textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1238 AM CDT Thu Mar 12 2026

Key Messages:

* Rain-free weather with a roller coaster temperature trend, and at times breezy conditons with elevated fire weather risks will prevail through mid next week.

* Elevated to critical fire weather risk expected on Thursday; a Fire Weather Watch remains in effect for Brooks, Hidalgo, Kenedy, Willacy, and Cameron counties, excluding the island from 10 AM CDT Thursday to 7 PM CDT Thursday evening (see FIRE WEATHER SECTION for more details).

* A heat spike with highs well into the 90s across many locations is expected to take place on Sunday ahead of a cool front; a record or two is possible.

DISCUSSION

Issued at 1030 PM CDT Wed Mar 11 2026

A benign, rain-free weather pattern punctuated with at times breezy conditions and elevated fire weather risks will take place through the forecast period or through the middle parts of next week. Driven by a second cool fropa late next weekend into early next week, a roller coaster temperature trend can be expected through the middle parts of next week.

An elevated to critical fire weather risk is possible on Thursday due to the combination of low relative humidity values, dry soils, and breezy north-northwest winds (see FIRE WEATHER SECTION for more details). A lot, however, will depend on the timing and strength of the winds as winds are expected to decrease through the afternoon hours while relative humidity values remain low (between 15-40%). Otherwise, expect for rain-free weather conditions to persist on Thursday with near seasonable temperatures (mid to upper 70s inland) behind the cool tonight's cool frontal passage.

Temperatures will warm through the weekend culminating to another heat spike on Sunday. Widespread 90s with maybe a few pockets of 100s are expected on Sunday across Deep South Texas and the Rio Grande Valley. The warmest temperatures will be located along and west of IH-69E. Record to near record-breaking high temperatures are possible for McAllen. The record high for McAllen for March 15th is 103F degrees set back in 2008. An enhanced sfc pressure gradient ahead of an approaching cool front will result in breezy to windy conditions on Sunday with south winds of 20-30 mpg and gusts up to 40 mph. Warm air advection (WAA) from these southerly winds will help in the surge of unseasonably warm temperatures on Sunday.

A strong cool front (the second in a week) will sweep through Deep South Texas and the Rio Grande Valley Sunday night. This will drop overnight low temperatures into the 50s over the Northern Ranchlands and 50s along the Rio Grande Valley (near normal levels). Full cool air advection (CAA) regime with blustery winds out of the north 20- 30 mph and a 1024 mb sfc high nearby will result in normal to cooler than normal high temperatures on Monday. Tuesday through Wednesday, another warming trend begins.

AVIATION

(06Z TAFS) Issued at 1238 AM CDT Thu Mar 12 2026

The passage of a cold front will occur during the overnight hours, resulting in breezy winds. These winds will then diminish around sunset Thursday. Limited cloud cover and no precipitation is also anticipated.

MARINE

Issued at 1030 PM CDT Wed Mar 11 2026

A Small Craft Advisory (SCA) for hazardous marine conditions either from high winds and/or seas is in effect till 1 AM CDT Friday for the Laguna Madre and the Gulf Waters. Marine conditions improve on Friday with a return to light to moderate seas and winds. Favorable marine conditions will persist through Saturday. On Sunday, breezy to windy conditions in response to an enhanced pressure gradient ahead of another cool front will result in adverse (i.e. Small Craft Exercise Caution) conditions on Sunday. Following the passage of the cool front, hazardous (Small Craft Advisory) conditions will develop Sunday night through Monday. Adverse to hazardous marine conditions could persist into Wednesday, though marine conditions will show gradual signs of improvement.

FIRE WEATHER

Issued at 1030 PM CDT Wed Mar 11 2026

An elevated to critical risk for fire weather is possible on Thursday in response to a continuation of low relative humidity (RH) values, ongoing dryness/drought conditions (i.e. D2 Severe Drought to D4 Exceptional Drought over the region), and at times breezy north- northwest winds.

Timing will be key as the strongest of winds will mostly be occurring early in the day at the time where RH values are elevated. During the afternoon hours, RH values will drop. Depending on how quickly the winds die down will dictate whether or not we reach criteria for either a Fire Danger Statement (RFD) or a Red Flag Warning. Currently, we have a Fire Weather Watch in effect for Thursday for Brooks, Hidalgo, Kenedy, Willacy, and Cameron counties, excluding the island from 10 AM CDT Thursday till 7 Pm CDT Thursday evening.

According to the Texas A&M Forest Service, High Fire Danger is highlighted across much of the region with a pocket of Very High Fire danger over the Lower Valley. Additionally, Energy Release Component (ERC) values are expected to be elevated with values ranging between 75-96%, and fuels are expected to be dry to critically dry.

Additional fire weather concerns are possible through the forecast period or through the middle parts of next week due to continued antecedent dryness/ongoing drought and at times breezy conditions with low relative humidity levels.

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 51 81 61 85 / 0 0 0 0 HARLINGEN 48 83 58 89 / 0 0 0 0 MCALLEN 52 86 62 93 / 0 0 0 0 RIO GRANDE CITY 47 85 58 94 / 0 0 0 0 SOUTH PADRE ISLAND 61 73 67 77 / 0 0 0 0 BAYVIEW/PORT ISABEL 53 79 61 84 / 0 0 0 0

BRO WATCHES/WARNINGS/ADVISORIES

TX...Fire Weather Watch from 10 AM CDT this morning through this evening for TXZ250-251-253>255-351-353>355.

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

GM...Small Craft Advisory until 1 AM CDT Friday for GMZ130-132-135- 150-155-170-175.