Matt Lanza

In brief: Houston’s rinse and repeat of periodic fog and very warm, humid conditions will continue through at least Sunday. Rain chances nudge up a bit next week, and we still suspect a front may eventually, possibly arrive here later in the week. We also dive in further on sea fog today.

More on sea fog

Eric’s talked a lot about sea fog this week, and it remains a pestilence across the coastal waters. Galveston finally broke free of fog for a while late yesterday. But, it’s back now. And if you’re asking yourself whether or not this is normal, the answer is actually yes. February and December are our two biggest fog months in Houston, particularly near the coast. Why? As Eric explained earlier this week, the process of sea fog involves cool shelf waters and warm, humid air crossing over them. In December, it’s a combination of our first cold of the winter, followed by a warm-up. Or it could be driven by non-sea fog, or what we call “radiation fog,” which is just fog that happens over land due to radiational cooling under clear skies at night, not the advective sea fog. The key difference? Radiation fog usually dissipates by mid to late morning. Sea fog may stick around or appear at random points during the entire day.

February usually marks the transition to spring, and the cold of winter has taken its toll on the shelf waters just offshore. The combination of that first taste of spring-like warmth and the cold Gulf water happens most often between February and early March. Once we get to mid-March, the cold spells usually relax, the shelf waters begin to warm, and the mechanism for sea fog disappears. Thus, the frequency of dense fog advisories plummets.

My previous day job role in the LNG industry required some serious fog forecasting chops, and let me tell you, for those operating or running critical businesses in Gulf Coast ports or forecasting for them, these events are full of stress. I have likened the stress of working a one-week fog event to that of the stress involved with forecasting a hurricane. You can click here to view a near-real time ship traffic map. Notice the clusters of ships amassing off the coast? They’re waiting to arrive in ports like Houston, Beaumont-Port Arthur, Sabine Pass, etc. Harder to see are the numerous vessels also “stuck” in port that have to depart. Each day lost to fog can cost companies tens of millions of dollars or more. Stack it up over a week, and you can do the math. It’s a lot of money. No pressure.

Today through Sunday

Does it end? How many more records can we break? This is the 6th warmest four day stretch on record in winter (December through February) in Houston. We’ve averaged about 75.1° so far this week. The record for four days is 76.4° set back in December of 2021. Yesterday was our fourth consecutive record high (83°), breaking 2019’s 82°.

Today’s record of 86° from 2017 seems safe. Clouds and fog should again hold us back a bit, so again look for low-80s for highs. Tomorrow? It may be a tick or two warmer, but the record of 87°, also set in 2017 would appear safe at the moment. Let’s not forget Super Sunday! More of the same. Another day in the low-80s, which is hopefully around the same value as Patrick Mahomes’s passer rating. Fly Eagles, Fly!

As for the fog, look for continued chances of afternoon or early evening clearing at the coast and a bit less inland fog than we’ve seen this week. Still, it will be around, and it will be dense at times, so use caution driving particularly in the morning hours.

Next week

The first attempt at a cold front will actually occur Sunday. The front may sneak into the Brazos Valley or as far south as Huntsville or even Conroe. It won’t severely knock back temperatures, but it could cool things temporarily up that way by 10 degrees or so. It appears that the front retreats back north Monday and Tuesday before maybe finally making a swipe at the area Wednesday or Thursday.

We may begin to see more showers crop up each afternoon starting Tuesday. That could transition into a better chance of showers and storms by Thursday, pending an actual front getting here. I would not get too worked up about rain chances at this time; they don’t look too exciting. Still, we’ll see how the weekend changes affect that story Monday.

How cold will it get behind the front? Well, at this point, we’re fighting a battle between very, very warm conditions over the Southeast and very, very cold conditions up north. Western Canada looks to get punished next week. The forecast high temperature in Calgary from the European ensemble next Friday is -22 degrees. It may not get any warmer than minus 20 degrees there on a couple days. Will any of that cold get down here? A modified version of it might later next week, but I don’t know that we see even a widespread light freeze at this point. For now, expect a couple rounds of more muted cold here into mid-February with details to be sorted out next week.

In brief: The weather over the next 3 or 4 days looks stellar, seasonably mild, and quiet in Houston. Outdoor activities will be just fine. The return of dreary, possibly foggy weather awaits us after Monday. Our next front is penciled in for next weekend.

Yesterday’s rainfall did little to the region, with most areas seeing under a quarter-inch. A narrow corridor from Bellaire through the Timbergrove saw between a quarter and half-inch, as did the area from Alvin through Baytown and Mont Belvieu. The real heavy stuff fell from portions of Hill Country (which is good because they need it) all the way through Dallas and to just west of Texarkana. As much as 4 to 5 inches of rain fell between Dallas and the Red River.

