Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 310
The Storm Prediction Center issued this mesoscale discussion at Mar 29, 2011, 8:13 PM CDT for 22 counties in Arkansas; 13 counties in Mississippi; 7 counties in Tennessee. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 29, 2011, 8:13 PM CDT (01:13 UTC)
- Expired
- Mar 29, 2011, 10:15 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
All 42 counties
Arkansas County, AR, Cleveland County, AR, Crittenden County, AR, Cross County, AR, Dallas County, AR, Faulkner County, AR, Grant County, AR, Hot Spring County, AR, Jackson County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Panola County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Chester County, TN, Fayette County, TN, Hardeman County, TN, Haywood County, TN, McNairy County, TN, Shelby County, TN, Tipton County, TN
The radar
The Little Rock radar (KLZK), 131 km from the middle of the area, began a volume at 01:14 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 00:00Z, 1.2 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
- 1 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 463 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 394 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.6
The text
As transmitted, in the capitals the NWS used until 2016.
463
ACUS11 KWNS 300114
SWOMCD
SPC MCD 300113
TNZ000-MSZ000-ARZ000-300315-
MESOSCALE DISCUSSION 0310
NWS STORM PREDICTION CENTER NORMAN OK
0813 PM CDT TUE MAR 29 2011
AREAS AFFECTED...CNTRL/ERN AR...NRN MS...SWRN TN
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 300113Z - 300315Z
ISOLATED SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL
WILL BE POSSIBLE ACROSS CNTRL/ERN AR...NRN MS...AND SWRN TN THIS
EVENING. DUE TO THE ANTICIPATED LOW COVERAGE OF SEVERE STORMS...A WW
WILL NOT BE NEEDED.
LOW-LEVEL ISENTROPIC ASCENT AUGMENTED BY A COUPLED UPPER-LEVEL JET
STRUCTURE /ONE JET STREAK APPROACHING FROM NRN OK AND THE OTHER JET
STREAK OVER THE OHIO VALLEY AND LOWER GREAT LAKES REGION/ WILL
SUPPORT THE DEVELOPMENT OF ELEVATED CONVECTION ACROSS THE MID-SOUTH
REGION THIS EVENING. STEEP MID-LEVEL LAPSE RATES /8 C PER KM/ WERE
NOTED IN THE 00Z KLZK SOUNDING...WITH RUC OBJECTIVE ANALYSIS
INDICATING MUCAPE VALUES AOA 250 J/KG OVERSPREADING MUCH OF THE
DISCUSSION AREA. CLOUD-BEARING WIND SHEAR MAGNITUDES OF 40 TO 50 KT
WILL PROVIDE ADDITIONAL SUPPORT FOR STRONG UPDRAFTS...WITH THE
POTENTIAL FOR OCCASIONALLY ORGANIZED STORM STRUCTURES. GIVEN THE
ELEVATED NATURE OF THE CONVECTION...HAIL TO THE SIZE OF QUARTERS
WILL BE A POSSIBILITY WITH THE DEEPER/MORE PERSISTENT CORES.
HOWEVER...WITH GREATER INSTABILITY CONFINED FARTHER SOUTH OVER THE
LOWER MS VALLEY REGION...ANY SEVERE STORMS ARE EXPECTED TO OCCUR ON
AN ISOLATED BASIS...AND THUS NO WW IS PLANNED NORTH OF SEVERE
THUNDERSTORM WATCH 74 ATTM.
..COHEN.. 03/30/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MEG...LZK...
LAT...LON 34218854 34278966 34269061 34069112 33659152 33499206
33649263 33989293 34409303 34939286 35389251 35629172
35688987 35468843 34708819 34218854SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 29, 7:40 PM CDT | Mesoscale Discussion | SPC | Chicot | 95 min |
| Mar 29, 8:56 PM CDT | Mesoscale Discussion | SPC | Amite, Forrest, George, Greene, Hancock, Harrison and 8 more | 64 min |
| Mar 29, 9:42 PM CDT | Tornado Watch | SPC | Amite, Clarke, Copiah, Covington, Forrest, Franklin and 21 more | 7 hr |
| Mar 29, 11:39 PM CDT | Mesoscale Discussion | SPC | Attala, Carroll, Chickasaw, Choctaw, Claiborne, Clarke and 28 more | 2 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.