textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1128 AM CST Mon Dec 1 2025

* A Small Craft Advisory has been extended through 00z tomorrow evening due to elevated winds and wave heights

* Adverse to hazardous marine conditions to persist through at least Tuesday.

* Temperatures are expected to remain cool through tomorrow then gradually warm mid-week before another cold front arrives Thursday into Friday. This will increase rain chances later in the week.

DISCUSSION

Issued at 1128 AM CST Mon Dec 1 2025

A coastal low has developed in the wake of a strong cold front that passed through the region over the weekend. This has kept skies cloudy, and due to the close proximity of the coastal low to the shore, stronger cold air advection due to higher northerly winds is continuing to funnel colder air into the region. The NAM is capturing this best when comparing to current observations over both land and water, so the NAM was utilized heavily in the immediate forecast for tonight. Low temperatures tonight should be in the upper 40s with continued cloudy skies.

For tomorrow, models are not consistent on how close the coastal low is going to stay within our area. If it stays close to the shore, skies will stay cloudier (limiting daytime heating) and the pressure gradient will remain tighter and winds will be stronger, resulting in continued CAA and cooler temps. However, if it moves further away from our area, the pressure gradient could relax and skies would clear a little bit more, resulting in slight gradual warming. The NAM is keeping temperatures cooler, whereas other guidance (including the NBM) has Deep South Texas warming a bit quicker, so to account for the uncertainty of the path of the coastal low the NAM was blended with the NBM for tomorrow and tomorrow night's forecast. High temperatures tomorrow should reach the upper 50s/lower 60s, with lows cooling to the lower 50s with a few ares in the Northern and Western Ranchlands still experiencing temperatures in the upper 40s.

The winds are expected to veer to a southerly direction ahead of another approaching shortwave by Wednesday, and skies should become much clearer. This will allow temperatures to warm into the mid-to- upper 70s Wednesday and Thursday, before the next cold front comes through with the next system. This next cold front also has the potential to be strong like the previous front. Current thinking is that Friday's highs will be in the mid-60s, but this surge of colder air could trend colder as additional guidance comes in, especially as snowpack becomes more established over the northern US.

Conditions should overall be dry through midweek, until the next shortwave trough comes through Thursday into Friday, which will increase rain chances throughout Deep South Texas. Chances will be low to moderate (30-40%) for the Western Ranchlands, with moderate (40-60%) chances for areas east of I-69C. Rain chances will linger but remain low (20-30%) through Friday.

Rip current risk remains high through tomorrow due to elevated winds and seas, creating hazardous surf conditions.

AVIATION

(18Z TAFS) Issued at 1128 AM CST Mon Dec 1 2025

MVFR conditions are being observed at area airports due to lower ceilings, with MFE having intermittent periods of IFR that are expected to improve to MVFR within the next few hours. Conditions should stay MVFR throughout the TAF period with overcast skies and light to moderate northerly winds

MARINE

Issued at 1128 AM CST Mon Dec 1 2025

A Small Craft Advisory has been extended through 00z tomorrow evening due to winds offshore and wave heights remaining elevated. Once conditions do get below Small Craft Advisory criteria, Small Craft Exercise Caution conditions will persist. Conditions could briefly improve later on Tuesday into Wednesday, but another frontal system Thursday into Friday will likely warrant more Small Craft Advisories later in the week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 51 59 52 73 / 0 0 0 20 HARLINGEN 48 58 51 71 / 0 0 0 10 MCALLEN 49 59 50 74 / 0 0 0 0 RIO GRANDE CITY 50 61 49 75 / 0 0 0 0 SOUTH PADRE ISLAND 57 64 54 76 / 40 20 0 30 BAYVIEW/PORT ISABEL 52 61 56 74 / 20 0 0 20

BRO WATCHES/WARNINGS/ADVISORIES

TX...High Rip Current Risk through Tuesday afternoon for TXZ451-454- 455.

GM...Small Craft Advisory until noon CST today for GMZ130-132-135-150- 155-170-175.