Alert archive / Oklahoma / Mesoscale Discussions in 2011
Mesoscale Discussion 556
The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 5:34 PM CDT for 7 counties in Arkansas; 17 counties in Oklahoma. It was in force for 26 min.
The area
The outline as issued.
The facts
- Issued
- Apr 24, 2011, 5:34 PM CDT (22:34 UTC)
- Expired
- Apr 24, 2011, 6:00 PM CDT
- In force
- 26 min
- Issued by
- the Storm Prediction Center
All 24 counties
Crawford County, AR, Franklin County, AR, Madison County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Marshall County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK
The radar
The Western Arkansas radar (KSRX), 74 km from the middle of the area, began a volume at 22:34 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
Norman, OK (KOUN), launched 12:00Z, 10.6 hours before the alert went out and 247 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 494 m above ground
- 0-6 km bulk shear
- 58 kt
- 0-1 km storm-relative helicity
- 504 m²/s²
- 0-3 km storm-relative helicity
- 705 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 14.8
The text
As transmitted, in the capitals the NWS used until 2016.
954
ACUS11 KWNS 242234
SWOMCD
SPC MCD 242234
ARZ000-TXZ000-OKZ000-242300-
MESOSCALE DISCUSSION 0556
NWS STORM PREDICTION CENTER NORMAN OK
0534 PM CDT SUN APR 24 2011
AREAS AFFECTED...PORTIONS ERN OK...WRN AR.
CONCERNING...SEVERE THUNDERSTORM WATCH 194...
VALID 242234Z - 242300Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 194
CONTINUES.
WW IS BEING REPLACED OVER ITS ERN PORTIONS BY TORNADO WW 197...GIVEN
PRESENCE OF
1. BAND OF STG-SVR TSTMS MOVING EWD INTO PROGRESSIVELY MORE
SFC-BASED/HIGH-THETAE INFLOW AIR WITH POTENTIAL QLCS CIRCULATIONS
2. FAVORABLE LOW-LEVEL SRH AND DEEP-LAYER SHEAR...EACH OF WHICH IS
FCST TO STRENGTHEN WITH TIME DURING NEXT FEW HOURS AS LLJ INCREASES
AND UPPER TROUGH APCHS...
3. SFC PRESSURE FALLS OVER SERN OK WARM SECTOR..AHEAD OF S-CENTRAL
OK SFC LOW. RELATED ISALLOBARIC FORCING SHOULD MAINTAIN BACKED
WINDS AND ENHANCED HODOGRAPH SIZE...
4. FAVORABLE MOISTURE/BUOYANCY ALONG AND S OF OUTFLOW BOUNDARY
ANALYZED AT 23Z FROM FAULKNER COUNTY AR WWD ACROSS LEFLORE COUNTY
OK...ALONG WHICH LOW-LEVEL VORTICITY SHOULD REMAIN MAXIMIZED...AND
5. POTENTIAL FOR LATER SFC-BASED SUPERCELL DEVELOPMENT IN
LLJ-ENHANCED SHEAR PROFILES OVER SERN OK/SWRN AR.
WRN PORTIONS OF WW 194 WILL REMAIN IN EFFECT UNTIL CLEARED LOCALLY.
..EDWARDS.. 04/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LZK...SHV...TSA...FWD...OUN...
LAT...LON 33629453 33909557 33969711 35169625 35809517 36219365
35399370 35009415 34879363 34269407 33629453SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 23, 8:09 PM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Clay, Cleburne, Conway, Craighead and 25 more | 2 hr |
| Apr 23, 8:19 PM CDT | Tornado Watch | SPC | Baxter, Clay, Craighead, Fulton, Greene, Independence and 9 more | 4 hr |
| Apr 23, 10:40 PM CDT | Mesoscale Discussion | SPC | Baxter, Benton, Boone, Carroll, Clay, Fulton and 8 more | 95 min |
| Apr 24, 11:58 AM CDT | Mesoscale Discussion | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Faulkner and 19 more | 62 min |
| Apr 24, 12:27 PM CDT | Tornado Watch | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Fulton and 16 more | 7 hr |
| Apr 24, 3:31 PM CDT | Mesoscale Discussion | SPC | Cleburne, Craighead, Greene, Independence, Izard, Jackson and 9 more | 59 min |
| Apr 24, 5:36 PM CDT | Tornado Watch | SPC | Conway, Crawford, Franklin, Garland, Johnson, Logan and 8 more | 7 hr |
| Apr 24, 6:23 PM CDT | Mesoscale Discussion | SPC | Baxter, Clay, Cleburne, Conway, Craighead, Faulkner and 32 more | 2 hr |
| Apr 23, 7:04 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Carter, Choctaw, Coal, Jefferson and 9 more | 86 min |
| Apr 23, 9:08 PM CDT | Mesoscale Discussion | SPC | Adair, Canadian, Cherokee, Cleveland, Craig, Creek and 26 more | 97 min |
| Apr 23, 9:53 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Atoka, Bryan, Caddo, Canadian, Carter and 47 more | 7 hr |
| Apr 24, 2:02 AM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Caddo, Canadian, Carter, Cherokee and 42 more | 88 min |
| Apr 24, 4:17 AM CDT | Mesoscale Discussion | SPC | Blaine, Caddo, Canadian, Cherokee, Cleveland, Coal and 29 more | 28 min |
| Apr 24, 1:13 PM CDT | Mesoscale Discussion | SPC | Atoka, Bryan, Carter, Choctaw, Coal, Cotton and 13 more | 92 min |
| Apr 24, 2:28 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more | 7 hr |
Nearby
Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Arkansas, 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.