Matt Lanza

The tropics are beginning to resemble what is more normal for this time of year, but the good news at least for us is that there’s nothing of immediate concern on our radar. We will start to pick up the cadence a bit, however.

Tropical outlook in a sentence

While no activity is anticipated to directly impact Texas, there are several disturbances we will be watching over the next week or so.

Invest 97L

The first item up for discussion is Invest 97L, way out in the deep Atlantic. Recall, invests are just a naming convention for disturbances that the National Weather Service believes merit further investigation. They cycle from 90 to 99 and then repeat. It allows us to see more data, input better data into our regular weather models, and see some initial runs of specialized tropical models on the disturbance.

In this case, Invest 97L is chugging along southwest of the Cabo Verde Islands.

The satellite image above does not inspire much enthusiasm for this disturbance at this point. It has a minimal amount of thunderstorm activity (convection) around it, and it seems to be struggling a bit in a rather hostile Atlantic environment. If the first batch of wind shear near it does not completely shred it, the second batch just east of the islands probably will.

With this sort of wind shear around right now, it would seem that anything coming west is going to struggle. Weather models are split on how this looks over the next week or two, with the GFS knocking back the shear some, and the European model keeping the party going. But as long as this shear is in place, it’s good news for us with respect to anything coming off Africa.

The starting lineup

Speaking of, the “wave train” predicted to emerge off Africa is rather congested right now. We have two in line to emerge over the next week or so, and there’s a third in eastern Africa that should emerge sometime next week.

While these disturbances are lined up and ready to play in the Atlantic, again, the wind shear story is one that will have to change for any of them to have a chance. It’s also somewhat notable that there’s a pretty healthy gap between the first two disturbances and the third one. Quiet in late August would be rare. All in all, you probably couldn’t paint a better picture right now in the Atlantic; some activity to watch but nothing imminent.

Gulf update

Seasons like this can lull you to sleep, but I want to just close today with a look at the Gulf. Because of the situation in the Atlantic, the most risk in Texas for the rest of August may come from something much closer to home in the Gulf. Do we see anything worth watching? The short answer is no.

The longer answer is that we have a couple fronts trying to nudge their way to the coast over the next week or two that we should probably keep a side eye on. But at this point in time, there’s nothing signaling anything of legitimate concern.

We officially topped off at 101° yesterday for the third straight day, but we think the next few days will feature more tolerable temperatures, as rain chances inch upward. And it’s needed, as drought has expanded across the Houston area with 12 percent of the area in exceptional drought (level 4/4).

This was underscored by the deadly grass fire in the Cypress area yesterday. Grass fires can happen in the Houston area, so please use caution, even if you get a good bit of rain in the coming days.

Today

With a disturbance in the middle levels of the atmosphere moving toward Matagorda Bay, we are already seeing numerous showers and storms develop — over the Gulf.

As the day goes on, we’ll see rainfall expand onshore. I still don’t think everyone will see rain today, but most places near the coast should see showers, with more scattered coverage as you go inland from there. Storms should move slowly but steadily today, so areas with the most persistent rains could see an inch or two, while some neighborhoods will only hear distant thunder. But coverage will be greater than it has been in recent days.

With clouds and showers nearby, look for highs ranging from the upper 80s at the coast to low 90s in Houston to middle or upper 90s to the north and west.

Weekend

We’re going to maintain pretty healthy rain chances into Saturday. Again, not everyone will see rain tomorrow, but there should be coverage along the lines of what we see today; initially at the coast in the morning, spreading inland as the day progresses. Rain totals will range from nothing to an inch or two in the most persistent or slowest moving storms. Morning lows in the 70s will give way to daytime highs similar to today, with upper-80s to low-90s for Houston south and east, building to the upper-90s to near 100 or so from Columbus to College Station to Madisonville.

Sunday looks to see very similar weather, with hit and miss storms and temperatures about where they will be on Saturday.

Overall, rain totals should average a quarter to half-inch or so across the area, with some neighborhoods seeing several inches of rain and others seeing next to nothing. Yes, someone will end up disappointed from this period of higher rain chances, but it’s our best opportunity in some time.

Early next week

Rain chances should ebb heading into Monday and Tuesday, or at least be more co-located with the daily sea breeze off the Gulf. So coverage should diminish but not disappear completely. Temperatures will respond, back up to the low-90s along the Gulf, mid-90s in Houston, and near 100 well inland.

Later next week

The back half of next week is sort of in flux right now. One model (the Euro) is trying to bring a front into our area, which would enhance shower and storm coverage, though it would be unlikely to bring heat relief. The GFS keeps that away, but it does have higher rain chances later next week. Bottom line? We need a couple days to sort out late next week. But expect some rain chances and hot (but not extremely hot) weather.

