Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 2201
The Storm Prediction Center issued this mesoscale discussion at Sep 25, 2011, 6:10 PM CDT for 9 counties in Arkansas; 8 counties in Mississippi; Fayette County, Shelby County, Tennessee. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- Sep 25, 2011, 6:10 PM CDT (23:10 UTC)
- Expired
- Sep 25, 2011, 7:45 PM CDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
Counties Arkansas County, AR, Ashley County, AR, Chicot County, AR, Crittenden County, AR, Desha County, AR, Drew County, AR, Lee County, AR, Lincoln County, AR, Phillips County, AR, Bolivar County, MS, Coahoma County, MS, DeSoto County, MS, Marshall County, MS, Quitman County, MS, Tate County, MS, Tunica County, MS, Washington County, MS, Fayette County, TN, Shelby County, TN
The radar
The Little Rock radar (KLZK), 153 km from the middle of the area, began a volume at 23:13 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 12:00Z, 11.2 hours before the alert went out and 114 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
- 552 J/kg
- Mixed-layer CIN
- -212 J/kg
- Mixed-layer LCL
- 1112 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km storm-relative helicity
- 127 m²/s²
- 0-3 km storm-relative helicity
- 295 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
439
ACUS11 KWNS 252310
SWOMCD
SPC MCD 252310
TNZ000-MSZ000-ARZ000-LAZ000-260045-
MESOSCALE DISCUSSION 2201
NWS STORM PREDICTION CENTER NORMAN OK
0610 PM CDT SUN SEP 25 2011
AREAS AFFECTED...PARTS OF SERN AR...WRN TN...NWRN MS
CONCERNING...TORNADO WATCH 855...
VALID 252310Z - 260045Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 855 CONTINUES.
VIGOROUS CONVECTIVE DEVELOPMENT AND SLOW SOUTHEASTWARD PROGRESSION
OF THE COLD FRONT IS BEGINNING TO STABILIZE THE NARROW PRE-FRONTAL
INSTABILITY AXIS...WHERE STRONGEST DAYTIME HEATING OCCURRED...ACROSS
NORTHEAST AND EAST CENTRAL ARKANSAS. STORMS APPEAR TO BE GENERALLY
WEAKENING AS THEY PROGRESS EASTWARD AND INGEST MORE STABLE BOUNDARY
LAYER AIR OVER WESTERN TENNESSEE. SIMILAR TRENDS SEEM PROBABLE WITH
STORMS EAST AND NORTHEAST OF PINE BLUFF AS THEY CROSS THE
MISSISSIPPI RIVER INTO NORTHWEST MISSISSIPPI. HOWEVER...A RESIDUAL
FOCUSED AREA OF STRONGER WARM ADVECTION...ON THE NOSE OF THE
PRE-FRONTAL LOW-LEVEL THERMAL RIDGE EXTENDING EAST NORTHEASTWARD OUT
OF CENTRAL TEXAS...APPEARS LIKELY TO REMAIN A FOCUS FOR ADDITIONAL
STRONG/SEVERE STORM DEVELOPMENT NEAR/NORTH OF MONTICELLO AR INTO THE
GREENVILLE MS AREA THROUGH THE 00-03Z TIME FRAME. SUPERCELLS ARE
POSSIBLE...PRIMARILY WITH THE RISK FOR LARGE HAIL...PERHAPS LOCALLY
DAMAGING WIND GUSTS. BUT EVEN WITH FAIRLY SIZABLE SUB-CLOUD
TEMPERATURE/DEW POINT SPREADS... CLOCKWISE CURVED LOW-LEVEL
HODOGRAPHS ARE LARGE ENOUGH TO SUPPORT POTENTIAL FOR AN ISOLATED
TORNADO.
..KERR.. 09/25/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MEG...JAN...LZK...
LAT...LON 34019199 34819089 35339023 35458950 35048914 34089033
33499066 32899089 32919172 33249192 34019199SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 25, 2:03 PM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Crittenden and 21 more | 2 hr |
| Sep 25, 3:19 PM CDT | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 12 more | 9 hr |
Nearby
Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Mississippi, 2011Mesoscale Discussions in Tennessee, 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.