Alert archive / Mississippi / Mesoscale Discussions in 2011

Mesoscale Discussion 973

May 25, 20118 counties in Alabama; 20 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at May 25, 2011, 10:27 PM CDT for 8 counties in Alabama; 20 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 25, 2011, 10:27 PM CDT (03:27 UTC)
Expired
May 26, 2011, 12:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 28 counties

Colbert County, AL, Fayette County, AL, Franklin County, AL, Lamar County, AL, Lawrence County, AL, Marion County, AL, Pickens County, AL, Winston County, AL, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Lee County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Oktibbeha County, MS, Pontotoc County, MS, Prentiss County, MS, Tishomingo County, MS, Webster County, MS, Winston County, MS

The radar

The Columbus AFB radar (KGWX), 30 km from the middle of the area, began a volume at 03:30 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

Little Rock, AR (KLZK), launched 00:00Z, 3.5 hours before the alert went out and 164 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, Little Rock, AR at 00:00Z on 2011-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2 joules per kilogram.LCLEL10008507005003002001001 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, Little Rock, AR at 00:00Z on 2011-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 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
2 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
2470 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
163 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.

718 
ACUS11 KWNS 260328
SWOMCD
SPC MCD 260327
ALZ000-MSZ000-260530-

MESOSCALE DISCUSSION 0973
NWS STORM PREDICTION CENTER NORMAN OK
1027 PM CDT WED MAY 25 2011

AREAS AFFECTED...CNTRL LA INTO MS

CONCERNING...TORNADO WATCH 377...

VALID 260327Z - 260530Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 377 CONTINUES.

RADAR TRENDS SUGGEST CONVECTIVE INHIBITION IS RESULTING IN A
THINNING OUT OF STORM COVERAGE OVER LA INTO WRN MS. A FEW ISOLATED
CELLS REMAIN...AND WILL HAVE THE POTENTIAL FOR LARGE HAIL AND GUSTY
WINDS...AND PERHAPS A TORNADO BUT 00Z SOUNDINGS SHOW MARGINAL
BOUNDARY LAYER RH.

THE GREATEST THREAT FOR SEVERE WILL BE OVER NRN SECTIONS OF THE
WATCH...IN CLOSER PROXIMITY TO THE LOW LEVEL JET CORE AND WHERE AN
ORGANIZED LINE PERSISTS. HOWEVER...WITH TIME... OUTFLOW WITH THESE
STORMS MAY UNDERCUT THEM AND COMBINE WITH CAPPING TO REDUCE
COVERAGE. UNTIL THAT TIME...DAMAGING WINDS AND LARGE HAIL SHOULD BE
THE MAIN THREATS...BUT WITH STRONG SHEAR PROFILES...TORNADOES WILL
REMAIN POSSIBLE ESPECIALLY WITH ANY ISOLATED CELLS AWAY FROM
OUTFLOW.

..JEWELL.. 05/26/2011

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

ATTN...WFO...BMX...HUN...MEG...JAN...

LAT...LON   32748986 33229080 34138920 34678872 34918736 34688686
            34018724 33318788 32748986

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 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, 10:39 AM CDTMesoscale DiscussionSPCBaldwin, Coffee, Conecuh, Covington, Dale, Escambia and 3 more96 min
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 25, 7:22 PM CDTMesoscale DiscussionSPCAlcorn, Benton, Bolivar, Coahoma, DeSoto, Lafayette and 11 more53 min
May 25, 9:43 PM CDTTornado WatchSPCAdams, Attala, Carroll, Choctaw, Claiborne, Clay and 33 more5 hr
May 26, 2:05 AM CDTMesoscale DiscussionSPCAmite, Forrest, Greene, Hancock, Harrison, Jones and 8 more85 min
May 26, 5:18 PM CDTMesoscale DiscussionSPCGeorge, Hancock, Harrison, Jackson, Pearl River, Stone57 min

Nearby

Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Alabama, 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.