122 ACUS01 KWNS 250055 SWODY1 SPC AC 250053 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0653 PM CST FRI FEB 24 2012 VALID 250100Z - 251200Z ...NO SVR TSTM AREAS FORECAST... ...NC OUTER BANKS... WEAKENING SHOWERS WITH A FEW EMBEDDED TSTMS SHOULD CONTINUE TO RAPIDLY PROGRESS EWD ALONG THE ERN NC COAST DURING THE NEXT HOUR. 50 KT SWLYS AT 2000 FT AGL DEPICTED IN THE 00Z MHX RAOB SUPPORTS POTENTIAL FOR A STRONG WIND GUST OR TWO BEFORE ACTIVITY PUSHES OFFSHORE. ELSEWHERE...SPORADIC ELEVATED TSTMS SHOULD PERSIST ALONG PORTIONS OF THE WRN GULF COAST WITHIN A MID-LEVEL MOISTURE PLUME DOWNSTREAM OF A SHORT WAVE IMPULSE OVER CHIHUAHUA. FINALLY...A FEW LIGHTNING STRIKES MAY DEVELOP ALONG PORTIONS OF THE WA/ORE COAST TONIGHT AS AN UPPER-LEVEL TROUGH SHIFTS INLAND AND MID-LEVEL LAPSE RATES STEEPEN. ..GRAMS.. 02/25/2012  704 ACUS01 KWNS 250520 SWODY1 SPC AC 250518 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1118 PM CST FRI FEB 24 2012 VALID 251200Z - 261200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... A PROGRESSIVE PATTERN WILL EMERGE ACROSS THE CONUS TODAY. AN AMPLIFIED TROUGH ACROSS THE EASTERN THIRD OF THE COUNTRY IS EXPECTED TO CONTINUE E/NEWD...LIFTING INTO NEW ENGLAND BEFORE MOVING OFFSHORE INTO THE WESTERN ATLANTIC. AT THE SFC...STRONG HIGH PRESSURE WILL BUILD EWD FROM THE CENTRAL STATES INTO THE OHIO VALLEY AND SOUTHEAST...LEAVING A VERY DRY AIR MASS IN THE WAKE OF THE AFOREMENTIONED TROUGH. FURTHER SOUTH...A SHORTWAVE DISTURBANCE NEAR THE S TX/MEXICO BORDER AT THE BEGINNING OF THE PERIOD WILL TRACK EWD ACROSS FAR S TX THIS MORNING BEFORE MOVING INTO THE WRN GULF AND TOWARD SRN LA BY SUNDAY MORNING. ...FAR SOUTH TX... WHILE THE AFOREMENTIONED SOUTHERN STREAM SHORTWAVE DISTURBANCE WILL PROVIDE SOME UPPER LEVEL SUPPORT FOR DEEP LAYER ASCENT...A FEW FACTORS WILL LIMIT THUNDERSTORM POTENTIAL TODAY. THE FIRST BEING THE VERY MARGINAL NATURE OF BUOYANCY AVAILABLE TO SUSTAIN UPDRAFTS /LESS THAN A COUPLE HUNDRED J/KG AT BEST...MAINLY ABOVE 700 MB/. ADDITIONALLY...RELATIVELY WARM EQUILIBRIUM LEVEL TEMPERATURES WILL MITIGATE CHARGE SEPARATION DUE TO LIMITED ICE CRYSTAL PRODUCTION. A 10 PERCENT THUNDER AREA WILL THEREFORE NOT BE DELINEATED AT THIS TIME ALTHOUGH A STRIKE OR TWO IS POSSIBLE IN THE 12-15Z TIME FRAME UNTIL THE SHORTWAVE TROUGH MOVES OFFSHORE AND A FEW STRIKES WILL THEN BE POSSIBLE OVER THE GULF WATERS. ..LEITMAN/GRAMS/MOSIER.. 