textproduct: Houston/Galveston

KEY MESSAGES

- Freezing rain and potentially sleet are expected across much of the region starting later today in our northern zones, expanding southward towards the Houston Metro and potentially the coast by Sunday morning. Ice may be heavy enough to result in power outages in some areas, particularly in our northern counties.

- Ice Storm Warnings, Winter Storm Warnings, and Winter Weather Advisories are in effect across the region.

- ANY amount of ice can result in dangerous travel conditions. Travel impacts will last until at least Monday as moisture refreezes on roadways. Impacts possible through Tuesday in the Piney Woods and Brazos valley. - Extended periods of below freezing temperatures along with hard freezes are expected Sunday morning through Tuesday morning. Portions of the Piney Woods and Brazos Valley will stay below freezing for multiple days.

- Dangerously cold wind chills are expected, with values ranging from as low as 10 degrees at the coast and as low as -5 degrees in the Piney Woods and Brazos Valley. - Residents are encouraged to winterize their home and make plans to keep themselves and loved ones warm during the work week prior to the arrival of the Arctic air.

DISCUSSION

Issued at 1122 PM CST Fri Jan 23 2026

There's a lot to unpack in this AFD with a major winter storm and prolonged cold affecting the CWA over the coming days. To make this easier to follow, we'll break the forecast down into chapters.

Chapter 1: The Set Up

Water vapor imagery depicts a robust mid/upper-level low over the Baja Peninsula. The system is deep, with a closed low above 700 mb and an associated trough from about 700 mb to the surface. The system's tilt has gradually evolved from a positive orientation to a more neutral structure. With time, the system is expected to assume a more negative tilt as it progresses eastward across northern Mexico. As it pushes east, the mid/upper heights gradient overhead will steepen, fomenting a strengthening and increasingly diffluent jet across northern Mexico and the Lone Star State on Saturday into Sunday. This diffluence will be accompanied by strong positive vorticity advection, enhancing synoptic ascent. Lower in the atmosphere (925-850 mb), strong south to southeasterly flow supports efficient moisture transport from the Gulf, contributing to the scattered to widespread precipitation across much of Texas and Oklahoma overnight.

Meanwhile at the surface, a ~1050 mb high is centered over the northern plains, pushing frigid arctic air southward. The leading edge of this shallow arctic air (as of midnight) has already reached Central Texas. Thus, much of the activity on radar across western and northern Texas is snow, sleet, and freezing rain. So far, most computer models have biased too slow with both the progression of the front and the rate of temperature decrease in the font's wake, suggesting a lean towards colder model guidance is scientifically prudent. The arctic air will continue surging southward Saturday, as the aforementioned ML/UL low approaching from the west induces ascent in a moisture rich environment. These ingredients support very high precipitation chances and tumbling temperatures this weekend across our region, with frozen precipitation becoming increasingly likely later today, tonight, and into Sunday. And with robust WAA aloft, the frozen precip will likely be in the form of freezing rain, and maybe some sleet.

Chapter 2: Saturday Morning Thunderstorms?

The strengthening WSW mid/upper jet and enhanced south to southeast LL flow will result in a helical and increasingly sheared vertical wind profile this morning. This will be especially true south of the arctic front. Normally this would be seen as a sign for severe weather. But instability will be lacking due to the increasingly cold near sfc atmosphere. But HREF ensembles are hinting at some enhanced LL CAPE (~500 J/KG) trying to sneak its way northward into the Matagorda Bay region before arctic air sweeps that instability out to sea. The window is brief, but we will need to keep a watchful eye on the radar in the vicinity of Matagorda Bay for a strong thunderstorm or two in the 5AM to 10AM time frame.

Chapter 3: Rain and Tumbling Temperatures Saturday Afternoon.

Scattered to widespread precipitation is expected on Saturday as temperatures fall. By the afternoon, most areas north of the Houston metro are expected to be in the 30s, with 40s farther south. Some of the heaviest showers (and even a few thunderstorms) will occur during the morning hours. Depending on how quickly arctic air surges southward, we could have freezing rain in our northern counties by this afternoon. 50th percentile HREF suggests light ice accumulations will occur in our northern Piney Woods zones as early as midday. We've been treating HREF 90th percentile as a reasonably worst case scenario, which suggests rain could change to freezing rain by midday as far south as College Station. That's earlier than our forecast depicts, but you never want to underestimate the speed of arctic air.

Chapter 4: An Icy Changeover Saturday Night into Sunday

This is where the forecast becomes quite tricky given that small errors in the temperature can mean the difference between plain cold rain and freezing rain. Confidence is pretty high that our northern counties should transition to freezing rain by this evening (if not by afternoon). Sub-freezing air will continue to filter south and east, as waves of precipitation stream into the region from the southwest. By Sunday morning, we expect freezing rain will expand southward into Houston. The ECMWF is adamant that Houston will remains south of the ice zone. Yes, the ECMWF is a great model. But it has had a poor initialization of the arctic air looming behind the front. And given arctic air's tendency to over perform, we are thinking that this isn't the ECMWF's moment to shine. Instead, we look to the better initialized HREF, AIGFS, AIECMWF, and the GFS (yes, the GFS has a better initialization than the ECMWF). This guidance suggest that frozen precip will make it down to interior portions of our coastal counties. Thus, our forecast brings "light" ice accumulations almost to the coast. I put "light" in quotes since ANY amount of ice can cause dangerous travel conditions.

