Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 618
The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2011, 8:40 AM CDT for 34 counties in Arkansas; 10 counties in Missouri; 5 counties in Oklahoma. It was in force for 65 min.
The area
The outline as issued.
The facts
- Issued
- Apr 27, 2011, 8:40 AM CDT (13:40 UTC)
- Expired
- Apr 27, 2011, 9:45 AM CDT
- In force
- 65 min
- Issued by
- the Storm Prediction Center
All 49 counties
Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Perry County, AR, Pope County, AR, Pulaski County, AR, Randolph County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, White County, AR, Yell County, AR, Barry County, MO, Carter County, MO, Christian County, MO, Douglas County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Ripley County, MO, Stone County, MO, Taney County, MO, Adair County, OK, Cherokee County, OK, Haskell County, OK, LeFlore County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 95 km from the middle of the area, began a volume at 13:42 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
Springfield, MO (KSGF), launched 12:00Z, 1.7 hours before the alert went out and 135 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
- 1 J/kg
- Mixed-layer CIN
- -327 J/kg
- Mixed-layer LCL
- 497 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 96 m²/s²
- 0-3 km storm-relative helicity
- 226 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
904
ACUS11 KWNS 271340
SWOMCD
SPC MCD 271340
ARZ000-MOZ000-OKZ000-271445-
MESOSCALE DISCUSSION 0618
NWS STORM PREDICTION CENTER NORMAN OK
0840 AM CDT WED APR 27 2011
AREAS AFFECTED...FAR ERN OK...NRN AR...FAR SRN MO
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 271340Z - 271445Z
PORTIONS OF FAR ERN OK...NRN AR...AND FAR SRN MO ARE BEING MONITORED
FOR INCREASING SVR WEATHER THREAT AND WW ISSUANCE.
SURFACE ANALYSIS AT 13Z SHOWS LOW PRESSURE RESIDING NEAR THE OK/AR
BORDER...WITH A STATIONARY FRONT EXTENDING NEWD TOWARD NERN AR/SERN
MO. OBSERVED 12Z RAOBS FROM SGF AND LZK INDICATE THE PRESENCE OF
STEEP MIDLEVEL LAPSE RATES RESIDING ABOVE A MOIST BUT SOMEWHAT
STABLE BOUNDARY LAYER. THESE THERMODYNAMIC PROFILES ARE SUPPORTING
MUCAPE VALUES NEAR 1500 J/KG...FAVORABLE FOR STRONG/SVR
THUNDERSTORMS. IN ADDITION...EFFECTIVE BULK SHEAR VALUES FROM 40-60
KT ARE PRESENT. THIS ENVIRONMENT MAY SUPPORT A LARGE HAIL RISK AS
STORMS TRACK NEWD ALONG THE STATIONARY FRONT.
..GARNER.. 04/27/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...
LAT...LON 34629495 35029528 35639527 36359463 37189295 37049076
36239034 34759199 34629495SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 26, 7:59 PM CDT | Mesoscale Discussion | SPC | Chicot | 2 hr |
| Apr 26, 8:53 PM CDT | Mesoscale Discussion | SPC | Calhoun, Clark, Columbia, Dallas, Grant, Hempstead and 10 more | 97 min |
| Apr 26, 9:13 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clay, Craighead, Crittenden, Cross, Desha and 21 more | 62 min |
| Apr 26, 9:33 PM CDT | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 11 more | 7 hr |
| Apr 26, 9:58 PM CDT | Tornado Watch | SPC | Craighead, Crittenden, Cross, Greene, Jackson, Lee and 8 more | 7 hr |
| Apr 26, 11:33 PM CDT | Mesoscale Discussion | SPC | Chicot, Desha, Phillips | 117 min |
| Apr 27, 3:29 AM CDT | Mesoscale Discussion | SPC | Hempstead, Lafayette, Little River, Miller | 2 hr |
| Apr 27, 4:53 AM CDT | Severe Thunderstorm Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 19 more | 5 hr |
| Apr 27, 6:25 AM CDT | Mesoscale Discussion | SPC | Arkansas, Cleburne, Crittenden, Cross, Desha, Faulkner and 15 more | 65 min |
| Apr 27, 9:48 AM CDT | Mesoscale Discussion | SPC | Ashley, Bradley, Calhoun, Chicot, Clark, Cleveland and 10 more | 27 min |
| Apr 27, 11:02 AM CDT | Tornado Watch | SPC | Ashley, Chicot | 8 hr |
| Apr 27, 12:42 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Crittenden and 19 more | 5 hr |
| Apr 27, 3:06 PM CDT | Mesoscale Discussion | SPC | Clay, Craighead, Greene, Mississippi, Poinsett | 54 min |
| Apr 27, 3:29 PM CDT | Tornado Watch | SPC | Mississippi | 5 hr |
| Apr 26, 7:08 PM CDT | Mesoscale Discussion | SPC | Beaver, Beckham, Blaine, Bryan, Caddo, Canadian and 28 more | 97 min |
Nearby
Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Oklahoma, 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.