Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 322

March 31, 201128 counties in Florida

The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2011, 12:12 PM EDT for 28 counties in Florida. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Mar 31, 2011, 12:12 PM EDT (16:12 UTC)
Expired
Mar 31, 2011, 1:15 PM EDT
In force
63 min
Issued by
the Storm Prediction Center
All 28 counties

Brevard County, FL, Charlotte County, FL, Citrus County, FL, DeSoto County, FL, Glades County, FL, Hardee County, FL, Hendry County, FL, Hernando County, FL, Highlands County, FL, Hillsborough County, FL, Indian River County, FL, Lake County, FL, Lee County, FL, Levy County, FL, Manatee County, FL, Marion County, FL, Martin County, FL, Okeechobee County, FL, Orange County, FL, Osceola County, FL, Palm Beach County, FL, Pasco County, FL, Polk County, FL, Saint Lucie County, FL, Sarasota County, FL, Seminole County, FL, Sumter County, FL, Volusia County, FL

The radar

The Tampa radar (KTBW), 78 km from the middle of the area, began a volume at 16:16 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 12:00Z, 4.2 hours before the alert went out and 78 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 12:00Z on 2011-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 728 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2011-03-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 543 square meters per square second.1939587897Sfc1 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
728 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
787 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
543 m²/s²
0-3 km storm-relative helicity
606 m²/s²
Significant tornado parameter
0.0
Supercell composite
8.9

Open this sounding in Storm Lab

The text

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

585 
ACUS11 KWNS 311612
SWOMCD
SPC MCD 311612 
FLZ000-311715-

MESOSCALE DISCUSSION 0322
NWS STORM PREDICTION CENTER NORMAN OK
1112 AM CDT THU MAR 31 2011

AREAS AFFECTED...CNTRL/SRN FL PENINSULA

CONCERNING...TORNADO WATCH 80...

VALID 311612Z - 311715Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 80 CONTINUES.

...TORNADO WATCH WILL BE REPLACED BY 17Z ACROSS MUCH OF THE
CNTRL/SRN FL PENINSULA...

FAST-MOVING BOW-TYPE ECHO IS RACING EWD AT ROUGHLY 50KT OVER POLK
COUNTY.  GIVEN THIS SPEED/MOVEMENT...IT APPEARS THE LEADING EDGE
WILL MOVE OFF THE ATLANTIC COAST BY 18Z.  ADDITIONALLY...TRAILING
TSTMS WILL LIKELY INTENSIFY SWWD TOWARD THE GULF COAST THEN SPREAD
ACROSS MUCH OF THE PENINSULA AS FLOW GRADUALLY VEERS.  DESPITE THIS
VEERING FLOW IT APPEARS SUFFICIENT SHEAR EXISTS FOR A CONTINUED
TORNADO THREAT...ESPECIALLY NEAR CONVECTIVE OUTFLOW FROM EARLIER
ACTIVITY.  FOR THIS REASON CONDITIONS WILL WARRANT A NEW TORNADO
WATCH SHORTLY.  FARTHER SOUTH...SEVERE THREAT MAY BE DELAYED ACROSS
EXTREME SRN FL AND MUCH OF MFL COUNTY WARNING AREA MAY NOT
EXPERIENCE STRONG/SEVERE STORMS UNTIL LATER THIS AFTERNOON/EVENING.

..DARROW.. 03/31/2011

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

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

LAT...LON   29378322 29368074 26367969 26368211 29378322

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 31, 4:40 AM EDTMesoscale DiscussionSPCAlachua, Bradford, Citrus, Columbia, Dixie, Franklin and 19 more2 hr
Mar 31, 6:00 AM EDTTornado WatchSPCBrevard, Charlotte, Citrus, DeSoto, Flagler, Glades and 25 more7 hr
Mar 31, 9:39 AM EDTMesoscale DiscussionSPCBrevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 21 more66 min
Mar 31, 12:46 PM EDTTornado WatchSPCBrevard, Charlotte, DeSoto, Glades, Hardee, Hendry and 15 more7 hr
Mar 31, 2:56 PM EDTMesoscale DiscussionSPCBrevard, Charlotte, DeSoto, Glades, Hardee, Highlands and 10 more64 min
Mar 31, 6:22 PM EDTMesoscale DiscussionSPCBrevard, Charlotte, DeSoto, Glades, Hardee, Highlands and 10 more83 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.