Alert archive / Florida / Mesoscale Discussions in 2011

Mesoscale Discussion 978

May 26, 20119 counties in Alabama; 12 counties in Florida; 6 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at May 26, 2011, 10:39 AM CDT for 9 counties in Alabama; 12 counties in Florida; 6 counties in Georgia. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
May 26, 2011, 10:39 AM CDT (15:39 UTC)
Expired
May 26, 2011, 12:15 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 27 counties

Baldwin County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gadsden County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Liberty County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Clay County, GA, Decatur County, GA, Early County, GA, Miller County, GA, Quitman County, GA, Seminole County, GA

The radar

The Eglin Afb radar (KEVX), 50 km from the middle of the area, began a volume at 15:41 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, 3.7 hours before the alert went out and 201 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, Tallahassee Rgnl, FL at 12:00Z on 2011-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1079 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, Tallahassee Rgnl, FL at 12:00Z on 2011-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939Sfc1 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
1079 J/kg
Mixed-layer CIN
-117 J/kg
Mixed-layer LCL
742 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
-53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

814 
ACUS11 KWNS 261539
SWOMCD
SPC MCD 261539 
FLZ000-GAZ000-ALZ000-261715-

MESOSCALE DISCUSSION 0978
NWS STORM PREDICTION CENTER NORMAN OK
1039 AM CDT THU MAY 26 2011

AREAS AFFECTED...SRN AL...FL PANHANDLE...SWRN GA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 261539Z - 261715Z

LATEST WV IMAGERY SUGGESTS A WEAK UPPER VORT MAY BE EMBEDDED WITHIN
THE BASE OF THE LARGER TROUGH OVER SERN MS.  THIS FEATURE IS
SHIFTING EAST TOWARD SRN AL/FL PANHANDLE AND APPEARS TO BE AIDING
ONGOING CONVECTION THAT HAS GRADUALLY INTENSIFIED OVER THE LAST
HOUR.  RADAR DATA SUGGEST THIS ACTIVITY IS MOVING EAST AT ROUGHLY
35KT AND IS SLOWLY TAKING ON CHARACTERISTICS OF A LINEAR MCS.  GIVEN
THE PROGRESSIVE NATURE OF THE UPPER TROUGH LATEST THINKING IS
ONGOING TSTMS WILL MIGRATE ACROSS SRN AL INTO THE FL PANHANDLE AND
PERHAPS EVEN SWRN GA BY 21Z.  DAMAGING WINDS MAY BE NOTED WITH THIS
CONVECTION AND A SEVERE TSTM WATCH IS BEING CONSIDERED.

..DARROW.. 05/26/2011

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

ATTN...WFO...TAE...BMX...MOB...

LAT...LON   31478770 31888495 30638427 29498515 30098823 31478770

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 8:33 PM CDTTornado WatchSPCBibb, Colbert, Cullman, Fayette, Franklin, Jefferson and 12 more7 hr
May 25, 10:27 PM CDTMesoscale DiscussionSPCColbert, Fayette, Franklin, Lamar, Lawrence, Marion and 2 more2 hr
May 26, 7:56 AM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Chilton, Clay and 22 more94 min
May 26, 9:15 AM CDTSevere Thunderstorm WatchSPCAutauga, Barbour, Bibb, Blount, Bullock, Calhoun and 38 more9 hr
May 26, 12:22 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Bullock, Butler, Calhoun and 33 more83 min
May 26, 2:32 PM CDTMesoscale DiscussionSPCCherokee58 min
May 26, 2:44 PM CDTSevere Thunderstorm WatchSPCHenry6 hr
May 26, 3:36 PM CDTMesoscale DiscussionSPCCalhoun, Chambers, Cherokee, Clay, Cleburne, Etowah and 6 more84 min
May 26, 4:10 PM CDTSevere Thunderstorm WatchSPCElbert, Franklin, Habersham, Hart, Rabun, Stephens7 hr
May 26, 6:12 PM CDTMesoscale DiscussionSPCColumbia, Lincoln, McDuffie93 min

Nearby

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