Alert archive / Texas / Mesoscale Discussions in 2020

Mesoscale Discussion 430

April 21, 2020Hemphill County, Lipscomb County, Wheeler County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2020, 8:12 PM CDT for Hemphill County, Lipscomb County, Wheeler County, Texas. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Apr 21, 2020, 8:12 PM CDT (01:12 UTC)
Expired
Apr 21, 2020, 9:15 PM CDT
In force
63 min
Issued by
the Storm Prediction Center

Counties Hemphill County, TX, Lipscomb County, TX, Wheeler County, TX

The radar

The Amarillo radar (KAMA), 129 km from the middle of the area, began a volume at 01:14 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.2 hours before the alert went out and 129 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, Amarillo Airport, TX at 00:00Z on 2020-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 262 joules per kilogram.LCLEL10008507005003002001001 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, Amarillo Airport, TX at 00:00Z on 2020-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 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
262 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
2114 m above ground
0-6 km bulk shear
76 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

105 
ACUS11 KWNS 220112
SWOMCD
SPC MCD 220112 
OKZ000-TXZ000-220215-

Mesoscale Discussion 0430
NWS Storm Prediction Center Norman OK
0812 PM CDT Tue Apr 21 2020

Areas affected...Eastern Texas Panhandle

Concerning...Severe Thunderstorm Watch 129...

Valid 220112Z - 220215Z

The severe weather threat for Severe Thunderstorm Watch 129
continues.

SUMMARY...A couple of supercells will exit WW 129 to WW 130 over the
next hour. A break in activity is expected before the possibility of
additional strong to severe thunderstorm development overnight.

DISCUSSION...Two robust supercells are ongoing in Hemphill county in
the far eastern Texas Panhandle. These storms have produced several
reports of large hail and gusty winds over the last hour. The severe
weather threat is expected to continue across the eastern portions
of WW 129 for 1 to 2 more hours before storms exit to the east.
Intensity should be maintained as low-level moisture advection and
shear are expected to strengthen with the onset of the nocturnal
low-level jet. Sufficiently steep mid-level lapse rates of 7 to 7.5 
C/km and MLCAPE of 500-1000 J/kg supports large hail and damaging
outflow winds as the primary threats. Additional strong to severe
storms may develop across portions of the Oklahoma and Texas
Panhandles later tonight as upper level lift from the main shortwave
trough shifts east from the southern Rockies.

..Lyons/Grams.. 04/22/2020

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...OUN...AMA...

LAT...LON   36270082 36379999 35360001 35350029 35380075 35900079
            36270082

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 1:21 AM CDTMesoscale DiscussionSPCFannin, Lamar, Red River84 min
Apr 22, 1:46 AM CDTSevere Thunderstorm WatchSPCFannin, Lamar, Red River4 hr
Apr 22, 2:16 AM CDTMesoscale DiscussionSPCCarson, Dallam, Hansford, Hartley, Hemphill, Hutchinson and 7 more119 min
Apr 22, 10:38 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Blanco and 50 more2 hr
Apr 22, 10:55 AM CDTTornado WatchSPCAnderson, Angelina, Austin, Bastrop, Brazos, Burleson and 31 more6 hr
Apr 22, 1:10 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Austin, Bastrop, Bell, Brazos and 35 more65 min
Apr 22, 1:12 PM CDTMesoscale DiscussionSPCClay, Collin, Cooke, Dallas, Delta, Denton and 15 more63 min
Apr 22, 2:33 PM CDTTornado WatchSPCCollin, Cooke, Dallas, Delta, Denton, Fannin and 12 more6 hr
Apr 22, 2:53 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Cherokee, Houston, Nacogdoches, Panola and 5 more67 min
Apr 22, 4:24 PM CDTMesoscale DiscussionSPCAngelina, Brazos, Cherokee, Grimes, Hardin, Houston and 14 more96 min
Apr 22, 4:43 PM CDTMesoscale DiscussionSPCGrayson62 min
Apr 22, 4:47 PM CDTMesoscale DiscussionSPCAngelina, Polk, San Augustine, San Jacinto, Trinity, Tyler and 1 more88 min
Apr 22, 5:01 PM CDTTornado WatchSPCAngelina, Cherokee, Grimes, Harrison, Houston, Jasper and 14 more9 hr
Apr 22, 5:38 PM CDTMesoscale DiscussionSPCCamp, Collin, Dallas, Delta, Fannin, Franklin and 10 more97 min
Apr 22, 5:53 PM CDTMesoscale DiscussionSPCAngelina, Polk, Trinity, Tyler37 min
Apr 22, 6:39 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Marion, Morris, Red River and 2 more66 min

Nearby

Mesoscale Discussions in Texas, 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.