Heavy Snow — Kenedy, Texas

2017-12-08 · Kenedy, Texas

Event narrative

A single moderate to heavy snow band developed across the Kenedy County King Ranch around daybreak on December 8th, continuing in waves until 1030 AM before precipitation ended. Cooperative observers 7 miles east of Sarita and 4 miles southeast of Armstrong (northern and central portions of the county) reported 2 inches each. County-wide, proxy data from Brooks and Willacy County suggested fairly widespread 2 inch totals, with the exception of the northwest corner between Sarita and Falfurrias, where 3 inches may have fallen. It was unknown whether slush accumulated on the elevated portion of US 77 around Sarita.

Wider weather episode

Overnight on December 7th and continuing into the 8th, an embedded upper level disturbance descended the back side of a growing upper level trough that would soon stretch across the entire eastern two'thirds of the nation. The disturbance provided several critical pieces of the atmospheric puzzle that would change miserable biting rain into a snowscape that brought impromptu celebrations of the season on a Friday, less than three weeks before Christmas. Light rain mixed with sleet and snow before changing to all snow, from northwest to southeast, during the pre-dawn hours of the 8th. The initial changeover occurred across the Rio Grande Plains of Jim Hogg and Zapata County between midnight and 2 AM, and would quickly scoot through the remaining ranch country before 4 AM, and reach much of the populated Valley before 6 AM. Because the low levels of the atmosphere were marginally conducive to snow, the highest accumulations were seen in stronger bands that fell before sunrise at the slightly higher elevation of the ranchlands, which allowed temperatures to fall to 32 or 33F for the duration of the band. In locations where the bands tapered off, or where bands were less intense, snow accumulation was limited and often the snow mixed with rain again. Highest accumulation, ranging from 3 to nearly 6 inches, fell in a stripe from southwest Zapata County through northwest and northern Starr, southern Jim Hogg, and western Brooks County, extending northeast to areas west of Kingsville and ultimately to the Corpus Christi metro area, where 4 to 6 inches piled up before daybreak. Multiple bands developed or re'developed between 5 AM and noon, with additional snow for the aforementioned stripe from Zapata through Brooks but also sliding into the more populated Rio Grande Valley, mainly along and north of Interstate 2. Much of these bands fell after daybreak, which allowed low'latitude daylight to counter the moderate snow and hold accumulation down to around an inch. The final band exited southeast Cameron County (Brownsville to South Padre Island) soon after noon.

Source: NOAA Storm Events Database, event_id 734497. Narrative written by the NWS forecast office that issued the report.