Alert archive / Florida / Mesoscale Discussions in 2003

Mesoscale Discussion 451

April 9, 200318 counties in Florida; 16 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2003, 1:44 PM EDT for 18 counties in Florida; 16 counties in Georgia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 9, 2003, 1:44 PM EDT (17:44 UTC)
Expired
Apr 9, 2003, 3:45 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 34 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Clay County, FL, Columbia County, FL, Dixie County, FL, Duval County, FL, Flagler County, FL, Gilchrist County, FL, Hamilton County, FL, Lafayette County, FL, Madison County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Atkinson County, GA, Ben Hill County, GA, Berrien County, GA, Brantley County, GA, Brooks County, GA, Camden County, GA, Charlton County, GA, Clinch County, GA, Coffee County, GA, Cook County, GA, Echols County, GA, Irwin County, GA, Lanier County, GA, Lowndes County, GA, Pierce County, GA, Ware County, GA

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 5.7 hours before the alert went out and 115 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-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 2003-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 12:00Z on 2003-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 55 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
3 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
756 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
55 m²/s²
0-3 km storm-relative helicity
55 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.

860 
ACUS11 KWNS 091744
SWOMCD
SPC MCD 091744 
FLZ000-GAZ000-091945-

MESOSCALE DISCUSSION 0451
NWS STORM PREDICTION CENTER NORMAN OK
1244 PM CDT WED APR 09 2003

AREAS AFFECTED...PORTIONS NRN FL...SRN GA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 091744Z - 091945Z

SCATTERED TO WIDELY SCATTERED TSTMS IN A LINE WILL MOVE EWD
ACROSS PORTIONS SRN GA/NRN FL THROUGH AT LEAST 20Z.  OCCASIONAL
BOW/LEWP FORMATIONS MAY DEVELOP WITH POTENTIAL FOR GUSTS NEAR
SEVERE LEVELS.	WW NOT ANTICIPATED ATTM.

SFC MESOANALYSIS SHOWS SYNOPTIC FRONT FROM CENTRAL GA SSWWD
ACROSS APALACHEE BAY...UPON WHICH SOME TSTMS HAVE DEVELOPED. 
THIS FRONT WILL MOVE EWD 25-30 KT ACROSS REGION...REINFORCED BY
CONVECTIVE OUTFLOW.  ANOTHER FRONTAL ZONE -- DEMARCATING SRN
PERIPHERY OF MID ATLANTIC/CAROLINAS COLD-AIR DAMMING REGIME -- IS
QUASISTATIONARY ACROSS SRN GA FROM ABOUT 40 N VLD PAST AYS AND
OFFSHORE NEAR ST SIMONS ISLAND.  MODIFIED RAOBS AND RUC SOUNDINGS
SUGGEST SHALLOW MIXED BOUNDARY LAYER IN WARM SECTOR BETWEEN THESE
FRONTS...VERY RICH IN OBSERVED MOISTURE WITH SFC DEW POINTS LOW
70S F...AND WITH ROUGHLY 1500-2000 J/KG MLCAPE.  BOUNDARY LAYER
WINDS WILL CONTINUE WITH SIGNIFICANT WLY COMPONENT...MINIMIZING
POTENTIAL FOR STRONG CONVERGENCE ALONG CONVECTIVE LINE WITHOUT
FAST FORWARD MOTIONS TO ENHANCE SR INFLOW.  UNIDIRECTIONAL
VERTICAL WIND PROFILES ARE EXPECTED...SUGGESTING LINEAR
CONVECTIVE MODE WILL REMAIN FAVORED.  40-50 KT 0-6 KM AGL SHEAR
POSSIBLE...SUPPORTING POTENTIAL FOR A FEW MESOCYCLONES TO
DEVELOP...ALBEIT WITH LIMITED LIFESPANS.  ISOLATED HAIL IS ALSO
POSSIBLE.

..EDWARDS.. 04/09/2003

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

ATTN...WFO...MLB...TBW...JAX...FFC...TAE...

29558420 31858327 30968131 29098128

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 9, 11:44 AM EDTMesoscale DiscussionSPCBrevard, Broward, Charlotte, Collier, DeSoto, Glades and 15 more3 hr

Nearby

Mesoscale Discussions in Florida, 2003Mesoscale Discussions in Georgia, 2003Every mesoscale discussion in 2003

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.