Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 1676
The Storm Prediction Center issued this mesoscale discussion at Aug 1, 2012, 4:48 PM CDT for 32 counties in Arkansas; 19 counties in Missouri; 6 counties in Oklahoma. It was in force for 87 min.
The area
The outline as issued.
The facts
- Issued
- Aug 1, 2012, 4:48 PM CDT (21:48 UTC)
- Expired
- Aug 1, 2012, 6:15 PM CDT
- In force
- 87 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 57 counties
Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Cleburne County, AR, Conway County, AR, Crawford County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Perry County, AR, Pope County, AR, Randolph County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, White County, AR, Yell County, AR, Barry County, MO, Carter County, MO, Christian County, MO, Douglas County, MO, Greene County, MO, Howell County, MO, Lawrence County, MO, McDonald County, MO, Newton County, MO, Oregon County, MO, Ozark County, MO, Reynolds County, MO, Ripley County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Texas County, MO, Webster County, MO, Wright County, MO, Adair County, OK, Cherokee County, OK, Delaware County, OK, Haskell County, OK, LeFlore County, OK, Sequoyah County, OK
The nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 9.8 hours before the alert went out and 122 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
- 323 J/kg
- Mixed-layer CIN
- -264 J/kg
- Mixed-layer LCL
- 1990 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- 224 m²/s²
- 0-3 km storm-relative helicity
- 287 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
433
ACUS11 KWNS 012149
SWOMCD
SPC MCD 012148
ARZ000-MOZ000-OKZ000-012315-
MESOSCALE DISCUSSION 1676
NWS STORM PREDICTION CENTER NORMAN OK
0448 PM CDT WED AUG 01 2012
AREAS AFFECTED...SWRN/S-CNTRL MO...WRN/NRN AR...FAR ERN OK
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 012148Z - 012315Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...THUNDERSTORM CLUSTERS ARE RAPIDLY DEVELOPING OVER SWRN MO
AND NWRN/N-CNTRL AR...WITH ADDITIONAL/ISOLATED ACTIVITY POSSIBLY
DEVELOPING OVER PORTIONS OF FAR ERN OK DURING THE NEXT FEW HRS.
STORMS WILL POSE A THREAT OF DAMAGING WIND GUSTS AND LARGE HAIL AS
THEY SPREAD S-SEWD DURING THE EVENING. TRENDS WILL CONTINUE TO BE
MONITORED FOR A WW.
DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS AN MCV MOVING SEWD
ACROSS SWRN MO. SURFACE AIRMASS AHEAD OF THIS FEATURE IS HOT
/TEMPERATURES FROM 100-105 F/ AND FAIRLY MOIST /DEWPOINTS GENERALLY
IN THE MID 60S/...WHICH IS SUPPORTING MODERATE TO STRONG INSTABILITY
WITH ESTIMATES OF MLCAPE RANGING FROM 1000-2500 J/KG. AS A
RESULT...THUNDERSTORM CLUSTERS HAVE RECENTLY DEVELOPED AHEAD OF THE
MCV OVER SWRN MO AND NWRN/N-CNTRL AR. NWLY MIDLEVEL FLOW FROM 20-40
KT RESIDES ALONG THE ERN PERIPHERY OF AN UPPER-LEVEL
ANTICYCLONE...WHICH IS CONTRIBUTING TO EFFECTIVE BULK SHEAR NEAR 40
KT ACROSS THE AREA. GIVEN THE STRONG INSTABILITY AND FAVORABLE
DEEP-LAYER SHEAR...ORGANIZED MULTICELL CLUSTERS ACQUIRING BRIEF
MIDLEVEL ROTATION WILL BE LIKELY...AND WILL POSE A THREAT FOR
DAMAGING WIND GUSTS AND LARGE HAIL. IF CONFIDENCE IN GREATER SVR
COVERAGE INCREASES DURING THE NEXT FEW HRS...THEN THE NEED FOR A WW
MAY BECOME NECESSARY.
..GARNER/HART.. 08/01/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...MEG...LSX...LZK...SGF...TSA...
LAT...LON 34619419 34949512 36019532 36809481 37499280 37469090
36149050 35019152 34619419Nearby
Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Oklahoma, 2012Every mesoscale discussion in 2012
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.