Alert archive / Florida / Mesoscale Discussions in 2004

Mesoscale Discussion 1421

June 25, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2004, 4:51 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Jun 25, 2004, 4:51 PM CDT (21:51 UTC)
Expired: Jun 25, 2004, 6:15 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center

Counties Baldwin County, AL, Covington County, AL, Escambia County, AL, Mobile County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Plaquemines Parish, LA, Saint Bernard Parish, LA, George County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS

The radar

The Mobile radar (KMOB), 109 km from the middle of the area, began a volume at 21:51 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 523Jun 25, 5:10 PM CDT

The nearest sounding before it

Slidell Radar S, LA (KSIL), launched 12:00Z, 9.9 hours before the alert went out and 111 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: 149 J/kg
Mixed-layer CIN: -79 J/kg
Mixed-layer LCL: 908 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 171 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.9

Open this sounding in Storm Lab

The text

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

145 
ACUS11 KWNS 252151
SWOMCD
SPC MCD 252151 
FLZ000-ALZ000-MSZ000-LAZ000-252315-

MESOSCALE DISCUSSION 1421
NWS STORM PREDICTION CENTER NORMAN OK
0451 PM CDT FRI JUN 25 2004

AREAS AFFECTED...SRN MS...SRN AL...FL PANHANDLE

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 252151Z - 252315Z

...DAMAGING WINDS MAY ACCOMPANY SQUALL LINE AS IT PROPAGATES EWD
ALONG THE CENTRAL GULF COAST.  SEVERE THUNDERSTORM WATCH MAY BE
ISSUED..

AN EXPANSIVE AREA OF CONVECTION OVER THE CENTRAL GULF COAST STATES
HAS GENERATED A COLD POOL WHICH IN TURN APPEARS PARTLY RESPONSIBLE
FOR RECENT EWD SURGE TO SQUALL LINE ACROSS SRN MS.  LEADING EDGE OF
THE STRONGEST ACTIVITY IS MOVING ENEWD AT ROUGHLY 35KT AND WILL
SPREAD INTO SRN AL SHORTLY.  DAMAGING WINDS ARE POSSIBLE WITH THIS
CONVECTION AS IT SPREADS ALONG OLD OUTFLOW BOUNDARY FROM EARLIER
CONVECTION.

..DARROW.. 06/25/2004

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

ATTN...WFO...TAE...MOB...LIX...

28719032 29668952 30678951 31448624 30698551 28558938

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 25, 5:10 PM CDT	Severe Thunderstorm Watch	SPC	Baldwin, Coffee, Conecuh, Covington, Dale, Escambia and 5 more	5 hr
Jun 24, 7:31 PM CDT	Mesoscale Discussion	SPC	Saint Bernard	29 min

Nearby

Mesoscale Discussions in Florida, 2004 Mesoscale Discussions in Alabama, 2004 Mesoscale Discussions in Mississippi, 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.