Alert archive / Arkansas / Mesoscale Discussions in 2012
Mesoscale Discussion 1774
The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2012, 1:26 PM CDT for 36 counties in Arkansas; 11 counties in Oklahoma. It was in force for 64 min.
The area
The outline as issued.
The facts
- Issued
- Aug 16, 2012, 1:26 PM CDT (18:26 UTC)
- Expired
- Aug 16, 2012, 2:30 PM CDT
- In force
- 64 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 47 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, Garland County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Montgomery County, AR, Newton County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Randolph County, AR, Saline 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, Adair County, OK, Cherokee County, OK, Delaware County, OK, Haskell County, OK, LeFlore County, OK, Mayes County, OK, McIntosh County, OK, Muskogee County, OK, Rogers County, OK, Sequoyah County, OK, Wagoner County, OK
The nearest sounding before it
Springfield, MO (KSGF), launched 12:00Z, 6.4 hours before the alert went out and 176 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
- 1719 J/kg
- Mixed-layer CIN
- -126 J/kg
- Mixed-layer LCL
- 1553 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 37 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
221
ACUS11 KWNS 161827
SWOMCD
SPC MCD 161826
ARZ000-OKZ000-161930-
MESOSCALE DISCUSSION 1774
NWS STORM PREDICTION CENTER NORMAN OK
0126 PM CDT THU AUG 16 2012
AREAS AFFECTED...E-CNTRL OK INTO NW AND CNTRL AR
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 161826Z - 161930Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...SPORADIC STRONG/LOCALLY DAMAGING WIND GUSTS WILL BE
POSSIBLE THIS AFTERNOON RELATED TO PULSE-TYPE CONVECTION. A WW IS
NOT ANTICIPATED AT THIS TIME BUT TRENDS WILL CONTINUE TO BE
MONITORED FOR INCREASED ORGANIZATION AS COLD FRONT TRACKS SEWD
TOWARD THE REGION LATE THIS AFTERNOON/EARLY EVENING.
DISCUSSION...THUNDERSTORMS ARE EXPECTED TO CONTINUE DEVELOPING
ACROSS THE MCD AREA THIS AFTERNOON. LATEST VIS SATELLITE IMAGERY
SHOWED EXPANSIVE CU FIELD IN A MODERATELY UNSTABLE ENVIRONMENT AHEAD
OF A COLD FRONT LOCATED FROM CNTRL MO INTO WRN OK. STEEP LOW LEVEL
LAPSE RATES WILL ALLOW FOR SPORADIC STRONG/LOCALLY DAMAGING WIND
GUSTS. HOWEVER...WEAK DEEP LAYER SHEAR LESS THAN 20 KT WILL PREVENT
WIDESPREAD ORGANIZATION AND RESULT MAINLY IN PULSE CONVECTION.
STORMS MAY BEGIN TO ORGANIZE TOWARD LATE AFTERNOON/EVENING AS COLD
FRONT PUSHES E/SE TOWARD THE REGION. THAT SCENARIO IS STILL LIKELY
SEVERAL HOURS AWAY AND A WW IS NOT ANTICIPATED FOR THE NEAR TERM
SPORADIC CONVECTION. IN ADDITION TO STRONG WINDS...PW VALUES OVER
1.5 INCHES COUPLED WITH WEAK STEERING FLOW WILL RESULT IN HEAVY
DOWNPOURS.
..LEITMAN/CARBIN.. 08/16/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MEG...LZK...SHV...TSA...
LAT...LON 36389093 35069163 34289252 34019338 34209443 34789518
35469579 36189587 36479553 36389093SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 16, 5:25 PM CDT | Mesoscale Discussion | SPC | Clay | 2 hr |
| Aug 16, 4:45 PM CDT | Mesoscale Discussion | SPC | Beckham, Caddo, Canadian, Cleveland, Creek, Grady and 15 more | 2 hr |
Nearby
Mesoscale Discussions in Arkansas, 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.