERS WILL DEEPEN WHILE DEVELOPING NEWD...BEFORE EVENTUALLY OCCLUDING OVER THE UPPER OH VALLEY TONIGHT. A TRAILING...STRONG COLD FRONT WILL SWEEP EWD THROUGH THE GULF COAST STATES WITH SECONDARY CYCLONE DEVELOPMENT FORECAST ALONG THE FRONT IN THE LEE OF THE CNTRL OR SRN APPALACHIANS TONIGHT. THIS SECONDARY LOW PRESSURE WILL DEVELOP NEWD INTO THE TIDEWATER REGION BY WEDNESDAY MORNING WITH THE TRAILING COLD FRONT SURGING OFF THE SERN ATLANTIC COAST. ...CNTRL/ERN GULF STATES INTO THE SRN APPALACHIANS TODAY INTO THIS EVENING... STRONG...ZONAL FLOW IN THE MID-TROPOSPHERE HAS RESULTED IN THE EWD ADVECTION OF A WELL-DEFINED EML FROM THE SRN PLAINS AND MEXICAN PLATEAU WITH 700-500-MB LAPSE RATES OF AROUND 8 C/KM OBSERVED AS FAR E AS JAN AS OF 12Z. MEANWHILE...CURRENT SURFACE OBSERVATIONS AND REGIONAL SOUNDING DATA INDICATE THE RETURN OF A MODIFIED CP AIR MASS NWD/NEWD THROUGH THE DEVELOPING WARM SECTOR...CHARACTERIZED BY BOUNDARY LAYER DEWPOINTS IN THE LOW TO MID 50S. BOTH WIDESPREAD CLOUDS AND THE MARGINAL MOISTURE CONTENT WILL LIMIT THE DEGREE OF AIR MASS DESTABILIZATION TODAY AHEAD THE COLD FRONT WITH LATEST MODEL GUIDANCE INDICATING MLCAPE OF GENERALLY 300-400 J/KG BY AFTERNOON ACROSS PARTS OF AL INTO WRN GA. A RECENT INCREASE IN ELEVATED TSTMS HAS BEEN NOTED OVER NRN MS WITH STORMS LIKELY ROOTED WITHIN THE EML AND FORCED BY HEIGHT FALLS/DCVA AHEAD OF THE EVOLVING...LARGE-SCALE TROUGH. THESE STORMS SHOULD CONTINUE EWD WITH A RISK FOR SOME HAIL APPROACHING SEVERE LEVELS. SURFACE-BASED STORM DEVELOPMENT IS ANTICIPATED THIS AFTERNOON ALONG THE COLD FRONT FROM NWRN GA INTO AL WITH ACTIVITY GROWING UPSCALE INTO A BROKEN CONVECTIVE BAND. GIVEN THE STRONG LOW-LEVEL AND DEEP-LAYER SHEAR FORECAST...THE POTENTIAL WILL EXIST FOR EMBEDDED BOWING AND/OR SUPERCELL STRUCTURES WITH A RISK FOR DAMAGING WINDS AND PERHAPS A TORNADO. EXPECT THE SEVERE WEATHER THREAT TO DIMINISH LATER THIS EVENING INTO TONIGHT AS THE BOUNDARY LAYER GRADUALLY COOLS AND STABILIZES. ..MEAD/BOTHWELL.. 03/05/2013  104 ACUS01 KWNS 051632 SWODY1 SPC AC 051630 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1030 AM CST TUE MAR 05 2013 VALID 051630Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON/EVENING FOR ERN AL...CENTRAL AND N GA...AND EXTREME WRN SC... ...SYNOPSIS... A DEEP MIDLEVEL LOW OVER IA IS IN THE PROCESS OF PHASING WITH A SEPARATE SRN STREAM SPEED MAX OVER NE TX. THE NE TX SPEED MAX WILL TRANSLATE QUICKLY EWD TO THE SRN APPALACHIANS THIS EVENING...AND THE UPSTREAM LOW WILL BEGIN A DEEPENING PROCESS TONIGHT. A SURFACE CYCLONE INVOF WRN KY AS OF 15Z WILL DEEPEN AND OCCLUDE ACROSS SRN OH TONIGHT...AS