Alert archive / Florida / Mesoscale Discussions in 2004

Mesoscale Discussion 554

May 2, 200411 counties in Florida; Camden County, Glynn County, McIntosh County, Georgia

The Storm Prediction Center issued this mesoscale discussion at May 2, 2004, 11:32 AM EDT for 11 counties in Florida; Camden County, Glynn County, McIntosh County, Georgia. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 2, 2004, 11:32 AM EDT (15:32 UTC)
Expired: May 2, 2004, 2:00 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Brevard County, FL, Clay County, FL, Duval County, FL, Flagler County, FL, Nassau County, FL, Orange County, FL, Osceola County, FL, Putnam County, FL, Saint Johns County, FL, Seminole County, FL, Volusia County, FL, Camden County, GA, Glynn County, GA, McIntosh County, GA

The radar

The Jacksonville radar (KJAX), 112 km from the middle of the area, began a volume at 15:33 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 nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 3.5 hours before the alert went out and 114 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: 798 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 613 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 49 m²/s²
0-3 km storm-relative helicity: 41 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.

182 
ACUS11 KWNS 021532
SWOMCD
SPC MCD 021532 
FLZ000-GAZ000-021800-

MESOSCALE DISCUSSION 0554
NWS STORM PREDICTION CENTER NORMAN OK
1032 AM CDT SUN MAY 02 2004

AREAS AFFECTED...NRN FL PEN ATLANTIC COASTAL AREAS INTO SE GA

CONCERNING...CONVECTIVE TRENDS 

VALID 021532Z - 021800Z

CONVECTION APPEARS LIKELY TO INCREASE NEAR THE JACKSONVILLE/ORLANDO/
MELBOURNE AREAS BY MID AFTERNOON.  ISOLATED DOWNBURSTS ARE
POSSIBLE...BUT LOCALLY HEAVY RAIN MAY BECOME PRIMARY THREAT BY LATE
AFTERNOON.

SURFACE HEATING OF MOIST BOUNDARY LAYER WITH 70F+ SURFACE DEW POINTS
IS CONTRIBUTING TO WEAKENING CONVECTIVE INHIBITION ACROSS PARTS OF
THE NORTHERN FLORIDA PENINSULA AND SOUTHEASTERN GEORGIA.  LOW-LEVEL
CONFLUENT BAND APPEARS TO BE SETTING UP JUST INLAND OF COASTAL
AREAS...WHERE SEA BREEZE WILL ENHANCE CONVERGENCE THROUGH THE
AFTERNOON HOURS.  AS MEAN MIXED LAYER CAPE INCREASES UP TO 2000
J/KG...VIGOROUS CONVECTIVE DEVELOPMENT APPEARS LIKELY TO DEVELOP/
INCREASE THROUGH THE 18-21Z TIME FRAME.  THERMODYNAMIC ENVIRONMENT
APPEARS RATHER WARM FOR SUBSTANTIAL HAIL THREAT...THUNDERSTORM
ACTIVITY COULD BECOME FAIRLY EXTENSIVE BY LATE AFTERNOON...WITH 
LOCALLY HEAVY RAINFALL LIKELY IN SLOW MOVING STORMS.

..KERR.. 05/02/2004

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

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

28148146 28948156 29738200 30788213 31698178 31598116
30628140 29168106 28268058 27538094

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 2:37 AM EDT	Mesoscale Discussion	SPC	Bay, Calhoun, Escambia, Franklin, Gadsden, Gulf and 9 more	113 min
May 2, 12:33 PM EDT	Mesoscale Discussion	SPC	Baldwin, Bleckley, Bulloch, Burke, Candler, Columbia and 23 more	117 min
May 2, 1:10 PM EDT	Severe Thunderstorm Watch	SPC	Appling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 45 more	6 hr
May 2, 3:26 PM EDT	Mesoscale Discussion	SPC	Screven	2 hr
May 2, 4:50 PM EDT	Severe Thunderstorm Watch	SPC	Bryan, Chatham, Effingham, Liberty, Long	5 hr

Nearby

Mesoscale Discussions in Florida, 2004 Mesoscale Discussions in Georgia, 2004 Every mesoscale discussion in 2004

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.