Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 352

March 24, 201217 counties in Florida; 14 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 6:25 PM EDT for 17 counties in Florida; 14 counties in Georgia. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: Mar 24, 2012, 6:25 PM EDT (22:25 UTC)
Expired: Mar 24, 2012, 7:30 PM EDT
In force: 65 min
Issued by: the Storm Prediction Center

All 31 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Citrus County, FL, Clay County, FL, Columbia County, FL, Duval County, FL, Flagler County, FL, Gilchrist County, FL, Hamilton County, FL, Levy County, FL, Marion County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Suwannee County, FL, Union County, FL, Brantley County, GA, Bryan County, GA, Camden County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Echols County, GA, Glynn County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Pierce County, GA, Ware County, GA, Wayne County, GA

The radar

The Jacksonville radar (KJAX), 37 km from the middle of the area, began a volume at 22:25 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

Severe Thunderstorm Watch 110Mar 24, 8:45 PM EDT

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 10.4 hours before the alert went out and 36 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 139 J/kg
Mixed-layer CIN: -87 J/kg
Mixed-layer LCL: 982 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 90 m²/s²
0-3 km storm-relative helicity: 121 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

467 
ACUS11 KWNS 242225
SWOMCD
SPC MCD 242225 
FLZ000-SCZ000-GAZ000-242330-

MESOSCALE DISCUSSION 0352
NWS STORM PREDICTION CENTER NORMAN OK
0525 PM CDT SAT MAR 24 2012

AREAS AFFECTED...SERN GA...NRN FL PENINSULA

CONCERNING...SEVERE THUNDERSTORM WATCH 104...

VALID 242225Z - 242330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 104
CONTINUES.

REMAINING VALID PORTIONS OF SVR TSTM WATCH 104 SHOULD BE ALLOWED TO
EXPIRE ON SCHEDULE AT 23Z. EARLIER CONVECTIVE OVERTURNING ACROSS A
LARGE PART OF THE WW AREA HAS RESULTED IN SUFFICIENT STABILIZATION
TO GREATLY REDUCE ANY ADDITIONAL SVR THREAT ACROSS WW AREA. VISIBLE
SATELLITE IMAGERY REVEALS A BOUNDARY STRETCHING NE-SW ACROSS SERN GA
INTO THE FL PANHANDLE -- I.E. NEAR THE NRN FRINGES OF THE WW AREA --
REPRESENTING THE AGGREGATE EFFECTS OF A SEA BREEZE CONVERGENCE ZONE
AND CONVECTIVE OUTFLOW. THE SHALLOW NATURE OF THIS
FEATURE...COMBINED WITH THE INCREASINGLY NARROW WINDOW FOR DIURNAL
INSTABILITY...WILL GREATLY LIMIT ADDITIONAL CONVECTIVE POTENTIAL
INVOF THIS BOUNDARY. MEANWHILE...A BAND OF LOW-LEVEL CONFLUENCE OVER
THE NERN GULF OF MEXICO IS SUPPORTING CLUSTERS OF CONVECTION...WHICH
WILL APPROACH THE FL BIG BEND DURING THE NEXT COUPLE OF
HOURS...AFFECTING AREAS IMMEDIATELY SOUTH OF WW104. WHILE GUSTY
WINDS AND PERHAPS SOME SMALL HAIL WILL ACCOMPANY THIS ACTIVITY AS IT
MOVES ONSHORE...THIS AREA IS WELL REMOVED WELL SOUTH OF A ZONE OF
STRONGER DEEP-LAYER FLOW...WHICH WILL MITIGATE THE THREAT FOR MORE
ORGANIZED CONVECTION. FURTHERMORE...NOCTURNAL STABILIZATION OVER
INLAND AREAS WILL ALSO LIMIT STORM STRENGTH.

..COHEN.. 03/24/2012

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

ATTN...WFO...CHS...MLB...TBW...JAX...TAE...

LAT...LON   32158160 32128112 31858075 30978085 29888098 28898160
            28748252 29218307 30518313 31328269 31828211 32158160

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 24, 10:16 AM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 8 more	59 min
Mar 24, 10:45 AM EDT	Severe Thunderstorm Watch	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 7 more	8 hr
Mar 24, 12:29 PM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 4 more	61 min
Mar 24, 4:19 PM EDT	Mesoscale Discussion	SPC	Baker, Bradford, Clay, Columbia, Duval, Hamilton and 4 more	86 min
Mar 24, 4:16 PM EDT	Mesoscale Discussion	SPC	Richmond	59 min
Mar 24, 5:52 PM EDT	Mesoscale Discussion	SPC	Chattooga, Dade, Walker	53 min

Nearby

Mesoscale Discussions in Florida, 2012 Mesoscale Discussions in Georgia, 2012 Every mesoscale discussion in 2012

Sources

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.