textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1036 PM CST Fri Dec 26 2025 * A strong cold front will bring windy conditions along with well below normal temperatures to the region on Monday.

* There is a medium to likely (40-60%) chance of showers late Sunday night through Monday.

* Hazardous beach and marine conditions are likely Monday into Tuesday.

DISCUSSION

Issued at 1036 PM CST Fri Dec 26 2025

The subtropical ridge drops further south through the weekend, maintaining dry conditions and well-above normal, to near record breaking, heat across Deep South Texas through Sunday. A strong cold front arrives on Monday with the next chance of rain, especially along the coast and lower valley. High pressure and drier air behind the front will diminish rain chances Tuesday through the remainder of the forecast period.

Temperatures behind the front have consistently trended cooler with each model run, just getting into the range of the NAM guidance, which handles these shallow cold air masses very well. Current NAM guidance early Monday morning shows a rather quick 20 degree drop just behind the front, likely keeping the ranchlands in the low to mid 50s and cooling the RGV into the mid to upper 50s into the afternoon, around 30 degrees cooler than the highs on Sunday. Skies begin to clear out on Tuesday, leading to the coldest night of the week Tuesday night, due to efficient radiational cooling, with mid 30s possible across the ranchlands and upper 30s to near 40 degrees in the RGV. Have adjusted down from NBM accordingly.

We will continue to monitor relative humidity values behind the front, with model guidance trying to dry the air mass out relatively quickly, while northerly winds are strong enough to potentially reach RFD criteria. If RH stays up, or winds drop off quicker, there will be no fire weather concerns. Temperatures gradually warm Wednesday through Friday from just below normal to above normal.

Persistent and strong CAA with surface temperatures at or below 50 degrees across the Laguna Madre and nearshore Gulf waters from Monday afternoon into Wednesday afternoon may lead to an early season cold stun event for sea turtles, mainly in the bay and shallow coastal waters. Pelicans may also land on coastal bridges and roadways Monday evening into Tuesday. Beach conditions will deteriorate through Monday, with life-threatening rip currents, elevated surf, and minor coastal flooding expected into Tuesday. Conditions gradually improve through the remainder of the week.

AVIATION

(06Z TAFS) Issued at 1036 PM CST Fri Dec 26 2025

VFR conditions are expected to give way to MVFR ceilings and patchy fog overnight reducing visibility near daybreak. Conditions improve by mid Saturday morning.

MARINE

Issued at 1036 PM CST Fri Dec 26 2025

Light to moderate southeasterly onshore flow continues through this weekend with a gradually increasing swell and SCEC conditions each afternoon on the bay. A strong cold front arrives on Monday with moderate to strong northerly winds occasionally reaching gale force, a medium to likely (35-70%) chance of showers and isolated thunderstorms, and hazardous marine conditions. Patchy fog may reduce visibility at times along the bay and nearshore waters tonight, mainly north of Port Mansfield. A Gale Watch may be needed for Monday, with at least Small Craft Advisory conditions continuing into Tuesday.

FIRE WEATHER

Issued at 1036 PM CST Fri Dec 26 2025

Relative humidity is expected to drop behind the front on Monday, while northerly winds remain moderate to strong. This may lead to a period of Fire Danger Statement criteria being met, especially across Jim Hogg, Brooks, and Hidalgo counties Monday afternoon into early Monday evening.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 69 84 69 84 / 0 0 0 0 HARLINGEN 66 86 65 87 / 0 0 0 0 MCALLEN 69 88 69 90 / 0 0 0 0 RIO GRANDE CITY 67 89 66 90 / 0 0 0 0 SOUTH PADRE ISLAND 70 77 71 78 / 0 0 0 0 BAYVIEW/PORT ISABEL 67 83 67 84 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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