Alert archive / Arkansas / Mesoscale Discussions in 2012

Mesoscale Discussion 416

April 2, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2012, 3:18 PM CDT for 4 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Apr 2, 2012, 3:18 PM CDT (20:18 UTC)
Expired
Apr 2, 2012, 5:15 PM CDT
In force
117 min
Issued by
the Storm Prediction Center
All 54 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Conway County, AR, Dallas County, AR, Drew County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Logan County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Union County, AR, Yell County, AR, Union Parish, LA, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McCurtain County, OK, Pittsburg County, OK, Pushmataha County, OK, Bowie County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Rains County, TX, Red River County, TX, Titus County, TX

The radar

The Shreveport radar (KSHV), 131 km from the middle of the area, began a volume at 20:20 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 8.3 hours before the alert went out and 130 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, Shreveport, LA at 12:00Z on 2012-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1679 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, Shreveport, LA at 12:00Z on 2012-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -91 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
1679 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
558 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-91 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

443 
ACUS11 KWNS 022019
SWOMCD
SPC MCD 022018
ARZ000-LAZ000-TXZ000-OKZ000-022215-

MESOSCALE DISCUSSION 0416
NWS STORM PREDICTION CENTER NORMAN OK
0318 PM CDT MON APR 02 2012

AREAS AFFECTED...NERN TX/NRN LA/SERN OK/SRN AR

CONCERNING...SEVERE THUNDERSTORM WATCH 127...

VALID 022018Z - 022215Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 127
CONTINUES.

THREAT FOR DAMAGING WINDS AND HAIL CONTINUES AS STORMS MOVE NWD
ACROSS WW 127.

LATEST RADAR LOOP SHOWS THE EXPANDING/ARCING BAND OF STORMS ACROSS
WW 127 CONTINUING TO MOVE NWD AT 35 TO 40 KT...THROUGH A MODERATELY
UNSTABLE ENVIRONMENT.  WHILE INSTABILITY DROPS OFF A BIT WITH NRN
EXTENT INTO PARTS OF NERN OK/NRN AR...FAVORABLE THERMODYNAMIC
ENVIRONMENT APPEARS TO EXTEND FAR ENOUGH N OF WW 127 THAT SEVERE
POTENTIAL MAY CONTINUE EXPANDING NWD.  THUS...NEW WW MAY BE REQUIRED
IN THE NEXT HOUR N OF THE EXISTING WATCH.

..GOSS.. 04/02/2012

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

ATTN...WFO...JAN...LZK...SHV...TSA...FWD...OUN...

LAT...LON   32599604 33219634 34029652 35179598 35589430 35199224
            33969171 33569129 32989195 32479199 32989317 33249415
            33029555 32599604

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 2, 12:15 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Clark, Cleveland and 17 more90 min
Apr 2, 12:41 PM CDTSevere Thunderstorm WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Dallas and 11 more6 hr
Apr 2, 12:50 PM CDTSevere Thunderstorm WatchSPCAshley, Chicot7 hr
Apr 2, 3:23 PM CDTMesoscale DiscussionSPCAshley, Chicot2 hr
Apr 2, 3:49 PM CDTSevere Thunderstorm WatchSPCArkansas, Conway, Crawford, Desha, Faulkner, Franklin and 19 more4 hr
Apr 2, 5:58 PM CDTMesoscale DiscussionSPCArkansas, Clark, Cleveland, Conway, Dallas, Desha and 23 more62 min
Apr 2, 9:57 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 27 more63 min
Apr 2, 10:10 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 31 more7 hr
Apr 2, 5:36 PM CDTMesoscale DiscussionSPCOrleans, Saint Bernard, Saint Tammany54 min
Apr 2, 3:00 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Beckham, Blaine, Caddo, Canadian and 16 more2 hr
Apr 2, 3:37 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Beaver, Beckham, Blaine, Caddo, Comanche and 16 more7 hr
Apr 2, 5:16 AM CDTMesoscale DiscussionSPCAustin, Brazoria, Chambers, Colorado, Fayette, Fort Bend and 13 more2 hr
Apr 2, 6:51 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Clay, Coleman and 17 more54 min

Nearby

Mesoscale Discussions in Arkansas, 2012Mesoscale Discussions in Texas, 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; radar from the NEXRAD Level II archive.