Alert archive / Arkansas / Mesoscale Discussions in 2011
Mesoscale Discussion 686
The Storm Prediction Center issued this mesoscale discussion at May 1, 2011, 7:31 PM CDT for 26 counties in Arkansas; Ripley County, Missouri. It was in force for 59 min.
The area
The outline as issued.
The facts
- Issued
- May 1, 2011, 7:31 PM CDT (00:31 UTC)
- Expired
- May 1, 2011, 8:30 PM CDT
- In force
- 59 min
- Issued by
- the Storm Prediction Center
All 27 counties
Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Faulkner County, AR, Garland County, AR, Greene County, AR, Howard County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Lawrence County, AR, Montgomery County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Ripley County, MO
The radar
The Little Rock radar (KLZK), 67 km from the middle of the area, began a volume at 00:31 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, 0.5 hours before the alert went out and 200 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
- 5 J/kg
- Mixed-layer CIN
- 0 J/kg
- Mixed-layer LCL
- 396 m above ground
- 0-6 km bulk shear
- 69 kt
- 0-1 km storm-relative helicity
- 614 m²/s²
- 0-3 km storm-relative helicity
- 776 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 10.6
The text
As transmitted, in the capitals the NWS used until 2016.
857
ACUS11 KWNS 020031
SWOMCD
SPC MCD 020031
ARZ000-MOZ000-020130-
MESOSCALE DISCUSSION 0686
NWS STORM PREDICTION CENTER NORMAN OK
0731 PM CDT SUN MAY 01 2011
AREAS AFFECTED...W-CNTRL TO NERN AR
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 020031Z - 020130Z
ELEVATED TSTMS SHOULD CONTINUE TO POSE A THREAT FOR ONLY MARGINALLY
SEVERE HAIL. A WW ISSUANCE DOES NOT APPEAR NECESSARY.
00Z SURFACE ANALYSIS PLACED A 1007 MB MESOLOW NEAR GGG WITH A
QUASI-STATIONARY FRONT EXTENDING NEWD ACROSS SRN AR TOWARDS MEM. AS
ALLUDED TO IN MCD 684/685...ELEVATED TSTMS HAVE BLOSSOMED N OF THIS
BOUNDARY FROM W-CNTRL THROUGH N-CNTRL AR WHERE SURFACE TEMPERATURES
HAVE COOLED INTO THE MIDDLE 40S AND 50S. 00Z LZK RAOB SAMPLES THE
ELEVATED INFLOW ENVIRONMENT WELL WITH MUCAPE AROUND 2000 J/KG AND
STRONG EFFECTIVE SHEAR AROUND 60 KT. SEVERAL REPORTS OF MARGINALLY
SEVERE HAIL HAVE OCCURRED AND THIS OUGHT TO CONTINUE...ESPECIALLY
ALONG THE SRN PERIPHERY OF THE ACTIVITY WHERE BUOYANCY WILL REMAIN
LARGEST. WITH ZERO SURFACE-BASED INSTABILITY...ANY TORNADO THREAT IN
N-CNTRL AR WILL REMAIN NIL.
..GRAMS.. 05/02/2011
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LZK...SGF...SHV...
LAT...LON 34829196 33979378 34069415 34499433 35369334 36499152
36699095 36629064 36389039 35759062 35459075 34829196SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 8:10 PM CDT | Mesoscale Discussion | SPC | Arkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 24 more | 35 min |
| May 2, 1:28 AM CDT | Mesoscale Discussion | SPC | Howard, Little River, Miller, Sevier | 3 hr |
| May 2, 1:51 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Desha, Drew | 2 hr |
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.