textproduct: Brownsville/Rio Grande Valley

UPDATE

Issued at 640 AM CDT Wed Jun 11 2025

The latest radar imagery depicts a line of showers and strong thunderstorms translating across Deep South Texas early this morning. Most activity has remained below severe limits, but wind gusts of 30 to 50 mph, small hail, heavy rainfall, and lighting are expected as the system continues to track towards the Gulf waters. Updated PoPs and QPF to better reflect current trends. Otherwise, additional convection may develop once again late this afternoon into tonight.

SHORT TERM

(Tonight through Thursday night) Issued at 1034 PM CDT Tue Jun 10 2025

Low pressure begins to settle into North Texas and the Southern Plains into Thursday before lifting northeast. A handful of severe thunderstorms are working southeast down the Rio Grande, with newer guidance generally weakening the severe threat or keeping much of it across the border through late tonight. Model soundings still show plenty of CAPE, some weak shear, and strong DCAPE, which points to an elevated threat for damaging winds, but also much drier air than previously advertised. The 00z sounding from BRO observed even drier air than this morning.

SPC has extended the Marginal Risk (level 1 of 5) of severe weather east across Brooks and into Kenedy counties, to go with Zapata, Jim Hogg, and Starr counties through tonight. WPC holds a Marginal Risk (level 1 of 4) of excessive rainfall for Zapata, Jim Hogg, and Starr through tonight, highlighting the threat of flooding.

SPC extends the Marginal Risk across the entire CWA during the day Wednesday and Wednesday night, with WPC highlighting most of the CWA with a Marginal Risk for excessive rainfall and a Slight Risk (level 2 of 4) across northern Brooks and Kenedy counties. By Thursday, WPC only highlights portions of the ranchlands with a Marginal Risk for excessive rainfall and SPC has a general thunderstorm outlook.

LONG TERM

(Friday through next Wednesday) Issued at 1034 PM CDT Tue Jun 10 2025

The subtropical ridge strengthens across northern Mexico and a weak Bermuda high sandwiches weak low pressure along the western Gulf through the forecast period. This will maintain a daily chance of showers and thunderstorms, mainly along the sea breeze and any roaming convective outflow boundaries. PWAT values occasionally reach 2.0 to 2.2 inches along and east of US281, abnormal for mid June. This maintains a chance of heavy rainfall through Wednesday, especially along the coastal counties, although POPs have trended slightly lower this evening with new guidance. Less POPs and less cloud cover would bump high temperatures a few degrees up in the mid to upper valley and across the ranchlands, pushing Heat Indices of 105 to 110 each afternoon.

AVIATION

(12Z TAFS) Issued at 640 AM CDT Wed Jun 11 2025

A line of convection is currently moving southeast across the region, likely impacting MFE and HRL through the next hour or two. There is lower confidence on the line maintaining its intensity as it approaches BRO, so opted to only prevail SHRA and VCTS at this time. The main impacts with this activity is gusty west to northwest winds, lightning, and heavy rainfall. Amendments will likely be needed if the line of convection maintains its strength over the next several hours. Otherwise, expect VFR with intermittent periods of MVFR to prevail through the period with southeast winds around 10-15 knots and higher gusts. Additional convection may develop late this evening and overnight once again.

MARINE

Issued at 1034 PM CDT Tue Jun 10 2025

Now through Wednesday...High pressure across the eastern Gulf and weak low pressure settling along the lower Texas coast will maintain moderate southeasterly winds with moderate seas through the forecast period. The chance of thunderstorms increases into next week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 95 81 94 81 / 40 40 30 20 HARLINGEN 96 79 95 78 / 40 30 20 20 MCALLEN 100 81 99 80 / 60 30 20 10 RIO GRANDE CITY 99 79 99 79 / 70 30 20 10 SOUTH PADRE ISLAND 88 82 88 81 / 40 40 30 30 BAYVIEW/PORT ISABEL 94 80 93 80 / 40 40 30 20

BRO WATCHES/WARNINGS/ADVISORIES

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