109
ACUS11 KWNS 220130
SWOMCD
SPC MCD 220129
SCZ000-NCZ000-GAZ000-220400-
MESOSCALE DISCUSSION 0203
NWS STORM PREDICTION CENTER NORMAN OK
0829 PM CDT SUN MAR 21 2010
AREAS AFFECTED...PORTIONS ERN GA...MUCH OF SC...EXTREME S-CENTRAL
NC.
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 220129Z - 220400Z
BAND OF CONVECTION EXPECTED TO INCREASE IN COVERAGE/ORGANIZATION
THROUGH ABOUT 04Z...WHILE MOVING NEWD FROM SAV RIVER REGION ACROSS
SC. POTENTIALLY DAMAGING GUSTS NEAR SVR LEVELS MAY OCCUR WITH
STRONGEST SEGMENTS/SMALL BOWS. MRGL TORNADO POTENTIAL ALSO EXISTS.
ATTM...SVR THREAT APPEARS TOO MRGL/CONDITIONAL FOR WW.
ENVIRONMENTAL SHEAR IS AND WILL REMAIN VERY FAVORABLE ACROSS THIS
REGION AHEAD OF FRONT DESCRIBED BELOW...70 KT THROUGH 0-6 KM AGL
WITH 0-1 KM SRH 200-400 J/KG. HOWEVER...LIMITING FACTORS WILL BE
THERMODYNAMIC. NEARLY NEUTRAL LAPSE RATES ALOFT WILL KEEP BUOYANCY
WEAK -- MUCAPE GENERALLY BELOW 300 J/KG MOST AREAS -- WITH SMALL
CAPE DENSITY. BUOYANT PROFILES WHOSE DEPTH CHANGES GREATLY WITH
JUST 1-2 DEG C OF THETAE CHANGE ALSO WILL LEAD TO WIDELY VARYING
EFFECTIVE SHEAR VALUES...AND FOR PREDOMINANTLY SHALLOW
PROFILES...LIMITING LIGHTNING PRODUCTION.
SFC MESOANALYSIS SHOWS LEADING/PRIMARY FRONTAL SEGMENT AS OF 01Z
BETWEEN ATL-AHN...SEWD TOWARD AYS AND WRN FRINGES JAX AREA...THEN
SWD ALONG FL PENINSULA. LOW LEVEL ASCENT/MOISTURE WILL BE
CONCENTRATED JUST AHEAD OF THIS BOUNDARY AS IT MOVES NEWD ACROSS
DISCUSSION AREA NEXT FEW HOURS. LOOSELY ORGANIZED BAND OF CONVECTION
-- WITH WIDELY SCATTERED EMBEDDED TSTMS -- HAS FORMED IN ZONE OF
MAXIMIZED CONVERGENCE/THETAE...AND WAS EVIDENT AT 00Z NEAR A VDI-AHN
LINE...EXPANDING IN WIDTH WITH NWWD EXTENT. MODIFIED RAOBS AND FCST
SOUNDINGS SUGGEST THETAE PLUME WILL SHIFT NEWD NEARLY IN STEP WITH
PRIMARY CONVECTIVE BAND. THEREFORE...ALTHOUGH NEAR-SFC AIR MASS
BECOMES MUCH MORE STABLE WITHIN SHORT DISTANCE NEWD FROM CURRENT
POSITION OF BAND...CONVECTION MAY BE MAINTAINED...AND PERHAPS EVEN
INCREASE IN MOVING ZONE OF WAA ACCOMPANYING BROAD/40-50 KT LLJ.
PORTIONS OF THIS ACTIVITY WILL BE REINFORCED BY LOW-LEVEL THETAE
ADVECTION...OFFSETTING STABILIZING EFFECTS OF SFC DIABATIC COOLING
JUST ENOUGH TO MAINTAIN EFFECTIVE INFLOW PARCELS ROOTED AT OR VERY
NEAR SFC. AS SUCH...DAMAGING GUST OR TORNADO CANNOT BE RULED OUT.
