textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 620 AM CDT Sun Oct 4 2026

- Heavy rainfall from showers and thunderstorms will be the primary concern this weekend into Tuesday which could lead to flash flooding, mainly across the mid to lower RGV and lower Texas coast.

- A Coastal Flood Statement is in effect tonight for tidal runup ahead of and after high tide at 222 AM. Life-threatening rip currents are expected by Sunday.

-A Small Craft Advisory is in effect early Sunday morning into Monday afternoon.

-There is a 20% chance of tropical development over the Bay of Campeche/Southwestern Gulf over the next 7 days.

DISCUSSION

Issued at 1041 PM CDT Sat Oct 3 2026

The frontal boundary and developing coastal trough near the lower Texas coast will continue to be the main weather driver through the forecast period. As the the frontal boundary sits along or just offshore the lower Texas coast, ample moisture will keep the threat for rainfall in the forecast through early week. The main axis for heavy rain will continue to be along the coast tonight into Tuesday. PWATs remain around 2.5 inches which translates to the potential for very heavy rainfall at times. We have seen rainfall rates near 4"/hr at times tonight, but fortunately most of that has remained offshore. However, if these rainfall rates fall over land it could lead to localized flooding. Areas that see multiple rounds of heavy rain and/or training precipitation will also be at a higher risk for flooding. Higher end probabilities continue to show a low (10%) chance of isolated 5 to 8 inch rainfall totals across the coastal counties between tonight and Tuesday.

The Weather Prediction Center maintains a Slight Risk (at least 15 percent chance) for flooding rainfall for areas along and east of US- 281/I-69C through tonight, with a Marginal Risk (at least 5 percent chance) for flooding rainfall for locations west. There remains additional flooding concerns into early Tuesday, mainly along the coast, with a Marginal to Slight Risk Sunday into Monday across most of the Rio Grande Valley and lower Texas coast, and a Marginal Risk along the coast Monday into Tuesday.

As we head into mid to late week, rain chances will continue as a coastal trough remains just offshore, but activity will be more diurnally driven. Given the rainfall over the past few days and what is expected through early week, this activity could also lead to isolated areas of flooding.

Temperatures will remain near to above normal through the period but will not be quite as blisteringly hot as the previous week thanks to rain and excess cloud cover.

Will continue to monitor beach and marine hazards through the weekend, with a potential for tidal run-up near high tides continuing tonight and an elevated risk of life-threatening rip currents Sunday into next week. A Coastal Flood Statement has been issued for tonight and may need to be issued Sunday night as well.

Finally, the National Hurricane Center is keeping an eye on the southwestern Gulf/Bay of Campeche this week. There are some indications an area of broad low pressure may form and with slow topical development. Right now chances are at 0% over the next 2 days and 70% over the next 7 days. At this time we do not anticipate any major impacts to Deep South Texas but will continue to monitor the situation closely.

AVIATION

(12Z TAFS) Issued at 620 AM CDT Sun Oct 4 2026

Challenging flying conditions are expected through the next 24 hours, with waves of moderate to heavy showers and low ceilings with light to moderate winds. Pure VFR will be hard to find through the next 24 hours.

MARINE

Issued at 1041 PM CDT Sat Oct 3 2026

A slow-moving frontal boundary, coastal trough, and surface low pressure along the lower Texas coast this weekend into next week will lead to continued showers and thunderstorms through the period. As the pressure gradient strengthens tonight into Sunday, adverse marine conditions are expected, primarily across the northern waters. A Small Craft Advisory has been issued for all northern waters from 4 AM Sunday morning until 1 PM on Monday. Could see some elevated winds in seas with any shower or thunderstorm activity as well.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 88 77 87 76 / 90 80 90 80 HARLINGEN 86 73 86 71 / 90 90 80 60 MCALLEN 85 74 86 74 / 90 90 80 40 RIO GRANDE CITY 84 73 86 72 / 90 80 70 30 SOUTH PADRE ISLAND 86 80 85 79 / 90 80 90 90 BAYVIEW/PORT ISABEL 88 76 87 75 / 90 90 90 80

BRO WATCHES/WARNINGS/ADVISORIES

TX...High Rip Current Risk through Monday evening for TXZ451-454-455.

GM...Small Craft Advisory until 1 PM CDT Monday for GMZ135-155-175.