Alert archive / Missouri / Mesoscale Discussions in 2011
Mesoscale Discussion 672
The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2011, 7:49 PM CDT for 5 states. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Apr 30, 2011, 7:49 PM CDT (00:49 UTC)
- Expired
- Apr 30, 2011, 8:45 PM CDT
- In force
- 56 min
- Issued by
- the Storm Prediction Center
All 33 counties
Clay County, AR, Greene County, AR, Izard County, AR, Lawrence County, AR, Randolph County, AR, Sharp County, AR, Stone County, AR, Alexander County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Union County, IL, Ballard County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Livingston County, KY, McCracken County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Lake County, TN, Obion County, TN
The radar
The Paducah radar (KPAH), 131 km from the middle of the area, began a volume at 00:52 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, 0.8 hours before the alert went out and 199 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
- 1745 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 528 m above ground
- 0-6 km bulk shear
- 52 kt
- 0-1 km storm-relative helicity
- 281 m²/s²
- 0-3 km storm-relative helicity
- 322 m²/s²
- Significant tornado parameter
- 3.2
- Supercell composite
- 14.0
The text
As transmitted, in the capitals the NWS used until 2016.
819
ACUS11 KWNS 010050
SWOMCD
SPC MCD 010049
KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-010145-
MESOSCALE DISCUSSION 0672
NWS STORM PREDICTION CENTER NORMAN OK
0749 PM CDT SAT APR 30 2011
AREAS AFFECTED...NERN AR...SERN MO...AND EXTREME PARTS OF NWRN
TN...WRN KY AND SRN IL
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 010049Z - 010145Z
A SEVERE TSTM WATCH IS POSSIBLE TO THE NORTHEAST OF WW 258...
ESPECIALLY IF RADAR TRENDS SUGGEST COVERAGE AND INTENSITY OF STORMS
MOVING NEWD FROM WW 258 WILL PERSIST FARTHER DOWNSTREAM.
PROBABILITY OF WATCH ISSUANCE IS 40 PERCENT.
00Z SURFACE ANALYSIS INDICATED LITTLE MOVEMENT OF THE COLD FRONT
SINCE 21Z...WITH THIS BOUNDARY EXTENDING FROM ERN IA SSWWD THROUGH
CENTRAL MO...ERN OK AND INTO CENTRAL TX. ZONE OF LOW LEVEL
CONVERGENCE WAS LOCATED AHEAD OF THE COLD FRONT FROM CENTRAL INTO
NERN AR AND COMBINED WITH A WEAK MIDLEVEL IMPULSE OVER THE ARKLATEX
HAS SUPPORTED TSTM DEVELOPMENT THUS FAR OVER WRN-NERN AR.
MEANWHILE...A SURFACE TROUGH EXTENDED SSEWD FROM NERN AR TO SRN MS
AND DELINEATED HIGHER MOISTURE VALUES TO ITS WEST OVER AR/LA...AND
DRIER AIR TO THE EAST.
STORMS TRACKING AND OR DEVELOPING NEWD OF WW 258 WILL BECOME
INCREASINGLY ELEVATED ATOP A MORE STABLE BOUNDARY LAYER...ATTRIBUTED
TO THE DRIER AIR EAST OF THE AFOREMENTIONED SURFACE TROUGH.
ACTIVITY OVER NERN AR WILL BE CLOSER TO STRONGER INSTABILITY AND
EFFECTIVE BULK SHEAR FOR A FEW STORMS TO MAINTAIN INTENSITY AND
ORGANIZATION. THUS...ISOLATED HAIL WILL BE THE PRIMARY THREAT WITH
THE ELEVATED ACTIVITY. HOWEVER...AS STORMS DEVELOP AND/OR MOVE
FARTHER NEWD AWAY FROM THE BETTER INSTABILITY...THE OVERALL SEVERE
WEATHER THREAT IS EXPECTED TO DECREASE.
..PETERS.. 05/01/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...
LAT...LON 37088836 36178891 35899013 35899166 35749226 35809260
36499142 37399027 37618907 37588834 37088836SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 8:47 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Conway, Faulkner, Garland, Grant and 12 more | 58 min |
| Apr 30, 9:26 PM CDT | Mesoscale Discussion | SPC | Hempstead, Howard, Little River, Miller, Sevier | 64 min |
| Apr 30, 11:39 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Cleburne, Conway, Craighead, Cross and 31 more | 66 min |
| May 1, 1:16 AM CDT | Mesoscale Discussion | SPC | Arkansas, Clark, Cleburne, Conway, Craighead, Crittenden and 37 more | 59 min |
| May 1, 3:50 AM CDT | Mesoscale Discussion | SPC | Lee, Monroe, Phillips | 2 hr |
| May 1, 8:30 AM CDT | Mesoscale Discussion | SPC | Clark, Dallas, Garland, Hempstead, Hot Spring, Howard and 9 more | 30 min |
| May 1, 8:45 AM CDT | Severe Thunderstorm Watch | SPC | Clark, Columbia, Dallas, Garland, Hempstead, Hot Spring and 10 more | 6 hr |
| May 1, 12:12 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 34 more | 93 min |
| May 1, 12:47 PM CDT | Tornado Watch | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more | 8 hr |
| May 1, 3:18 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more | 87 min |
| May 1, 5:42 PM CDT | Mesoscale Discussion | SPC | Clark, Dallas, Garland, Grant, Hempstead, Hot Spring and 14 more | 3 hr |
| May 1, 5:43 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more | 92 min |
Nearby
Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Kentucky, 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.