SECONDARY CYCLOGENESIS OCCURS IN THE LEE OF THE APPALACHIANS ACROSS NC/VA. THE INLAND WARM/MOIST SECTOR WILL NOT BE LARGE TODAY...BUT SUFFICIENT DESTABILIZATION IS EXPECTED FROM AL INTO PARTS OF GA/SC TO SUPPORT A RISK OF AT LEAST ISOLATED SEVERE STORMS THIS AFTERNOON/EVENING. ...ERN AL/CENTRAL AND N GA/WRN SC THIS AFTERNOON AND EVENING... BOUNDARY LAYER DEWPOINTS OF 55-60 F ARE SPREADING NEWD IN ADVANCE OF THE COLD FRONT CROSSING THE ARKLAMISS...AND BENEATH STEEP MIDLEVEL LAPSE RATES PER 12Z SOUNDINGS. THE LAPSE RATE PLUME IS RELATIVELY WARM COMPARED TO THE MAGNITUDE OF THE MOISTURE...AND THIS WILL TEND TO LIMIT THE MAGNITUDE OF BUOYANCY THROUGH THE PERIOD. ALSO...WIDESPREAD CLOUDS WILL SLOW SURFACE HEATING...AND THE CAP ASSOCIATED WITH THE STEEP LAPSE RATES WILL INHIBIT SURFACE-BASED THUNDERSTORM DEVELOPMENT UNTIL MID-LATE AFTERNOON WHEN THE MID 50S DEWPOINTS REACH CENTRAL AL/GA. THUNDERSTORM DEVELOPMENT WILL BECOME INCREASINGLY PROBABLE ALONG THE COLD FRONT IN THE 21-00Z TIME FRAME ACROSS ERN AL AND CENTRAL/N GA...WHEN ASCENT ALONG THE FRONT WILL COINCIDE WITH MLCAPE OF 250-500 J/KG AND SOME WEAKENING OF CONVECTIVE INHIBITION. THOUGH INSTABILITY WILL BE MARGINAL...STRONG DEEP-LAYER WIND PROFILES WILL SUPPORT A RISK FOR DAMAGING WINDS WITH LINE SEGMENTS AND EMBEDDED CELLS NEAR THE COLD FRONT. LOW-LEVEL SHEAR WILL BE STRONGER FROM CENTRAL/N GA TO THE SAVANNAH RIVER VALLEY THIS EVENING...WHERE AN ISOLATED SPINUP WILL BE POSSIBLE PRIOR TO THE CONVECTION EXHAUSTING THE LIMITED INSTABILITY. ..THOMPSON/DIAL.. 03/05/2013  296 ACUS02 KWNS 051657 SWODY2 SPC AC 051655 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1055 AM CST TUE MAR 05 2013 VALID 061200Z - 071200Z ...NO SVR TSTM AREAS FORECAST... ...SYNOPSIS... A SERIES OF UPPER IMPULSES WILL ROUND THE BASE OF A STATIONARY TROUGH OVER THE PAC NW ON WED AND EJECT NEWD ACROSS NRN CA INTO THE NRN INTERMOUNTAIN W. MEANWHILE IN THE LOW-LEVELS...A COLD FRONT WILL SHIFT E-SEWD ACROSS THE GREAT BASIN DURING THE AFTERNOON AND NIGHT. COLD MIDLEVEL TEMPERATURES RANGING FROM -20 TO -30 C AT 500 MB AND STEEP LAPSE RATES WILL AID IN ISOLATED THUNDERSTORM DEVELOPMENT INVOF THE TROUGH OVER NRN CA...AND NEAR THE COLD FRONT OVER NRN UT/SERN ID. ...SACRAMENTO VALLEY... MODERATE MIDLEVEL WSWLYS SPREADING ACROSS THE COASTAL MOUNTAINS OF NRN CA WILL AID IN BACKING LOW-LEVEL FLOW TO SLY OVER THE SACRAMENTO VALLEY DURING WED AFTERNOON. THIS WILL YIELD SHEAR PROFILES THAT COULD POTENTIALLY SUPPORT ORGANIZED THUNDERSTORM DEVELOPMENT. HOWEVER...COOL BOUNDARY LAYER TEMPERATURES AND DEWPOINTS WILL SUPPORT MEAGER BUOYANCY /MUCAPE VALUES AOB 200 J PER KG/...WHICH IS EXPECTED TO PRECLUDE A SEVERE WEATHER THREAT ATTM. ..GARNER.. 