18Aug

Houston’s hot, but all eyes on Monday’s eclipse forecast

Lots to get to today, including Monday’s eclipse and the tropics. But first, we have some breaking news: August in Houston is brutal. It continues in 2017 like almost every other August. Our last 5 days have seen high temperatures of 97°, 96°, 97°, 96°, and 97°. By that metric, today should see a high temperature of 96°, right? Potentially. These temperatures, while blistering hot, aren’t a whole lot hotter than normal. But when combined with the humidity, it’s felt pretty terrible. This will mostly continue.

Today & Weekend

Lather, rinse, repeat. This forecast should be pretty straightforward. Expect sunshine and hot, humid weather. High temperatures will top off in the mid or upper 90s. We’re running just a little cooler this morning than we have seen lately, so perhaps we can avoid more Heat Advisories today or tomorrow. Regardless of whether we do or not, take it easy outdoors. An isolated downpour is entirely possible on any given afternoon in one or two spots. The best chance for this would probably be on Sunday.

Monday & Eclipse

The more I watch Monday’s forecast the more I get a little uneasy. Now, I still think the vast majority of the region will have a fine opportunity to view our partial eclipse. But I’m watching a tropical wave and upper level low moving across the Gulf early next week. The timing of the arrival of the leading edge of this disturbance is Monday afternoon. Models insist the best available moisture for the most clouds will remain out over the Gulf to our east. That’s encouraging. So for now, we’re going to continue to spin the forecast optimistically. Yes, a chance of a downpour or thunderstorm will exist in the area, especially south and east of Houston by eclipse time. But I suspect we aren’t going to see too many serious clouds. So, I feel optimistic, but we’ll be watching the evolution of this forecast closely through the weekend.

(Space City Weather)

Elsewhere across East Texas, other than passing cumulus clouds, it looks pretty good. For those of you traveling to another state, here’s an update:

Green and purple on this map indicates the best chance for clouds and/or showers during the eclipse. (Weather Bell)

Washington, Oregon, and Idaho may see some low clouds or haze issues in spots, but Wyoming and western Nebraska look good. Eastern Nebraska into northwest Missouri has the best shot at cloud cover it appears. Conditions should improve near the peak eclipse spots of southern Illinois and Kentucky. A few showers may be possible in the Southeast, but I suspect they’ll be hit or miss.

An early look at solar eclipse weather

Locally, the weather this week will be pretty standard for mid-August. It’s going to be hot. There will be a few opportunities for storms, but the majority of the week will see the majority of Southeast Texas dry. More on this in a second. First, let’s talk solar eclipse.

Eclipse outlook

We’re one week from one of the most talked about astronomical events in the U.S. in a long time. It’s certainly exciting, and understandably, there’s demand for eclipse weather forecasts. So, we’ll be happy to offer up our opinions here. First, locally, I think we look pretty standard in terms of thunderstorm chances. Odds are it will be partly to mostly sunny with just a few developing showers, mainly south and east of downtown Houston.

The initial outlook for eclipse viewing in Houston looks pretty typical for mid to late August: Sun, some passing clouds, and developing showers southeast of town.

The good news is that, assuming standard summer weather here in Houston, you probably won’t have to drive very far to get out of a downpour and into sunshine. All in all, I’m optimistic on our weather for the eclipse right now. We’ll keep you posted.

Some of you may be considering traveling into the path of totality of the eclipse, which stretches from Oregon into Wyoming across Missouri and offshore from South Carolina. We take a crack at things here, using some major cities along the path (Hopkinsville and Carbondale are the approximate locations of the greatest eclipse and longest duration of the eclipse respectively).

It’s a bit early to pin down exactly how things will look, but initially, the greatest chance of disappointment may be on the eastern edge of the eclipse path over the U.S., in South Carolina. This can certainly change, however.

