Mesoscale Discussion 1252

Issued

Jun 23, 2012, 4:44 PM EDT (20:44 UTC)

Expired

Jun 23, 2012, 7:15 PM EDT

In force

3 hr

Issued by

the Storm Prediction Center

Chance of a watch

20%

Counties Charlotte County, FL, Collier County, FL, DeSoto County, FL, Hendry County, FL, Lee County, FL, Monroe County, FL, Sarasota County, FL

The Key West radar (KBYX), 123 km from the middle of the area, began a volume at 20:47 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

971 
ACUS11 KWNS 232045
SWOMCD
SPC MCD 232044
FLZ000-232315-

MESOSCALE DISCUSSION 1252
NWS STORM PREDICTION CENTER NORMAN OK
0344 PM CDT SAT JUN 23 2012

AREAS AFFECTED...PORTIONS SWRN FL PENINSULA...EVERGLADES...KEYS.

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 232044Z - 232315Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...TORNADO POTENTIAL CANNOT BE RULED OUT WITH OUTER/ERN-MOST
FRINGES OF CYCLONIC ENVELOPE OF SYSTEM OVER GULF.  THREAT APPEARS
TOO ISOLATED AND LIMITED IN AREAL EXTENT TO JUSTIFY WW ATTM.
STILL...THIS REGIME WILL BE MONITORED FOR SUBSTANTIAL CHANGES IN
ENVIRONMENTAL PARAMETERS AS LONG AS SOME PORTION OF THIS SYSTEM
REMAINS OVERLAND.

DISCUSSION...SFC MESOANALYSIS AND REFLECTIVITY ANIMATIONS INDICATE
CURVED CONVERGENCE BAND OFFSHORE SW COAST...ALONG WITH SUBTLE
DIFFERENTIAL-HEATING/OUTFLOW BOUNDARY FROM WRN COLLIER COUNTY NWD
NEAR GIF THAT APPEARS TO MARK WRN FRINGES OF MOST BUOYANT
BOUNDARY-LAYER AIR INLAND.  EYW-AREA VWP HAS EXHIBITED SMALL BUT
ENLARGING LOW-LEVEL HODOGRAPHS DURING PAST 1-2 HOURS...WITH ENOUGH
CURVATURE SUCH THAT DERIVED 0-1 KM AGL SRH HAS BEGUN TO EXCEED 150
J/KG IN SOME VOLUME SCANS...FOR SUBSTANTIALLY RIGHTWARD DEVIANT CELL
MOTIONS TOWARD SLIGHTLY E OF DUE N.  THIS REPRESENTS CONTINUING
GRADUAL INCREASE IN SRH SINCE 12Z RAOB THAT HAS CORRESPONDED WITH
STRENGTHENING OF PARENT SYSTEM NOTED BY NHC.  MEANWHILE...SFC TEMPS
80S F INLAND AND DEW POINTS MID-70S SUPPORT AREAS OF ROUGHLY 2000
J/KG MLCAPE IN MODIFIED RAOBS AND FCST SOUNDINGS.  MARINE BOUNDARY
LAYER ALSO WILL SUPPORT BUOYANT SFC-BASED PARCELS OVER LOWER-MIDDLE
KEYS FOR ANY ACTIVITY MOVING NWD FROM CUBA/STRAITS.  SRM ANIMATIONS
HAVE INDICATED INCREASE IN NUMBER OF CELLS WITH HORIZONTAL/CYCLONIC
SHEAR IN LOW LEVELS...OVER MAINLAND MONROE/COLLIER COUNTIES AS WELL
AS OFFSHORE...THOUGH BULK OF THOSE SIGNATURES HAVE REMAINED WEAKER
THAN THOSE TYPICAL OF MOST WELL-ORGANIZED SUPERCELLULAR TC TORNADO
EVENTS.  NONETHELESS...AT ABOUT 20Z...POSSIBLE TORNADO WAS REPORTED
WITH CELL NEAR APF THAT SINCE HAS BECOME ABSORBED BY OTHER
CONVECTION.

..EDWARDS/WEISS.. 06/23/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...MFL...KEY...TBW...

LAT...LON   27518271 27418216 27328175 26788109 25878061 25068049
            24708102 24548162 24508190 24548219 24638294 24648284
            24618211 24588174 24768156 24838132 25098114 25228117
            25368114 25508122 25708132 25888156 25908163 25808166
            26088182 26348185 26468198 26408209 26468220 26848230
            27518271

Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.