The SCW Q&A: Dripping faucets, storm or no?, I-10 divider, inconsistent apps, whither La Niña?

By the skin of our teeth, we’ve got the January SCW Q&A out the door. Many of the questions we got this month were – no surprise – inspired by our recent snowstorm.

Got a question of your own? Hit the Contact link in the blog’s header, or leave it in the comments below.


Q. The city asks people not to let faucets drip because it lowers water pressure. I understand there are ways to keep pipes warm, but how much does a dripping faucet actually help prevent pipes from bursting anyway? I’d rather have lower water pressure than broken pipes but wonder if letting faucets drip even helps much.

A. We get asked this question so often, and our standard response is: We are not plumbers. We are just not experts in this area. So we can offer some general thoughts, but you should really consult a plumber, and your water utility.

My best advice, as a homeowner in Houston, is to know where the main water shut-off switch is to your house, and if you’re concerned about freezing pipes, shut off the water supply and drain your pipes (i.e. run faucets until nothing comes out) before going to bed on nights when the temperature is expected to be below 25 degrees.

To drip or not to drip: That is the question. (Angelsharum / Wikimedia Commons)

As for dripping faucets, cities do not like that because it is not great for pump-based water systems. If too many people do it, it can reduce overall water pressure. If that gets too low, contaminants can get into the water supply, which can then result in a boil-water notice – and nobody wants that.

In unincorporated Harris County and those areas served by Municipal Utility Districts, it’s OK to drip pipes because water pressure there is generated by gravity – water towers and tanks – not pumps. During a freeze, your water utility will let you know what’s best.

So while homeowners may find comfort in dripping faucets, and many plumbers recommend it, be aware of what your utility is saying.

As my wife will attest, I am just about the least handy person on the face of the Earth when it comes to home maintenance.

– Eric

Q. Was it (January’s snow) really a “storm”? Traditionally, a storm is a violent event, typically bringing high winds, heavy precipitation, lightning, thunder, and other various tumults. While this event was unusual by Texas standards, it would barely have attracted notice in more northern locales. So my philosophically pedantic question is, does just being ‘unusual’ justify the use of the ‘storm’ moniker?

A. Ah yes, this is the kind of question we battle a lot in meteorology. Is it hot or warm? Cold or cool? A storm or just rain? And it gets to the heart of a more important question my colleague and friend Nick Lilja has asked, which is “What is severe weather, really?” Everyone has their own perceptions and definitions and to one-size-fits-all it is difficult.

But to the original question: The American Meteorological Society defines “storm” as a “disturbed state of Earth’s atmosphere, which can manifest itself in temperature, humidity, pressure, wind velocity, cloud cover, lightning, and precipitation.” Which seems to imply it’s OK to call our recent snow a “storm.” That is a really, really broad definition though. The AMS goes on to further define things. “Storms are organized disturbances that range in size from meters to a few kilometers (microscale, e.g., tornadoes), to a few to several hundred kilometers (mesoscale, e.g., mesoscale convective systems), to many hundreds of kilometers (synoptic, e.g., tropical and extratropical cyclones).” That still tracks with last week. So far so good.

Yep, looks like a storm to us. (Dwight Silverman photo)

The definition further goes on to read “Inclement and potentially destructive weather is often implied with a storm; threats can include heavy precipitation, flash flooding/river flooding, and high winds. From a local and special-interest viewpoint, a storm is a transient occurrence identified by its most destructive or spectacular aspect(s). In this manner we speak of rainstorms, windstorms, hailstorms, snowstorms, etc. Notable special cases are blizzards, ice storms, sandstorms, and dust storms.”

So from a meteorological and scientific point of view, last week’s snow was definitely a “storm.” Or more specifically a “winter storm.” But your mileage may vary. You may think a thunderstorm with frequent, intense lightning is very severe. By definition, lightning has nothing to do with a “severe thunderstorm,” which is strictly defined as a storm that produces one of one inch or larger hail, wind of 58 mph or stronger, or a tornado. Like any other definition in meteorology, there is a little vagueness to it from a human standpoint, and you’re not always wrong for thinking something is or isn’t a particular defined phenomenon.

Matt

Q. When you say south of I-10, do you mean Galveston? Or does that mean anywhere directly below I-10 (Montrose, Downtown, Medical Center, etc).