02/25/2012  847 ACUS02 KWNS 250548 SWODY2 SPC AC 250547 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1147 PM CST FRI FEB 24 2012 VALID 261200Z - 271200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... PROGRESSIVE AND SOMEWHAT HIGH-AMPLITUDE SHORTWAVE PATTERN IS FCST ACROSS CONUS THROUGH DAY-2. TROUGHING NOW OVER SERN CANADA AND ERN CONUS WILL HAVE MOVED AWAY BY START OF PERIOD...WHILE PERTURBATION NOW OVER COASTAL PAC NW MOVES EWD AND FORMS CLOSED 500-MB LOW OVER ND. IN SRN STREAM...CLOSED LOW NOW OVER N-CENTRAL MEX WILL DEAMPLIFY/ACCELERATE ENEWD...REACHING PORTIONS MS/AL IN FORM OF POSITIVELY TILTED/WEAKENING VORTICITY BANNER BY 26/12Z...THEN MOVING OFFSHORE CAROLINAS BETWEEN 27/00Z-27/06Z. SEPARATE SHORTWAVE TROUGHS -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER SERN AK MAINLAND AND OVER WRN PORTIONS GULF OF AK -- ARE FCST TO PHASE LATE IN PERIOD. THIS SHOULD RESULT IN DEEP SHORTWAVE TROUGH OVER PAC TIME ZONE...PERHAPS FORMING ELONGATED AND CLOSED CYCLONE BY 27/12Z OVER SIERRA NV...NERN CA HIGH DESERTS AND/OR PORTIONS CENTRAL/ERN ORE. AT SFC...COLD FRONT NOW MOVING SEWD OVER FL AND CENTRAL/SERN GULF OF MEXICO WILL DECELERATE/STALL DAY-1 OVER E-CENTRAL THROUGH SWRN GULF...WITH SOME NWD RETREAT PSBL LATE IN PERIOD OFFSHORE VERACRUZ/TAMPICO CORRIDOR. HOWEVER...SFC FRONT SHOULD REMAIN WELL SE OF BRO THROUGH PERIOD. ...ERN GULF COAST... WIDELY SCATTERED TO SCATTERED ELEVATED TSTMS SHOULD DEVELOP OVER PORTIONS CENTRAL/NERN GULF. ACTIVITY WILL OCCUR IN ELONGATED/LOW-LEVEL WAA CONVEYOR ABOVE POSTFRONTAL BOUNDARY LAYER...AND ASSOCIATED WITH DEAMPLIFYING PERTURBATION PASSING OVER SERN CONUS. GREATEST ELEVATED BUOYANCY WILL BE OVER CENTRAL/NERN GULF...DECREASING CONSIDERABLY WITH NEWD EXTENT. NRN PERIPHERY OF THIS ACTIVITY MAY BRUSH COASTAL AREAS OF FL PANHANDLE OR NW FL. HOWEVER...LACK OF MORE ROBUST INSTABILITY ALOFT INDICATES POTENTIAL INLAND IS TOO LOW/CONDITIONAL FOR CATEGORICAL OUTLOOK ATTM. ..EDWARDS.. 02/25/2012  912 ACUS03 KWNS 250648 SWODY3 SPC AC 250646 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1246 AM CST SAT FEB 25 2012 VALID 271200Z - 281200Z ...SYNOPSIS... WRN CONUS TROUGH AMPLIFICATION DISCUSSED IN DAY-2 OUTLOOK SHOULD RESULT IN DEVELOPMENT OF EMBEDDED CYCLONE OVER GREAT BASIN DURING 17/12Z-18/00Z TIME FRAME. 500-MB LOW THEN SHOULD MOVE ENEWD ACROSS WY BY END OF PERIOD...S OF WHICH BROAD BELT OF CYCLONIC FLOW WILL PREVAIL. AT 250 MB...NEARLY CONJOINED SWLY JET MAXIMA OF 125-140 KT ARE POSSIBLE OVER NRN CHIHUAHUA...FAR W TX AND NM BY END OF PERIOD. STG...FULL-LATITUDE...LOW-LEVEL WAA REGIME WILL BE UNDERWAY OVERNIGHT AS LLJ MAX STRENGTHENS TO AOA 60 KT OVER CENTRAL LOW PLAINS AND LOWER MO VALLEY REGION. AT SFC...INITIAL CYCLONE OVER GREAT BASIN SHOULD SHIFT ENEWD OVER INTERMOUNTAIN REGION