Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 82

February 14, 202141 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 14, 2021, 7:04 PM CST for 41 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 14, 2021, 7:04 PM CST (01:04 UTC)
Expired
Feb 15, 2021, 1:00 AM CST
In force
6 hr
Issued by
the Storm Prediction Center
Concerning
Heavy snow
All 41 counties

Bandera County, TX, Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Coryell County, TX, Edwards County, TX, Falls County, TX, Fayette County, TX, Freestone County, TX, Gillespie County, TX, Grimes County, TX, Guadalupe County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Kinney County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Mason County, TX, McLennan County, TX, Medina County, TX, Milam County, TX, Real County, TX, Robertson County, TX, Travis County, TX, Uvalde County, TX, Walker County, TX, Washington County, TX, Williamson County, TX, Zavala County, TX

The radar

The Austin/San Antonio radar (KEWX), 87 km from the middle of the area, began a volume at 01:05 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

Del Rio, TX (KDRT), launched 00:00Z, 1.1 hours before the alert went out and 230 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, Del Rio, TX at 00:00Z on 2021-02-15Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 00:00Z on 2021-02-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -163 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
655 m above ground
0-6 km bulk shear
89 kt
0-1 km storm-relative helicity
-163 m²/s²
0-3 km storm-relative helicity
189 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

907 
ACUS11 KWNS 150104
SWOMCD
SPC MCD 150104 
TXZ000-150700-

Mesoscale Discussion 0082
NWS Storm Prediction Center Norman OK
0704 PM CST Sun Feb 14 2021

Areas affected...Portions of Texas Hill Country into Southeast Texas

Concerning...Heavy snow 

Valid 150104Z - 150700Z

SUMMARY...Pockets of moderate to heavy snow are possible in parts of
the DFW metro and eastward in the short term. The next area of heavy
snow to develop will likely be within the Edwards Plateau perhaps by
8-10 PM CST. This heavy snow will develop eastward into Southeast
Texas through the evening and overnight.

DISCUSSION...Current water vapor imagery shows another area of
mid-level ascent moving through the Big Bend region. This ascent is
forecast to pivot through the base of the broad upper-level trough
as it moves east. MRMS radar imagery shows heavier bands of
precipitation developing in Mexico that should begin to move into
the Edwards Plateau within the next 1-3 hours. 1 inch per hour
snowfall rates are possible as the favorable lift within the
dendritic growth layer moves through the region.

A band of moderate to heavy snow now moving east through the DFW
metro area will continue to bring around 1 inch per hour rates.
However, this is expected to decrease with time as the more
favorable synoptic ascent shifts to the south.

..Wendt.. 02/15/2021

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

ATTN...WFO...HGX...FWD...EWX...SJT...

LAT...LON   29310099 29760093 30140079 30769962 31429820 31989708
            32019670 31799599 31089549 30539554 29999663 29099846
            28729991 28850060 29190093 29310099

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 14, 10:53 PM CSTMesoscale DiscussionSPCChambers, Hardin, Jasper, Jefferson, Liberty, Newton and 2 more4 hr
Feb 15, 1:08 AM CSTMesoscale DiscussionSPCAnderson, Angelina, Bowie, Camp, Cass, Cherokee and 27 more6 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.