Based on a brief look at the weather models for next Monday around the time of the eclipse, the best chance of rain may be in the Carolinas. Models disagree further west (including Nashville, Hopkinsville, Carbondale, and St. Louis), with a chance of rain showers potentially. For now, I’d spin it optimistically. I don’t see any reason to be overly nervous in any given place. I am watching a band of cloud cover showing up on some models from northern Colorado into Wyoming and perhaps the Plains (think Lincoln, NE & Kansas City). Again, it’s quite early for a precise cloud cover forecast, but we wanted to offer up an early opinion for you. Look for further updates this week.

Dog days of Houston’s summer to roll along

Houston officially clocked in at 97° on Thursday, registering our hottest day since way back on July 29th, when we hit the century mark. So, yeah, summer is back in style. And it’s not going to be in any hurry to let go.

Today & Weekend

We’re gradually settled back in to a typical late summer pattern of high heat, high humidity, and at least a handful of showers and storms each afternoon. For today, a Heat Advisory has been issued for the Houston metro area, Galveston, and College Station. Heat index values near 110° at times will be possible this afternoon. Actual temperatures today will top off in the mid or upper-90s.

It never hurts to reacquaint yourself with the symptoms of heat stress. (NWS)

Meanwhile, as showers and storms go, it appears today will see the highest coverage this weekend, which is to say it will be fairly similar to how Thursday ended up. Expect scattered noisy storms by mid-afternoon spreading inland from the south and east. Some folks see nothing, others may see an inch or two in some downpours. No serious trouble is expected. On the whole, we’ll call it about a 30 percent chance of storms today.

The going forecast for Saturday and Sunday is mainly sunny and dry. That said, in my experience, I wouldn’t be entirely floored if storm coverage is a bit higher than expected. I’m not talking a washout or anything, but I am talking about keeping an umbrella handy, just in case. We’re not in a strong, stable dry and hot pattern just yet. So there’s still enough opportunities for some storms to pop up. And I think it’s at least worth a mention.

Temperatures will top off in the mid-90s this weekend as well. While heat indices may be a bit lower Saturday and Sunday than we’ll see today, it will still get uncomfortable at times. Be sure to drink plenty of water and take it slow outdoors.

Rains tonight likely east of Houston

We aren’t quite done with rains yet in the Houston area, but there is some good news at least.

Taking a look at the satellite imagery from the still-not-quite-operational GOES-16 satellite this afternoon, you can see a “swirl” in the clouds over Southeast Texas. Specifically, this swirl is centered over southeast Montgomery County.

Preliminary and non-operational GOES-16 imagery shows a “swirl” in the clouds north of Houston. The system responsible for last night’s flooding has moved a bit farther east today. (University of Wisconsin SSEC)

This is the mesoscale convective vortex (or MCV) that’s been partially responsible for the mayhem across Texas the last couple days. This was over the Brazos Valley yesterday evening, and the heavy storms tend to develop on the eastern flank of these things. With that roughly over Spring now, that would seem to imply that widespread storms and rain tonight will probably develop east of I-45 and east of the hardest hit areas from this morning. That’s the good news.

In fact, we have some validation for this from the HRRR model, which did an acceptable job with the setup last night.

The HRRR model shows more widespread showers & storms mainly east of Houston tonight. Still, it’s close enough that you should stay aware of the weather tonight. (Weather Bell)

This suggests, yes, perhaps some scattered downpours around Houston this evening and tonight, but the sustained, heavier rains that could cause problems will probably be east of Houston, lined up roughly on an axis from Galveston through Winnie into Beaumont. Those areas can handle a little more rainfall than, say, Katy or Jersey Village can. Still, if you live in Galveston or Baytown or east of Houston, obviously you’ll want to stay alert tonight. And even if you live in Houston, it’s smart to remain cognizant of the situation. Though it’s unlikely we see a repeat of what we just went through, it’s always a good idea to stay weather aware during these heavy rainfall patterns.

A Flash Flood Watch is in effect for Harris, Chambers, Montgomery, Liberty, Polk, and San Jacinto Counties through Wednesday morning.

The bottom line? A repeat of this morning is not expected in Houston tonight. Areas east of Houston stand the best chance of heavy rain tonight. Regardless, in Houston and east of Houston, it’s a smart idea to stay aware of the weather tonight and Wednesday morning.

Posted at 2:55 PM Tuesday by Matt