03/05/2013  900 ACUS11 KWNS 051911 SWOMCD SPC MCD 051911 GAZ000-TNZ000-ALZ000-052115- MESOSCALE DISCUSSION 0243 NWS STORM PREDICTION CENTER NORMAN OK 0111 PM CST TUE MAR 05 2013 AREAS AFFECTED...CNTRL AND ERN AL...NWRN GA CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 051911Z - 052115Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...STORMS ARE EXPECTED TO INCREASE IN INTENSITY AND ORGANIZATION LATER THIS AFTERNOON MAINLY ACROSS CNTRL AL INTO WRN GA. DAMAGING WINDS...HAIL AND A COUPLE TORNADOES WILL BE POSSIBLE. DISCUSSION...A COLD FRONT CONTINUES TO PROGRESS RAPIDLY EWD ACROSS AL AND SRN MS...AND WILL MOVE ACROSS NWRN AND WRN GA BEFORE 00Z. AHEAD OF THE FRONT...EXTENSIVE CLOUDS EXISTED AS OF 19Z BUT GRADUAL THETA-E ADVECTION WAS OCCURRING WITH TEMPERATURES NEAR 70 F AND DEWPOINTS RISING INTO THE MID 50S F JUST AHEAD OF THE FRONT. STORMS SHOULD GRADUALLY GROW DEEPER WITH TIME...AS INSTABILITY INCREASES AND SHEAR ACTS ON THE UPDRAFTS. A FEW EMBEDDED SUPERCELLS MAY EVENTUALLY MATERIALIZE...WHICH MAY ENHANCE SEVERE WIND...HAIL...AND TORNADO POTENTIAL IN LOCALIZED SWATHS. ..JEWELL/THOMPSON.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...FFC...BMX...HUN...MOB... LAT...LON 32788438 32128497 31948581 31988661 32118728 32428761 32738778 33088758 33968685 34748646 34908596 35008519 34968445 34908373 34508372 33498400 32788438  476 ACUS11 KWNS 051911 SWOMCD SPC MCD 051911 GAZ000-TNZ000-ALZ000-052115- MESOSCALE DISCUSSION 0243 NWS STORM PREDICTION CENTER NORMAN OK 0111 PM CST TUE MAR 05 2013 AREAS AFFECTED...CNTRL AND ERN AL...NWRN GA CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 051911Z - 052115Z PROBABILITY OF WATCH ISSUANCE...80 PERCENT SUMMARY...STORMS ARE EXPECTED TO INCREASE IN INTENSITY AND ORGANIZATION LATER THIS AFTERNOON MAINLY ACROSS CNTRL AL INTO WRN GA. DAMAGING WINDS...HAIL AND A COUPLE TORNADOES WILL BE POSSIBLE. DISCUSSION...A COLD FRONT CONTINUES TO PROGRESS RAPIDLY EWD ACROSS AL AND SRN MS...AND WILL MOVE ACROSS NWRN AND WRN GA BEFORE 00Z. AHEAD OF THE FRONT...EXTENSIVE CLOUDS EXISTED AS OF 19Z BUT GRADUAL THETA-E ADVECTION WAS OCCURRING WITH TEMPERATURES NEAR 70 F AND DEWPOINTS RISING INTO THE MID 50S F JUST AHEAD OF THE FRONT. STORMS SHOULD GRADUALLY GROW DEEPER WITH TIME...AS INSTABILITY INCREASES AND SHEAR ACTS ON THE UPDRAFTS. A FEW EMBEDDED SUPERCELLS MAY EVENTUALLY MATERIALIZE...WHICH MAY ENHANCE SEVERE WIND...HAIL...AND TORNADO POTENTIAL IN LOCALIZED SWATHS. ..JEWELL/THOMPSON.