Alert archive / Florida / Mesoscale Discussions in 2012

Mesoscale Discussion 1265

June 25, 201220 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2012, 12:46 AM EDT for 20 counties in Florida. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
Jun 25, 2012, 12:46 AM EDT (04:46 UTC)
Expired
Jun 25, 2012, 2:15 AM EDT
In force
89 min
Issued by
the Storm Prediction Center

Counties Alachua County, FL, Charlotte County, FL, Citrus County, FL, DeSoto County, FL, Dixie County, FL, Gilchrist County, FL, Hardee County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Lafayette County, FL, Lake County, FL, Marion County, FL, Orange County, FL, Osceola County, FL, Pasco County, FL, Polk County, FL, Seminole County, FL, Sumter County, FL, Taylor County, FL

The radar

The Tampa radar (KTBW), 92 km from the middle of the area, began a volume at 04:47 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.

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 4.8 hours before the alert went out and 92 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 2012-06-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2192 joules per kilogram.LCLEL10008507005003002001001 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, Tampa Bay, FL at 00:00Z on 2012-06-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 287 square meters per square second.19395878Sfc1 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
2192 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
526 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
287 m²/s²
0-3 km storm-relative helicity
322 m²/s²
Significant tornado parameter
2.4
Supercell composite
15.2

Open this sounding in Storm Lab

The text

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

234 
ACUS11 KWNS 250447
SWOMCD
SPC MCD 250446
FLZ000-250615-

MESOSCALE DISCUSSION 1265
NWS STORM PREDICTION CENTER NORMAN OK
1146 PM CDT SUN JUN 24 2012

AREAS AFFECTED...CNTRL AND NRN FL PENINSULA

CONCERNING...TORNADO WATCH 423...

VALID 250446Z - 250615Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 423 CONTINUES.

SUMMARY...THREAT FOR ISOLATED TORNADOES WILL PERSIST NEXT COUPLE
HOURS MAINLY OVER THE WRN HALF OF THE FL PENINSULA.

DISCUSSION...TS DEBBY REMAINS NEARLY STATIONARY AND IS FORECAST BY
NHC TO DRIFT ONLY VERY SLOWLY NWD TONIGHT. THIS WILL LEAVE THE FL
PENINSULA IN A FAVORABLE ZONE EAST OF THE TS CENTER FOR A CONTINUED
THREAT FOR ISOLATED TORNADOES. EXTENSIVE SQUALL LINE THAT MOVED
THROUGH THE FL PENINSULA EARLIER THIS EVENING IS EXITING THE EAST
COAST. BOUNDARY LAYER OVER MUCH OF THE CNTRL FL PENINSULA HAS BEEN
TEMPORARILY STABILIZED IN WAKE OF THIS FEATURE. THE STABILIZING
EFFECTS OF EARLIER CONVECTION AND TIME OF DAY MAY SERVE AS LIMITING
FACTORS FOR A MORE ROBUST THREAT. HOWEVER...RECENT TRENDS HAVE BEEN
FOR SHOWERS TO INCREASE WITHIN CONVERGENCE BANDS OVER THE ERN GULF
AND ALONG THE WRN FL COAST. HODOGRAPHS REMAIN LARGE IN THE PRESENCE
OF RICH LOW LEVEL MOISTURE...AND AT LEAST A MODEST POTENTIAL REMAINS
FOR ISOLATED CELLS WITHIN THE BANDS TO EVOLVE INTO LOW TOPPED
SUPERCELLS WITH AN ATTENDANT TORNADO THREAT.

..DIAL.. 06/25/2012

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

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

LAT...LON   26678214 27758247 29308282 29978430 30238420 30078302
            29288132 28398077 26978147 26678214

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 24, 10:16 PM EDTMesoscale DiscussionSPCBrevard, Charlotte, Citrus, Collier, DeSoto, Dixie and 20 more59 min
Jun 25, 4:07 AM EDTMesoscale DiscussionSPCBradford, Charlotte, Clay, Collier, DeSoto, Duval and 21 more83 min
Jun 25, 4:37 AM EDTTornado WatchSPCAlachua, Brevard, Charlotte, Citrus, Collier, DeSoto and 35 more9 hr
Jun 25, 12:06 PM EDTMesoscale DiscussionSPCAlachua, Bradford, Brevard, Citrus, Clay, Dixie and 25 more54 min
Jun 25, 1:48 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 45 more9 hr
Jun 25, 6:27 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 45 more63 min

Nearby

Mesoscale Discussions in Florida, 2012Every mesoscale discussion in 2012

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.