Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 103

February 16, 202113 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 16, 2021, 6:59 PM CST for 13 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 16, 2021, 6:59 PM CST (00:59 UTC)
Expired
Feb 16, 2021, 11:00 PM CST
In force
4 hr
Issued by
the Storm Prediction Center
Concerning
Heavy snow

Counties Armstrong County, TX, Briscoe County, TX, Carson County, TX, Castro County, TX, Childress County, TX, Collingsworth County, TX, Donley County, TX, Floyd County, TX, Gray County, TX, Hall County, TX, Potter County, TX, Randall County, TX, Swisher County, TX

The radar

The Amarillo radar (KAMA), 67 km from the middle of the area, began a volume at 00:59 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, 1.0 hours before the alert went out and 66 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 2021-02-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2021-02-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 194 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
5 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
424 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
194 m²/s²
0-3 km storm-relative helicity
196 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

085 
ACUS11 KWNS 170100
SWOMCD
SPC MCD 170059 
TXZ000-OKZ000-170500-

Mesoscale Discussion 0103
NWS Storm Prediction Center Norman OK
0659 PM CST Tue Feb 16 2021

Areas affected...Portions of the Texas Panhandle

Concerning...Heavy snow 

Valid 170059Z - 170500Z

SUMMARY...Pockets of heavy snow are possible with a slowly
southward-moving band now along the I-40 corridor. This band may
persist another 4-6 hours.

DISCUSSION...A narrow band of heavy snow has set up roughly oriented
along the I-40 corridor. Heavy snow has been observed in Amarillo
over the last 45 minutes. This band appears to be related to 850 mb
warm advection. As 850 mb wind veer this evening, this band will
slowly shift southward along with the strongest warm advection. A
few areas of heavy snow are possible as this bands move south. There
is some uncertainty with the duration of the band, but some guidance
suggests it may persist another 4-6 hours.

..Wendt.. 02/17/2021

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

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

LAT...LON   35420034 34760004 34499991 34150029 34040122 34100204
            34290220 34550233 34800236 35430237 35580170 35420034

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 16, 8:14 PM CSTMesoscale DiscussionSPCArcher, Clay, Cooke, Grayson, Jack, Montague and 2 more4 hr
Feb 16, 9:41 PM CSTMesoscale DiscussionSPCBell, Brazos, Burleson, Burnet, Falls, Lampasas and 5 more4 hr
Feb 17, 1:55 AM CSTMesoscale DiscussionSPCAngelina, Austin, Bastrop, Brazos, Burleson, Colorado and 31 more6 hr
Feb 17, 7:38 AM CSTMesoscale DiscussionSPCJasper, Newton, Sabine4 hr
Feb 17, 9:15 AM CSTMesoscale DiscussionSPCBowie, Cass6 hr

Nearby

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

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.