textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1019 PM CST Sat Nov 22 2025

- Above average and record-breaking, or near record-breaking, high temperatures continue through Tuesday.

- There is a medium to likely (40-60%) chance of rain across the region Tuesday night into Wednesday morning in association with the passage of a cold front.

- Near average temperatures follow behind the front along with a low (15-20%) chance of rain along and east of I-69 E continuing into next weekend.

DISCUSSION

Issued at 1019 PM CST Sat Nov 22 2025

A lingering frontal boundary situated just north of our County Warning Area (CWA) is expected to generate a low to medium (20-40%) chance of rain across the northern ranchlands and along the immediate coastline this morning. As southeasterly winds return throughout the day, this boundary is expected to lift northward and diminish probabilities of precipitation (POP's) from south to north, resulting in dry conditions (<10% PoP's) across all of Deep South Texas by this evening, continuing into Tuesday. Meanwhile, a mid- level trough is projected to translate northeastward from the Desert Southwest today into the Central Plains on Monday, extending another frontal boundary southward, possibly arriving to and stalling near the Rio Grande Plains Monday evening into Tuesday. Lift provided by this boundary and upper level divergence ahead of a weak trough over western Texas are currently expected to gradually increase chances of rain to a low (15-20%) chance across most of the CWA by Tuesday evening. Meanwhile, an amplifying shortwave trough moving eastward over the Northern Plains is likely to initiate a cold front, with moisture pooling ahead of it increasing chances of rain overnight Tuesday to a medium to likely (40-60%) chance by Wednesday morning as the front pushes through, bringing northeasterly to northerly winds. Following, PoP's diminish throughout most of inland Deep South Texas by Wednesday night, though coastal troughing could maintain a low (15-20%) chance of rain along and east of I-69 E into next weekend, with southeasterly winds returning on Friday.

Sustained onshore flow and/or warm air advection via southeasterly/southerly surface winds are expected to continue to result in very warm and humid conditions through Tuesday. Temperatures will continue to run 10-15 degrees F above average during this time with record-breaking, or near record-breaking, highs in the 80's to lower 90's followed by overnight low temperatures in the 60's and 70's. The passage of the cold front and increased cloud cover on Wednesday, and beyond, will drop temperatures to near average on Wednesday and Thursday, followed by a warming trend into next weekend as southeasterly winds return on Friday.

A medium risk of rip currents continues through the day today.

AVIATION

(06Z TAFS) Issued at 1019 PM CST Sat Nov 22 2025

With the exception of KBRO, which is expected to remain VFR throughout tonight and tomorrow, MVFR ceilings are expected to develop at KHRL and KMFE later tonight, perhaps between 08-10Z, lowering to IFR, or even possibly as low as near LIFR at KHRL, within the hours surrounding sunrise. Following, broken skies (at KHRL/KMFE) become scattered VFR by the afternoon hours with a moderate southeasterly breeze continuing through the late afternoon. Recent runs of the HRRR have indicated the possibility of some brief showers developing overnight tonight or early morning, possibly impacting KHRL and KBRO. However, given the low confidence, have excluded rain from the TAF's.

MARINE

Issued at 1019 PM CST Sat Nov 22 2025

Mostly moderate southeasterly winds and slight to moderate (2-3 feet) seas during the day today become moderate to fresh, possibly near strong, south-southeasterly winds tonight into Monday morning as a pressure gradient tightens, resulting in moderate seas of 4-6 feet as well likely Small Craft Exercise Caution (SCEC) headlines. A shorter-fused Small Craft Advisory may be possible as well. Conditions improve briefly throughout Monday night, leading to gentle to moderate southeasterly winds and moderate (3-4 feet) seas. A cold front drops through late Tuesday night or early Wednesday morning, likely bringing another round of SCEC headlines through Wednesday night, followed by mainly moderate winds and moderate seas into next weekend. Chances of rain decrease from a low to medium (20- 50%) chance today to less than 10% chance into Monday. Chances of rain gradually build Monday night to as much as a medium to likely (40-60%) chance Tuesday night before diminishing to a low to medium (15-40%) by Thursday and beyond.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 72 86 73 87 / 20 20 0 0 HARLINGEN 69 88 69 90 / 20 20 0 0 MCALLEN 72 90 73 92 / 30 20 0 0 RIO GRANDE CITY 70 90 70 91 / 40 20 0 0 SOUTH PADRE ISLAND 75 82 76 83 / 30 20 0 0 BAYVIEW/PORT ISABEL 71 85 71 87 / 30 20 0 0

BRO WATCHES/WARNINGS/ADVISORIES

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