A. Great question, and it’s one we get often. One of the challenges of forecasting in the Houston area is that it is big! We are covering, basically, an area from Sealy in the west to Beaumont in the east, from Conroe in the north down to Galveston by the Gulf. Interstate 10 is a key dividing line we often refer to because a) most people know where it is, and b) it very roughly separates “coastal” from “inland” areas.

The Houston area is big. How big? This big! (Apple Maps screenshot)

However, with that said, there are distinct differences between, say, Hobby Airport and Galveston Island. So yes, “south of Interstate 10” does include Galveston, but it also includes half of this huge metro area. When we want to call out the coast specifically we’ll say “coastal counties” i.e. Brazoria, Galveston, and Chambers counties. When we seek to highlight only areas very near the Gulf, which includes Galveston Island, we’ll sometimes say “immediate coast.”

By the same token, when we write something like “far inland areas” we mean areas along and north of Highway 105. And when we write “a place that sucks” we’re referring to Dallas.

– Eric

Q. Could you explain why there are so many variations among weather apps? For example, the AccuWeather app shows (last) Tuesday being having a high of 38 while almost all the TV weather is showing Tuesday not going above freezing. If all meteorologists pull from the same info why such a wide difference in the forecasts?

A. There are a couple reasons for this. I’ve been doing this 20 years, and one thing I’ve said is tried and true: Put 20 meteorologists in the same room with the same data, and you will get 20 different forecasts. And I don’t mean widely varying forecasts; just a lot of differences in specifics.

But there are a couple areas where broadcasters, apps, and even the data we see on websites differs. Let’s say the high temperature occurs at midnight because a cold front is pushing through, but the daytime temperature is going to be 10 degrees colder. What’s the high temperature that day? What matters to you planning your day? Broadcasters, sites like ours, and the NWS website will all illustrate this either explaining it or by using arrows to indicate that something is changing that day. Your app almost certainly will not.

The Space City Weather app, as seen on a Mac.

But more important than that, every app uses its own special sauce. In other words, they are all deriving their forecasts from raw model data provided by NOAA, the European Centre (ECMWF), etc. They then work it through some proprietary algorithm that they’ve developed that essentially “bias corrects” the model data. They could be using the last week of verification, the last month, etc. Every app is different in that regard. I saw a presentation recently at the American Meteorological Society’s annual meeting in New Orleans from someone at AccuWeather that discussed this topic. One difference in their forecast is that their forecasters can actually go in and override data for a location or area if they have a strong conviction to disagree. Most apps do not come with that. I would assume The Weather Channel app does something similar.

So ultimately, each forecaster has their own opinion. For the apps, most of the “opinion” is bias correction of data, whereas for TV broadcasts or our comments, the opinion is based on our assessing the data and our past experiences. There will always be differences, but one reason I like our app is that it’s pulling forecasts straight from the National Weather Service. Their forecasts are usually solid and steady, and they’re derived locally. But as a consumer, I would always encourage you to shop around to get a sense of what everyone is thinking.

Matt

Q. I have a question- where did La Niña (warm and dry) go? Where do you think we’ll be Spring and Summer of 2025 – La Niña, El Niño or neutral?

A. According to NOAA’s most recent outlook, from late January, La Niña conditions are still present in the equatorial Pacific Ocean. Most modeling indicates that La Niña will persist through the spring before transitioning to neutral conditions. As for what happens after that, well, it’s kind of a crapshoot. Most of the guidance indicates neutral conditions lasting into the summer (and the Atlantic hurricane season). However, as we like to say here on Space City Weather, we’ll see.

Most recent forecast for ENSO. (NOAA)

I think you may be asking why have we not had a warmer and drier winter, which is typical during La Niña? To which I would say let’s see where the average temperature and rainfall end up at the end of February. I think it’s quite possible we end this winter with warmer than normal temperatures and near normal precipitation, which would be consistent with what one expects from La Niña. We’ll be sure to report back on that at the end of winter about a month from now.

– Eric

A fantastic mid-winter weekend awaits Houston

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.

By Monday we have a shot to begin hitting 80 degrees away from the coast. (Pivotal Weather)

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.

The potential for widespread low clouds and fog (purple) is rather high next Tuesday and Wednesday. (ECMWF model via Pivotal Weather)

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.

Showers and thunderstorms possible today as a front moves through

In brief: Houston faces the potential for a few thunderstorms as a cold front rolls through the area this afternoon. Once it moves offshore we’ll see several splendid, sunny days through the weekend. Next week looks warmer, and decidedly spring-like.

