textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1108 AM CST Thu Dec 25 2025 * A medium risk for rip currents continues today through Friday afternoon.

* Patchy to areas of dense fog is likely tonight, with a Dense Fog Advisory or Special Weather Statement (SPS) possible for inland Deep South Texas.

* Very warm temperatures continue, rising into the mid/upper 80s, with near record to record-breaking highs possible through Sunday.

* A tightened pressure gradient ahead of and behind a cold front passing through late Sunday night or early Monday morning could result in gusts up to 20-30 mph from Saturday into next Tuesday, with hazardous coastal and marine conditions likely.

* Showers and thunderstorms associated with the front is currently expected to increase chances of rain Sunday night through Monday night to as much as a medium (40-60%) chance Monday morning.

DISCUSSION

Issued at 1108 AM CST Thu Dec 25 2025

The first focus of the forecast is the expectation for another round of patchy to areas of dense fog setting up tonight across most of Deep South Texas as light southeasterly winds continue to advect moist air inland underneath mainly clear skies. Although guidance is inconsistent at this time, a Dense Fog Advisory is possible again tonight, likely for inland locations, as visibility could reduce to a quarter mile or less for several hours. If guidance and conditions change throughout today, later shifts may issue an SPS for visibilities of 1-3 miles, with some locations possibly experiencing visibilities of less than a mile.

Mid to upper level ridging continues to be the dominant pattern aloft over Deep South Texas throughout the next 7 days, aside from troughing Saturday through Sunday. At the surface, southeasterly to southerly winds continue around a surface high pressure holding steady over the northern and northeastern Gulf. This will continue to result in temperatures soaring to 10-15 F above average, perhaps even warmer, with near record to record-breaking highs, with inland highs reaching mostly the mid/upper 80s through Sunday. A pressure gradient tightens over the weekend, leading to breezy south- southeasterly winds with gusts possibly up to 20-25 mph. Such strong warm air advection may result in a few locations near the US/Mexico border in the middle and upper RGV hitting 90 F. In contrast, highs in the 70s along the immediate coast. Overnight lows remain toasty for this time of year, falling to the mid/upper 60s inland and lower 70s through Saturday night.

A drastic, though somewhat brief, change is expected to start next week as a moderately strong cold front passes through the County Warning Area late Sunday night or early Monday morning. Chances of rain increase overnight Sunday to as much as a medium (40-60%) chance by Monday morning as showers and thunderstorms accompany the front. PoPs steadily decrease throughout Monday afternoon and night down to less than 10% by Tuesday morning. A tightened pressure gradient behind the front is likely to result in breezy to windy conditions as northerly winds could gust up to 25-30 mph, or higher on Monday. In turn, strong cold air advection is expected on Monday, continuing into Tuesday. Temperatures are expected to fall throughout Monday, so the most notable difference is likely to be on felt Monday night through Tuesday night as overnight lows could bottom out in the low to mid 40s and highs only reaching the 50s on Tuesday, which is 15-20 F below average. However, surface high pressure moves back into the Gulf by midweek, setting up for southeasterly winds and temperatures rising back to near to above normal.

There is a medium risk for rip currents today, tonight and Friday as periods of around 7 seconds continue.

AVIATION

(18Z TAFS) Issued at 1108 AM CST Thu Dec 25 2025

At this time, skies range from scattered VFR skies at KBRO, broken MVFR at KHRL (ceilings arond 2,200 ft), while scattered VFR, broken IFR at times (ceilings of around 600 ft) continue at KMFE. Over the next few hours, all terminals are expected to become VFR as clouds continue to become scattered and rise along with light to gentle (5-10 knots) southeasterly winds. Overnight, winds become light to calm, with patchy to areas of fog, locally dense, with visibilities of 0.25, or less, possible again. Conditions gradually improve throughout Friday morning.

MARINE

Issued at 1108 AM CST Thu Dec 25 2025

Surface high pressure maintains gentle to moderate south- southeasterly winds and slight to moderate (2-4 ft) seas through Friday night, becoming moderate to fresh with moderate seas (3-5 ft) over the weekend as a pressure gradient tightens. Late Sunday night or early Monday morning, a cold front passes through, bringing showers and thunderstorms, increasing chances of rain Sunday night to as much as a medium to likely (50-70%) chance of rain by Monday morning. Chances of rain decrease throughout Monday night down to less than 10% on Tuesday. Additionally, strong northerly winds with potentially gale force gusts and rough seas are likely to result in Small Craft Advisories or Gale Watches/Warnings Monday into Tuesday, with improvement expected into the middle of next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 84 68 84 69 / 10 0 0 0 HARLINGEN 84 65 86 65 / 10 0 0 0 MCALLEN 87 68 88 69 / 0 0 0 0 RIO GRANDE CITY 87 65 88 67 / 0 0 0 0 SOUTH PADRE ISLAND 76 70 77 70 / 10 0 0 0 BAYVIEW/PORT ISABEL 81 66 82 67 / 10 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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