TO WY IN STEP WITH MID-UPPER CYCLONE. AFTER 00Z...STG SFC CYCLOGENESIS AND COLD FRONTOGENESIS IS FCST OVER CENTRAL HIGH PLAINS...WHILE WARM FRONTOGENESIS OCCURS EWD ACROSS CENTRAL PLAINS. PROGS STILL VARY CONSIDERABLY ON DETAILS OF STRENGTH/POSITION OF SFC LOW AT END OF PERIOD...AS WELL AS WARM-FRONTAL POSITION/EVOLUTION THROUGH 28/00Z-28/12Z TIME FRAME. COLD FRONT NOW EVIDENT OVER SWRN/CENTRAL GULF AND FL PENINSULA SHOULD STALL DAY-2...THEN BECOME DIFFUSE/SHALLOW OVER WRN GULF DAY-3 AS LIMITED MOISTURE RETURNS NWD OVER SRN/CENTRAL PLAINS. THOUGH AIRMASS MODIFICATION WILL BE FAR FROM COMPLETE...SFC DEW POINTS 50S F MAY RETURN TO PORTIONS KS/OK BY END OF PERIOD...60S IN CENTRAL/S TX. BY 28/12Z...DIFFUSE DRYLINE MAY DEFINE WRN BOUND OF MRGL MOIST SECTOR...FROM WRN KS SSWWD ACROSS PERMIAN BASIN REGION OF W TX. ...CENTRAL CONUS... STG DEEP-LAYER SHEAR AND LARGE LOW-LEVEL HODOGRAPHS ARE SHOWN IN FCST SOUNDING ACROSS MUCH OF SRN/CENTRAL PLAINS. WITH MORE MOISTURE...THIS PATTERN COULD PRODUCE SUBSTANTIAL SEVERE-WEATHER EVENT. HOWEVER...DIURNAL/SFC-BASED CONVECTION E OF ROCKIES WILL BE LIMITED...IF NOT ENTIRELY PREVENTED...BY STG CAPPING RELATED TO ADVECTION OF ELEVATED MIXED-LAYER AIR OVER IMMATURE MOIST SECTOR. LOW-LEVEL WAA/MOISTURE TRANSPORT MAY BE SUFFICIENT FOR ELEVATED TSTMS TO DEVELOP AFTER DARK FROM ERN OK/WRN AR REGION NWD ACROSS ERN NEB/WRN IA...BUT ROOTED WELL ABOVE SFC WITH MUCAPE AOB 500 J/KG MOST AREAS. OVERNIGHT SVR POTENTIAL APPEARS TOO WEAK/CONDITIONAL FOR 5% SVR AREA WITH WAA PLUME ATTM. OTHERWISE...ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE OVER GREAT BASIN/CENTRAL INTERMOUNTAIN/CENTRAL ROCKIES REGION...UNDER COLD-CORE REGION OF MID-UPPER CYCLONE. WEAK LOW-LEVEL THETAE WILL PRECLUDE ORGANIZED SVR THREAT. ..EDWARDS.. 02/25/2012  412 ACUS03 KWNS 250655 SWODY3 SPC AC 250654 DAY 3 CONVECTIVE OUTLOOK CORR 1 NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CST SAT FEB 25 2012 VALID 271200Z - 281200Z CORRECTED FOR DATE TYPOS ...SYNOPSIS... WRN CONUS TROUGH AMPLIFICATION DISCUSSED IN DAY-2 OUTLOOK SHOULD RESULT IN DEVELOPMENT OF EMBEDDED CYCLONE OVER GREAT BASIN DURING 27/12Z-28/00Z TIME FRAME. 500-MB LOW THEN SHOULD MOVE ENEWD ACROSS WY BY END OF PERIOD...S OF WHICH BROAD BELT OF CYCLONIC FLOW WILL PREVAIL. AT 250 MB...NEARLY CONJOINED SWLY JET MAXIMA OF 125-140 KT ARE POSSIBLE OVER NRN CHIHUAHUA...FAR W TX AND NM BY END OF PERIOD. STG...FULL-LATITUDE...LOW-LEVEL WAA REGIME WILL BE UNDERWAY OVERNIGHT AS LLJ MAX STRENGTHENS TO AOA 60 KT OVER CENTRAL LOW PLAINS AND LOWER MO VALLEY REGION. AT SFC...INITIAL CYCLONE OVER GREAT