A sharp upper level trough diving and developing through the nation's midsection drove a strong, but dry, cold front deep into Mexico on February 26th.  Strong high pressure followed quickly behind the front overnight, and the combination of very dry and chilly air with nearly calm winds set the stage for a minor freeze around sunrise on the 27th.  The freeze exacerbated drought conditions across the region and maintained the threat of wildfire growth into early March as fuels remained highly cured.

Frost/Freeze in BROOKS, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: COOP Observer

A collection of observations between Encino and Falfurrias indicated a freeze, likely with frost in some locations.  Minimum temperatures fell to between 26 and 33, with times estimated through proxy observation at mesonet/remote automated weather station (RAWS) sites, as well as NWS Cooperative sites.  The cooperative site just west of Falfurrias recorded the lowest value of 26 at around 7 AM.

Frost/Freeze in INLAND KENEDY COUNTY, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: COOP Observer

A collection of mesonet and cooperative observations between Armstrong and Sarita reached freezing temperatures around sunrise on February 27.  Minimum temperatures fell to between 28 and 33, with times estimated through proxy observation at mesonet/remote automated weather station (RAWS) sites. The cooperative site 4 miles southeast of Armstrong recorded a low of 28 degrees at around 7 AM.

Frost/Freeze in JIM HOGG, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: Mesonet

Proxy observations based on sheltered/wind protected locations in neighboring Brooks, Starr, and Zapata Counties suggested a light freeze in much of ranch-owned Jim Hogg County around sunrise on February 27th. Low temperatures in these areas likely ranged from 28 to 33 degrees.  At the Jim Hogg County Airport, low temperatures reached 33 degrees.

Frost/Freeze in NORTHERN HIDALGO COUNTY, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: COOP Observer

In rural northern Hidalgo County, minimum temperatures fell to between 29 and 32 degrees around sunrise on February 27th.  Duration of the freezing temperatures was gleaned from the mesowest/remote automated weather station (RAWS) location at Linn/San Manuel. The cooperative observer in San Manuel reported a low of 30 degrees.

Frost/Freeze in STARR, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: COOP Observer

In much of Starr County, based on observations from multiple sites along the Rio Grande and other proxy locations in Zapata, Brooks, and northern Hidalgo County, minimum temperatures fell to between 28 and 32 degrees around sunrise on the 27th. At the cooperative observing station in Rio Grande City, the minimum temperature reached the freezing point right around sunrise.

Frost/Freeze in ZAPATA, TEXAS
From 27-FEB-20 04:30:00 to 27-FEB-20 07:30:00 (CST-6)
Property damage: 0.00K
Reported by: AWOS

In much of Zapata County, based on observations from multiple sites along the Rio Grande and other proxy locations in southwest Starr County, minimum temperatures fell to or just below freezing around sunrise on the 27th. Zapata County Airport dropped to 31 degrees, while the remote automated weather station (RAWS) at Falcon Lake, just south of the county line, dropped to 28 degrees.