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...MRX...FFC...BMX...HUN...MOB... LAT...LON 32788438 32128497 31948581 31988661 32118728 32428761 32738778 33088758 33968685 34748646 34908596 35008519 34968445 34908373 34508372 33498400 32788438  801 ACUS11 KWNS 051936 SWOMCD SPC MCD 051936 INZ000-MIZ000-ILZ000-052330- MESOSCALE DISCUSSION 0244 NWS STORM PREDICTION CENTER NORMAN OK 0136 PM CST TUE MAR 05 2013 AREAS AFFECTED...NERN IL THROUGH NRN IND CONCERNING...HEAVY SNOW VALID 051936Z - 052330Z SUMMARY...AREAS OF MODERATE TO LOCALLY HEAVY SNOW WILL PERSIST ACROSS NERN IL THE REMAINDER OF THE AFTERNOON...WITH HEAVIER SNOWS GRADUALLY DEVELOPING EWD THROUGH NCTNRL AND NRN IND LATER THIS AFTERNOON INTO THE EVENING. SNOWFALL RATES COULD LOCALLY EXCEED 1 INCH PER HOUR AT TIMES. DISCUSSION...INVERTED SFC TROUGH AXIS PERSISTS FROM NRN IL SEWD THROUGH CNTRL IND. SFC LOW OVER KY SHOULD DEEPEN AS IT MOVES NEWD THROUGH THE OH VALLEY WITHIN ZONE OF UPPER DIVERGENCE ASSOCIATED WITH EJECTING NEGATIVE TILT SHORTWAVE TROUGH. AS SFC LOW DEVELOPS EWD...AXIS OF DEFORMATION WILL SLOWLY PIVOT COUNTERCLOCKWISE AND BECOME MORE E-W ORIENTED ACROSS NRN PORTIONS OF THE OH VALLEY. THE CORRIDOR OF DIVERGENCE ALOFT WILL CONTINUE TO INTERACT WITH DEFORMATION AXIS RESULTING IN EWD EXPANSION OF ZONE OF FRONTOGENETIC FORCING AND DEEPER ASCENT THROUGH CNTRL AND NRN IND THIS AFTERNOON INTO THE EARLY EVENING. THIS PROCESS WILL LIKELY RESULT IN OCCASIONAL HEAVY SNOWFALL RATES PERSISTING FROM NERN IL THIS AFTERNOON...EXPANDING THROUGH NCNTRL AND NRN IND THIS AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...IWX...IND...LOT... LAT...LON 42368795 41628736 41878571 41228484 40178497 39648617 40988799 42298864 42368795  933 ACUS11 KWNS 051936 SWOMCD SPC MCD 051936 INZ000-MIZ000-ILZ000-052330- MESOSCALE DISCUSSION 0244 NWS STORM PREDICTION CENTER NORMAN OK 0136 PM CST TUE MAR 05 2013 AREAS AFFECTED...NERN IL THROUGH NRN IND CONCERNING...HEAVY SNOW VALID 051936Z - 052330Z SUMMARY...AREAS OF MODERATE TO LOCALLY HEAVY SNOW WILL PERSIST ACROSS NERN IL THE REMAINDER OF THE AFTERNOON...WITH HEAVIER SNOWS GRADUALLY DEVELOPING EWD THROUGH NCTNRL AND NRN IND LATER THIS AFTERNOON INTO THE EVENING. SNOWFALL RATES COULD LOCALLY EXCEED 1 INCH PER HOUR AT TIMES. DISCUSSION...INVERTED SFC TROUGH AXIS PERSISTS FROM NRN IL SEWD THROUGH CNTRL IND. SFC LOW OVER KY SHOULD DEEPEN AS IT MOVES NEWD THROUGH THE OH VALLEY WITHIN ZONE OF UPPER DIVERGENCE ASSOCIATED WITH EJECTING NEGATIVE TILT SHORTWAVE TROUGH. AS SFC LOW DEVELOPS EWD...AXIS OF DEFORMATION WILL SLOWLY PIVOT COUNTERCLOCKWISE AND BECOME MORE E-W ORIENTED ACROSS NRN PORTIONS OF THE OH VALLEY. THE CORRIDOR OF DIVERGENCE ALOFT WILL CONTINUE TO INTERACT WITH DEFORMATION AXIS RESULTING IN EWD EXPANSION OF ZONE OF FRONTOGENETIC FORCING AND DEEPER ASCENT THROUGH CNTRL AND NRN IND THIS AFTERNOON INTO THE EARLY EVENING. THIS PROCESS WILL LIKELY RESULT IN OCCASIONAL HEAVY SNOWFALL RATES PERSISTING FROM NERN IL THIS AFTERNOON...EXPANDING THROUGH NCNTRL AND NRN IND THIS AFTERNOON INTO THE EARLY EVENING. ..DIAL.