BASIN SHOULD SHIFT ENEWD OVER INTERMOUNTAIN REGION TO WY IN STEP WITH MID-UPPER CYCLONE. AFTER 00Z...STG SFC CYCLOGENESIS AND COLD FRONTOGENESIS IS FCST OVER CENTRAL HIGH PLAINS...WHILE WARM FRONTOGENESIS OCCURS EWD ACROSS CENTRAL PLAINS. PROGS STILL VARY CONSIDERABLY ON DETAILS OF STRENGTH/POSITION OF SFC LOW AT END OF PERIOD...AS WELL AS WARM-FRONTAL POSITION/EVOLUTION THROUGH 28/00Z-28/12Z TIME FRAME. COLD FRONT NOW EVIDENT OVER SWRN/CENTRAL GULF AND FL PENINSULA SHOULD STALL DAY-2...THEN BECOME DIFFUSE/SHALLOW OVER WRN GULF DAY-3 AS LIMITED MOISTURE RETURNS NWD OVER SRN/CENTRAL PLAINS. THOUGH AIRMASS MODIFICATION WILL BE FAR FROM COMPLETE...SFC DEW POINTS 50S F MAY RETURN TO PORTIONS KS/OK BY END OF PERIOD...60S IN CENTRAL/S TX. BY 28/12Z...DIFFUSE DRYLINE MAY DEFINE WRN BOUND OF MRGL MOIST SECTOR...FROM WRN KS SSWWD ACROSS PERMIAN BASIN REGION OF W TX. ...CENTRAL CONUS... STG DEEP-LAYER SHEAR AND LARGE LOW-LEVEL HODOGRAPHS ARE SHOWN IN FCST SOUNDING ACROSS MUCH OF SRN/CENTRAL PLAINS. WITH MORE MOISTURE...THIS PATTERN COULD PRODUCE SUBSTANTIAL SEVERE-WEATHER EVENT. HOWEVER...DIURNAL/SFC-BASED CONVECTION E OF ROCKIES WILL BE LIMITED...IF NOT ENTIRELY PREVENTED...BY STG CAPPING RELATED TO ADVECTION OF ELEVATED MIXED-LAYER AIR OVER IMMATURE MOIST SECTOR. LOW-LEVEL WAA/MOISTURE TRANSPORT MAY BE SUFFICIENT FOR ELEVATED TSTMS TO DEVELOP AFTER DARK FROM ERN OK/WRN AR REGION NWD ACROSS ERN NEB/WRN IA...BUT ROOTED WELL ABOVE SFC WITH MUCAPE AOB 500 J/KG MOST AREAS. OVERNIGHT SVR POTENTIAL APPEARS TOO WEAK/CONDITIONAL FOR 5% SVR AREA WITH WAA PLUME ATTM. OTHERWISE...ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE OVER GREAT BASIN/CENTRAL INTERMOUNTAIN/CENTRAL ROCKIES REGION...UNDER COLD-CORE REGION OF MID-UPPER CYCLONE. WEAK LOW-LEVEL THETAE WILL PRECLUDE ORGANIZED SVR THREAT. ..EDWARDS.. 02/25/2012  240 ACUS48 KWNS 250959 SWOD48 SPC AC 250959 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0359 AM CST SAT FEB 25 2012 VALID 281200Z - 041200Z ...DISCUSSION... WRN CONUS TROUGHING DESCRIBED IN DAY-3 OUTLOOK WILL LEAD TO STG/DEEP-LAYER CYCLONE TRACKING FROM CENTRAL HIGH PLAINS TO UPPER MS VALLEY DAY-4/28TH-29TH. MOST CONFIDENT SVR POTENTIAL...INCLUDING THREAT FOR TORNADOES...IS OVERNIGHT OVER PORTIONS OZARKS/MID-SOUTH/ARKLATEX REGIONS. STG MID-UPPER WINDS -- I.E. 50-70 KT AT 500 MB -- AND HODOGRAPH-ENLARGING LLJ SHOULD OVERSPREAD SFC DEW POINTS INCREASING TO 60S F. FARTHER N...PRIND MOISTURE RETURN WILL BE MEAGER INTO AREA NEAR SFC LOW...ALTHOUGH STRENGTH OF DEEP-LAYER LIFT AND WIND FIELDS SHOULD BE SUFFICIENT TO SUPPORT AT LEAST MRGL