Eric Berger

In brief: After a wetter and cooler start to summer major changes are coming to Houston’s weather. Also, our days are now getting shorter!

Sunday, the summer transition day

Sunday marked the summer solstice, the day when the Sun reaches the highest point in the sky. Slowly, now, our days will start to get shorter. If you’re keeping count, today will be about two seconds shorter than Sunday. This process accelerates until the autumnal equinox, in September, by which point we are losing 1 minute, 45 seconds of daylight every 24 hours.

Sunday also marked an important transition day for our weather. Up until this point our average high temperature this month has been below 90 degrees. This is largely because, for a majority of days this June, we have received at least a smidgeon of rain. On some days, the showers have been absolute downpours. Over the last 30 days the majority of the Houston area has picked up 8 to 16 inches of rainfall, more than twice as much as normal. The clouds and rains have kept a lid on daytime highs. Some days it has been, dare I say—almost—nice outside?

That will now change abruptly, with the arrival of high pressure. Houston is unlikely to see any rainfall for at least the next seven days. And far from daytime highs in the upper 80s, we’re much more likely to see highs in the mid-90s. We are shifting from early summer, which had a good run, directly into Mid summer.

Monday through Friday

There’s really not much of a forecast to make with high pressure in control of things. High temperatures this week will, each day, reach into the mid-90s in Houston. Coastal areas will be a few degrees cooler, and inland areas a few degrees warmer. Winds will be light in the morning, with afternoon gusts reaching about 20 mph from the south.

Humidity will be high, but not quite as high as we experienced late last week. Overnight lows will generally fall into the mid- to upper 70s. Skies will be mostly sunny, but we’ll likely see some clouds during the morning hours before everything clears out. Daily rain chances will be about 10 percent, or less. In short, it will very much feel like summer in Houston.

Saturday or Sunday

Probably nothing changes. If I squint maybe there’s a slight chance of rain on Saturday or Sunday, but probably not. Highs likely remain in the mid-90s or thereabouts.

Next week

With these high pressure systems the question is always when things break down. For now, that does not seem likely before the end of June. But possibly we may see some showers return by the middle of next week. But then again, it’s just as likely as they will not. Welcome to Houston summers yall. When it’s not flooding, the heat is next level.

In brief: We are issuing a Stage 1 flood alert for Saturday due to the possibility of slow moving storms capable of producing rainfall rates of 1 to 2 inches per hour. Activity should wane this evening, with less coverage on Sunday.

After a fairly quiet start to the day, we are seeing storms firing up along an area of convergent winds near the coast. At 11 am CT these storms have formed roughly along a line from Bay City to Pearland to Clear lake to Baytown. The heaviest of these storms may briefly produce rainfall rates of 1 to 2 inches per hour.

So what will happen during the rest of today? Our high resolution modeling guidance has not been, to put it politely, great. But given the high levels of precipitable water (well above 2 inches for most of the region) we are now leaning toward a fairly active day today in terms of showers and thunderstorms. Some parts of the metro area will get hit, while others just hear distant thunder. Because some of this activity may be slow-moving, we are going to issue a Stage 1 flood alert through this evening, which indicates the possibility of street flooding.

Creeks and bayous across the Houston region are generally in good condition, so we don’t expect more than nuisance flooding (that is, streets, feeder roads, etc) for today. But this activity could definitely put a damper on outdoor activities. Beyond heavy rainfall there is the threat of thunder and lightning, but no real indication of severe weather such as damaging winds or hail.

Our expectation is that storm activity will begin to wane this evening and then should die off overnight. Rain chances should be lower on Sunday, probably in the vicinity of 20 percent. Rain chances next week will be near zero, with sunny skies and highs in the mid-90s (at least) as high pressure asserts control. So if you’re tired of the rain, its end is at hand. Just not quite yet.

In brief: We talk about why, when Arthur’s center was closest to Houston on Wednesday evening, its winds died off. Also, we look ahead to calmer and hotter conditions for the next couple of days, and some rain chances over the weekend.