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...IWX...IND...LOT... LAT...LON 42368795 41628736 41878571 41228484 40178497 39648617 40988799 42298864 42368795  348 ACUS01 KWNS 051953 SWODY1 SPC AC 051951 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0151 PM CST TUE MAR 05 2013 VALID 052000Z - 061200Z ...THERE IS A SLGT RISK OF SVR TSTMS FOR ERN AL...CNTRL/NRN GA AND WRN SC... ...ERN AL...CNTRL/NRN GA...WRN SC THIS AFTERNOON AND EVENING... AFTERNOON WV IMAGERY SHOWS A WELL DEFINED UPPER DISTURBANCE PROGRESSING RAPIDLY EWD ACROSS MS. ASSOCIATED SURFACE LOW OVER KY WILL DEEPEN IN RESPONSE THROUGH AFTERNOON...WHILE COLD FRONT TRAILING SWWD INTO SERN LA ACCELERATES EWD INTO THE WRN CAROLINAS/ERN GA BY EVENING. AT THE SURFACE...TEMPERATURES HAVE WARMED INTO THE LOW 70S AHEAD OF THE COLD FRONT FROM CNTRL INTO SRN AL...WHILE 60S WERE MORE COMMON ACROSS NRN/CNTRL GA. HOWEVER...VISIBLE SATELLITE IMAGERY SHOWS PARTIAL CLEARING OVER GA...WHICH SHOULD AID IN ADDITIONAL HEATING DURING THE AFTERNOON. THIS HEATING COMBINED WITH LOW/MID 50S DEWPOINTS AND STEEP MIDLEVEL LAPSE RATES WILL YIELD MLCAPE VALUES UP TO 500 J/KG. BROKEN LINE OF STORMS HAS FORMED ALONG THE COLD FRONT OVER AL DURING THE PAST FEW HOURS...AND THIS IS EXPECTED TO BE THE PREDOMINANT CONVECTIVE MODE AS THE FRONT ADVANCES E INTO GA AND WRN SC. GIVEN 40 KT OF FLOW OUT OF THE SW AT 1 KM AGL OCCURRING BENEATH AN 80 KT MIDLEVEL WLY JET...QUASI-LINEAR STORM MODE ALONG THE COLD FRONT...AND INCREASING TEMPERATURE/DEWPOINT SPREADS AT THE SURFACE...DAMAGING WIND GUSTS ARE EXPECTED TO BE THE PRIMARY SVR WEATHER THREAT. STEEP MIDLEVEL LAPSE RATES AND 0-6 KM BULK SHEAR IN EXCESS OF 60 KT WILL ALSO FAVOR LARGE HAIL...THROUGH MEAGER BUOYANCY AND THE LINEAR CONVECTIVE MODE WILL LIKELY PRECLUDE DIAMETERS MUCH ABOVE 1 INCH. THE TORNADO THREAT WILL ALSO BE LIMITED BY THE WEAK/NARROW ZONE OF CAPE...BUT IS NON-ZERO GIVEN THE PRESENCE OF STRONG SPEED SHEAR OVER THE LOWEST FEW KM/S AGL. REF MCD 243 AND WW 47 FOR ADDITIONAL SHORT-TERM DETAILS. ..GARNER.. 