Tropics

All remains quiet into early next week.

The Atlantic continues to lie dormant as August begins, which is good news for those hoping to avoid hurricanes. While the quiet is almost certainly going to break eventually, each day that goes by in August and September without a storm is a good day.

Tropical outlook in a sentence

Things remain quiet in the Atlantic basin with no real development expected over the next week.

Where to watch in August

As the calendar flips to August, we get into the heart of hurricane season. Basically, mid-August through late September is our marathon stretch. For Houston, our risks in August are still mostly close to home.

Using NOAA’s fantastic historic hurricane tool, we can get a sense of where to watch specific to Houston. Since the 1800s, Houston has had 10 hurricanes pass within 100 miles of downtown in the month of August. If you expand this to include tropical storms, the number increases to 17. With the exception of the 1915 storm (one that is worthy of a blog post of its own one day), all of August’s hurricanes in Houston formed in either the far western Caribbean or Gulf. In other words, while we watch the deep Atlantic and often discuss long-tracking hurricanes, they typically don’t impact us in August. That doesn’t mean they can’t, as 1915 proves, but our attention should be primarily focused close to home this month.

Yes, we’re talking tropical waves that struggle across the Atlantic, but hold together enough to ultimately develop in the Gulf. But we’re also looking for thunderstorm complexes that roll off the Gulf Coast into the open water. Or early season (weak) cold fronts that die off in the Gulf.

Notably, of the 17 total hurricanes and tropical storms (including Harvey) to pass within 100 miles of Houston in August, 15 formed in the Gulf or far western Caribbean. Again, closer to home is where the meat of our risk lies in August. This also means storms can form quickly, so it’s important to have a plan and preparations in place should something form.

Anything to watch now?

If we take a look across the Atlantic Ocean, there’s honestly not much happening at the moment.

We have a couple waves that are disorganized out in the open Atlantic, but none that is currently expected to develop as it comes west. There are a handful of model ensemble members trying to sort of develop one of the next couple waves that emerges off Africa. But as of today at least, no reliable model guidance shows anything in the Gulf over the next 7-10 days or more. That said, with fairly frequent storm clusters hovering near the northern Gulf over the next week or so, I wouldn’t entirely rule out something trying to weakly organize, though I think it would stay east of Texas.

But for August 2nd, this is about as good as it gets. The Atlantic remains stuck on 3 named storms and is now beginning to run below average for the season in terms of storm intensity. Still, using that metric, 92 percent of the season lies in front of us. It’s still far too early to declare the season a “bust,” and it’s critically important to remember that one storm can spoil the whole season for any given place. Alicia did just that to Houston in 1983, the 5th quietest hurricane season on record. So be wary of making bold declarations on August 2nd.

Yesterday was Thirsty Thursday in parts of the Houston area. While the coverage of showers and storms was a bit less than Wednesday, some pretty heavy rain fell in spots, even leading to some street flooding. On the map below, the teal color is generally about an inch, green is an inch and a half, and pink/blue starts ratcheting up to 2 to 3 inches. Obviously, the hardest hit areas yesterday were in parts of Fort Bend County, Sharpstown, Bellaire, West U, and close to Pasadena.

We remain in drought, however. In fact, as of Tuesday, extreme drought had expanded to cover half of the Houston region.

These showers aren’t heavy enough over a wide enough area to really seriously dent the drought, but they offer considerable short-term relief. Hopefully we can get some more.

Today

Coverage of showers should be similar to more extensive than Thursday. We have a little extra help today coming courtesy of a little disturbance moving west across the Gulf. Like yesterday, generally slow moving showers could lead to a quick inch or two or even a bit more in spots. Plenty of places won’t see rain today. Outside of the storms, mid to upper-90s once more.

Weekend

I do think we’ll see a noticeable decrease in shower coverage this weekend. We’re sort of at the mercy of exactly how an upper level system tracks, currently expected to pass offshore far enough to sort of “rob” what’s needed for showers. A few places could see an isolated storm or two, especially on Sunday. Additionally, look for some haze, courtesy of Saharan dust. Mid to upper-90s should dominate for highs, with 70s for lows.

Next week

Rain chances should bounce back a little bit on Monday again, before diminishing Tuesday and perhaps Wednesday and Thursday as high pressure settles in overhead.

By the end of the week, there are a few more questions. With high pressure expected to anchor in North Texas, Oklahoma, or Kansas this should keep us hot and humid, but it may be just far enough away to keep the door cracked each day for shower and storm chances. More on that next week.

The heat will be with us though with mid to upper-90s each day. We’ll have a couple shots at 100+ here or there too, but I’d expect to see more 98s and 99s. Does it matter? Not really, but it’s something I guess. More Monday!