SVR THREAT WITH ANY SUSTAINED/SFC-BASED CONVECTION THAT CAN FORM. POTENTIAL OVER CORN BELT APPEARS TOO CONDITIONAL ATTM TO EXTEND CATEGORICAL AREA THERE. MIDWEST SYSTEM SHOULD DEAMPLIFY SOMEWHAT AND OUTPACE GULF MOISTURE RETURN DAY-5/29TH-1ST...THOUGH SVR POTENTIAL IN SRN APPALACHIANS/PIEDMONT REGION AND CAROLINAS CANNOT BE RULED OUT. NEXT SUBSTANTIAL MID-UPPER TROUGH SHOULD CROSS CENTRAL/NRN ROCKIES DAY-6/1ST-2ND...WITH SFC CYCLOGENESIS OVER CENTRAL HIGH PLAINS. SOME SVR IS POSSIBLE DAYS 6-7/1ST-3RD FROM SRN/CENTRAL PLAINS TOWARD LOWER OH VALLEY AS SFC CYCLONE EJECTS FROM HIGH PLAINS...HOWEVER SPREAD IN VARIOUS MREF/OPERATIONAL PROGS IS TOO LARGE TO ASSIGN CATEGORICAL OUTLOOK ATTM. ..EDWARDS.. 02/25/2012  287 ACUS01 KWNS 251257 SWODY1 SPC AC 251255 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0655 AM CST SAT FEB 25 2012 VALID 251300Z - 261200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... PATTERN WILL REMAIN PROGRESSIVE THIS PERIOD...WITH THE MAIN BELT OF THE WLYS CONTINUING FROM THE PACIFIC NW/NRN GRT BASIN ACROSS THE MID/UPR MS VLYS TO THE MID ATLANTIC CST. FARTHER S...A WEAKER SRN BRANCH WILL PREVAIL FROM NRN MEXICO TO N FL. THE TRAILING SW PART OF THE DEEP TROUGH THAT AFFECTED THE ERN/SERN U.S. YESTERDAY IS OVER THE OH VLY ATTM. THIS FEATURE WILL CONTINUE E TO THE MID ATLANTIC REGION BY EARLY AFTN AND OFF THE MID ATLANTIC CST TNGT. VERY COOL MID LVL TEMPS /AOB MINUS 30 C AT 500 MB/ WILL CONTRIBUTE TO VERY STEEP LOW LVL LAPSE RATES/SCTD CONVECTION FROM THE CNTRL APPALACHIANS NE INTO PARTS OF NY/NJ AND SRN NEW ENGLAND BY AFTN. AN OCCASIONAL LIGHTNING STRIKE MAY OCCUR GIVEN CYCLONIC/WEAKLY CONFLUENT NATURE OF LOW LVL FLOW. HOWEVER...RELATIVELY DRY/COOL LOW LVL PROFILES AND...LATER TODAY...INCREASING SUBSIDENCE SHOULD PRECLUDE MORE WIDESPREAD ACTIVITY. IN THE SRN BRANCH...WEAK INSTABILITY IS PRESENT IN THE 700-500 MB LAYER OVER DEEP S TX...AHEAD OF WEAKENING DISTURBANCE MOVING ENE FROM NE MEXICO. SATELLITE SUGGESTS THAT APPRECIABLE ASCENT IS OCCURRING OVER THE REGION ATTM. THIS ASCENT SHOULD...HOWEVER... MOVE E INTO THE GULF THIS AFTN AS THE TROUGH DEAMPLIFYS AND CONTINUES ENE TOWARD SRN LA. A STRAY LIGHTNING STRIKE OR TWO COULD OCCUR THIS MORNING OVER DEEP S TX AND THE ADJACENT CSTL WATERS AS THE ZONE OF ASCENT ENCOUNTERS MAX PW AXIS NOW PRESENT THERE. BUT CONTINUED PROGRESSION OF UPR IMPULSE...AND SHALLOW/WARM NATURE OF THE ELEVATED BUOYANCY...SUGGEST THAT SUSTAINED TSTMS ARE UNLIKELY. ELSEWHERE...WARM LAYER ALOFT SHOULD PROHIBIT STORM DEVELOPMENT ALONG WEAKENING/INCREASINGLY SHALLOW COLD FRONT CROSSING S FL...AND DRY/COOL PROFILES SHOULD KEEP ANY LIGHTNING VERY ISOLD AS UPR TROUGH NOW CROSSING WA CONTINUES ESE INTO ID LATER TODAY. ..CORFIDI/JIRAK.. 