In brief: Hit or miss showers will continue across Houston into the weekend, with coverage slowly increasing each day. A more concentrated heavy rain/storm chance is in the cards Monday and Tuesday with some flash flooding possible. Temperatures heat up later next week and weekend.

Some parts of Houston are in the “rain o’clock” phase of summer, where you hit the right time of day, and the storms start to fire. Rain totals this week have been quite variable, with some places seeing nothing and others, like the East End through Galena Park and Cloverleaf seeing 2 to 4 inches of rain. As we head toward next week, more places will participate in rainfall once again.

Today and Saturday

Both today and tomorrow look fairly similar with isolated to perhaps scattered afternoon thunderstorms developing across the area. Once again, many locations will come up empty, but some could easily pick up a quick inch or two. Tomorrow may have slightly higher coverage of storms than today. Either way, outside of that it will be seasonably hot and humid with highs in the low-90s.

Sunday

More of the same is expected here, however coverage of storms on Sunday could be a tinge higher than Saturday. Highs will be near 90 degrees or in the low-90s.

Next week

Here’s where the pattern begins to get more active. As high pressure builds over the Northern Plains and Midwest, southeast Texas will be on the southern periphery of the high, meaning the door to Gulf moisture will be wide open.

The clockwise flow around high pressure basically allows anything underneath to move east to west, so this strong upper level storm system over the Deep South will act as an enhancement for thunderstorms Monday and Tuesday. While the strongest “forcing” with this disturbance will go north of Houston, the combination of this, a stalled weak front, and a bunch of Gulf moisture will likely produce pockets of heavy rainfall that could lead to flash flooding early next week. The eastern part of the area is in a slight risk (level 2/4) for flooding risk on Monday, and it’s likely this will be expanded or pushed into Tuesday for us.

I would expect some level of our flood scale to go up for Monday and Tuesday, probably Stage 1, maybe Stage 2. Eric will have an update for you on Monday morning, possibly Sunday if our confidence is high.

Things should quiet down some after Tuesday, with perhaps even a couple days off from rain chances. This does mean temperatures should begin to heat up with mid-90s by later next week, and possibly a bit hotter by the weekend. Stay tuned.

In brief: In today’s post we discuss our ongoing daily rain chances. They will increase over the weekend, but we don’t expect a total washout. At this point the highest likelihood of rain appears to come early next week. Also, what’s going on with the Atlantic hurricane season?

So what’s going on in the tropics

The short answer is … nothing. It is dead quiet out there for a number of reasons, including the fact that July is often a fairly low-key month when it comes to the Atlantic tropics. But probably the main reason right now is dust. It’s blowing off the Saharan desert and spreading far and wide in the atmosphere between Africa and the Caribbean Sea.

There are also other background factors like generally sinking air, and the bottom line is that we anticipate the Atlantic tropics to remain quiet for the next week, and possibly longer. Maybe a storm will pop up of the Carolinas, in the Atlantic Ocean, but even that appears to be a low-end threat. I don’t think Texas has much to worry about any time soon.

It is still early in the Atlantic season, and historically things don’t really start to pick up for at least a month from now. But it is worth noting that the level of activity recorded to date is only about 10 percent of historical levels for this time of year. So that’s something we can all be happy about. And it would be lovely if that trend continued.

Also this week the team at Colorado State University released their updated seasonal forecast, and they’ve continued to revise their projections downward. The forecasters now predict 9 named storms this season, down from their projection of 11 in June, and 13 back in April. “We anticipate the powerful El Niño being the dominant factor for the upcoming hurricane season, driving high levels of tropical Atlantic vertical wind shear,” the team said in their latest update. “We are forecasting a well below-average probability for major hurricane landfalls along the continental United States coastline and in the Caribbean.”

For now it’s all good news. But the Houston region still has about 2.5 months to go for this season, so we’re not going to throw any parties just yet.

Thursday and Friday

These days will be similar to what we’ve experienced this week, with mostly sunny conditions for most of Houston, with high temperatures in the mid- to upper-90s for inland areas, and slightly cooler conditions near the coast. We are likely to continue to see the development of scattered showers and thunderstorms during the afternoon and evening hours, along the sea breeze. These showers will be hit or miss, and your overall likelihood of seeing rain is probably only 20 to 30 percent. Overnight lows will be warm, with temperatures only falling to about 80 degrees.

Saturday and Sunday

Rain chances increase to about 50 percent, each day, for the weekend as atmospheric moisture levels increase. Generally, my expectation would be for showers to start out closer to the coast during the mid- to late-morning hours and then progress inland later in the day. Overall totals don’t look too impactful. Most of Houston is likely to pick up 0.5 inch or less, but there will probably be some higher bullseyes. Basically, if you have outdoor plans, have somewhere to take shelter. Because we should see a few more clouds, this may limit highs to the lower 90s.

