textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1242 AM CDT Mon Jul 20 2026

- Breezy and mainly dry conditions along with above average and near record heat (highs around 100 to 107+ F), afternoon heat indices of 105 to 110+ F and moderate to major heat risks (levels 2/4 and 3/4) are expected to continue.

- A Special Weather Statement (SPS) is in effect for Starr and Hidalgo counties as well as the coastal and inland portions of Cameron, Willacy and Kenedy counties, not including the barrier islands, from 12 PM to 7 PM Monday for heat indices of 108 to 111 F, potentially briefly higher. Additional SPSs or heat advisories are possible this week.

- A Fire Danger Statement (RFD) is in effect for all of deep south Texas, with the exception of the coastal and island areas, from 12 PM to 7 PM Monday and additional RFDs are possible throughout the forecast.

- We continue to monitor the tropics and updates from the National Hurricane Center (NHC) on Tropical Depression Two, currently located over the northeastern Gulf, and its potential impacts, if any, by the middle or later parts of the week.

- A moderate risk of life-threatening rip currents continues through Monday afternoon.

DISCUSSION

Issued at 1034 PM CDT Sun Jul 19 2026

A 594+ dam high pressure aloft over the Rockies gradually builds and shifts southeastward to a 597+ dam over the Southern Plains by mid- week before retreating westward later in the week to the Desert Southwest and the 4 Corners region over this upcoming weekend. Despite some uncertainty in the forecast by the middle to later parts of this week, a mostly dry, unseasonably hot and a bit breezy forecast remains on track across deep south Texas, bringing widespread, near record-tying or -breaking, high temperatures of low to mid 100s across inland areas, perhaps even encroaching on coastal areas, while upper 100s (107+ F) are possible across western portions of Starr and Zapata counties.

A SPS is in effect for Starr and Hidalgo counties as well as the coastal and inland portions of Cameron, Willacy and Kenedy counties (excepting the barrier islands) from 12 PM to 7 PM Monday as heat indices of 108 to 111 F are expected for several hours and could briefly exceed 111 F. Daily maximum afternoon apparent temperatures of 105 to 110+ F are likely, bringing a mainly moderate heat risk to the region along with major heat risks to the populated areas of the RGV as well as portions of the Rio Grande Plains. Additional SPSs and/or heat advisories are possible this week as well, particularly later in the week should chances of rain remain at 10% or less (discussed further below), which could also expand the coverage of major heat risks.

As drier than average moisture content and lower relative humidity combine with daytime breezy to gusty southeasterly winds (around 15- 25 mph, gusting to as high as 35 mph, or higher), there remains a concern for wildfire spread. A RFD is in effect from 12 PM to 7 PM Monday across all of deep south Texas, with the exception of the coastal areas and barrier islands. Additional RFDs are possible throughout the remainder of the week.

By far and large, the biggest uncertainty of the forecast resides within the possible outcomes of Tropical Depression Two, currently located over the northeastern Gulf, especially from the middle to later parts the week. Impacts and degree of subsidence aloft will be determined by its strength and track, which could lower or increase chances of rain as well as increase or lower temperatures, respectively. Yet, for the time being, chances of rain Wednesday night into Friday remain very low, generally 10% or less.

A medium risk of life-threatening rip currents continues through Monday afternoon.

AVIATION

(06Z TAFS) Issued at 1242 AM CDT Mon Jul 20 2026

VFR conditions are expected to prevail through the TAF period with breezy southeasterly winds from late Monday morning into early Monday evening.

MARINE

Issued at 1034 PM CDT Sun Jul 19 2026

Moderate to fresh southeasterly winds, moderate (3-4 ft) seas and periods of Small Craft Exercise Caution conditions are likely to become mostly gentle to moderate southeasterly winds with slight to moderate (1-3 ft) seas by Tuesday. There remains much uncertainty associated with the intensification, forecast track and impacts of Tropical Depression Two, currently located offshore western and northwestern Florida. At present, we anticipate a low (15-20%) chance of rain Wednesday night through Thursday night. However, forecast winds, seas and chances of rain for the middle to later parts of the week are subject to change in the coming days as confidence increases.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 78 98 78 99 / 0 0 0 0 HARLINGEN 74 103 74 102 / 0 0 0 0 MCALLEN 77 106 77 105 / 0 0 0 0 RIO GRANDE CITY 75 106 75 105 / 0 0 0 0 SOUTH PADRE ISLAND 79 88 79 89 / 0 0 0 10 BAYVIEW/PORT ISABEL 76 96 76 97 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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