Alert archive / Florida / Mesoscale Discussions in 2004

Mesoscale Discussion 2175

September 6, 200414 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2004, 7:48 AM EDT for 14 counties in Florida. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Sep 6, 2004, 7:48 AM EDT (11:48 UTC)
Expired
Sep 6, 2004, 9:15 AM EDT
In force
87 min
Issued by
the Storm Prediction Center

Counties Brevard County, FL, Charlotte County, FL, DeSoto County, FL, Hardee County, FL, Highlands County, FL, Lake County, FL, Lee County, FL, Manatee County, FL, Orange County, FL, Osceola County, FL, Polk County, FL, Sarasota County, FL, Seminole County, FL, Volusia County, FL

The watches that followed

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

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 11.8 hours before the alert went out and 51 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, Tampa Bay, FL at 00:00Z on 2004-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 joules per kilogram.10008507005003002001001 km2 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 00:00Z on 2004-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.1939Sfc1 km3 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
44 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
2432 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
155 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.

665 
ACUS11 KWNS 061151
SWOMCD
SPC MCD 061148 
FLZ000-061315-

MESOSCALE DISCUSSION 2175
NWS STORM PREDICTION CENTER NORMAN OK
0648 AM CDT MON SEP 06 2004

AREAS AFFECTED...CNTRL PENINSULA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 061148Z - 061315Z

POTENTIAL FOR TORNADOES WILL PERSIST ACROSS THE AREA THIS MORNING.
WW IS BEING ISSUED.

RADAR/IR SATELLITE IMAGERY INDICATE INTENSIFYING CONVECTIVE ELEMENTS
WITHIN RAINBAND FROM JUST S OF CHARLOTTE HARBOR NEWD INTO
POLK/OSCEOLA COUNTIES ON BACKSIDE OF FRANCES CIRCULATION. IT APPEARS
THAT LOCALIZED BOUNDARY-LAYER CONVERGENCE IS OVERCOMING
BROADER-SCALE PRESSURE RISES AND ENHANCING THIS CONVECTIVE BAND.
CURRENT TAMPA AND MELBOURNE VWPS INDICATE STRONG LOW-LEVEL SHEAR
THROUGH THIS SAME CORRIDOR WITH 0-1 KM SRH VALUES OF 300-400 J/KG.
THOUGH INSTABILITY REMAINS MARGINAL WITH MLCAPES OF AROUND 500
J/KG...CURRENT VISIBLE IMAGERY DOES SUGGEST SOME POTENTIAL FOR
DAYTIME HEATING AND RESULTANT DESTABILIZATION. 

GIVEN THE ANTICIPATED DECREASE IN STABILITY AND STRONG SHEAR
PROFILES...ENVIRONMENT IS EXPECTED TO BECOME INCREASINGLY FAVORABLE
FOR ISOLATED SUPERCELLS AND BRIEF TORNADOES.

..MEAD.. 09/06/2004

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

ATTN...WFO...MFL...MLB...TBW...JAX...

26468306 28428201 29318149 29018089 28168049 26358174
25948274

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 8:35 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more9 hr
Sep 6, 12:12 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more2 hr
Sep 6, 4:06 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more84 min
Sep 6, 4:50 AM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 11 more9 hr
Sep 6, 7:55 AM EDTTornado WatchSPCBrevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 21 more6 hr
Sep 6, 12:28 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 36 more92 min
Sep 6, 1:20 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 38 more7 hr
Sep 6, 3:55 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 10 more2 hr
Sep 6, 7:12 PM EDTMesoscale DiscussionSPCBaker, Columbia, Duval, Nassau, Union2 hr
Sep 6, 7:45 PM EDTTornado WatchSPCBradford, Clay, Duval, Flagler, Nassau, Putnam and 1 more9 hr

Nearby

Mesoscale Discussions in Florida, 2004Every 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.