Alert archive / Florida / Mesoscale Discussions in 2011
Mesoscale Discussion 320
The Storm Prediction Center issued this mesoscale discussion at Mar 31, 2011, 4:40 AM EDT for 25 counties in Florida. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 31, 2011, 4:40 AM EDT (08:40 UTC)
- Expired
- Mar 31, 2011, 6:45 AM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 25 counties
Alachua County, FL, Bradford County, FL, Citrus County, FL, Columbia County, FL, Dixie County, FL, Franklin County, FL, Gilchrist County, FL, Gulf County, FL, Hamilton County, FL, Hernando County, FL, Hillsborough County, FL, Jefferson County, FL, Lafayette County, FL, Leon County, FL, Levy County, FL, Liberty County, FL, Madison County, FL, Marion County, FL, Pasco County, FL, Pinellas County, FL, Sumter County, FL, Suwannee County, FL, Taylor County, FL, Union County, FL, Wakulla County, FL
The radar
The Tallahassee radar (KTLH), 130 km from the middle of the area, began a volume at 08:43 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
Tallahassee Rgnl, FL (KTLH), launched 00:00Z, 8.7 hours before the alert went out and 129 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.
- Mixed-layer CAPE
- 156 J/kg
- Mixed-layer CIN
- -94 J/kg
- Mixed-layer LCL
- 644 m above ground
- 0-6 km bulk shear
- 87 kt
- 0-1 km storm-relative helicity
- 69 m²/s²
- 0-3 km storm-relative helicity
- 11 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.4
The text
As transmitted, in the capitals the NWS used until 2016.
480
ACUS11 KWNS 310840
SWOMCD
SPC MCD 310840
FLZ000-GAZ000-311045-
MESOSCALE DISCUSSION 0320
NWS STORM PREDICTION CENTER NORMAN OK
0340 AM CDT THU MAR 31 2011
AREAS AFFECTED...PORTIONS OF NRN/NWRN FL
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 310840Z - 311045Z
STORMS ARE EXPECTED TO INCREASE IN COVERAGE ACROSS THE NERN GULF OF
MEXICO AND ACROSS PORTIONS OF NRN FL...WITH PRIMARILY A HAIL THREAT.
SURFACE ANALYSIS SHOW FALLING PRESSURE WITHIN A PRE-FRONTAL TROUGH
EXTENDING NEWD ACROSS THE GULF OF MEXICO TOWARDS APALACHEE BAY.
WHILE SURFACE CONDITIONS INLAND ARE EITHER STABLE OR MARGINALLY
UNSTABLE...A 30-40 KT SWLY LOW LEVEL JET WILL PERSIST AND HELP TO
FEED STORMS AS THEY FORM OVER THE WATER.
WITH STRONG DEEP LAYER SHEAR PROFILES IN PLACE...SOME CELLS ARE
BEGINNING TO SPLIT...AND WILL AFFECT LAND OVER THE NEXT FEW HOURS.
FORECAST SOUNDINGS DO SHOW STEEP MID LEVEL LAPSE RATES/COOL PROFILES
ALOFT...BUT ALSO SOME SUBSTANTIAL DRY MID LEVEL AIR WHICH MAY LIMIT
HOW FAR INLAND STORMS CAN PERSIST...AT LEAST IN A SEVERE STATE.
NONETHELESS...IT APPEARS AT LEAST A MARGINAL THREAT OF LARGE HAIL
WILL EXIST...AND INCREASE WITH TIME AS AN UPPER SPEED MAX ROTATES
AROUND THE TROUGH AND STORMS BECOME MORE NUMEROUS.
..JEWELL.. 03/31/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MLB...TBW...JAX...TAE...
LAT...LON 29808373 29918414 29618468 29588517 29798537 30258493
30498450 30618370 30658311 30548258 29948189 28918170
28028195 27878236 27848294 28648278 29028300 29358329
29808373SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 31, 6:00 AM EDT | Tornado Watch | SPC | Brevard, Charlotte, Citrus, DeSoto, Flagler, Glades and 25 more | 7 hr |
| Mar 31, 9:39 AM EDT | Mesoscale Discussion | SPC | Brevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 21 more | 66 min |
| Mar 31, 12:12 PM EDT | Mesoscale Discussion | SPC | Brevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 22 more | 63 min |
| Mar 31, 12:46 PM EDT | Tornado Watch | SPC | Brevard, Charlotte, DeSoto, Glades, Hardee, Hendry and 15 more | 7 hr |
| Mar 31, 2:56 PM EDT | Mesoscale Discussion | SPC | Brevard, Charlotte, DeSoto, Glades, Hardee, Highlands and 10 more | 64 min |
| Mar 31, 6:22 PM EDT | Mesoscale Discussion | SPC | Brevard, Charlotte, DeSoto, Glades, Hardee, Highlands and 10 more | 83 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.