Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 770
The Storm Prediction Center issued this mesoscale discussion at May 12, 2011, 9:41 PM CDT for 28 counties in Arkansas; 9 counties in Missouri; 4 counties in Oklahoma. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- May 12, 2011, 9:41 PM CDT (02:41 UTC)
- Expired
- May 12, 2011, 10:45 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
All 41 counties
Baxter County, AR, Boone County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Perry County, AR, Polk County, AR, Pope County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Dent County, MO, Douglas County, MO, Howell County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Taney County, MO, Texas County, MO, Wright County, MO, Bryan County, OK, Latimer County, OK, LeFlore County, OK, Pushmataha County, OK
The radar
The Springfield radar (KSGF), 116 km from the middle of the area, began a volume at 02:44 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
Springfield, MO (KSGF), launched 00:00Z, 2.7 hours before the alert went out and 94 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
- 1521 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 1233 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 84 m²/s²
- 0-3 km storm-relative helicity
- 153 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 6.8
The text
As transmitted, in the capitals the NWS used until 2016.
031
ACUS11 KWNS 130242
SWOMCD
SPC MCD 130241
ARZ000-MOZ000-OKZ000-TXZ000-130345-
MESOSCALE DISCUSSION 0770
NWS STORM PREDICTION CENTER NORMAN OK
0941 PM CDT THU MAY 12 2011
AREAS AFFECTED...FAR NORTH TX AND SOUTH-CENTRAL/EASTERN OK AND
NORTHERN AR/SOUTH-CENTRAL MO
CONCERNING...SEVERE THUNDERSTORM WATCH 293...
VALID 130241Z - 130345Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 293
CONTINUES.
GIVEN THE SCHEDULED 03Z EXPIRATION OF SEVERE TSTM WATCH 293...A
REPLACEMENT WATCH WILL NEED TO BE CONSIDERED FOR PORTIONS OF THE
REGION.
A BROKEN CORRIDOR OF STRONG/SEVERE TSTMS CONTINUES FROM FAR
NORTH-CENTRAL AR SOUTHWESTWARD INTO SOUTHEAST OK LATE THIS EVENING.
AS AN UPPER VORT MAX PIVOTS EASTWARD/HEIGHT FALLS OCCUR...ADDITIONAL
STRONG/SEVERE TSTM DEVELOPMENT IS POSSIBLE INTO THE OVERNIGHT WITHIN
A RESIDUALLY UNSTABLE AIRMASS FROM SOUTHEAST OK INTO MUCH OF AR.
WITH A CONTINUING CONCERN FOR AT LEAST ISOLATED BOUTS OF SEVERE
HAIL/DAMAGING WINDS...A REPLACEMENT SEVERE TSTM WATCH MAY BE NEEDED.
..GUYER.. 05/13/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...SHV...TSA...FWD...
OUN...
LAT...LON 37689244 37689132 35229103 33839666 35179505 36209345
37689244SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 12, 10:03 PM CDT | Severe Thunderstorm Watch | SPC | Baxter, Cleburne, Conway, Crawford, Faulkner, Franklin and 26 more | 7 hr |
| May 12, 10:09 PM CDT | Mesoscale Discussion | SPC | Clay | 66 min |
| May 13, 12:01 PM CDT | Mesoscale Discussion | SPC | Arkansas, Clay, Craighead, Crittenden, Cross, Greene and 13 more | 89 min |
| May 13, 12:31 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more | 6 hr |
| May 13, 2:44 PM CDT | Mesoscale Discussion | SPC | Crittenden, Mississippi | 2 hr |
| May 12, 9:16 PM CDT | Mesoscale Discussion | SPC | Atchison | 59 min |
| May 13, 4:40 PM CDT | Mesoscale Discussion | SPC | Lincoln, Saint Charles, Saint Louis, City of Saint Louis | 95 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.