textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Issued at 608 PM CST Sun Nov 8 2026

- There is increased potential for heavy rainfall and localized flash flooding across the lower Rio Grande Valley this afternoon into Monday morning. Flood Watch for the Upper RGV and northern Ranchlands have been cancelled.

- Residents living along the Los Olmos Creek near Falfurrias in Brooks county should monitor the potential for elevated river levels to even minor river flooding overnight tonight into Monday morning due to excessive rainfall upstream.

- There is also the potential for a couple of waterspouts over the Gulf waters and even a landspout or two across our Eastern zones this afternoon. An isolated downburst from the torrential rainfall also cannot be ruled out.

- Surf becoming more dangerous through Monday, with a High Risk of Rip Currents forecast to develop Sunday.

DISCUSSION

Issued at 241 PM CST Sun Nov 8 2026

Main update was to take down the Flood Watch across Jim Hogg, Zapata, Starr and Brooks county. While we cannot rule out redevelopment of heavy rainfall across the aforementioned areas, the concern for flash flooding has now shifted to east of US-281/I-69C with hi-res guidance suggesting rounds of efficient, heavy rainfall. The BRO 12z upper air sounding and SPC RAP mesoanalysis shows PWATs of 1.8 to 1.9 inches across the lower RGV, which is equivalent to near daily climatological maximum for our region. In fact, we issued a Flash Flood Warning for southern Cameron county with Brownsville metro and surrounding areas picking up 2-3, locally 4 inches of rainfall in just a couple of hours leading reports of localized flash flooding.

Additionally, SPC has also put the northeastern portion of our CWA in a Day 1 Marginal risk of severe weather, with a 2% probability for tornadoes and 5% probability for severe winds. Looking at the 12z BRO sounding shows veering winds in the 1000-700mb layer. While the winds are light, if we can get breaks in the clouds, we can't rule out a couple of waterspouts over the Gulf waters and perhaps even a landspout or two inland this afternoon. And of course, any torrential downpours that become convective (lightning has been few and far in between and even then they have been cloud to cloud) is capable of producing a brief downburst.

Lastly, we hoisted a Flood Advisory for the Los Olmos Creek near Falfurrias in Brooks county as excessive rainfall upstream in the CRP CWA will likely lead to action stage or even minor river flooding by overnight tonight. Residents in the Advisory area near Los Olmos Creek should pay close attention to changing conditions.

Rain chances are forecast to decrease Monday night, with daily low (20-30%) rain chances lingering through Thursday.

AVIATION

(00Z TAFS) Issued at 608 PM CST Sun Nov 8 2026

Scattered to widespread showers are forecast to continue across the area into the day Monday, with rain chances decreasing through the afternoon. Generally MVFR to VFR conditions are forecast through much of the period, though IFR to LIFR conditions may be possible at times, especially with any stronger showers that move over the airfields.

MARINE

Issued at 241 PM CST Sun Nov 8 2026

Hazardous marine conditions along the Lower Texas Coast will continue. Small Craft Advisories are in effect through Monday morning. Conditions are expected to begin improving Monday afternoon, with generally favorable winds and seas forecast to continue through the remainder of the period.

HYDROLOGY

Issued at 241 PM CST Sun Nov 8 2026

Los Olmos Creek near Falfurrias in Brooks county (FAFT2) as excessive rainfall upstream in the CRP CWA will likely lead to action stage or even minor river flooding by overnight tonight. Residents in the Advisory area near Los Olmos Creek should pay close attention to changing conditions. Please refer to water.noaa.gov/gauges/FAFT2 for the latest forecast.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 72 81 70 81 / 60 80 40 30 HARLINGEN 69 79 67 80 / 70 80 30 40 MCALLEN 70 80 68 80 / 90 70 40 30 RIO GRANDE CITY 65 76 63 76 / 90 70 60 30 SOUTH PADRE ISLAND 74 78 73 78 / 50 70 30 30 BAYVIEW/PORT ISABEL 70 79 69 80 / 60 70 20 30

BRO WATCHES/WARNINGS/ADVISORIES

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

GM...Small Craft Advisory until 6 AM CST Monday for GMZ130-132-135- 150-155-170-175.