Alert archive / Mississippi / Mesoscale Discussions in 2012

Mesoscale Discussion 1129

June 11, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jun 11, 2012, 7:33 PM CDT for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Jun 11, 2012, 7:33 PM CDT (00:33 UTC)
Expired
Jun 11, 2012, 8:30 PM CDT
In force
57 min
Issued by
the Storm Prediction Center
All 51 counties

Fayette County, AL, Greene County, AL, Hale County, AL, Lamar County, AL, Marion County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Ashley County, AR, Chicot County, AR, Drew County, AR, East Carroll Parish, LA, Franklin Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Richland Parish, LA, Tensas Parish, LA, West Carroll Parish, LA, Attala County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Kemper County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Monroe County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Jackson/Brandon,MS radar (KDGX), 71 km from the middle of the area, began a volume at 00:34 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

Jackson, MS (KJAN), launched 00:00Z, 0.6 hours before the alert went out and 68 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, Jackson, MS at 00:00Z on 2012-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2745 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, Jackson, MS at 00:00Z on 2012-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
2745 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
1430 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

392 
ACUS11 KWNS 120033
SWOMCD
SPC MCD 120033 
ALZ000-MSZ000-ARZ000-LAZ000-120130-

MESOSCALE DISCUSSION 1129
NWS STORM PREDICTION CENTER NORMAN OK
0733 PM CDT MON JUN 11 2012

AREAS AFFECTED...AL...MS...LA...AR

CONCERNING...SEVERE THUNDERSTORM WATCH 375...

VALID 120033Z - 120130Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 375
CONTINUES.

SUMMARY...STRONG WINDS WILL CONTINUE ALONG LEADING EDGE OF MCS AS IT
SPREADS SOUTH THIS EVENING.

DISCUSSION...LONG-LIVED MCS CONTINUES ITS FORWARD MOTION AT ROUGHLY
30-35KT AS IT PROGRESSES INTO THE MIDDLE PORTIONS OF WW 375.  STRONG
OUTFLOW...WITH ISOLATED SEVERE WIND GUSTS IN EXCESS OF 50KT...WILL
BE COMMON ALONG THE LEADING EDGE OF THIS COMPLEX OF STORMS.  WHILE
00Z SOUNDINGS FROM SHV/JAN EXHIBIT MINOR INHIBITION...BMX HAS NO
APPARENT CAP AND THIS ENTIRE REGION ALONG THE I-20 CORRIDOR IS QUITE
UNSTABLE WITH STEEP LAPSE RATES.  FOR THIS REASON IT APPEARS THE MCS
WILL PERSIST FOR SOME TIME AND WILL LIKELY APPROACH THE SRN EDGE OF
THE WATCH AROUND 0200-0230Z.

..DARROW.. 06/12/2012

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

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

LAT...LON   31889182 33619184 34498712 32748713 31889182

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 11, 8:37 PM CDTSevere Thunderstorm WatchSPCBaldwin, Choctaw, Clarke, Mobile, Washington, Wilcox4 hr
Jun 11, 10:51 PM CDTMesoscale DiscussionSPCChoctaw, Clarke, Marengo, Sumter, Washington54 min
Jun 11, 9:25 PM CDTSevere Thunderstorm WatchSPCSebastian7 hr
Jun 11, 11:52 PM CDTSevere Thunderstorm WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 15 more6 hr
Jun 12, 2:54 AM CDTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Dallas, Hempstead, Howard and 8 more96 min
Jun 12, 3:21 AM CDTSevere Thunderstorm WatchSPCAshley, Chicot, Columbia, Hempstead, Lafayette, Little River and 3 more8 hr
Jun 12, 6:08 AM CDTMesoscale DiscussionSPCAshley, Chicot2 hr
Jun 12, 7:11 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more8 hr
Jun 12, 9:23 AM CDTMesoscale DiscussionSPCGrant, LaSalle, Natchitoches, Sabine67 min
Jun 12, 12:12 PM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Iberia and 5 more63 min

Nearby

Mesoscale Discussions in Mississippi, 2012Mesoscale Discussions in Alabama, 2012Mesoscale Discussions in Louisiana, 2012Every mesoscale discussion in 2012

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.