Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 301

March 28, 201115 counties in Florida; 7 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Mar 28, 2011, 6:12 PM EDT for 15 counties in Florida; 7 counties in Georgia. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Mar 28, 2011, 6:12 PM EDT (22:12 UTC)
Expired: Mar 28, 2011, 7:15 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

All 22 counties

Baker County, FL, Calhoun County, FL, Columbia County, FL, Gadsden County, FL, Gulf County, FL, Hamilton County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Liberty County, FL, Madison County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Wakulla County, FL, Brooks County, GA, Clinch County, GA, Decatur County, GA, Echols County, GA, Grady County, GA, Lowndes County, GA, Thomas County, GA

The radar

The Tallahassee radar (KTLH), 64 km from the middle of the area, began a volume at 22:14 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 10.2 hours before the alert went out and 61 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: 1893 J/kg
Mixed-layer CIN: -24 J/kg
Mixed-layer LCL: 532 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 149 m²/s²
0-3 km storm-relative helicity: 169 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 9.6

Open this sounding in Storm Lab

The text

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

291 
ACUS11 KWNS 282213
SWOMCD
SPC MCD 282212
FLZ000-GAZ000-282315-

MESOSCALE DISCUSSION 0301
NWS STORM PREDICTION CENTER NORMAN OK
0512 PM CDT MON MAR 28 2011

AREAS AFFECTED...ERN FL PANHANDLE / NRN FL PENINSULA / FAR SRN GA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 282212Z - 282315Z

ISOLATED STRONG TO SEVERE STORMS WILL BE POSSIBLE THROUGH 00Z ACROSS
PORTIONS OF THE ERN FL PANHANDLE...NRN FL PENINSULA...AND FAR SRN
GA. A WW IS NOT CURRENTLY ANTICIPATED.

SFC ANALYSIS AT 20Z DEPICTS A WARM FRONT DRAPED ACROSS THE FAR NRN
FL PENINSULA EXTENDING INTO A LOW 20 MILES NE OF PFN...WITH A COLD
FRONT EXTENDING SWWD FROM THE LOW ACROSS THE COASTAL/OFFSHORE WATERS
OF THE NERN GULF OF MEXICO. ENHANCED CONVERGENCE NEAR THE SFC LOW
HAS RESULTED IN RECENT CONVECTIVE INITIATION...INCLUDING SPLITTING
SUPERCELL STRUCTURES...OVER LIBERTY/CALHOUN COUNTIES. THE LEFT
MEMBER RECENTLY PRODUCED QUARTER SIZE HAIL NEAR BLOUNTSTOWN IN
CALHOUN COUNTY. THIS ACTIVITY WILL LIKELY PERSIST IN THE
SHORT-TERM...WITH ADDITIONAL DEVELOPMENT POSSIBLE NEAR THE WARM
FRONT. MODERATE INSTABILITY /1000 TO 1500 J PER KG/ AND EFFECTIVE
BULK SHEAR MAGNITUDES OF 40 TO 50 KT PER RUC OBJECTIVE ANALYSIS
COULD SUPPORT OCCASIONALLY ORGANIZED STORM /SUPERCELLULAR/
STRUCTURES. AN ATTENDANT THREAT FOR DAMAGING WINDS AND LARGE HAIL
WILL OCCUR...ESPECIALLY WITH ANY STORMS INVOF THE WARM FRONT...WHERE
GREATER LOW-LEVEL WIND SHEAR WILL BE PRESENT. DUE TO THE ANTICIPATED
LOW COVERAGE OF STORMS...A WW IS NOT CURRENTLY ANTICIPATED.

..COHEN.. 03/28/2011

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

ATTN...WFO...JAX...TAE...

LAT...LON   30048200 29848388 29788526 30608561 30968461 31008233
            30048200

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 28, 1:59 AM EDT	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Columbia, Dixie, Gadsden and 11 more	91 min
Mar 28, 2:43 AM EDT	Severe Thunderstorm Watch	SPC	Alachua, Baker, Bradford, Columbia, Dixie, Franklin and 12 more	3 hr
Mar 28, 6:31 AM EDT	Mesoscale Discussion	SPC	Charlotte, Collier, Glades, Hendry, Lee, Martin and 3 more	59 min
Mar 28, 6:48 AM EDT	Severe Thunderstorm Watch	SPC	Broward, Charlotte, Collier, DeSoto, Glades, Hendry and 7 more	5 hr
Mar 28, 5:49 PM EDT	Mesoscale Discussion	SPC	Broward, Charlotte, Collier, Hendry, Lee, Miami-Dade and 1 more	56 min

Nearby

Mesoscale Discussions in Florida, 2011 Mesoscale Discussions in Georgia, 2011 Every 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.