Two more hot days before a major change in Houston, partly clear skies for Perseids tonight

Houston has now had four consecutive days of 100-degree or warmer weather, and I’m afraid we’re going to have to suffer from the heat for a little bit longer before some relief arrives. But more moderate (for August) weather is indeed coming, and it should be here by the weekend.

Today and Friday

For most of the Houston area—with the exception of far eastern portions of the region—high pressure should remain more or less dominant through Friday. This means we’ll see the possibility of a few stray afternoon showers and thunderstorms, but the main story will remain heat, and lots of it. We’ll have a decent chance to hit 100 degrees both days, and low temperatures will remain pretty brutal as well, likely falling only to about 80 degrees. A heat advisory remains in effect.

Saturday

By Saturday we’ll see a transition of sorts. High pressure should weaken, and a cool front will move into northern Texas. Meanwhile, off to the east of Houston, a potent low pressure system will be bringing lots of rain to Louisiana. Houston should see some energy from the front (not particularly cool air, unfortunately) and moisture from the Louisiana system. They should combine to produce highs in the mid-90s, with a 30 to 40 percent chance of rain.

Sunday through Wednesday

By Sunday we should be in the midst of a full-blown pattern change, with highs most days in the low 90s, mostly cloudy weather and good daily rain chances. At this time it doesn’t look like the area will see any extreme rainfall, although there almost certainly will be some thunderstorms. Hopefully we just get about 1 to 3 inches across most of the region, taking the edge off of our burgeoning drought conditions.

Higher rain accumulations are more likely on the east side of Houston. (Weather Bell)
Higher rain accumulations are more likely on the east side of Houston. (Weather Bell)

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Houston to remain in the grip of excessive heat for a bit longer

The greater Houston region saw a rare “excessive heat warning” on Tuesday as low-level moisture stayed put during the afternoon hours, allowing heat indices to briefly exceed 113 degrees. Such conditions will remain for a couple of more days before clouds and increasing rain chances finally bring some relief to the area.

(National Weather Service)
(National Weather Service)

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Houston has reached peak summer—it’s all downhill from here

We’ve previously discussed why summer peaks so late along the Texas coast, a phenomenon known as seasonal lag. But now we’re finally here. For Houston’s official weather station, Bush Intercontinental Airport, today is climatologically the warmest day of the year. For Hobby Airport, it’s August 10. For College Station it’s August 11, and for Galveston its August 13.

Peak summer in the United States, by location. (Brian Brettschneider)
Peak summer in the United States, by location. (Brian Brettschneider)

 

Peak summer is here, and that means it can finally go. Unfortunately, it’s going to go slowly. (Thanks to Brian Brettschneider for the data).

Today through Saturday

Houston hit 100 degrees on Monday, marking the fourth time this year we’ve hit the century mark. Unfortunately this pattern of very hot days with highs in the upper 90s to near 100 degrees is not going to change this week. We’re going to see hot weather, partly to mostly sunny days, with some scattered showers mainly during the afternoon hours. Summer in Houston is to be survived.

Accordingly, a heat advisory is in effect for today, and will likely continue so through Saturday.

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Hurricanes—Why do they go where they go?

It’s been nearly eight years since the last significant tropical system (Ike) impacted the greater Houston region. So understandably, when NOAA’s National Hurricane Center began tracking the tropical wave that became Hurricane Earl, the region became a little jumpy. Was it, after a record-breaking “hurricane drought” in the Gulf of Mexico, our turn again?

In the end, Earl came nowhere near Houston, instead making landfall as a Category 1 hurricane in Belize. Nevertheless we thought it worth discussing the factors that control the path a hurricane takes, so that the next time a system threatens the Gulf of Mexico we’ll all have a little more knowledge, and perhaps be less susceptible to any hype.

First advisory issued for Tropical Storm Earl on August 2nd, 2016 (Courtesy NWS)
First advisory issued for Tropical Storm Earl on August 2nd, 2016 (Courtesy NWS)

 

The graphic above is a version of the one we’re all familiar with—it shows the location of then Tropical Storm Earl at the time of the advisory, its projected track and intensity, the forecast cone, and any watches or warnings. Arguably, the most important information in this graphic is the track of the storm, because it (obviously) tells us where the storm is headed, and who will be potentially impacted.

What controls where a hurricane goes?

There are two main forces that control where a hurricane goes—the environment, and something called “beta drift”. The environment around a hurricane is the main force behind the direction the storm goes, “steering” it in one direction or another. The primary environmental steering for storms that form in the deep Atlantic tropics—these are the systems that move off Africa and spin into tropical lows—consists of the east-to-west moving trade winds, which drive storms across the Atlantic and toward the Caribbean and the Gulf of Mexico.

Diagram showing typical tracks of North Atlantic hurricanes (courtesy NOAA)
Diagram showing typical tracks of North Atlantic hurricanes (courtesy NOAA)

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