Remnants of the atmospheric river storm system that dumped several inches of rain on southern California earlier this month made their way into Northern Texas over the weekend. The storm began with rain in the evening on February 10th before transitioning to snow overnight. Heavy snow bands persisted into the night before tapering off around midnight on February 12th.
The synoptic set-up of this storm was not ideal for producing a deep low pressure system on account of the positive tilt to the trough axis. This caused the low pressure system to be disorganized and the wind speeds to not be very intense, thus there was no blizzard associated with this event. Despite this there was sufficient positive vorticity advection to provide a lifting mechanism that, along with the ample supply of moisture, produced heavy precipitation over the area with snow totals reaching 14 inches in some areas.
GFS 300mb heights in dam (black contours) and winds in kt (barbs, and fill pattern), accessed from pivotalweather.com .
As previously mentioned there is an overnight transition from rain to snow that occurs in Northern Texas. This occurred due to cold air being advected into the area on the cold north west corner of the low pressure system. While the transition between rain and snow can be observed and measured on the ground there is also evidence of this transition in radar reflectivity plots! Due to the shape and size of snow flakes, they appear much smoother on radar than rain does. As shown in the plot below the region where snow was present is far smoother than the area to the south where it was still raining and individual storm cells could be discerned. As the day progressed the snowfall rates increased and several bands of heavy snow set up which lead to an area of 8+ inches of snow surrounding Plainview, TX.
Radar image from 6:35 AM Feb, 11th in Lubbock, TX showing the rain to snow transition. Accessed from the NWS Lubbock X page.
Unofficial snow totals from 5 PM Feb, 11th within the range of the Lubbock TX NWS forecast area showing the heavy snow received in Northern Texas. Accessed from the NWS Lubbock X page.