textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1226 AM CDT Mon Mar 23 2026

Key Messages:

- Above average daytime highs and near-to-above average overnight lows continue through the work week.

- There is an elevated fire weather concern Tuesday into Friday, with Fire Danger Statements possible, especially across the inland portions of the easternmost counties as winds increase.

- A weak frontal boundary may stall across, or pass through, our region next weekend, which could cool temperatures to near average.

DISCUSSION

Issued at 1032 PM CDT Sun Mar 22 2026

An anomalously strong subtropical ridge builds 500 mb heights across the western and southwestern US through the middle of the week as a mid/upper level high shifts eastward to western Texas, leading to mainly clear skies and likely dry conditions across Deep South Texas and the Rio Grande Valley through next weekend. At the surface, high pressure over the Gulf maintains mostly southeasterly to southerly winds. A series of low pressure systems traversing across the Northern Plains result in a tightening pressure gradient Tuesday into Thursday, with gusts up to 25 mph on Tuesday and Wednesday afternoons increasing to 25-30 mph, or greater, by Thursday afternoon. Despite lower relative humidity, Fire Danger Statements are likely to be avoided on Monday due to borderline-to-low 20 foot winds speeds and onshore easterly winds. However, fire weather concerns elevate Tuesday into Friday as afternoon minimum relative humidity values coincide with increasingly breezier conditions, especially across the easternmost inland counties (Kenedy, Willacy and Cameron) on Thursday. It is highly urged to refrain from outdoor burning due to the abundant cured fuels across our drought-sticken region. Daytime high temperatures remain around 5-10 degrees above average through Friday, likely rising from mainly the lower 90s on Monday to mostly low-to-mid 90s Tuesday into Friday while reaching the mid-to-upper 70s at the coast. Clear to partly cloudy skies each night promote efficient radiational cooling, maintaining near to 5 degrees above normal overnight lows, in the 60s inland and low 70s closer to the coast.

The only changes to this pattern is a very low (less than 15%) chance of rain from an isolated shower or two for southern portions of the Lower and Middle RGV on Tuesday afternoon as a weak mid-level disturbance passes over eastern Texas. Later in the week, a building surface high pressure and ridge aloft over the Plains, behind a departing strong surface low pressure system, are anticipated to push the low's attendant cold front through most of Texas Thursday into Friday, with the front losing momentum as it moves further south. The front may pass the region, possibly Friday night or Saturday, shifting winds from southeasterly to northeasterly. There is currently a low (at most, 15%) chance of rain on Saturday, however this is likely to change, depending on the timing and strength of the front. Behind the front, temperatures fall to near average Saturday and Sunday, maximizing in the 80s and minimizing in the 50s/60s.

A low risk of rip currents continues through Monday afternoon though is likely to elevate into the middle to later parts of this week.

AVIATION

(06Z TAFS) Issued at 1226 AM CDT Mon Mar 23 2026

VFR will prevail at the aerodromes through the next 24 hours, with generally light winds and clear to partly cloudy skies.

MARINE

Issued at 1032 PM CDT Sun Mar 22 2026

Gentle to moderate easterly to southeasterly winds continue through Tuesday along with slight to moderate (2-3 feet) seas. A pressure gradient tightens Wednesday into Thursday, leading to moderate to fresh southeasterly winds, moderate (3-4 feet) seas and possible Small Craft Exercise Caution headlines during the afternoon and evening hours. Gentle to moderate southeasterly winds resume by Friday, possibly becoming northeasterly on Saturday as a weak frontal boundary passes through. There is a low (15%) chance of rain on Saturday in association with the front.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 86 66 87 68 / 0 0 10 0 HARLINGEN 89 63 90 64 / 0 0 10 0 MCALLEN 92 67 94 69 / 0 0 10 0 RIO GRANDE CITY 92 63 93 65 / 0 0 0 0 SOUTH PADRE ISLAND 77 69 77 70 / 0 0 10 0 BAYVIEW/PORT ISABEL 83 65 84 66 / 0 0 10 0

BRO WATCHES/WARNINGS/ADVISORIES

None.