..EDWARDS.. 03/22/2010
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RAH...ILM...CHS...CAE...GSP...JAX...FFC...
LAT...LON 31958202 32878227 33948291 34548310 35298151 35018017
34097969 32987945 32927958 32777983 32627991 32587998
32588011 32458032 32518047 32378042 32268055 32298070
32208065 32098079 32068090 32028083 31848096 31568115
31178131 31298166 31618184 31958202
000
ACUS11 KWNS 220130
SWOMCD
SPC MCD 220129
SCZ000-NCZ000-GAZ000-220400-
MESOSCALE DISCUSSION 0203
NWS STORM PREDICTION CENTER NORMAN OK
0829 PM CDT SUN MAR 21 2010
AREAS AFFECTED...PORTIONS ERN GA...MUCH OF SC...EXTREME S-CENTRAL
NC.
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 220129Z - 220400Z
BAND OF CONVECTION EXPECTED TO INCREASE IN COVERAGE/ORGANIZATION
THROUGH ABOUT 04Z...WHILE MOVING NEWD FROM SAV RIVER REGION ACROSS
SC. POTENTIALLY DAMAGING GUSTS NEAR SVR LEVELS MAY OCCUR WITH
STRONGEST SEGMENTS/SMALL BOWS. MRGL TORNADO POTENTIAL ALSO EXISTS.
ATTM...SVR THREAT APPEARS TOO MRGL/CONDITIONAL FOR WW.
ENVIRONMENTAL SHEAR IS AND WILL REMAIN VERY FAVORABLE ACROSS THIS
REGION AHEAD OF FRONT DESCRIBED BELOW...70 KT THROUGH 0-6 KM AGL
WITH 0-1 KM SRH 200-400 J/KG. HOWEVER...LIMITING FACTORS WILL BE
THERMODYNAMIC. NEARLY NEUTRAL LAPSE RATES ALOFT WILL KEEP BUOYANCY
WEAK -- MUCAPE GENERALLY BELOW 300 J/KG MOST AREAS -- WITH SMALL
CAPE DENSITY. BUOYANT PROFILES WHOSE DEPTH CHANGES GREATLY WITH
JUST 1-2 DEG C OF THETAE CHANGE ALSO WILL LEAD TO WIDELY VARYING
EFFECTIVE SHEAR VALUES...AND FOR PREDOMINANTLY SHALLOW
PROFILES...LIMITING LIGHTNING PRODUCTION.
SFC MESOANALYSIS SHOWS LEADING/PRIMARY FRONTAL SEGMENT AS OF 01Z
BETWEEN ATL-AHN...SEWD TOWARD AYS AND WRN FRINGES JAX AREA...THEN
SWD ALONG FL PENINSULA. LOW LEVEL ASCENT/MOISTURE WILL BE
CONCENTRATED JUST AHEAD OF THIS BOUNDARY AS IT MOVES NEWD ACROSS
DISCUSSION AREA NEXT FEW HOURS. LOOSELY ORGANIZED BAND OF CONVECTION
-- WITH WIDELY SCATTERED EMBEDDED TSTMS -- HAS FORMED IN ZONE OF
MAXIMIZED CONVERGENCE/THETAE...AND WAS EVIDENT AT 00Z NEAR A VDI-AHN
LINE...EXPANDING IN WIDTH WITH NWWD EXTENT. MODIFIED RAOBS AND FCST
SOUNDINGS SUGGEST THETAE PLUME WILL SHIFT NEWD NEARLY IN STEP WITH
PRIMARY CONVECTIVE BAND. THEREFORE...ALTHOUGH NEAR-SFC AIR MASS
BECOMES MUCH MORE STABLE WITHIN SHORT DISTANCE NEWD FROM CURRENT
POSITION OF BAND...CONVECTION MAY BE MAINTAINED...AND PERHAPS EVEN
INCREASE IN MOVING ZONE OF WAA ACCOMPANYING BROAD/40-50 KT LLJ.
