Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 366

April 5, 201126 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2011, 8:30 AM EDT for 26 counties in Florida. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 5, 2011, 8:30 AM EDT (12:30 UTC)
Expired
Apr 5, 2011, 10:30 AM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 26 counties

Brevard County, FL, Broward County, FL, Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Highlands County, FL, Hillsborough County, FL, Indian River County, FL, Lake County, FL, Lee County, FL, Manatee County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL, Seminole County, FL, Volusia County, FL

The radar

The Miami radar (KAMX), 151 km from the middle of the area, began a volume at 12:29 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

Miami, FL (KMFL), launched 12:00Z, 0.5 hours before the alert went out and 139 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, Miami, FL at 12:00Z on 2011-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2028 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, Miami, FL at 12:00Z on 2011-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 155 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
2028 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
645 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
155 m²/s²
0-3 km storm-relative helicity
208 m²/s²
Significant tornado parameter
1.6
Supercell composite
9.0

Open this sounding in Storm Lab

The text

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

389 
ACUS11 KWNS 051230
SWOMCD
SPC MCD 051230 
FLZ000-051430-

MESOSCALE DISCUSSION 0366
NWS STORM PREDICTION CENTER NORMAN OK
0730 AM CDT TUE APR 05 2011

AREAS AFFECTED...PORTIONS FL PENINSULA.

CONCERNING...SEVERE THUNDERSTORM WATCH 105...

VALID 051230Z - 051430Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 105
CONTINUES.

WW MAY BE CLEARED BEHIND PRIMARY/SW-NE ALIGNED/QUASI-LINEAR
MCS...WHICH IS MOVING EWD 30-40 KT ACROSS NERN THROUGH W-CENTRAL FL
AS OF 1215Z.  DOMINANT SVR THREAT REMAINS DAMAGING GUSTS...THOUGH
BRIEF TORNADO CANNOT BE RULED OUT FROM EMBEDDED MESOCIRCULATIONS.

AS MID--UPPER TROUGH BEGINS TO PIVOT NEWD AND EJECT ACROSS CENTRAL
APPALACHIANS REGION...RELATED DEPARTURE OF STRONGEST LOW-LEVEL
ISALLOBARIC FORCING ACROSS MID-ATLANTIC SHOULD RESULT IN VEERING OF
LOW-LEVEL FLOW AHEAD OF MCS.  THIS IN TURN...SHOULD REDUCE LOW-LEVEL
CONVERGENCE AND SHEAR.  HOWEVER...SFC DIABATIC HEATING WILL REDUCE
ALREADY WEAK MLCINH...WHILE BOOSTING MLCAPE INTO 2000-3000 J/KG
RANGE.  THIS IS BASED ON MODIFIED MFL/TBW RAOBS...WHICH SHOW AREAS
OF VERY STEEP MIDLEVEL LAPSE RATES REMAINING FROM ELEVATED
MIXED-LAYER AIR ADVECTED OFF MEX PLATEAU AND ACROSS GULF.  STG
BUOYANCY SHOULD OFFSET REDUCTION IN KINEMATIC SUPPORT ENOUGH TO
MAINTAIN ORGANIZED SVR WIND THREAT INTO PORTIONS SRN FL THROUGH
REMAINDER MORNING.  OCCASIONAL LARGE HAIL ALSO MIGHT OCCUR...GIVEN
DEPTH OF BUOYANCY AND POTENTIAL FOR AT LEAST TRANSIENT SUPERCELLULAR
MORPHOLOGIES. ACCORDINGLY...AREAS S OF WW 105 MAY BE PLACED IN
ADDITIONAL WW BEFORE THIS SYSTEM CLEARS REGION.

..EDWARDS.. 04/05/2011

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

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

LAT...LON   29418108 28958083 28688064 28498046 28498059 28188059
            27678032 26928003 26338005 25678016 25328033 25198052
            25148079 25168086 25148109 25198118 25328112 25388111
            25728134 25908165 25798165 26328186 26468198 26378205
            26498222 26858230 27518274 27728277 27838279 29418108

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 10:05 PM EDTMesoscale DiscussionSPCBay, Calhoun, Gadsden, Holmes, Jackson, Leon and 3 more55 min
Apr 4, 10:28 PM EDTTornado WatchSPCBay, Calhoun, Gadsden, Gulf, Holmes, Jackson and 3 more6 hr
Apr 5, 12:21 AM EDTMesoscale DiscussionSPCBay, Calhoun, Gadsden, Gulf, Holmes, Jackson and 4 more84 min
Apr 5, 2:41 AM EDTTornado WatchSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 19 more6 hr
Apr 5, 2:55 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bay, Bradford, Calhoun, Clay and 22 more2 hr
Apr 5, 5:39 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 25 more2 hr
Apr 5, 7:04 AM EDTSevere Thunderstorm WatchSPCBrevard, DeSoto, Hardee, Hernando, Highlands, Hillsborough and 15 more7 hr
Apr 5, 11:02 AM EDTMesoscale DiscussionSPCBroward, Collier, Glades, Hendry, Highlands, Indian River and 7 more118 min

Nearby

Mesoscale Discussions in Florida, 2011Every mesoscale discussion in 2011

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.