Looking back at Arthur

Can we agree that it was an odd storm?

Here’s the National Hurricane Center forecast for the position of its center at 4 pm CT on Wednesday, along with a track forecast.

I received a couple of messages yesterday afternoon from readers asking if they should be concerned about this updated track because, as you can see, the center of the storm is forecast to pass directly over Houston on Wednesday evening. And if this were a typical tropical storm or hurricane, the answer would be yes. But I replied no, nothing really had changed with our forecast because the winds and rains associated with Arthur were located hundreds of miles to the east

In the graphic below you can see that the winds in Bay City, where the “center” of Arthur was located at the time, were almost dead calm. And while there were some fairly strong wind gusts at the time associated with Arthur, they were a couple of hundred miles distant from the center of circulation.

This can happen with weak tropical systems that have fairly poor defined centers of circulation. But it made for an odd situation on Wednesday during which Arthur’s strongest winds came several hours before the center of the storm itself arrived. A similar phenomenon happened with its rains, which were even further removed from the center.

Anyway, Arthur has dissipated and we can all hope this is the only named storm that makes “landfall” in Texas this year.

Thursday

We’re going to see a much calmer day. Mostly cloudy skies this morning should give way to mostly sunny skies this afternoon, with high temperatures reaching the low- to mid-90s for most of the Houston metro area. With dewpoints near 80 degrees, the humidity will be something fierce. Winds will be from the south at about 10 mph today, gusting up to 20 mph this afternoon. Low temperatures tonight probably will not fall below 80 for most of the region, so prepare to sweat. Rain chances are basically zero.

Friday

This should be a similar day to Thursday in terms of temperatures and humidity. There may be a few more clouds in the sky. By Friday evening a weak front (it won’t make it to Houston) will be dropping down from north Texas. This could serve as a focus for some isolated showers and thunderstorms from Friday evening into Saturday.

Saturday and Sunday

I expect skies to be partly to mostly sunny this weekend, with high temperatures generally in the lower 90s. Where we have some uncertainty is in the rain department. The aforementioned dying front could generate some additional showers and thunderstorms on Saturday in the Houston region, perhaps most likely north of I-10. I would put overall rain chances at about 40 percent during the morning and daytime hours, but I don’t have supreme confidence in the forecast at this point. There is a higher likelihood of Sunday remaining rain free.

Next week

By the end of the weekend we should see high pressure taking control of our weather, and this will hold sway for much of next week. We are looking at a sustained stretch of sunny skies and high temperatures in the mid-90s. It won’t be peak summer by any means, but it will likely be the warmest period of weather so far this year for Houston. These temperatures will also coincide with some of the longest days of the year, so be sure and use Sun protection.

In brief: Just a short update to note the formation of the Atlantic season’s first named storm, Arthur, and what it means for Houston today. In short: rains ending, but the next several hours will be windy near the coast.

Hello, Arthur

The Atlantic season’s first named storm, Arthur, has formed less than 100 miles from downtown Houston. Although that may sound concerning, we’re here to tell you it’s really not.

Our biggest concern from this system has been the potential for heavy rainfall, but that risk is now rapidly diminishing. The bulk of the precipitation from Arthur is falling well to the northeast of its center, and most of this is offshore. The scattered showers we are seeing across Houston as of 10 am CT on Wednesday will continue to diminish. We are likely to be rain free from the middle of today through Friday evening. For this reason we are ending our Stage 2 flood alert.

The biggest impact from Arthur is being felt right along the coast. Its sustained winds have been measured at 35 mph, or higher, along Galveston Island, with some gusts up to 50 mph. This has, frankly, exceeded our expectations. Even areas as far inland as Hobby Airport have recorded gusts up to about 30 mph. These winds should start to ease by this afternoon as the center of Arthur nears Galveston and starts to move away. After that we expect calm and sunny, albeit hot, conditions on Thursday and Friday.

We’ll have a full forecast for you, per usual, on Thursday morning.