Now, we move on to blue skies and a top 5 weekend of the year.

Today through Sunday

It may take a minute to clear out all the clouds today, especially southeast of Houston. But in general, all three days should be mostly sunny. Really, just near perfect weather. Look for highs in the 60s today with a bit of a breeze, near 70 tomorrow, and into the mid-70s on Sunday. Humidity should stay low. Morning lows should be generally in the 40s tomorrow and Sunday.

Monday

We’ll start next week in transition as onshore flow becomes firmly established in the area, bringing in Gulf moisture, driving up our humidity, and ensuring we see cloud cover. Monday will be in flux, so still look for sunshine, but some possible areas of fog could crop up near the coast through the day. Depending on how much sun we see, we could test 80 degrees Monday afternoon after lows in the 50s.

Tuesday and Wednesday

These will most likely be gray days in the Houston area, especially for the first half of the day.

With warm and humid air crossing the cooler nearshore waters of the Gulf, that’s a good recipe for low clouds and fog. How widespread it is and how long it sticks around each day is still uncertain, but I would anticipate morning low clouds and fog giving way to some breaks of afternoon sunshine. Areas near the coast may stay fogged in all day. We’ll likely see highs in the 70s and lows in the 60s, but we could push or pass 80 degrees with enough clearing each afternoon.

Next front?

It’s still a bit early to speculate, but it does look like our next front could come with a decent push of colder air. Not a freeze by any means but perhaps cooler than we’ll have seen since early this week. The timing is likely to be roughly next Saturday, give or take 12 to 24 hours. This front should come with at least a few showers and thunderstorms, but I wouldn’t set my expectations too high at this point.

In brief: The National Hurricane Center released their post-storm report on Hurricane Beryl late last week, bumping its landfall intensity in Texas from 80 mph to 90 mph. The report also features a number of nuggets of information, statistics, and images. This post summarizes some of the highlights.

Hard to believe it’s been over 6 months now since Hurricane Beryl thrashed the Houston area. As is customary, the National Hurricane Center released their post-storm analysis on Beryl late last week, and there were some notable changes to the storm’s history. It is important to be clear that this is a common thing. When the storm is hitting, forecasters are consuming so much data and issuing constant updates that they don’t always have a chance to lock down all the finer details of the storm. In the postseason, there is the the luxury of being able to scrutinize all available data to make an objective determination of a storm’s data points. National Hurricane Center forecasters do this with every storm.

Beryl was a strong category 1 storm

While Hurricane Beryl was presumed to have a landfall intensity of 80 mph when it came ashore in Texas, the postseason review determined that this was too low. Beryl got an upgrade to a strong category 1 storm, with 90 mph maximum sustained winds at landfall. This is interesting, and it makes the comparisons to Ike somewhat more relevant in a data sense.

Ike came ashore as a weakening category 2 storm with 110 mph maximum sustained winds. Beryl came ashore as a strengthening category 1 storm, having rapidly intensified from a 60 mph tropical storm to a 90 mph hurricane in about 14 hours. While that’s still 20 mph of difference in maximum sustained wind, the fact that the two storms were trending in opposite directions, and all else the same, the weaker side of Ike wasn’t that much stronger than the “dirty” side of Beryl, which Houston experienced. This makes the similarities between the storms in terms of widespread tree damage and power outages more comprehensible in retrospect.

Also worth noting, Beryl peaked in the Caribbean as a category 5 storm with ~165 mph maximum sustained winds, confirming the intensity reported in the advisories. The report stated that “the maximum intensity of Beryl is somewhat uncertain due to temporal gaps in the aircraft data near the time of peak intensity, and issues with (microwave) surface wind estimates that prevented their use in this evaluation.” In other words, some of the data was unusable, and the timing of the reconnaissance flight into Beryl may have differed from the exact time of peak intensity. Whatever the case, 165 mph is dang strong.

Beryl didn’t weaken immediately at landfall

One reason Beryl came in stronger than the typical category 1 storm is that the storm likely continued to strengthen just beyond landfall. Where the storm came ashore is not exactly terra firma. Given the geography around Matagorda Bay, the technical landfall may have occurred before the storm truly got on land. The NHC determined this by noting that the minimum pressures recorded near the Texas coast occurred after landfall, indicating that the storm had passed but pressures were still lowering instead of rising as is typically the case. Basically, much like a large ship trying to make a 180° turn, Beryl needed a moment before it could tap the brakes.

