Heavy Snowstorm for Texas/Louisiana

Using The Mega-Cluster Ensemble To Track Snow Risk In The East U.S.
01/07/2021, 1:25 pm EST
Cause of the China Cold Outbreak Late DEC/early JAN 2020-21
01/12/2021, 9:59 am EST
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The more conservative view (by the HRRR model) indicates the heaviest snowfall in west-central Texas (6-10 in.) while GFS is much heavier northwest of Houston area (up to 10-12 in.). Given the strength of the upper trough and rapid cooling of the lower atmosphere late today/this evening the heavier (GFS) totals are favored!

Highlight: Heavy snowstorm for Texas/Louisiana.

Fig. 1-2: Precipitation type profile across Texas for this afternoon and late evening features widespread heavy snow.

Heavy snowstorm for Texas into Louisiana: NOAA/NWS extends their Winter Storm Warning across west/central Texas eastward to the northern half of Louisiana. The projected precipitation type profile for 2PM this afternoon indicates heavy snow across most pf the northern half to 2/3 of Texas (Fig. 1). By late evening the profile indicates the snow is shifting into the northern half of Louisiana (Fig. 2). This is an all snow/sleet event with no freezing rain. Snowfall amount forecasts vary (Fig. 3-4). The more conservative view (by the HRRR model) indicates the heaviest snowfall in west-central Texas (6-10 in.) while GFS is much heavier northwest of Houston area (up to 10-12 in.). Given the strength of the upper trough and rapid cooling of the lower atmosphere late today/this evening the heavier (GFS) totals are favored!

Fig. 3-4: Snowfall amounts vary but the aggressive GFS model which indicates 10-12 in, of snow in east-central Texas may be on target given the strengthening of the supporting upper trough.

The storm winds down by dawn Monday in Texas and noontime (tomorrow) in Louisiana. There is limited cold advection following this storm. However, presence of snow cover, quite deep in some areas, means the cold night-time temperatures will be impressive (10’s/20’s western Texas) extending southward to near the Gulf Coast where minimum temperature flirts with sub-freezing levels (Table 1).

MON AMTUE AMWED AM
Dallas312731
Houston343237
Corpus Christi363335
Port Arthur343133
Lake Charles343032
Baton Rouge383031

Table 1: Projected low temperatures each of the next three mornings.