Alert archive / Texas / Mesoscale Discussions in 2014

Mesoscale Discussion 1849

October 10, 2014Lafayette County, Little River County, Miller County, Arkansas; 7 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Oct 10, 2014, 11:38 PM CDT for Lafayette County, Little River County, Miller County, Arkansas; 7 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
Oct 10, 2014, 11:38 PM CDT (04:38 UTC)
Expired
Oct 11, 2014, 12:45 AM CDT
In force
67 min
Issued by
the Storm Prediction Center
Chance of a watch
40%

Counties Lafayette County, AR, Little River County, AR, Miller County, AR, Bowie County, TX, Camp County, TX, Cass County, TX, Marion County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The radar

The Shreveport radar (KSHV), 109 km from the middle of the area, began a volume at 04:39 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

Shreveport, LA (KBAD), launched 00:00Z, 4.6 hours before the alert went out and 111 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 00:00Z on 2014-10-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1934 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 00:00Z on 2014-10-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 58 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
1934 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
995 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
58 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.7
Supercell composite
3.8

Open this sounding in Storm Lab

The text

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

427 
ACUS11 KWNS 110439
SWOMCD
SPC MCD 110438 
ARZ000-LAZ000-TXZ000-OKZ000-110545-

MESOSCALE DISCUSSION 1849
NWS STORM PREDICTION CENTER NORMAN OK
1138 PM CDT FRI OCT 10 2014

AREAS AFFECTED...ARKLATEX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 110438Z - 110545Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE THREAT FOR ISOLATED SEVERE WEATHER MAINLY IN THE FORM
OF DAMAGING WIND GUSTS MAY INCREASE OVER WRN PORTIONS OF THE
DISCUSSION AREA BY ABOUT 6Z. CONVECTIVE TRENDS ARE BEING MONITORED
FOR THE POSSIBILITY OF A WATCH.

DISCUSSION...OVER THE PAST HOUR...A QLCS HAS ORGANIZED ALONG A
STRENGTHENING COLD POOL FROM NEAR THE RED RIVER INTO N-CNTRL TX. THE
LEADING EDGE OF THE MOST INTENSE PORTION OF THIS CONVECTIVE SYSTEM
WAS SITUATED OVER FANNIN AND HUNT COUNTIES TX AS OF 0430Z. BASED ON
04Z MESOANALYSIS...IT APPEARS THAT THIS SECTION OF THE QLCS HAS OR
IS IN THE PROCESS OF OVERTAKING THE FRONT AND APPARENT MESOLOW INVOF
PRX. THE DOWNSTREAM AIR MASS ACROSS THE ARKLATEX REMAINS RELATIVELY
WARM AND QUITE MOIST WITH AT LEAST MODEST AMOUNTS OF INSTABILITY.
GIVEN AN OBSERVED ELY MOTION OF THIS SYSTEM OF ABOUT 35 KT...AT
LEAST SOME POTENTIAL FOR ISOLATED DAMAGING WIND GUSTS WILL EXIST AS
IT CONTINUES EWD ACROSS THE AREA.

SHOULD FURTHER INTENSIFICATION OCCUR...A WATCH MAY NEED TO BE
CONSIDERED.

..MEAD/BROYLES.. 10/11/2014

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

ATTN...WFO...SHV...

LAT...LON   33349523 33639509 33919501 33989453 33859404 33709364
            33499345 33219351 32909365 32669394 32649436 32779488
            32939517 33349523

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 10, 7:39 PM CDTMesoscale DiscussionSPCHoward, Little River, Montgomery, Pike, Polk, Scott and 2 more96 min
Oct 10, 9:39 PM CDTMesoscale DiscussionSPCHoward, Little River, Montgomery, Polk, Sevier66 min
Oct 10, 9:51 PM CDTSevere Thunderstorm WatchSPCBell, Bosque, Collin, Coryell, Dallas, Denton and 22 more3 hr
Oct 10, 10:42 PM CDTMesoscale DiscussionSPCCallahan, Coleman, Concho, Irion, Runnels, Taylor and 1 more63 min

Nearby

Mesoscale Discussions in Texas, 2014Mesoscale 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.