Alert archive / Florida / Mesoscale Discussions in 2008
Mesoscale Discussion 2139
The Storm Prediction Center issued this mesoscale discussion at Aug 23, 2008, 6:40 AM EDT for 4 counties in Florida. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 23, 2008, 6:40 AM EDT (10:40 UTC)
- Expired
- Aug 23, 2008, 8:45 AM EDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
Counties Dixie County, FL, Lafayette County, FL, Levy County, FL, Taylor County, FL
The radar
The Tallahassee radar (KTLH), 119 km from the middle of the area, began a volume at 10:39 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, 10.7 hours before the alert went out and 117 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
- 111 J/kg
- Mixed-layer CIN
- -5 J/kg
- Mixed-layer LCL
- 485 m above ground
- 0-6 km bulk shear
- 19 kt
- 0-1 km storm-relative helicity
- 312 m²/s²
- 0-3 km storm-relative helicity
- 431 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 231040 SWOMCD SPC MCD 231040 FLZ000-231245- MESOSCALE DISCUSSION 2139 NWS STORM PREDICTION CENTER NORMAN OK 0540 AM CDT SAT AUG 23 2008 AREAS AFFECTED...PARTS OF NRN FL INTO THE FL PANHANDLE CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 231040Z - 231245Z TORNADO POTENTIAL APPEARS TO BE INCREASING. IT IS STILL UNCLEAR WHETHER THIS WILL BE MORE THAN AN ISOLATED/BRIEF TORNADO THREAT THROUGH MID MORNING...BUT TRENDS ARE BEING CLOSELY MONITORED. AS THE CIRCULATION CENTER OF FAY CONTINUES TO SLOWLY MIGRATE WEST OF THE FLORIDA BIG BEND REGION...AN INFLUX OF VERY MOIST BOUNDARY LAYER AIR ON SOUTHERLY LOW-LEVEL FLOW OFF THE EASTERN GULF OF MEXICO IS CONTRIBUTING TO DEEPENING CONVECTIVE DEVELOPMENT IN A DEVELOPING CONFLUENCE BAND ON THE EASTERN PERIPHERY OF THE SYSTEM. THIS EXTENDS SOUTH SOUTHWEST THROUGH NORTH NORTHWEST OF CROSS CITY...WHERE LOW-LEVEL SHEAR IS NOT QUITE AS STRONG AS IN THE EASTERLY REGIME FARTHER NORTH. HOWEVER...CLOCKWISE CURVED LOW-LEVEL HODOGRAPHS ARE STILL SIZABLE AND SUPPORTIVE OF TORNADIC POTENTIAL...PARTICULARLY WHERE THE BOUNDARY LAYER IS MOST UNSTABLE NEAR IMMEDIATE COASTAL AREAS. ..KERR.. 08/23/2008 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...TBW...JAX...TAE... 29728367 30268388 30368318 29778289 29258282 29198328
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 22, 8:45 PM EDT | Mesoscale Discussion | SPC | Baker, Bradford, Clay, Columbia, Duval, Hamilton and 2 more | 2 hr |
| Aug 23, 7:18 AM EDT | Tornado Watch | SPC | Alachua, Citrus, Columbia, Dixie, Gilchrist, Hamilton and 10 more | 8 hr |
| Aug 23, 11:35 AM EDT | Mesoscale Discussion | SPC | Columbia, Dixie, Franklin, Gadsden, Gilchrist, Hamilton and 9 more | 115 min |
| Aug 23, 2:41 PM EDT | Mesoscale Discussion | SPC | Columbia, Dixie, Franklin, Gadsden, Gilchrist, Hamilton and 9 more | 2 hr |
| Aug 23, 5:24 PM EDT | Tornado Watch | SPC | Dixie, Gadsden, Jefferson, Lafayette, Leon, Madison and 2 more | 6 hr |
Nearby
Mesoscale Discussions in Florida, 2008Every mesoscale discussion in 2008
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.