Alert archive / Texas / Mesoscale Discussions in 2020

Mesoscale Discussion 152

March 4, 202017 parishes in Louisiana; 47 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 4, 2020, 4:20 AM CST for 17 parishes in Louisiana; 47 counties in Texas. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Mar 4, 2020, 4:20 AM CST (10:20 UTC)
Expired
Mar 4, 2020, 6:15 AM CST
In force
115 min
Issued by
the Storm Prediction Center
All 64 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, De Soto Parish, LA, Grant Parish, LA, Jackson Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Webster Parish, LA, Winn Parish, LA, Anderson County, TX, Angelina County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Cherokee County, TX, Comal County, TX, Coryell County, TX, Ellis County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Gregg County, TX, Grimes County, TX, Harrison County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Houston County, TX, Kendall County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, McLennan County, TX, Milam County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Robertson County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Travis County, TX, Trinity County, TX, Upshur County, TX, Van Zandt County, TX, Walker County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 169 km from the middle of the area, began a volume at 10:20 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 00:00Z, 10.3 hours before the alert went out and 235 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 2020-03-04Temperature 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 00:00Z on 2020-03-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
1591 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 4, 1:19 AM CSTMesoscale DiscussionSPCAvoyelles, Bienville, Bossier, Caddo, Caldwell, Catahoula and 24 more2 hr
Mar 4, 1:53 AM CSTTornado WatchSPCCatahoula, Concordia, East Carroll, East Feliciana, Franklin, Madison and 9 more8 hr
Mar 4, 5:02 AM CSTSevere Thunderstorm WatchSPCAllen, Avoyelles, Beauregard, Bienville, Caldwell, De Soto and 12 more7 hr
Mar 4, 10:50 AM CSTMesoscale DiscussionSPCAllen, Avoyelles, Beauregard, Bienville, Caldwell, Catahoula and 24 more115 min
Mar 4, 1:57 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Iberia, Iberville, Jefferson and 17 more2 hr
Mar 4, 5:05 PM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Livingston and 13 more2 hr
Mar 3, 9:05 PM CSTMesoscale DiscussionSPCBandera, Bastrop, Bell, Blanco, Burleson, Burnet and 23 more2 hr
Mar 4, 2:03 AM CSTMesoscale DiscussionSPCBandera, Edwards, Gillespie, Kendall, Kerr, Kimble and 11 more117 min
Mar 4, 2:28 AM CSTSevere Thunderstorm WatchSPCBandera, Bexar, Blanco, Burnet, Comal, Edwards and 13 more6 hr
Mar 4, 7:33 AM CSTSevere Thunderstorm WatchSPCAnderson, Brazos, Burleson, Falls, Freestone, Grimes and 10 more4 hr

Nearby

Mesoscale Discussions in Texas, 2020Mesoscale Discussions in Louisiana, 2020Every mesoscale discussion in 2020

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.