No surprises with rain or storm surge

Generally speaking, Beryl produced a surge height of 5 to 7 feet above ground level between Matagorda and Freeport. Much of this is based on high water mark assessments by teams following the storm. Surge values decreased to about 4 to 6 feet above ground level between Freeport and Galveston. Maximum rainfall was around 15 inches in Thompsons in Fort Bend County. That was an exception, as most locations generally saw 8 to 12 inches of rain.

The forecast was excellent—except here

The NHC track forecast beat their average errors at almost all lead times on average through Beryl. A notable exception? When Beryl was in the western Caribbean and the majority of model guidance favored a Mexico landfall. From the report: “The largest track forecast errors occurred during the time that Beryl was moving through the western Caribbean when the forecasts for landfall on the western Gulf coast had a strong left or southward bias. Indeed, the Texas landfall position in the best track is at the right/northward edge of the official forecasts, and the forecast landfall points shifted significantly to the north as the storm approached the coast.” They go on to state that the TABM model (which basically just assumes a medium intensity storm) did best, whereas the ECMWF (Euro) and GFS (American) models failed. The reasons for the failure are not clear at this time.

A glaring caveat to all this? They do not include the ICON or European AI model in track errors, which in my subjective view did best capturing the risks to Houston. One major change we implemented at Space City Weather was to give those models much more weight after Beryl, and they continued to perform well last season. Google’s AI GraphCast also did a very good job identifying the northward risks early on.

Beryl remains a warning to Houston

We’ve said this countless times in the wake of Beryl and since: It was a warning to this region. Beryl had 14 hours of favorable conditions over water to strengthen and went from a tropical storm to nearly a category 2 hurricane. What if it had 24 hours, and started from a 70 mph tropical storm? 36 hours? We’ve seen this play out in Florida, Louisiana, and the Coastal Bend several times since 2017 with storms in the Gulf of Mexico. Harvey, Michael, Ida, Ian, Idalia, Helene, Milton to name some others. It really is a matter of when, not if. We need to continue to focus on ensuring we’re prepared every year with our hurricane kits, getting more people to adopt that practice, and continuing to invest in resiliency and infrastructure improvements, which is to say: Build the damn Ike Dike.

In brief: Houston is emerging from the cold now with highs again in the 50s today and then 60s tomorrow and Sunday. Rain chances return Saturday night and Sunday. Locally heavy rain is likely on Sunday in parts of the area that could lead to some isolated street flooding. A much milder week is on tap next week, along with another chance of rain and storms later in the week.

After 4 straight mornings with lows in the 20s, Houston officially failed to drop below 30 this morning as we continue to thaw out. Still, keep an eye out for patchy black ice on area roads this morning. This weekend will feel and look more spring-like, however as rain returns to the forecast on Sunday, including some locally heavy rain.

Today

Yesterday was a chilly but nice day. Today will essentially be a carbon copy. Expect sunshine and highs well into the 50s.

Saturday

Onshore flow returns tomorrow, which means temperatures will get a boost into the 60s after morning lows in the mid to upper-30s. Look for sunshine to fade behind increasing clouds, a sign of things to come on Sunday.

Sunday & Monday

Scattered showers should begin to break out across the region around midnight or so Saturday night into Sunday morning. Look for coverage and intensity of showers to pick up after sunrise with the focus of the heavier downpours drifting from northwest to southeast. We wouldn’t be shocked to see a few places get multiple rounds of rain and thunderstorms on Sunday morning and afternoon.

With the amount of atmospheric moisture well above average (almost 200 percent of normal) on Sunday, there will almost certainly be enough heavy rain in spots to produce localized street flooding. If you have plans on Sunday, just keep that in mind. A cool front will nudge offshore Monday, likely ending the rain chances by mid to late morning.

Sunday morning lows will not drop below 50 degrees. Then, we’ll see a range of temperatures Sunday afternoon, with highs near 60 or so in Huntsville to near 70 in Lake Jackson. Mid to upper-60s should dominate in the city. Monday’s front has minimal “oomph” behind it, so look for temperatures to only be a few degrees cooler Monday.

Look for rain totals to average a half-inch to an inch on Sunday and Monday, but it’s likely that some more localized spots see 2 to 4 inches of rain. This seems especially possible from northern Harris into Montgomery, Liberty, and Polk Counties, but it can’t be entirely ruled out elsewhere.

Rest of next week

I am assuming next week is going to feature a lot of continued clouds, so soak up the sun while we have it around. Isolated showers are possible Tuesday and Wednesday. There is growing consensus in modeling that a somewhat stronger cold front is going to push through later next week. This seems likely to feature another round or two of rain and thunder. The details are TBD, but it’s possible we double down on some heavy rain risk later next week. Stay tuned. Temps look mild next week, with highs in the 60s and lows in the 50s.