Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 476

April 10, 2017Bryan County, Choctaw County, Oklahoma; 42 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2017, 12:17 PM CDT for Bryan County, Choctaw County, Oklahoma; 42 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 10, 2017, 12:17 PM CDT (17:17 UTC)
Expired
Apr 10, 2017, 2:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 44 counties

Bryan County, OK, Choctaw County, OK, Bastrop County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Burnet County, TX, Collin County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Falls County, TX, Fannin County, TX, Gillespie County, TX, Grayson County, TX, Hamilton County, TX, Hill County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Kimble County, TX, Lamar County, TX, Lampasas County, TX, Lee County, TX, Limestone County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Menard County, TX, Milam County, TX, Mills County, TX, Navarro County, TX, Rains County, TX, Rockwall County, TX, San Saba County, TX, Schleicher County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Williamson County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 79 km from the middle of the area, began a volume at 17:19 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

Fort Worth, TX (KFWD), launched 12:00Z, 5.3 hours before the alert went out and 105 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, Fort Worth, TX at 12:00Z on 2017-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 784 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, Fort Worth, TX at 12:00Z on 2017-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 313 square meters per square second.19395878Sfc1 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
784 J/kg
Mixed-layer CIN
-234 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
313 m²/s²
0-3 km storm-relative helicity
344 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

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
Apr 10, 2:26 PM CDTSevere Thunderstorm WatchSPCMcCurtain9 hr
Apr 10, 6:51 PM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Blanco, Bosque and 57 more84 min

Nearby

Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Oklahoma, 2017Every mesoscale discussion in 2017

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.