Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 548
The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 11:58 AM CDT for 25 counties in Arkansas; 9 counties in Missouri. It was in force for 62 min.
The area
The outline as issued.
The facts
- Issued
- Apr 24, 2011, 11:58 AM CDT (16:58 UTC)
- Expired
- Apr 24, 2011, 1:00 PM CDT
- In force
- 62 min
- Issued by
- the Storm Prediction Center
All 34 counties
Baxter County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Mississippi County, AR, Newton County, AR, Poinsett County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Butler County, MO, Carter County, MO, Dunklin County, MO, New Madrid County, MO, Oregon County, MO, Pemiscot County, MO, Ripley County, MO, Stoddard County, MO, Wayne County, MO
The radar
The Little Rock radar (KLZK), 116 km from the middle of the area, began a volume at 16:59 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
Little Rock, AR (KLZK), launched 12:00Z, 5.0 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
- 1899 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 664 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 189 m²/s²
- 0-3 km storm-relative helicity
- 23 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.0
The text
As transmitted, in the capitals the NWS used until 2016.
722
ACUS11 KWNS 241659
SWOMCD
SPC MCD 241658
KYZ000-MOZ000-TNZ000-ARZ000-241800-
MESOSCALE DISCUSSION 0548
NWS STORM PREDICTION CENTER NORMAN OK
1158 AM CDT SUN APR 24 2011
AREAS AFFECTED...NRN AR...EXTREME SERN MO
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 241658Z - 241800Z
INCREASING RISK FOR SEVERE WINDS...HAIL AND A COUPLE OF TORNADOES
THROUGH AFTERNOON IN NRN AR AND EXTREME SERN MO. PROBABILITY OF
WATCH ISSUANCE THROUGH MID-AFTERNOON ACROSS PARTS OF THE AREA 60
PERCENT.
THUNDERSTORMS OVER NWRN AR HAVE BEEN ACHIEVING STRONGER
REFLECTIVITY/VELOCITY VALUES LATE THIS MORNING AND MAY BE TAPPING
THE RECOVERING AIR MASS ACROSS NRN AR. CONCERN IS THAT COMPLEX WILL
YIELD INCREASING BOWING CHARACTERISTICS WITH APEX RUNNING ALONG THE
RETREATING WARM FRONT IN NCNTRL/NERN AR AND SERN MO THROUGH THE
AFTERNOON. REGION WILL REMAIN ALONG SRN FRINGE OF STRONG WSW FLOW
IN THE H85-H5 LAYER AND GIVEN THE STEEPENING LOW-LEVEL LAPSE RATES
AND MODEST COLD POOL DYNAMICS...DMGG WIND GUSTS AND PERHAPS
SMALL-SCALE MESOVORTICIES WILL EVOLVE ALONG WITH THE HAIL THREAT.
..RACY.. 04/24/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...
LAT...LON 34979382 35959334 37319027 36818943 35678997 34959184
34979382SPC 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, 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, 5:34 PM CDT | Mesoscale Discussion | SPC | Crawford, Franklin, Madison, Polk, Scott, Sebastian and 1 more | 26 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 24, 3:01 PM CDT | Mesoscale Discussion | SPC | Mississippi, New Madrid, Scott | 89 min |
Nearby
Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Missouri, 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.