textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Issued at 535 AM CST Fri Nov 6 2026

- A rainy pattern is expected this weekend into early next week, with widespread moderate to high (50-80%) rain chances.

- All of Deep South Texas is under a Marginal (level 1 of 4) Risk of Excessive Rainfall from Saturday morning to Monday morning. Isolated flash flooding is possible in areas that receive heavier rainfall.

- Cooler temperatures will continue into next week following the frontal passage.

DISCUSSION

Issued at 1126 PM CST Thu Nov 5 2026

Isolated showers continue to pop up along a stationary boundary across portions of the ranchlands and upper valley this evening, with moderate to briefly heavy rainfall in Kenedy County. A slow- moving cold front enters the region tonight, shifting winds northerly late, working from the northwest to the southeast.

Along and behind the front, expect an increase in convergence and coverage of showers or isolated thunderstorms late tonight into Friday morning, moving southeast into the RGV through the morning. Isolated to scattered showers will linger into the afternoon, with a period of drier conditions Friday evening into early Friday night.

By Saturday, things begin looking more wet. A couple factors will be at play here; isentropic upglide with cool air at the surface and coastal troughing offshore, a deepening trough over the desert SW with shortwaves on its' periphery, and a 200mb jetstreak overhead. These will all play a role in bringing widespread showers to the region Saturday through Monday before the trough exits to the east.

Widespread showers and thunderstorms, sub-severe thanks to limited instability, move into the region Saturday afternoon, generally persisting into Monday. Widespread rainfall amounts of 1 to 3 inches are expected, with some higher amounts of 4 to 5 inches or more near the coast, northern ranchlands, or where heavier and training showers persist.

Flash flood guidance is high across the CWA, allowing for rainfall rates from 2.5"/1hr in the RGV to 9"/1hr in the northern ranchlands. This means mostly beneficial rainfall is expected, but there is a chance that repeated, heavy showers bring a bit too much to an area, leaving isolated flash flooding possible. There is a Marginal (level 1 of 4) risk of excessive rainfall leading to flash flooding from 7 AM Saturday to 7 AM Monday.

Guidance continues to disagree on where the axis of heaviest rainfall will be... along with rainfall totals. This makes the forecast for this weekend tricky. There is a chance the axis of heaviest rainfall remains to our north in the Coastal Bend, but the axis could fall closer to the RGV, which would bring more heavy rain to Coastal Cameron/Willacy/Kenedy counties. An upgrade to the ERO is not out of the cards, but confidence is not high enough in pinpointing a location for highest expected rainfall yet. Given this uncertainty, forecast rainfall amounts are bound to change in the coming days, so check back for updates to the forecast.

Temperature-wise, things get pleasantly cooler through early next week. Behind the cold front, Friday's highs drop to the upper 70s to low 80s. Cloud coverage and cold air advection will continue through the weekend, gradually dropping highs into the 70s by Sunday, maybe a little further. Lows also gradually drop through the weekend, in the 60s Saturday morning, and 50s by Monday morning (except along the coast.. which should stay in the 60s).

Finally, expect beach hazards this weekend into early next week, including an increase in rip currents, periodic high surf, and minor coastal flooding, especially during high tide cycles. Multiple statements or advisories may be needed.

AVIATION

(12Z TAFS) Issued at 535 AM CST Fri Nov 6 2026

A cold front continues to push through portions of Deep South Texas early this morning. Some light fog and low stratus may develop along and ahead of the frontal boundary. Northerly winds and an increasing chance of showers and thunderstorms are forecast today in the wake of the front. VFR/MVFR conditions are expected to briefly become IFR/MVFR with the frontal passage and where showers or thunderstorms develop or persist. VFR conditions are expected this evening into tonight.

MARINE

Issued at 1126 PM CST Thu Nov 5 2026

A few strong to severe thunderstorms continue just north of the coastal waters with limited visibility, waterspouts, frequent lightning, and torrential rainfall. The boundary these storms are developing across is expected to get pushed further south by an arriving cold front tonight into Friday morning. Expect northerly winds and an increasing chance of showers and thunderstorms into Friday afternoon. The chance of showers and thunderstorms diminishes late Friday before a coastal trough of low pressure develops along the western Gulf.

Expect marine conditions to deteriorate on Saturday, including elevated seas, gusty northerly winds, and limited visibility, and remain hazardous into Monday before the trough works further offshore. Small Craft Advisories will likely be needed.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 82 71 82 71 / 70 20 30 40 HARLINGEN 81 68 81 69 / 70 30 30 40 MCALLEN 83 71 83 70 / 70 30 40 50 RIO GRANDE CITY 81 66 80 66 / 60 20 40 60 SOUTH PADRE ISLAND 78 74 79 74 / 70 30 30 40 BAYVIEW/PORT ISABEL 80 70 81 70 / 70 30 30 40

BRO WATCHES/WARNINGS/ADVISORIES

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