02/25/2012  888 ACUS01 KWNS 251606 SWODY1 SPC AC 251604 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1004 AM CST SAT FEB 25 2012 VALID 251630Z - 261200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... A PROGRESSIVE LARGE-SCALE PATTERN WILL CONTINUE...FEATURING THE EWD TRANSLATION OF A SHORT-WAVE TROUGH OFF THE E COAST...DOWNSTREAM FROM AN AMPLIFYING IMPULSE ADVANCING FROM THE NRN ROCKIES INTO NRN PLAINS. ELSEWHERE...A SUBTROPICAL-BRANCH PERTURBATION OVER S TX WILL WEAKEN WHILE LIFTING NEWD ALONG THE CNTRL GULF COAST. IN THE LOW LEVELS...AN EXPANSIVE SURFACE ANTICYCLONE WILL BUILD FROM THE SRN PLAINS TO CNTRL APPALACHIANS BY 26/12Z...EFFECTIVELY DRIVING A COLD FRONT THROUGH THE REMAINDER OF THE FL PENINSULA. MEANWHILE...A SURFACE LOW AND ATTENDANT PACIFIC FRONT OVER THE NRN ROCKIES INTO GREAT BASIN WILL PROGRESS EWD INTO THE NRN/CNTRL PLAINS TONIGHT INTO SUN MORNING. ISOLATED LIGHTNING STRIKES WILL POSSIBLE TODAY FROM PORTIONS OF THE WA/ORE COASTS INTO ID ON CYCLONIC SIDE OF 90-100 KT MIDLEVEL JET STREAK WHERE DEEP ASCENT AND COLD THERMODYNAMIC PROFILES WILL SUPPORT SHALLOW CONVECTION. OVER S FL...AN ISOLATED LIGHTNING STRIKE CANNOT BE RULED OUT...HOWEVER THE PRESENCE OF WARM MIDLEVEL TEMPERATURES WILL PROHIBIT THE DEVELOPMENT OF DEEPER CONVECTIVE UPDRAFTS. ELSEWHERE...A FEW LIGHTNING STRIKES WILL BE POSSIBLE ALONG THE S TX COAST AND IMMEDIATE COASTAL WATERS LATE THIS MORNING/EARLY AFTERNOON...AND THEN ALONG THE CNTRL GULF COAST LATE TONIGHT INTO SUN MORNING IN ADVANCE OF WEAKENING SUBTROPICAL IMPULSE. IN ALL CASES MENTIONED ABOVE...LIGHTNING POTENTIAL APPEARS TOO LIMITED TO WARRANT INCLUSION OF A GENERAL TSTM AREA. ..MEAD.. 02/25/2012  000 ACUS02 KWNS 251730 SWODY2 SPC AC 251729 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1129 AM CST SAT FEB 25 2012 VALID 261200Z - 271200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS... A FAIRLY PROGRESSIVE UPPER FLOW REGIME WILL PERSIST OVER THE CONUS THROUGH SUNDAY. RELEVANT TO CONVECTIVE POTENTIAL /ALBEIT LOW/...A SOUTHERN STREAM SHORTWAVE TROUGH NEAR COASTAL TX THIS AFTERNOON IS EXPECTED TO CONTINUE /AND OTHERWISE WEAKEN/ EAST-NORTHEASTWARD ACROSS THE GULF COAST/SOUTHEAST STATES ON SUNDAY. IN THE WEST...AN UPPER TROUGH IS EXPECTED TO AMPLIFY/DIG SOUTH-SOUTHEASTWARD ALONG THE ORE/CA COAST ESPECIALLY THE LAST HALF OF SUNDAY INTO EARLY MONDAY. ...FL GULF COAST... IN ASSOCIATION WITH THE AFOREMENTIONED WEAKENING SHORTWAVE TROUGH CROSSING THE GULF