Next week

My sense is that the first part of next week, Monday and Tuesday, will bring even higher rain chances. We are not expecting anything in the way of flooding, at least not right now. But a healthy 1 to 2 inches of rain would be helpful for area soils. Widespread rains could also limit some highs into the upper 80s. Matt will have more on this period in his forecast post tomorrow.

In brief: In today’s post we talk about the sea breeze, and how it will continue to drive the development of scattered showers this week during the afternoon and evening hours. Rain chances may turn even higher this weekend, particularly on Sunday.

What is the sea breeze, anyway?

We’ve been talking a lot, of late, about the sea breeze. It can be pretty impactful as we saw on Tuesday evening. Where it lines up, there can be the lift needed for moderate to heavy rainfall. Some locations near the Houston Ship Channel, including Galena Park, picked up 2 to 3 inches of rain during a relatively short period on Tuesday. For the rest of us, this produced a pretty spectacular light show on the horizon.

Essentially the sea breeze is what it sounds like. During the daytime the land heats up faster than the water (in this case, the Gulf and Galveston Bay). This produces sinking air offshore and therefore pressure to produce onshore winds. This is also why we often see wind gusts pick up from the southeast during the afternoon and evening hours.

Once onshore this sea breeze runs into hotter inland air, forming one or more boundaries along which there is rising air. If there is enough moisture near this boundary then you get localized, sometimes heavy rainfall with thunder and lightning. These storms are hit or miss, because areas not near a boundary are unlikely to see rain.

Wednesday, Thursday, and Friday

We are going to see a trio of days similar to what we’ve been experiencing so far this week. That is, mostly hot and sunny conditions with high temperatures generally in the mid- to upper-90s away from the coast. As for rainfall, each day will have about 30 percent chance, give or take. Again the pattern will be for showers and thunderstorms to fire up along the sea breeze during the afternoon and evening hours. Winds will peak during the afternoon hours, gusting perhaps to 15 mph. Overnight lows will only drop into the upper 70s, and only briefly.

Saturday and Sunday

We should see a few more clouds this weekend as atmospheric moisture levels rise further. With the upper-air pattern more or less remaining the same we should see continued sea breeze showers during the afternoon and evening hours, although with the additional moisture overall daily chances should be in the 50 percent range. Sunday could even be a little bit higher. Daily maximum temperatures will likely remain in the range of the mid-90s. As for humidity, well, you know that’s not changing in July.

Next week

There are some indications that higher rain chances will persist during the first half of next week, and that this could help keep a lid on highs (perhaps lower 90s). Through the middle of next week most of the Houston area will probably pick up between 1 and 2 inches of rainfall from this scattered activity, but as we’ve seen the last couple of days, the activity will be hit or miss so overall totals will vary widely.

In brief: Houston remains in a holding pattern this week, with rather warm temperatures but also some chances for afternoon showers and thunderstorms. Rain chances likely increase this weekend, but our overall confidence in this is not yet super high.

Big picture

Our weather will be in a holding pattern, more or less, for the rest of the work week. Houston is falling between high and low pressure systems, and given the time of year our weather will continue to be hot and mostly sunny. However, with the lack of a dominant high pressure system, we will remain susceptible to seabreeze-induced showers and thunderstorms during the afternoon and evening hours. Therefore, although the overall likelihood of rain in any one location is low, the probability of being able to go outside during the early evening hours and seeing lightning on the horizon is fairly high.

The pattern will shift a bit this weekend. On one hand high pressure from the west will become a little more prominent, but on the other it appears as though we will see a more pronounced flow of moisture into the atmosphere. The higher pressure favors lower rain chances, but the increased moisture levels favor higher rain chances. For now I’m leaning toward more widespread shower activity starting Saturday, but I’m about as confident in this forecast being locked down as I am in the play of the US Men’s Soccer Team goalie.

Tuesday through Friday

As noted above each of these days, at this vantage point, looks to be more or less the same. We expect high temperatures generally in the mid- to upper-90s across the Houston area, with a slight chance of rain showers. These daily rain chances are probably on the order of 20 to 30 percent. So a few parts of our region may pick up a quick inch of rainfall, whereas most locations see none. Also, these storms will be capable of producing lightning, so the ability to take cover is important.

With that said, for most of us, it will be mostly sunny most of the time. Low temperatures at night remain warm, only briefly falling below 80 degrees. Winds will generally be light, only picking up a little bit during the afternoon hours, with gusts up to 15 or 20 mph possible.

Saturday and Sunday

As noted above, we’ll see an increase in atmospheric moisture levels this weekend, and that could translate into more widespread shower activity. At this point I’m thinking daily rain chances are probably about 50 percent, but I want to caution that I still don’t feel confident yet in that prediction. Regardless, I do anticipate a few more clouds this weekend to go along with slightly lower temperatures.

Next week

Now we’re really in the dart throwing phase of the forecast. However at this point my guess is that we continue to see slightly cooler weather and better rain chances during the first half of next week. But of course “cooler” weather during July is a relative term. It’s still going to be plenty humid, as is always the case in Houston, in July.