Chapter 5: What To Do With Ice Accumulations?

I toiled over what to do with freezing rain accumulations. The uncertainty not only lies with temperature, but also the potential for robust frontogenesis induced banding near the end of the event Sunday morning. It's quite possible we may see a scenario with widespread light glazing of ice with bands of much heavier and potentially damaging ice. But the potential convective nature of the banding could lend towards interesting precipitation scenarios, possibly yielding to some sleet in the mix (if you believe the HRRR). Our latest forecast technically shows increasing ice accumulations across much of the CWA, enough to warrant an expansion of the Ice Storm Warning. But complex mesoscale processes may end up dictating not just the accumulations, but also the location of heaviest freezing rain, and maybe even sleet. So I lacked the confidence to change our winter warning products in this update. We will monitor trends overnight for a possible expansion of the warning this morning.

Chapter 6: Prolonged Cold

Many areas on Sunday afternoon may struggle to rise above freezing, especially when considering likely cloud cover and robust CAA. Cold temperatures will be accompanied by gusty winds, bringing wind chill values well below actual temperatures. By Sunday morning, we are expecting widespread teens to low 20s, with wind chills in the single digits and teens. The cold could greatly over perform Sunday night and Monday morning if there is enough ice / sleet cover coupled with clearer skies. This is particularly true over our northern counties, where 10th and 25th percentile NBM guidance suggests single digit temperatures are possible. Monday will be sunny. But temperatures may fail to rise above freezing in our northern zones, while areas farther south rise into the mid/upper 30s (maybe low 40s if we're lucky).

High pressure overhead will support efficient radiation cooling Monday night into Tuesday. Rural cold spots could easily drop well down into the teens, while low and mid 20s are expected in more urban and coastal areas. It may be tad warmer on the beaches, while locally cold spots in our northernmost zones could fall into the single digits if enough sleet / ice cover sticks around. Temperatures will modify as we approach mid-week, ending this strech of brutal cold. But temperatures are expected to remain colder than normal through the week.

Chapter 7: One Storm at a Time

There are signs of another interesting system by next weekend. But as the title of this chapter suggests, let's just take it one storm at a time.

Self

AVIATION

(00Z TAF Issuance) Issued at 512 PM CST Fri Jan 23 2026

IFR/LIFR conditions persist this evening and overnight as a strong Arctic cold front approaches the area. Light showers and drizzle should develop out ahead of the front with a band of heavier showers and thunderstorms expected as the front moves through Saturday morning. Could see a few stronger storms too. Only some modest improvement in CIGs will follow during the daytime. Light showers persist across the area in the wake of the front. As frigid, sub-freezing air rushes in behind the front, freezing rain and sleet will be possible. Some ice accumulations could occur during the daytime, primarily in areas north of IAH. However, the main timeframe to watch will be Saturday night into Sunday afternoon, as that is when the apex of the frozen precipitation should fall. KUTS is anticipated to see the brunt of the ice accumulations, but all TAF sites will be at risk of getting some icing.

03

MARINE

Issued at 128 AM CST Sat Jan 24 2026

A tightening pressure gradient will lead to increasing east winds and building seas overnight. Conditions could become quite gusty around the Galveston Bay area and adjacent coastal waters. Look for some showers and storms to move into the region from the west between 4-11am. A few storms could be strong.

An Arctic front will move into the waters during the day ushering in much colder temperatures, strong north winds, and elevated seas. Small Craft Advisories have been issued. Occasional gusts to near gale are possible offshore, especially Saturday night and Sunday. Additional rounds of precipitation are anticipated tonight into Sunday. As temperatures fall to the freezing mark overnight, freezing rain and possibly sleet is possible in the bays into Sunday morning.

Low water conditions are looking likely around low tide cycles Sunday night into Monday.

Mariners should take all of the above in consideration before beginning or continuing their transits.

47

PRELIMINARY POINT TEMPS/POPS

College Station (CLL) 22 27 13 31 / 100 40 0 0 Houston (IAH) 28 34 20 37 / 90 60 0 0 Galveston (GLS) 37 41 27 41 / 90 80 10 0

HGX WATCHES/WARNINGS/ADVISORIES

TX...Ice Storm Warning from 6 AM this morning to 6 PM CST Sunday for TXZ163-164-176>179.

Extreme Cold Warning from 6 PM this evening to noon CST Monday for TXZ163-164-176>179-195>200-210>214-226-227-235>238-300- 313-335>338-436>439.

Extreme Cold Watch from Monday afternoon through Tuesday morning for TXZ163-164-176>179-195>200-210>214-226-227-235>238-300- 313-335>338-436>439.

Winter Storm Warning from 6 AM this morning to 6 PM CST Sunday for TXZ195>199.

Winter Storm Warning from 6 PM this evening to 6 PM CST Sunday for TXZ200-210>213-226-227-235-300-313.

Winter Weather Advisory from midnight tonight to 6 PM CST Sunday for TXZ214-236>238-335>338-436>439.

GM...Small Craft Should Exercise Caution until 9 AM CST this morning for GMZ330-350-370.

Small Craft Advisory from 9 AM this morning to noon CST Monday for GMZ330-350-370.

Small Craft Advisory until noon CST Monday for GMZ335-355-375.