| January 09 2025 |
Southern Tier Winter Storm: (1/9/25 - 1/11/25)
By: Bryan Jackson, WPC Meteorologist
Meteorological Overview:
The January 9-11 Southern Plains, Mid-South, and Southeast Winter Storm began as a potent upper-level low that rapidly developed over Southern California on Tuesday, January 7. This developed low drifted south over northwest Mexico January 8 before opening that night into a positively-tilted trough over northern Mexico and the southern Rockies which was followed by a pivot into a further positively-tilted trough over Mexico and Texas January 10 before ejecting over the Southeast January 11.
Positively-tilted troughs allow broad swaths of precipitation downstream of the trough axis from an elongated fetch of southwesterly flow. Precipitation began in earnest as a band of wintry mix over southern New Mexico in the morning of January 8 as an impulse streaming south of the low/trough spread across the Rio Grande. Some reduced visibility and light snow accumulations occurred with this band before it dissipated in the afternoon.
Farther east over Texas, antecedent conditions were cold across the south due to an Arctic plunge that persisted after a cold frontal passage on January 5. A more potent shortwave ejected from the main trough as the low opened up over Mexico early on the 9th, allowing surface low pressure to develop downstream along the southern Texas coast; at the same time, a new reinforcing cold front was developing over the southern High Plains that crossed the Texas and Oklahoma Panhandles. Broad low level cyclonic flow between the two features, lift from the approaching wave, and enhanced Pacific moisture spreading east-northeast allowed a wintry mix to develop over west into central Texas overnight with heavy snow developing through the mid-to-late morning of the 9th over far North Texas, eastern Oklahoma, and central/northern Arkansas. This heavy snow area persisted for 12-18 hours as the coastal low rapidly developed, expanding the precipitation shield and causing a focused area of over six inches of snow from the central TX/OK border to the Missouri Boottheel and Memphis. The highest snow accumulations were around 12 inches in a stripe from southeast Oklahoma through central Arkansas including a 14.3 inch report near Mena, Arkansas in the Ouachita Mountains.
As the main area of heavy snow was developing on the 9th, the approach of the upper trough axis allowed a separate stripe of heavy snow to develop farther west over along the cold frontal zone in the Texas and Oklahoma Panhandles. The east-northeast movement of the low paralleled the front and allowed repeating heavy snows bands, including thundersnow, to develop and persist along a narrow corridor. Snowfall of 6 or more inches fell along this corridor from east-central NM into south-central KS through most of the 9th. A max stripe of 8-12 inches was reported in the immediate area of Amarillo, TX.
The surface low deepened to around 1006mb over the Upper Texas Coast by 06Z on the 10th and then began to fill/weaken as it tracked over the central Gulf Coast. The increased eastward movement, driven by an increasing upper jet flow that went from southwesterly max around 130 knots over west Texas at 00Z on the 10th to west-southwesterly max of 180kt over Texarkana by 00Z on the 11th limited precipitation duration east of Arkansas and resulted in more modest snow totals (less than six inches from central Tennessee through southern Virginia). However, a broad wintry mix area persisted through the track with stripes of quarter to one-third inch ice accretion around the Texarkana area through southern Arkansas, as well as north Georgia (including the Atlanta metro) into central North Carolina. Sleet was reported down to the coastal Carolinas including Charleston, SC.
Impacts:
As a first note, the strong winds and dry conditions associated with the developing low over Southern California on January 7 resulted in extreme fire weather conditions that led to the highly destructive Palisades and Eaton Fires in the Los Angeles metropolitan area.
On the winter side, this storm system produced impacts through the broad swath of wintry precipitation, most notably in three areas: in the narrow stripe of particularly heavy snow in the Texas Panhandle, the broad area of heavy snow from far North Texas through the Mid-South, and in areas of freezing rain in the Southeast including around Atlanta. The initial round of snow in southern New Mexico resulted in multiple crashes reported on I-10 between Las Cruces and Deming, NM around midday on the 8th due to low visibility.
The persistent and narrow snow bands over the TX and OK Panhandles on the 9th were accompanied by strong winds gusting 40-50mph allowing blizzard-like conditions. Drifts of 6 to 10 feet were reported in the zone with 6-12 inches of snowfall. The 9.3 inches measured at Amarillo was their 16th highest single day snowfall since their records began in 1892.
Farther east in the main area of heavy snow and wintry mix were many reported impacts. More than 3000 flights were canceled during the event, including many in Atlanta and Charlotte. The Oklahoma Highway Patrol reported over 500 traffic collisions including 85 with crashes that involved injuries. Portions of I-35 in southern Oklahoma and I-30 and I-40 in Arkansas were closed at times due to crashes on snow covered roads. 225 traffic collisions were reported in Georgia. Over 135,000 customers were without power at some point in the event with around 20,000 in Arkansas and the majority of the rest in the freezing rain zone in north Georgia.
