textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1258 PM CDT Sat Jun 13 2026

- There is a Moderate (level 1 of 4) to (expected) Slight (level 2 of 4) Risk of Excessive Rainfall across Deep South Texas Sunday into Wednesday with heavy rainfall expected at times, especially Monday night through Tuesday night. A Flood Watch may be needed. - Moderate (level 2 of 4) Heat Risk continues through Wednesday with a Moderate to Major (level 3 of 4) Heat Risk Thursday and Friday. Heat Advisories may be needed Thursday and Friday.

- There is a High Risk of life-threatening rip currents at area beaches this weekend. Increasing swell near high tide cycles may result in minor coastal flooding into early next week.

- The National Hurricane Center continues a low chance (20%) of tropical development with a broad area of low pressure near or across eastern Mexico out along the lower Texas coast and western Gulf over the next 7 days.

DISCUSSION

Issued at 1258 PM CDT Sat Jun 13 2026

Abundant tropical moisture continues to build across Deep South Texas this weekend, increasing the threat of flooding rainfall Monday into Wednesday as a frontal boundary works south. The National Hurricane Center has continued a low (10-20 percent) chance of tropical development in 48 hours and 7 days with a broad area of low pressure near eastern Mexico moving inland today, then interacting with the frontal boundary along the lower Texas coast and western Gulf through Wednesday.

Most activity into this afternoon has been moving at a decent speed, which will help limit rainfall totals. Expect additional showers and potentially isolated thunderstorms this afternoon into this evening, generally moving southeast to northwest. Latest model guidance leans into rain chances kicking up along the coast each night, increasing in coverage across the coastal counties each morning, then working westward and tapering off each afternoon and evening from east to west. The highest chance of rain arrives Monday and continues into Wednesday, edging back offshore into Thursday morning.

PWAT values are already above 2 inches, and expected to remain above 2 inches through Wednesday night, with a max near 2.7 inches developing Monday across portions of the upper valley and brush country that gradually works back east across the ranchlands and Rio Grande Valley Tuesday into Wednesday night. For context, the 90th percentile for mid June is 1.96 inches and max is around 2.3 inches, so 2.7 is concerning.

The Weather Prediction Center has placed all of Deep South Texas into a Marginal (level 1 of 4) Risk of Excessive Rainfall Sunday through Sunday night and Tuesday into Wednesday, with an expected Slight (level 2 of 4) Risk across all but the lower RGV Monday through Monday night. They may extend the Slight Risk into the Tuesday to Wednesday time frame. The level of concern for flooding rainfall increases Sunday into Tuesday night. A Flood Watch may be needed Monday into Wednesday. Overall, expecting around 1 to 2 inches this weekend, with an additional 2-4 inches Monday through Wednesday, with isolated amounts of 5-6 inches.

Expect temperatures to dip a little below normal where the rain persists, then ramp back up near the end of the week into next weekend as drier conditions return. These temperatures combined with higher humidity values maintain a Moderate (level 2 of 4) Heat Risk into Wednesday, with a Major (level 3 of 4) Heat Risk through the remainder of the week. Heat Advisories may be needed Thursday and Friday. Beach hazards are expected into mid- week with life- threatening rip currents and narrow beaches during high tide cycles. Rip Current and Coastal Flood Statements have been issued.

AVIATION

(18Z TAFS) Issued at 1258 PM CDT Sat Jun 13 2026

Showers and thunderstorms are expected to redevelop this afternoon across the RGV with VFR ceilings generally holding otherwise. MVFR ceilings return tonight with a better chance of showers into early Sunday morning. Expect southeasterly winds occasionally gusting to 20 kts. Brief heavy rainfall may bring IFR to LIFR conditions through the TAF period.

MARINE

Issued at 1258 PM CDT Sat Jun 13 2026

Increased southeasterly winds, due to the strengthening pressure gradient along the lower Texas coast, will drive Small Craft Advisory conditions this afternoon through Sunday afternoon. Shower and thunderstorm activity is expected to increase over the next 48 hours and continue into mid to late week. Expect heavy downpours and low visibility within these tropical showers and thunderstorms. Conditions may be conducive for waterspouts over the next few days, especially near the edges of heavy showers. Small Craft Advisories have been issued. Additional Small Craft Advisories may be needed mid to late week.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 81 92 80 90 / 60 60 50 80 HARLINGEN 78 91 77 89 / 50 70 40 80 MCALLEN 79 93 79 91 / 30 60 30 80 RIO GRANDE CITY 77 93 77 91 / 20 50 30 80 SOUTH PADRE ISLAND 83 88 82 86 / 60 60 70 70 BAYVIEW/PORT ISABEL 80 90 79 88 / 60 60 60 80

BRO WATCHES/WARNINGS/ADVISORIES

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

GM...Small Craft Advisory until 1 AM CDT Sunday for GMZ130-132-135.

Small Craft Advisory until 7 PM CDT Sunday for GMZ150-155-170- 175.