One of the year’s last summer-like weekends lies ahead

Good morning. Houston will see one more partly to mostly cloudy day before a string of mostly sunny days. Temperatures will likely reach the low 90s during the coming period, but we’re increasingly confident that some sort of front will make it through our area during the middle of next week. How strong? We’ll have to wait and see.

Thursday

Although Nicholas has dropped below tropical depression strength in Louisiana, we’re continuing to see wrap-around clouds and light northerly winds from the system. This will contribute to another mostly cloudy day, and should help to keep highs in the mid- to upper-80s for most of the area. A little bit of misty rain is possible, but most of us should remain dry. Lows tonight will drop into the mid-70s.

Friday

We’ll see a mix of sunshine and clouds on Friday, and the return of light southerly winds temperatures will probably nudge up to around 90 degrees. We can’t rule out a passing shower, but any rain should be fairly isolated and fleeting.

NOAA rain accumulation forecast for now through Sunday. (Weather Bell)

Saturday and Sunday

The weekend should see mostly sunny skies with highs in the neighborhood of 90 degrees. Some showers will be possible as moisture from the Gulf of Mexico increases, but rain chances on both days are probably only about 30 percent now. This should be one of the last truly summer-like weekends of 2021, so if the beach is your thing, do your thing.

Next week

We’ll remain in a summer-like pattern through about Wednesday of next week. After that time it does look like some sort of front will push through, although whether its the “upper 60s and some drier air” kind of front or something more like “60 and unbelievable” is yet to be determined.

Tropics outlook for Thursday morning. (National Hurricane Center)

Tropics

There’s nothing for the Gulf of Mexico to be concerned about now, or likely for at least the next several days. The end of the tropics season for Texas is near, but we’re not ready to make that call yet.

Houston’s weather to return to a more typical late-summertime pattern

Good morning. After a week of all-Nicholas, all-the time, we’re returning to a period of more normal late-summertime weather in the Houston region. As for the hurricane, it’s now a tropical depression nearing southwestern Louisiana, and should soon dissipate. After more clouds today our weather will turn more sunny, and highs around 90 degrees likely return for the weekend.

Wednesday

Some very light rain has fallen across parts of the area overnight, and additional spotty showers will be possible later today. But for the most part, this should simply be a cloudy day with moderate high temperatures of about 80 degrees. As we’re on the backside of Nicholas, winds will be out of the north or northwest for much of the day at 10 to 15 mph. Tonight should be mostly cloudy and pleasant, with lows dropping to around 70 degrees in the city.

High temperatures today will be near 80 degrees for most of Houston. (Weather Bell)

Thursday and Friday

Skies should start to become at least partly sunny on Thursday, and this will help to push highs into the mid- to upper 80s tomorrow, and possibly as high as 90 degrees on Friday. Rain chances for both days are low, perhaps 20 percent, but not non-existent.

Saturday and Sunday

After a few days of a drier overall flow, we’ll start to a see a more pronounced return of moisture from the Gulf of Mexico this weekend. This will result in rising rain chances, but I think there’s still a shot for mostly sunny skies on Saturday. Highs are likely in the low 90s. Even if most of us get through Saturday without too much rain, showers probably become more widespread on Sunday, with perhaps two-thirds of the area seeing some rain. Accumulations shouldn’t be huge, perhaps one-quarter to one-half inch for most.

Next week

Daily shower chances remain in the forecast through the middle of next week, with highs likely settling out in the upper 80s to low 90s. At that point we’re going to be looking for our first “fall” front of the season, which knocks temperatures below 65 degrees in Houston. It’s possible that is coming around next Thursday or so, but at this point we have no guarantees. But I’m ready. I suspect you’re ready as well.

Tropical outlook for Wednesday morning. (National Hurricane Center)

Tropics

The tropics remain very active, which is usual for this time of year. But we’re getting closer to the end game for the Texas coast, in terms of hurricanes. And while there is the potential for a few tropical systems to develop this week, none appear likely to trouble the Gulf of Mexico (even that ominous looking red blob in the eastern Atlantic). I suspect you’re OK with that as well.

It may not feel like it, but Houston narrowly escaped a much worse fate from Hurricane Nicholas

Well, they don’t call them natural disasters for nothing. For some residents, of course, last night was but a breezy affair. For others, especially along the coast, there is substantial wind and flood damage to contend with this morning from Hurricane Nicholas. And then there are the half a million customers in the greater Houston region without power this morning.

For those of you recovering today—and I count myself among you as power went out in my neighborhood, trees are down, my backyard flooded—it may not feel like it, but this storm could have been so so much worse. With this post I want to discuss that, but first lets update the status of Nicholas and present a short-term forecast.

Tropical Storm Nicholas

As of 10am CT, the center of Nicholas is very nearly directly over Houston, located just 10 miles southeast of downtown. As it has moved inland for nearly 10 hours, Nicholas has weakened to a storm with sustained winds of 45 mph. The storm is moving slowly, the northeast, at about 6 mph. It should continue to turn more easterly, and then dissipate over Louisiana in two or three days. The main rainfall threat has moved east, and the southern half of Louisiana could see 6 to 10 inches of rainfall over the next several days.