03/05/2013 .PREV DISCUSSION... /ISSUED 1030 AM CST TUE MAR 05 2013/ ...SYNOPSIS... A DEEP MIDLEVEL LOW OVER IA IS IN THE PROCESS OF PHASING WITH A SEPARATE SRN STREAM SPEED MAX OVER NE TX. THE NE TX SPEED MAX WILL TRANSLATE QUICKLY EWD TO THE SRN APPALACHIANS THIS EVENING...AND THE UPSTREAM LOW WILL BEGIN A DEEPENING PROCESS TONIGHT. A SURFACE CYCLONE INVOF WRN KY AS OF 15Z WILL DEEPEN AND OCCLUDE ACROSS SRN OH TONIGHT...AS SECONDARY CYCLOGENESIS OCCURS IN THE LEE OF THE APPALACHIANS ACROSS NC/VA. THE INLAND WARM/MOIST SECTOR WILL NOT BE LARGE TODAY...BUT SUFFICIENT DESTABILIZATION IS EXPECTED FROM AL INTO PARTS OF GA/SC TO SUPPORT A RISK OF AT LEAST ISOLATED SEVERE STORMS THIS AFTERNOON/EVENING. ...ERN AL/CENTRAL AND N GA/WRN SC THIS AFTERNOON AND EVENING... BOUNDARY LAYER DEWPOINTS OF 55-60 F ARE SPREADING NEWD IN ADVANCE OF THE COLD FRONT CROSSING THE ARKLAMISS...AND BENEATH STEEP MIDLEVEL LAPSE RATES PER 12Z SOUNDINGS. THE LAPSE RATE PLUME IS RELATIVELY WARM COMPARED TO THE MAGNITUDE OF THE MOISTURE...AND THIS WILL TEND TO LIMIT THE MAGNITUDE OF BUOYANCY THROUGH THE PERIOD. ALSO...WIDESPREAD CLOUDS WILL SLOW SURFACE HEATING...AND THE CAP ASSOCIATED WITH THE STEEP LAPSE RATES WILL INHIBIT SURFACE-BASED THUNDERSTORM DEVELOPMENT UNTIL MID-LATE AFTERNOON WHEN THE MID 50S DEWPOINTS REACH CENTRAL AL/GA. THUNDERSTORM DEVELOPMENT WILL BECOME INCREASINGLY PROBABLE ALONG THE COLD FRONT IN THE 21-00Z TIME FRAME ACROSS ERN AL AND CENTRAL/N GA...WHEN ASCENT ALONG THE FRONT WILL COINCIDE WITH MLCAPE OF 250-500 J/KG AND SOME WEAKENING OF CONVECTIVE INHIBITION. THOUGH INSTABILITY WILL BE MARGINAL...STRONG DEEP-LAYER WIND PROFILES WILL SUPPORT A RISK FOR DAMAGING WINDS WITH LINE SEGMENTS AND EMBEDDED CELLS NEAR THE COLD FRONT. LOW-LEVEL SHEAR WILL BE STRONGER FROM CENTRAL/N GA TO THE SAVANNAH RIVER VALLEY THIS EVENING...WHERE AN ISOLATED SPINUP WILL BE POSSIBLE PRIOR TO THE CONVECTION EXHAUSTING THE LIMITED INSTABILITY.  890 ACUS11 KWNS 052147 SWOMCD SPC MCD 052147 SCZ000-GAZ000-NCZ000-ALZ000-052315- MESOSCALE DISCUSSION 0245 NWS STORM PREDICTION CENTER NORMAN OK 0347 PM CST TUE MAR 05 2013 AREAS AFFECTED...SRN AL...WRN AND NRN GA...WRN SC CONCERNING...SEVERE THUNDERSTORM WATCH 47... VALID 052147Z - 052315Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 47 CONTINUES. SUMMARY...A SEVERE THREAT CONTINUES ACROSS WW 47...AND MAY EXTEND JUST S AND E OF THE WATCH. HOWEVER...IT IS UNCLEAR WHETHER ANOTHER WATCH WILL BE NEEDED. DISCUSSION...A LINE OF STORMS CONTINUES TO PROGRESS EWD WITH THE COLD FRONT. MOISTURE AND INSTABILITY AHEAD OF THE FRONT REMAIN MARGINAL WITH PRECIPITABLE WATER LESS THAN 0.90 INCHES. HOWEVER...WIND FIELDS REMAIN VERY STRONG. SURFACE ANALYSIS SHOWS TEMPERATURES INTO THE LOWER 70S ACROSS SERN AL AND SWRN GA...WHERE POCKETS OF HEATING AND GREATER INSTABILITY EXIST. AS A RESULT...SRN PORTIONS OF THE WATCH MAY HAVE THE GREATEST THREAT FOR SEVERE WINDS. NRN EXTENT OF THE SEVERE THREAT IS DENOTED BY THE FRONT EXTENDING FROM NRN GA INTO NRN SC WITH COLD STABLE AIR N OF THE BOUNDARY. ..JEWELL.