Alert archive / Florida / Mesoscale Discussions in 2004

Mesoscale Discussion 47

January 26, 200415 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jan 26, 2004, 7:31 PM EST for 15 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jan 26, 2004, 7:31 PM EST (00:31 UTC)
Expired: Jan 26, 2004, 10:00 PM EST
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Alachua County, FL, Baker County, FL, Bradford County, FL, Citrus County, FL, Clay County, FL, Dixie County, FL, Duval County, FL, Gilchrist County, FL, Hernando County, FL, Levy County, FL, Marion County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Union County, FL

The radar

The Jacksonville radar (KJAX), 99 km from the middle of the area, began a volume at 00:33 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 00:00Z, 0.5 hours before the alert went out and 100 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: 1054 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 903 m above ground
0-6 km bulk shear: 60 kt
0-1 km storm-relative helicity: 219 m²/s²
0-3 km storm-relative helicity: 247 m²/s²
Significant tornado parameter: 1.6
Supercell composite: 5.7

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 270031
SWOMCD
SPC MCD 270031 
GAZ000-FLZ000-270300-

MESOSCALE DISCUSSION 0047
NWS STORM PREDICTION CENTER NORMAN OK
0631 PM CST MON JAN 26 2004

AREAS AFFECTED...NRN FL...N CNTRL FL PEN

CONCERNING...CONVECTIVE TRENDS 

VALID 270031Z - 270300Z

NEW WW IS NOT CURRENTLY ANTICIPATED.

WEAK SHORT WAVE TROUGH EMBEDDED WITHIN SUBTROPICAL MID/UPPER MOIST
PLUME NOW APPEARS TO BE SHIFTING NORTHEASTWARD OFF THE SOUTH
ATLANTIC COASTAL AREAS.  HOWEVER...MID-LEVEL SHEAR AXIS TRAILS TO
THE SOUTHWEST ACROSS NORTHERN FLORIDA...TO THE WEST OF
JACKSONVILLE...INTO THE NORTHEASTERN GULF OF MEXICO.  THIS FEATURE
IS PROVIDING FORCING/FOCUS FOR NARROW LEADING CONVECTIVE BAND ACROSS
NORTHERN FLORIDA...WHICH IS CURRENTLY MOST ACTIVE WITH REGARD TO
CLOUD TO GROUND LIGHTNING STRIKES.

ISENTROPIC ASCENT/LIFT OF MOIST...POTENTIALLY UNSTABLE PARCELS OFF
THE NORTHEASTERN GULF OF MEXICO...ALONG 40 KT SOUTH SOUTHWESTERLY
LOW-LEVEL JET.... IS PROVIDING LOW-LEVEL FORCING FOR THUNDERSTORM
ACTIVITY.  ALTHOUGH CONVECTION APPEARS CURRENTLY ROOTED ABOVE
BOUNDARY LAYER...OBJECTIVE ANALYSIS/MODEL FORECAST SOUNDINGS AND
LATEST RAOB DATA SUGGEST AIR MASS TO THE IMMEDIATE SOUTH/WEST OF
JACKSONVILLE STILL POSSESSES WEAK TO MODERATE SURFACE-BASED
INSTABILITY.

MEAN MIXED LAYER CAPE EXCEEDS 1000 J/KG...BUT WEAK MID-LEVEL LAPSE
RATES APPEARS LIKELY TO CONTINUE TO MINIMIZE HAIL THREAT.  VEERED
LOW-LEVEL FLOW IS NOW MINIMIZING SIZE AND CLOCKWISE CURVATURE OF
LOW-LEVEL HODOGRAPHS WHICH SHOULD LIMIT TORNADO THREAT.  AN ISOLATED
DAMAGING WIND GUST...HOWEVER...STILL APPEARS POSSIBLE WITH
UNSATURATED MID-LEVEL AIR MASS ENHANCING EVAPORATIVE COOLING IN
DOWNDRAFTS...AND POTENTIAL FOR DOWNWARD TRANSFER OF HIGHER MOMENTUM
AIR ASSOCIATED WITH LOW-LEVEL JET.

WITH PRIMARY UPPER TROUGH STILL UPSTREAM...LINE WILL BE SLOW TO
PROGRESS EASTWARD ACROSS NORTHERN FLORIDA AND THE NORTHERN FLORIDA
PENINSULA...AND MAY NOT PROGRESS EAST OF JACKSONVILLE FOR ANOTHER
SEVERAL HOURS.

..KERR.. 01/27/2004

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

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

29548338 29968292 30368237 30568186 30758148 

29888115 29418164 28978187 28448259

Nearby

Mesoscale Discussions in Florida, 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.