COAST/SOUTHEAST STATES...WEAK DPVA AND WARM ADVECTION ATOP A POST-FRONTAL COOL/STABLE BOUNDARY LAYER WILL CONTRIBUTE TO SHOWERS/SOME TSTMS SUNDAY ACROSS THE OPEN GULF OF MEXICO WATERS...PERHAPS AS FAR NORTHEAST AS THE NEAR-COASTAL AREAS OF NORTHWEST FL. THE 12Z NAM APPEARS MOST FAVORABLE OF THE POTENTIAL...ALBEIT WITH DEPICTIONS OF ONLY SCANT CAPE BASED AROUND 750-800 MB. THAT SAID...THE TSTM POTENTIAL STILL APPEARS TOO LOW/UNCERTAIN IN THE DAY 2 JUNCTURE TO WARRANT A TSTM OUTLOOK FOR INLAND/NEAR-COASTAL AREAS OF FL. ...NORTHERN/CENTRAL CA COASTAL AREAS... TIED TO THE AMPLIFYING WEST COAST UPPER TROUGH...ANY TSTM POTENTIAL LATE SUNDAY APPEARS TOO LOW/FOCUSED OFFSHORE TO WARRANT A TSTM OUTLOOK GIVEN AN EXPECTED LACK OF MOISTENING/DESTABILIZATION TOWARD INLAND AREAS. ..GUYER.. 02/25/2012  656 ACUS01 KWNS 252001 SWODY1 SPC AC 251959 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0159 PM CST SAT FEB 25 2012 VALID 252000Z - 261200Z ...NO TSTM AREAS FORECAST... ...SYNOPSIS/FORECAST... NO CHANGES TO PRIOR OUTLOOK/THINKING AS BELOW. ..GUYER.. 02/25/2012 .PREV DISCUSSION... /ISSUED 1004 AM CST SAT FEB 25 2012/ ...SYNOPSIS/FORECAST... A PROGRESSIVE LARGE-SCALE PATTERN WILL CONTINUE...FEATURING THE EWD TRANSLATION OF A SHORT-WAVE TROUGH OFF THE E COAST...DOWNSTREAM FROM AN AMPLIFYING IMPULSE ADVANCING FROM THE NRN ROCKIES INTO NRN PLAINS. ELSEWHERE...A SUBTROPICAL-BRANCH PERTURBATION OVER S TX WILL WEAKEN WHILE LIFTING NEWD ALONG THE CNTRL GULF COAST. IN THE LOW LEVELS...AN EXPANSIVE SURFACE ANTICYCLONE WILL BUILD FROM THE SRN PLAINS TO CNTRL APPALACHIANS BY 26/12Z...EFFECTIVELY DRIVING A COLD FRONT THROUGH THE REMAINDER OF THE FL PENINSULA. MEANWHILE...A SURFACE LOW AND ATTENDANT PACIFIC FRONT OVER THE NRN ROCKIES INTO GREAT BASIN WILL PROGRESS EWD INTO THE NRN/CNTRL PLAINS TONIGHT INTO SUN MORNING. ISOLATED LIGHTNING STRIKES WILL POSSIBLE TODAY FROM PORTIONS OF THE WA/ORE COASTS INTO ID ON CYCLONIC SIDE OF 90-100 KT MIDLEVEL JET STREAK WHERE DEEP ASCENT AND COLD THERMODYNAMIC PROFILES WILL SUPPORT SHALLOW CONVECTION. OVER S FL...AN ISOLATED LIGHTNING STRIKE CANNOT BE RULED OUT...HOWEVER THE PRESENCE OF WARM MIDLEVEL TEMPERATURES WILL PROHIBIT THE DEVELOPMENT OF DEEPER CONVECTIVE UPDRAFTS. ELSEWHERE...A FEW LIGHTNING STRIKES WILL BE POSSIBLE ALONG THE S TX COAST AND IMMEDIATE COASTAL WATERS LATE THIS MORNING/EARLY AFTERNOON...AND THEN ALONG THE CNTRL GULF COAST LATE TONIGHT INTO SUN MORNING IN ADVANCE OF WEAKENING SUBTROPICAL IMPULSE. IN ALL CASES MENTIONED ABOVE...LIGHTNING POTENTIAL APPEARS TOO LIMITED TO WARRANT INCLUSION OF A GENERAL TSTM AREA.