Nearly all of the moisture associated with Nicholas is now east of Houston. (NOAA)

Short-term forecast

The forecast for today and Wednesday will allow for recovery in the greater Houston area. Some light, scattered showers will be possible today and Wednesday, but chances are fairly low and accumulations should be slight. The strongest winds, too, have moved east of the area despite the presence of Nicholas’ center.

If you’re without power, high temperatures today will be quite reasonable for this time of year, in the upper 70s. Humidity will be high, of course. Lows tonight will drop into the low 70s. Highs on Wednesday should reach the mid-80s with a mix of sunshine and clouds.

If you want a more hopeful thought, we’re seeing fairly strong hints in the models for a decently strong fall front moving into the region in nine or ten days time. That’s a long way out to forecast, so grain of salt and all that, but it is the right time of year for a front. So maybe, hopefully, fall is but 10 days away. I’m ready.

Nicholas could have been so much worse

First of all, if you can remember all the way back to Saturday, I presented three different scenarios for Nicholas’ track and eventual flooding in Houston. The first of these was the “Coast Hugger,” in which the storm remained close to the Gulf, brought 2 to 4 inches of rain to Houston and higher amounts along the coast, while keeping the heaviest rains offshore. This is largely what happened, with Nicholas remaining very close to the coast even after moving inland. If we look at satellite-derived precipitation totals for the last three days, the heaviest swath of 10-20 inches of rainfall came offshore.

Satellite estimated rainfall totals for Nicholas during the preceding 72 hours. (NOAA)

A track even 40 or 50 miles further inland would have set up those heaviest rains directly across the Houston metro area, and created a much more serious flood situation. Hopefully this offers you some insight into the challenge of predicting these kinds of rain events. It was a very close call, a matter of miles, between significant inland rainfall flooding in Houston, and relatively clean bayous this morning.

The second factor is wind. Nicholas turned out to be a fairly nasty storm in terms of wind gusts, and pushed a larger storm surge—as high as 6.1 feet into Clear Lake—than predicted. This is a reminder of the power of a hurricane, even one that was “only” a minimal Category 1 storm. The truth is that the track of the storm was very nearly a worst-case one for Houston in terms of winds and putting a maximum storm surge across Galveston Island and into Galveston Bay.

Image showing approximate track of Nicholas, with winds and surge overlaid. (NOAA)

It is September 14, the absolute peak of hurricane season in the Atlantic, and a time when sea surface temperatures in the Gulf of Mexico are at their warmest of the year. So this morning I’m thinking about what would have happened if we had not had some wind shear over the western Gulf of Mexico yesterday, or if Nicholas had been able to consolidate a more well defined and consistent center of circulation. It would have been much, much worse for all of us had a significantly stronger hurricane made landfall last night. So while we pick up the pieces this morning, realize Nicholas could have been much more of a terror.

Matt will have our next update—and probably our last update specific to Nicholas—at 5 pm CT today.

Nicholas makes landfall south of Houston, will pass over the city later this morning

Hurricane Nicholas made landfall at 12:30 am Tuesday on the eastern part of Matagorda Peninsula, about 10 miles west of the small city of Sargent. It had maximum winds of 75 mph at landfall. The storm is moving about 10 mph to the north-northeast, and along this track the storm should pass almost directly overhead Houston on Tuesday after sunrise. After that it should turn more to the northeast.

Winds

We’re starting to see wind gusts above 60 mph along the coast of Galveston Island, and we expect to see gusts in the 40s and 50s spreading inland over night. So far power outages in coastal counties range from about 90 percent of customers out in Matagorda County, closest to Nicholas, to about 20 percent in Brazoria County, to 10 percent in Galveston County. Further inland, Wharton and Austin counties have significant outages. More can be expected as Nicholas moves closer to Houston and Harris County this morning.

Forecast for maximum wind gusts through sunrise on Tuesday. (Weather Bell)

Rains

So far tonight we’ve seen a thick band of rain showers moving inland from Nicholas, and while the rains have been heavy they have not been excessively so. These rates of generally less than 2 inches per hour are helping to moderate totals. Overall accumulations through Tuesday should be 2 to 8 inches for coastal counties near Houston, with potentially more rain east near Beaumont as Nicholas tracks inland and slows down. Here is the latest rain accumulation forecast from NOAA for now through Wednesday morning.

NOAA rain accumulation forecast for now through Tuesday night. (Weather Bell)

For the Houston area, it’s likely that the heavier rainfall will wind down between sunrise and noon on Tuesday, with lesser chances afterward. Winds should die down as well. A sense of normalcy should return to our weather by Tuesday afternoon.

“Dirty” side of the storm

We often talk about the “dirty” side of a hurricane, which is located to the right of a storm’s center. This is where the strongest winds, rains, and surge typically lie. And this evening as Nicholas was moving into the Texas coast, its radar signature provided a textbook example of all the activity falling on the east side of the storm, with virtually nothing occurring to the west of the center.

Radar signature of Nicholas, with the center highlighted, shows the “dirty” versus “clean” side of the storm. (RadarScope)

Matt will have our next update by or before 5:30 am CT.