textproduct: Brownsville/Rio Grande Valley

KEY MESSAGES

Updated at 1250 PM CST Mon Jan 26 2026

* First Arctic airmass of the 2025/2026 winter season is upon us.

* Another cold night with record to near record-breaking low temperatures will occur tonight into Tuesday morning; widespread freezing/hard freezing temperatures are expected/

* A Freeze Warning and Cold Weather Advisory is in effect for tonight into Tuesday morning. Plan to protect people, pets, plants, and pipes and limit outside exposure. Please refer to www.weather.gov/safety/cold for tips on how to protect yourself and others.

* A Small Craft Advisory remains in effect through this evening. A High Risk for Rip Currents and High Surf Advisory are also in effect till this evening before conditions improve on Tuesday.

* Rain chances increase Thursday night into Friday ahead of yet another potentially strong cold front that's set to arrive late this week into next weekend.

DISCUSSION

Issued at 1250 PM CST Mon Jan 26 2026

The coldest airmass of the season and the coldest since January 21- 22, 2025 is upon us. Low temperatures from this morning revealed widespread freezing temperatures (20s/30s) across Deep South Texas and the Rio Grande Valley with much of the Northern Ranchlands under a hard freeze. Record low temperatures were set at all three climate sites (Brownsville BRO, Harlingen HRL, and McAllen MFE) this morning. The latest sfc observations depicted the 1030-1040 mb Arctic high overhead with the center over central Texas under sunny to mostly sunny skies this morning. Another night of very cold temperatures is expected before this Arctic airmass finally begins to depart the region and retreat to the north. In anticipation of the very cold temps tonight, we've issued another Freeze Warning and Cold Weather Advisory for all of Deep South Texas with the exception of the barrier islands from 9 PM CST this evening to 10 AM CST Tuesday morning.

A highly amplified large-scale pattern in the middle to upper levels of the atmosphere, driven by a negative Arctic Oscillation (-AO) and a positive Pacific North American Oscillation (+PNA) has resulted in the collapse of a Polar Vortex (PV) lobe, which explains this significant cold air outbreak/winter storm that's impacted much of the nation. Moving forward towards the tail end of January/first part of February, medium range computer models and ensembles continue to depict that this pattern will remain in place meaning that there could be additional cold air intrusions taking place over the next week at least. In fact, we continue to closely monitor the potential for another (second) cold shot taking place late next week into the following weekend (Jan 30-Feb 2 timeframe).

High temperatures today will struggle in many places to make it out of the 40s (well below normal levels) under sunny to mostly sunny skies.

For tonight, sufficient radiational cooling on mainly clear skies on top of additional cold air advection (CAA) will result in another cold night with another opportunity for record to near record breaking low temperatures (see CLIMATE SECTION for more details). Similar to last night, widespread sub-freezing (temperatures <32F degrees) are expected across Deep South Texas and the Rio Grande Valley. Widespread hard freezes (temperatures <28F for 2+ hours) are expected to take place tonight as well. NBM has high (70-100%) chances for temperatures falling below 32F tonight across much of Deep South Texas from roughly the northwestern parts of Cameron County and points northwest. NBM has a medium-high (50-90%) chance for a hard freeze (temperatures <28F) from north of IH-2 towards the Northern Ranchlands. There is a low chance south of that corridor (i.e. Cameron County and far south Hidalgo County).

Tuesday through Thursday, we'll see temperatures moderate as the aforementioned 1030-1040 mb sfc high and anomalously strong central/east U.S. trough departs further to our east and before retreating northward. Despite the moderation or brief reprieve from the Arctic airmass, temperatures Tuesday through Thursday will still be below normal levels for this time of year. High temps on Tuesday are progged to climb into the lower 60s along the RGV and 50s elsewhere. Wednesday, we'll see high temps mainly in the 60s across Deep South Texas, and on Thursday we'll see highs getting into the lower 70s along the RGV and 60s elsewhere. Overnight low temps Tuesday and Wednesday nights will be in the 30s/40s. By Thursday night, lows are projected to be in the 40s/50s.

Thursday night into Friday, ahead of yet another potentially strong cold front, rain chances (PoPs) are expected to increase (mainly near the coast and over the Gulf Waters). Some weak moisture influx and warm air advection (WAA) on east-southeasterly winds coupled with a developing weak shortwave trough nearby could drive up the chances for showers Thursday night into Friday. Things have trended drier over the past 24 hours. Currently, we have 20-30% PoPs Thursday night confined east of IH-69C.

As touched on earlier with the description of the large-scale pattern regime (i.e. -AO/+PNA) we're in, forecast models and ensembles are indicating yet another (second) cold front to sweep through the region Friday night into Saturday. Based on some computer projections and synoptic analysis, this cold front could yield another round of freezing temperatures to at least parts of Deep South Texas (i.e. Northern Ranchlands) as Arctic air envelopes much of the central/east U.S. Greatest uncertainties at this point is just how far south the cold air will penetrate and the eastward placement of the full fetch of Arctic cold air (i.e. over the Plains vs. east of the Mississippi River). That said, temperatures will remain below normal late next week through next weekend. Temperatures look to rebound early next week.

AVIATION

(18Z TAFS) Issued at 1250 PM CST Mon Jan 26 2026

Through 18z Tuesday....VFR conditions are expected to prevail through the 18z TAF period.

Winds will continue out of the north today with speeds between 10-15 kts and gusts as high as 25 kts. Later this evening/tonight winds will wane with speeds between 5-10 kts.

MARINE

Issued at 1250 PM CST Mon Jan 26 2026

Hazardous marine conditions will continue through this evening. A Small Craft Advisory remains in effect till 9 PM CST this evening. Marine conditions improve on Tuesday with conditions becoming favorable with light to moderate winds and seas. Favorable marine conditions will persist into Thursday evening. Marine conditions could yet again become adverse/hazardous in response to another cold frontal passage Friday into Saturday, before potentially improving late weekend into early next week.

CLIMATE

Issued at 1250 PM CST Mon Jan 26 2026

The first Arctic airmass of the 2025/2026 winter season, and the coldest since January 21-22, 2025 has arrived across Deep South Texas and the Rio Grande Valley. Adequate radiational cooling on clearer skies on top of additional cold air advection (CAA) will once again result in record to near record-breaking overnight low temps tonight into Tuesday. Below are the all-time record low temperatures for Brownsville, Harlingen, and McAllen for January 27.

Record Low Temperatures for January 27:

Brownsville: 32F degrees in 1948 Harlingen: 30F degrees in 1966 McAllen: 30F degrees in 1966

PRELIMINARY POINT TEMPS/POPS

BROWNSVILLE 33 62 49 66 / 0 0 10 10 HARLINGEN 28 62 44 66 / 0 0 0 0 MCALLEN 31 63 46 67 / 0 0 0 0 RIO GRANDE CITY 24 60 38 67 / 0 0 0 0 SOUTH PADRE ISLAND 44 61 55 63 / 0 0 10 10 BAYVIEW/PORT ISABEL 34 62 49 65 / 0 0 10 0

BRO WATCHES/WARNINGS/ADVISORIES

TX...Cold Weather Advisory from 9 PM this evening to 10 AM CST Tuesday for TXZ248>255-351-353>355.

Freeze Warning from 9 PM this evening to 10 AM CST Tuesday for TXZ248>255-351-353>355.

High Rip Current Risk until 6 PM CST this evening for TXZ451-454- 455.

High Surf Advisory until 6 PM CST this evening for TXZ451-454- 455.

GM...Small Craft Advisory until 9 PM CST this evening for GMZ130-132- 135-150-155-170-175.