PORTIONS OF THIS ACTIVITY WILL BE REINFORCED BY LOW-LEVEL THETAE
ADVECTION...OFFSETTING STABILIZING EFFECTS OF SFC DIABATIC COOLING
JUST ENOUGH TO MAINTAIN EFFECTIVE INFLOW PARCELS ROOTED AT OR VERY
NEAR SFC. AS SUCH...DAMAGING GUST OR TORNADO CANNOT BE RULED OUT.
..EDWARDS.. 03/22/2010
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RAH...ILM...CHS...CAE...GSP...JAX...FFC...
LAT...LON 31958202 32878227 33948291 34548310 35298151 35018017
34097969 32987945 32927958 32777983 32627991 32587998
32588011 32458032 32518047 32378042 32268055 32298070
32208065 32098079 32068090 32028083 31848096 31568115
31178131 31298166 31618184 31958202
181
ACUS11 KWNS 211916
SWOMCD
SPC MCD 211915
FLZ000-212045-
MESOSCALE DISCUSSION 0202
NWS STORM PREDICTION CENTER NORMAN OK
0215 PM CDT SUN MAR 21 2010
AREAS AFFECTED...PORTIONS OF CENTRAL/SOUTHERN FL PENINSULA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 211915Z - 212045Z
A SEVERE THREAT MAY DEVELOP/INCREASE THROUGH 20-21Z ACROSS PORTIONS
OF THE SOUTH CENTRAL/EAST CENTRAL FL PENINSULA. A WATCH IS NOT
CURRENTLY ANTICIPATED...BUT CONVECTIVE TRENDS WILL CONTINUE TO BE
MONITORED.
A RELATIVE MAXIMA OF SURFACE PRESSURE FALLS ARE NOTED COINCIDENT
WITH RECENT CLOUD BREAKS ACROSS THE SOUTH CENTRAL FL
PENINSULA...SOUTH OF A NORTHEAST-SOUTHWEST ORIENTED/CONVECTIVE LINE
INDUCED RAIN-COOLED EFFECTIVE BOUNDARY. AHEAD OF THE AFOREMENTIONED
CONVECTIVE LINE...SOME QUASI-DISCRETE CELLULAR DEVELOPMENT HAS BEEN
NOTED OVER THE PAST HOUR IN THE GENERAL VICINITY OF SEBRING/AVON
PARK. WHILE A WARM LAYER ALOFT AROUND 700-800 MB NOTED PER A 16Z XMR
OBSERVED RAOB/MORE RECENT ACARS SOUNDINGS MAY STILL BE CAPPING MUCH
OF THE WARM SECTOR...NEAR SURFACE CINH CONTINUES TO GRADUALLY ERODE
GIVEN CLOUD BREAKS COINCIDENT WITH THE CONTINUED STEADY NORTHWARD
DEVELOPMENT OF UPPER 60S/AROUND 70 F SURFACE DEWPOINTS ACROSS THE
SOUTHERN HALF OF THE FL PENINSULA. AN INCREASINGLY WARM/MOIST
BOUNDARY LAYER...AND SUFFICIENT LOW LEVEL/STRONG DEEP LAYER WIND
PROFILES PER MLB/TBW DERIVED WSR-88D VWP DATA...SUPPORTS SOME
POSSIBILITY FOR AN INCREASING DAMAGING WIND/TORNADO RISK OVER THE
NEXT HOUR OR TWO...AT LEAST IN AN ISOLATED SENSE. THIS WOULD BE VIA
QUASI-DISCRETE DEVELOPMENT AHEAD OF/STORM MERGERS WITH THE
CONVECTIVE LINE AND/OR LINE-EMBEDDED TYPE CIRCULATIONS CAPABLE OF
DAMAGING WINDS/POSSIBLY A TORNADO...PERHAPS MOST LIKELY AS STORMS
INTERACT WITH THE EAST COAST VICINITY SEA BREEZE.
..GUYER.. 03/21/2010
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MFL...MLB...TBW...
LAT...LON 28078108 28208067 27918045 27178037 26218118 26818172
28078108
