Alert archive / Texas / Mesoscale Discussions in 2013

Mesoscale Discussion 166

February 18, 20134 states

The Storm Prediction Center issued this mesoscale discussion at Feb 18, 2013, 1:29 PM CST for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Feb 18, 2013, 1:29 PM CST (19:29 UTC)
Expired
Feb 18, 2013, 3:30 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
60%
All 53 counties

Clark County, AR, Columbia County, AR, Crawford County, AR, Franklin County, AR, Garland County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Logan County, AR, Miller County, AR, Montgomery County, AR, Nevada County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, De Soto Parish, LA, Webster Parish, LA, LeFlore County, OK, McCurtain County, OK, Sequoyah County, OK, Anderson County, TX, Bowie County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Delta County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Hopkins County, TX, Houston County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Nacogdoches County, TX, Panola County, TX, Rains County, TX, Red River County, TX, Rusk County, TX, Shelby County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 115 km from the middle of the area, began a volume at 19:32 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, 7.5 hours before the alert went out and 116 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 2013-02-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2013-02-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 510 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
668 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
510 m²/s²
0-3 km storm-relative helicity
670 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 18, 2:19 PM CSTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Carroll, Clark, Cleveland and 42 more7 hr
Feb 18, 3:52 PM CSTMesoscale DiscussionSPCCalhoun, Clark, Columbia, Conway, Dallas, Garland and 15 more83 min
Feb 18, 4:54 PM CSTMesoscale DiscussionSPCArkansas, Desha, Drew, Independence, Jackson, Jefferson and 7 more66 min
Feb 18, 5:59 PM CSTMesoscale DiscussionSPCBradley, Calhoun, Cleveland, Columbia, Dallas, Jefferson and 5 more91 min
Feb 18, 2:08 PM CSTMesoscale DiscussionSPCBeauregard, De Soto, Natchitoches, Red River, Sabine, Vernon67 min
Feb 18, 5:06 PM CSTMesoscale DiscussionSPCSabine84 min

Nearby

Mesoscale Discussions in Texas, 2013Mesoscale Discussions in Arkansas, 2013Mesoscale Discussions in Louisiana, 2013Every mesoscale discussion in 2013

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.