Alert archive / Arkansas / Mesoscale Discussions in 2014

Mesoscale Discussion 855

June 6, 201414 counties in Arkansas

The Storm Prediction Center issued this mesoscale discussion at Jun 6, 2014, 12:49 PM CDT for 14 counties in Arkansas. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Jun 6, 2014, 12:49 PM CDT (17:49 UTC)
Expired
Jun 6, 2014, 1:45 PM CDT
In force
56 min
Issued by
the Storm Prediction Center

Counties Conway County, AR, Faulkner County, AR, Grant County, AR, Hot Spring County, AR, Jefferson County, AR, Lonoke County, AR, Monroe County, AR, Perry County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Van Buren County, AR, White County, AR

The radar

The Little Rock radar (KLZK), 5 km from the middle of the area, began a volume at 17:48 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 (KBYH), launched 12:00Z, 5.8 hours before the alert went out and 215 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.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 12:00Z on 2014-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1935 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 12:00Z on 2014-06-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 111 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1935 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
787 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
111 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.9
Supercell composite
3.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

277 
ACUS11 KWNS 061750
SWOMCD
SPC MCD 061749 
ARZ000-061845-

MESOSCALE DISCUSSION 0855
NWS STORM PREDICTION CENTER NORMAN OK
1249 PM CDT FRI JUN 06 2014

AREAS AFFECTED...CENTRAL ARKANSAS

CONCERNING...SEVERE THUNDERSTORM WATCH 239...

VALID 061749Z - 061845Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 239
CONTINUES.

SUMMARY...THE DAMAGING-WIND RISK IS SPREADING EWD ACROSS CNTRL AR.

DISCUSSION...THE LEADING CONVECTIVE LINE OF A TRAILING-STRATIFORM
MCS CONTINUES SPREADING EWD ACROSS CNTRL AR WITH FORWARD MOTION
AROUND 20-25 KT. THE DOWNSHEAR AIR MASS CONTINUES TO DESTABILIZE
WITH MIDDLE 80S SFC TEMPS AMIDST LOWER 70S DEWPOINTS SUPPORTING
AROUND 3000 J/KG MLCAPE PER A MODIFIED 12Z LZK RAOB. MID-LEVEL FLOW
IS ONLY MODEST -- AROUND 15-20 KT -- PER LZK VWP...BUT THE STRONG
BUOYANCY SHOULD FAVOR DOWNSHEAR REGENERATIVE CONVECTION AT THE
LEADING EDGE OF THE COLD POOL. DMGG WINDS WILL REMAIN POSSIBLE WITH
THIS ACTIVITY AS IT SPREADS EWD...REACHING THE LITTLE ROCK AREA IN
THE NEXT HOUR OR SO.

..COHEN.. 06/06/2014

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LZK...

LAT...LON   34259307 35459322 35659270 35509137 34689118 34209154
            34259307

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 5, 9:14 PM CDTMesoscale DiscussionSPCBenton, Carroll3 hr
Jun 5, 9:36 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Madison, Washington7 hr
Jun 6, 9:52 AM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Conway and 32 more53 min
Jun 6, 10:18 AM CDTSevere Thunderstorm WatchSPCArkansas, Baxter, Benton, Boone, Bradley, Calhoun and 51 more5 hr
Jun 6, 11:22 AM CDTMesoscale DiscussionSPCCrittenden, Lee, Phillips, St. Francis83 min
Jun 6, 11:51 AM CDTSevere Thunderstorm WatchSPCAshley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more7 hr
Jun 6, 2:43 PM CDTMesoscale DiscussionSPCArkansas, Cleburne, Craighead, Crittenden, Cross, Desha and 22 more92 min

Nearby

Mesoscale Discussions in Arkansas, 2014Every mesoscale discussion in 2014

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.