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GSP...MRX...FFC...BMX... LAT...LON 35008282 32378385 32358560 32868506 33888453 35028403 35008282  247 ACUS11 KWNS 052147 SWOMCD SPC MCD 052147 SCZ000-GAZ000-NCZ000-ALZ000-052315- MESOSCALE DISCUSSION 0245 NWS STORM PREDICTION CENTER NORMAN OK 0347 PM CST TUE MAR 05 2013 AREAS AFFECTED...SRN AL...WRN AND NRN GA...WRN SC CONCERNING...SEVERE THUNDERSTORM WATCH 47... VALID 052147Z - 052315Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 47 CONTINUES. SUMMARY...A SEVERE THREAT CONTINUES ACROSS WW 47...AND MAY EXTEND JUST S AND E OF THE WATCH. HOWEVER...IT IS UNCLEAR WHETHER ANOTHER WATCH WILL BE NEEDED. DISCUSSION...A LINE OF STORMS CONTINUES TO PROGRESS EWD WITH THE COLD FRONT. MOISTURE AND INSTABILITY AHEAD OF THE FRONT REMAIN MARGINAL WITH PRECIPITABLE WATER LESS THAN 0.90 INCHES. HOWEVER...WIND FIELDS REMAIN VERY STRONG. SURFACE ANALYSIS SHOWS TEMPERATURES INTO THE LOWER 70S ACROSS SERN AL AND SWRN GA...WHERE POCKETS OF HEATING AND GREATER INSTABILITY EXIST. AS A RESULT...SRN PORTIONS OF THE WATCH MAY HAVE THE GREATEST THREAT FOR SEVERE WINDS. NRN EXTENT OF THE SEVERE THREAT IS DENOTED BY THE FRONT EXTENDING FROM NRN GA INTO NRN SC WITH COLD STABLE AIR N OF THE BOUNDARY. ..JEWELL.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...GSP...MRX...FFC...BMX... LAT...LON 35008282 32378385 32358560 32868506 33888453 35028403 35008282  590 ACUS11 KWNS 052321 SWOMCD SPC MCD 052320 SCZ000-GAZ000-060015- MESOSCALE DISCUSSION 0246 NWS STORM PREDICTION CENTER NORMAN OK 0520 PM CST TUE MAR 05 2013 AREAS AFFECTED...NERN TO SRN GA...WRN SC CONCERNING...SEVERE THUNDERSTORM WATCH 47... VALID 052320Z - 060015Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 47 CONTINUES. SUMMARY...LINE OF SHOWERS WITH EMBEDDED TSTMS WILL PROGRESS E OF WW 47 IN THE NEXT HOUR. A THREAT FOR LOCALIZED DAMAGING WINDS SHOULD STILL PERSIST FOR A FEW MORE HOURS...BUT MAY REMAIN TOO MARGINAL TO WARRANT A NEW WW OR AREAL EXTENSION OF WW 47. DISCUSSION...NNE-SW ORIENTED QLCS EXTENDED FROM NERN GA INTO FAR SERN AL AS OF 2315Z...WITH CLOUD TOPS HAVING WARMED AND LIGHTNING TRENDS SUBSIDING SOMEWHAT OVERALL COMPARED TO A FEW HOURS AGO. FAR NRN PORTION OF THIS LINE INTERSECTS A QUASI-STATIONARY FRONT IN NWRN SC. WITH A MOSTLY LEADING STRATIFORM MODE AMIDST A MINIMALLY BUOYANT AIR MASS...THE PROSPECT FOR AN APPRECIABLE INCREASE IN INTENSITY