Thursday

A line of showers and thunderstorms associated with a cold front is near Austin and Waco this morning, and it will move steadily southeast toward Houston today. It is likely to reach areas west (Katy) and north of Houston (The Woodlands) by or before noon, and push off the coast by around 4 or 5 pm CT. For most of us, I expect these to be briefly passing showers, but some areas may see thunderstorms and damaging winds. Ahead of the front expect temperatures in the lower 70s, dropping 10 degrees after its passage. Lows tonight will fall to around 50 degrees in Houston.

Simulated radar reflectivity for 1 pm CT today. This is for illustration purposes only. (Weather Bell)

Friday

Sunshine returns on Friday, with much drier air. We’ll see gusty winds from the north, perhaps reaching about 20 mph, during the daytime. Highs will likely rise to near 70 degrees. As winds die down we’ll see our coldest night on Friday night, as temperatures dip into the 40s by Saturday morning.

Saturday

This will be a fine day for just about anything. Expect low humidity and high temperatures of about 70 degrees. Skies will be clear and sunny, with light winds. Lows on Saturday night will fall to around 50 degrees in Houston, with cooler conditions further inland.

Temperatures on Saturday morning should be the coldest of the forecast period. (Weather Bell)

Sunday

As the flow turns more southerly, conditions on Sunday will be a tad warmer, with highs perhaps reaching the mid-70s. Skies will remain sunny, however. Lows on Sunday night will only drop to around 60 degrees in Houston.

Next week

This will be the warmest week of 2025 so far, and feel much more spring-like than winter-like. Expect highs in the mid-70s to 80 degrees, with a mix of sunshine and clouds. With dewpoints in the 60s it will feel modestly, but not oppressively humid. Nighttime lows will be in the 60s. There probably will be some scattered showers on some of the days, but I don’t see a huge signal for any rain showers. It does look like some sort of front arrives by next Saturday or Sunday to cool us down, and remind us that it’s still February. My guess is that it knocks lows back into the 40s, but we’ll just have to wait and see.

Houston turns warmer and muggier for a couple of days before clear and cooler weather this weekend

In brief: There’s a little something for everyone in today’s forecast. We’ve got clouds and some rain during the next couple of days before a nice stretch of sunny and low-humidity weather to take us through the weekend. Only thing to watch for is the low-end potential of some storms on Thursday afternoon.

Wednesday

It’s a fairly dreary morning outside, with light, misty rainfall and areas of fog. This drizzle and fog may persist for much of the morning before we’re simply left with a layer of clouds. With a warmer, southeasterly flow in place we can expect temperatures to warm to about 70 degrees this afternoon, with increasing humidity levels. A chance of drizzle remains overnight, as lows only drop into the lower 60s.

NOAA storm outlook for Thursday and Thursday night.

Thursday

This will be a fairly warm day, despite the cloudy skies, as high temperatures rise into the mid-70s with humidity to match. Some scattered showers will be possible during the morning hours, along with gusty southeasterly winds. During the afternoon, a cold front will approach the area, likely reaching Katy and Tomball an hour or two after noon. What I think we’re likely to see is a broken line of showers that may possibly fill in as it moves through Houston during the afternoon. There is a slight chance of some severe weather with the front, and this is most likely to occur as it passes to the east of the Interstate 45 corridor. This includes the potential for severe thunderstorms or damaging winds. (There is a very low-end chance of hail or a tornado). For most of us, the front should be a fairly modest event, with drier air moving in behind. Lows will drop into the low 50s on Thursday night with clearing skies.

Saturday morning looks to be the coldest of the week. (Weather Bell)

Friday, Saturday, and Sunday

Sunshine is back on the menu, along with a nice slug of drier air and sunshine. Winds from the north will be a bit gusty on Friday morning, but should back down after that. We’re looking at highs on Friday and Saturday of around 70 degrees, with temperatures at night falling into the mid- to upper-40s. Sunday will be a little warmer, with highs in the lower- to mid-70s, but still with plenty of dry air. I can’t wait to take a long bike ride and soak up some sun.

Next week

The atmosphere turns a bit messier next week, but generally I expect we’ll see warm, partly sunny days with highs in the 70s, and nights with lows around 60 degrees. There may be some slight, daily rain chances. Some kind of front works its way toward Houston by the weekend, but an Arctic blast it will not be.