Alert archive / Arkansas / Mesoscale Discussions in 2012

Mesoscale Discussion 48

January 22, 201225 counties in Arkansas

The Storm Prediction Center issued this mesoscale discussion at Jan 22, 2012, 6:48 PM CST for 25 counties in Arkansas. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Jan 22, 2012, 6:48 PM CST (00:48 UTC)
Expired
Jan 22, 2012, 7:45 PM CST
In force
57 min
Issued by
the Storm Prediction Center
All 25 counties

Arkansas County, AR, Bradley County, AR, Calhoun County, AR, Cleveland County, AR, Craighead County, AR, Cross County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Grant County, AR, Greene County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Lonoke County, AR, Monroe County, AR, Ouachita County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR

The radar

The Little Rock radar (KLZK), 65 km from the middle of the area, began a volume at 00:50 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, 0.8 hours before the alert went out and 159 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 00:00Z on 2012-01-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 998 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 00:00Z on 2012-01-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 475 square meters per square second.1939587897117136Sfc1 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
998 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
455 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
475 m²/s²
0-3 km storm-relative helicity
474 m²/s²
Significant tornado parameter
0.0
Supercell composite
10.8

Open this sounding in Storm Lab

The text

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

274 
ACUS11 KWNS 230048
SWOMCD
SPC MCD 230048 
ARZ000-MOZ000-230145-

MESOSCALE DISCUSSION 0048
NWS STORM PREDICTION CENTER NORMAN OK
0648 PM CST SUN JAN 22 2012

AREAS AFFECTED...CNTRL/ERN AR

CONCERNING...TORNADO WATCH 5...

VALID 230048Z - 230145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 5 CONTINUES.

SEVERE POTENTIAL CONTINUES TO INCREASE ACROSS CNTRL AR AND INCIPIENT
REGIONAL TORNADO OUTBREAK APPEARS TO BE UNFOLDING...WITH PROBABLE
SIGNIFICANT TORNADOES DEVELOPING ACROSS S-CNTRL INTO NERN AR.

AS OF 0045Z...LEAD BROKEN BAND OF TSTMS EXTENDED IN A NNE-SSW
ORIENTATION FROM RANDOLPH TO COLUMBIA COUNTIES. SEVERAL EMBEDDED
MESOCYCLONES CONTINUE TO INTENSIFY WITH INITIAL TORNADO WARNINGS
HAVING BEEN RECENTLY ISSUED ACROSS S-CNTRL AR. MODIFIED 00Z
LZK/SHV/JAN RAOBS SUGGEST MLCAPE OF 750-1250 J/KG IS PREVALENT AHEAD
OF THIS BAND FROM S-CNTRL TO E-CNTRL AR. WITH EFFECTIVE SRH NOW IN
EXCESS OF 500-600 M2/S2...EXTREME LOW-LEVEL SHEAR/VERY LARGE
HODOGRAPHS BREEDS HIGH CONFIDENCE IN SUSTAINED/LONG-TRACKED
SUPERCELLS CAPABLE OF PRODUCING SIGNIFICANT TORNADOES.

..GRAMS.. 01/23/2012

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

ATTN...WFO...MEG...JAN...LZK...

LAT...LON   33599294 34599229 35819144 36129113 36209053 35869026
            34919056 33629133 33479170 33309213 33449260 33599294

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 22, 6:07 PM CSTMesoscale DiscussionSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 10 more53 min
Jan 22, 7:59 PM CSTMesoscale DiscussionSPCBradley, Calhoun, Columbia, Ouachita, Union91 min
Jan 22, 8:37 PM CSTMesoscale DiscussionSPCArkansas, Bradley, Chicot, Clay, Craighead, Crittenden and 14 more83 min
Jan 22, 9:47 PM CSTMesoscale DiscussionSPCAshley, Chicot, Crittenden, Desha, Phillips58 min
Jan 22, 10:59 PM CSTTornado WatchSPCAshley, Chicot7 hr

Nearby

Mesoscale Discussions in Arkansas, 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; radar from the NEXRAD Level II archive.