ON THE NRN HALF OF THE QLCS APPEARS UNLIKELY. NEVERTHELESS...WITH THE LLJ STRENGTHENING THIS EVENING...IT IS POSSIBLE THAT DOWNWARD MOMENTUM TRANSPORT COULD STILL SUPPORT LOCALIZED WIND GUSTS CAPABLE OF PRODUCING TREE DAMAGE. FARTHER S FROM CNTRL GA SWD...WHERE SURFACE TEMPERATURES HAD WARMED INTO THE UPPER 60S TO LOWER 70S AND LOW-LEVEL LAPSE RATES ARE STEEPER...AN OCCASIONAL FLAREUP ALONG THE QLCS COULD SUPPORT ISOLATED DAMAGING WINDS. HOWEVER...AS THE BOUNDARY LAYER BEGINS TO STABILIZE AND WITH THE STRONGER FORCING FOR ASCENT PULLING AWAY TO THE NE DURING THE EVENING...SEVERE THREAT HERE SHOULD WANE. ..GRAMS.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAE...GSP...FFC...TAE... LAT...LON 34998279 34958169 33678187 32268258 31318348 31408502 32078480 32548390 33518342 34938289 34998279  367 ACUS11 KWNS 052321 SWOMCD SPC MCD 052320 SCZ000-GAZ000-060015- MESOSCALE DISCUSSION 0246 NWS STORM PREDICTION CENTER NORMAN OK 0520 PM CST TUE MAR 05 2013 AREAS AFFECTED...NERN TO SRN GA...WRN SC CONCERNING...SEVERE THUNDERSTORM WATCH 47... VALID 052320Z - 060015Z THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 47 CONTINUES. SUMMARY...LINE OF SHOWERS WITH EMBEDDED TSTMS WILL PROGRESS E OF WW 47 IN THE NEXT HOUR. A THREAT FOR LOCALIZED DAMAGING WINDS SHOULD STILL PERSIST FOR A FEW MORE HOURS...BUT MAY REMAIN TOO MARGINAL TO WARRANT A NEW WW OR AREAL EXTENSION OF WW 47. DISCUSSION...NNE-SW ORIENTED QLCS EXTENDED FROM NERN GA INTO FAR SERN AL AS OF 2315Z...WITH CLOUD TOPS HAVING WARMED AND LIGHTNING TRENDS SUBSIDING SOMEWHAT OVERALL COMPARED TO A FEW HOURS AGO. FAR NRN PORTION OF THIS LINE INTERSECTS A QUASI-STATIONARY FRONT IN NWRN SC. WITH A MOSTLY LEADING STRATIFORM MODE AMIDST A MINIMALLY BUOYANT AIR MASS...THE PROSPECT FOR AN APPRECIABLE INCREASE IN INTENSITY ON THE NRN HALF OF THE QLCS APPEARS UNLIKELY. NEVERTHELESS...WITH THE LLJ STRENGTHENING THIS EVENING...IT IS POSSIBLE THAT DOWNWARD MOMENTUM TRANSPORT COULD STILL SUPPORT LOCALIZED WIND GUSTS CAPABLE OF PRODUCING TREE DAMAGE. FARTHER S FROM CNTRL GA SWD...WHERE SURFACE TEMPERATURES HAD WARMED INTO THE UPPER 60S TO LOWER 70S AND LOW-LEVEL LAPSE RATES ARE STEEPER...AN OCCASIONAL FLAREUP ALONG THE QLCS COULD SUPPORT ISOLATED DAMAGING WINDS. HOWEVER...AS THE BOUNDARY LAYER BEGINS TO STABILIZE AND WITH THE STRONGER FORCING FOR ASCENT PULLING AWAY TO THE NE DURING THE EVENING...SEVERE THREAT HERE SHOULD WANE. ..GRAMS.. 03/05/2013 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...CAE...GSP...FFC...TAE... LAT...LON 34998279 34958169 33678187 32268258 31318348 31408502 32078480 32548390 33518342 34938289 34998279