textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1035 PM CST Tue Dec 23 2025 * Patchy fog and dense fog are expected tonight, especially across the ranchlands. Additional dense fog is likely Christmas Eve into Christmas morning.

* A strong cold front arrives late Sunday with below normal temperatures into Wednesday morning

* There is a medium (30-45%) chance of showers and isolated thunderstorms Sunday night into Monday

DISCUSSION

Issued at 1035 PM CST Tue Dec 23 2025

The subtropical ridge holds across Deep South Texas through the weekend, maintaining well-above normal temperatures, over 10 degrees above normal, through Christmas and the last weekend of 2025. A strong cold front late Sunday into Monday brings a medium (30-45 percent) chance of rain and below normal temperatures into mid next week. The best chance of thunderstorms will be along the frontal boundary late Sunday into early Monday. Have dropped daytime highs on Monday a few degrees along the coast and Cameron County.

Confidence in widespread dense fog tonight remains too low for any Dense Fog Advisories at this time. Will issue an SPS to cover patchy fog and dense fog. There is a better signal for fog Christmas Eve into Christmas morning. Will continue to monitor and brief the North Pole on the potential need for Rudolph across Deep South Texas.

AVIATION

(06Z TAFS) Issued at 1035 PM CST Tue Dec 23 2025

VFR conditions are expected to deteriorate overnight with patchy fog and dense fog developing, especially near HRL towards daybreak. An hour or two of IFR to LIFR conditions are possible around daybreak, mainly due to visibilities, with VFR conditions returning by mid to late Wednesday morning.

MARINE

Issued at 1035 PM CST Tue Dec 23 2025

Southeasterly onshore flow continues into this weekend with a gradually increasing swell. A strong cold front arrives late Sunday into Monday with moderate to strong northerly winds, a medium (30-50%) chance of showers and isolated thunderstorms, and hazardous marine conditions. Patch fog and dense fog will reduce visibility at times along the bay and nearshore waters tonight and again Christmas Eve into Christmas morning. Small Craft Advisories will likely be needed Monday into Tuesday.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 67 83 66 83 / 10 10 0 0 HARLINGEN 64 84 63 84 / 0 10 0 0 MCALLEN 68 86 67 86 / 10 0 0 0 RIO GRANDE CITY 65 86 66 87 / 10 0 0 0 SOUTH PADRE ISLAND 70 76 69 76 / 0 10 0 0 BAYVIEW/PORT ISABEL 65 80 64 80 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

TX...None. GM...None.