Alert archive / Georgia / Mesoscale Discussions in 2008

Mesoscale Discussion 2321

October 9, 200815 counties in Florida; 26 counties in Georgia; 8 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Oct 9, 2008, 1:45 PM EDT for 15 counties in Florida; 26 counties in Georgia; 8 counties in South Carolina. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Oct 9, 2008, 1:45 PM EDT (17:45 UTC)
Expired
Oct 9, 2008, 2:45 PM EDT
In force
60 min
Issued by
the Storm Prediction Center
All 49 counties

Alachua County, FL, Baker County, FL, Bradford County, FL, Clay County, FL, Columbia County, FL, Duval County, FL, Flagler County, FL, Gilchrist County, FL, Hamilton County, FL, Marion County, FL, Nassau County, FL, Putnam County, FL, Saint Johns County, FL, Suwannee County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Echols County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Jeff Davis County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Pierce County, GA, Screven County, GA, Tattnall County, GA, Ware County, GA, Wayne County, GA, Allendale County, SC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC, Jasper County, SC

The radar

The Jacksonville radar (KJAX), 53 km from the middle of the area, began a volume at 17:48 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

Jacksonville, FL (KJAX), launched 12:00Z, 5.8 hours before the alert went out and 51 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, Jacksonville, FL at 12:00Z on 2008-10-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 223 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, Jacksonville, FL at 12:00Z on 2008-10-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 91 square meters per square second.193958Sfc1 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
223 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
933 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 091745
SWOMCD
SPC MCD 091745 
SCZ000-FLZ000-GAZ000-091845-

MESOSCALE DISCUSSION 2321
NWS STORM PREDICTION CENTER NORMAN OK
1245 PM CDT THU OCT 09 2008

AREAS AFFECTED...NRN FL...SERN GA...COASTAL SC

CONCERNING...SEVERE THUNDERSTORM WATCH 914...

VALID 091745Z - 091845Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 914
CONTINUES.

DEEP CONVECTION CONTINUES TO MODULATE AHEAD OF PRIMARY LEAD SFC
CONFLUENCE ZONE FROM THE NERN GULF OF MEXICO...NEWD INTO SWRN SC. 
AT TIMES EMBEDDED UPDRAFTS HAVE DISPLAYED SOME ROTATION...HOWEVER
MULTIPLE STORM MERGERS AND CONVECTIVE OUTFLOW HAS NOW RESULTED IN
ROUGHLY 3-4 PRIMARY CONVECTIVE CLUSTERS.  OTHER STORMS ARE NOW
DEVELOPING/INTENSIFYING BENEATH THE UPPER LOW OVER SWRN GA WHERE
BOUNDARY LAYER HAS WARMED BENEATH COOL MID LEVEL TEMPERATURES. 
LARGE HAIL IS THE MOST LIKELY SEVERE THREAT WITH ACTIVITY BENEATH
THE UPPER LOW...WHILE HAIL/WIND MAY ACCOMPANY CONVECTION DOWNSTREAM.

..DARROW.. 10/09/2008

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

ATTN...WFO...ILM...CHS...CAE...MLB...TBW...JAX...FFC...TAE...

31808295 31948232 32318222 32548207 32898211 32908177
33168147 33038108 33538002 32947895 32577948 31988036
31378088 30728110 29498076 29498112 29278115 29268139
29378141 29318165 28958164 29008254 29218251 29238235
29478241 29608293 29958295 30138320 30418317 30658322
30668311 30888299 31168299 31468315

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 8, 9:51 PM EDTMesoscale DiscussionSPCColumbia, Dixie, Gilchrist, Hamilton, Lafayette, Suwannee and 1 more84 min
Oct 9, 8:52 AM EDTMesoscale DiscussionSPCBaker, Columbia, Hamilton, Madison, Nassau, Suwannee and 1 more83 min
Oct 9, 10:57 AM EDTSevere Thunderstorm WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 9 more7 hr
Oct 9, 3:49 PM EDTMesoscale DiscussionSPCBrevard, Citrus, Hernando, Lake, Orange, Pasco and 3 more56 min

Nearby

Mesoscale Discussions in Georgia, 2008Mesoscale Discussions in Florida, 2008Mesoscale Discussions in South Carolina, 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.