Expect another day of widespread rainfall as our Stage 1 flood alert continues

In brief: We are maintaining a Stage 1 flood alert today due to the potential for street flooding from showers and thunderstorms. Hopefully we’ll start to see a break in the action this afternoon. Conditions turn hot and sunny by this weekend, and then we should stay in that pattern for awhile.

Storm overview

Nearly all of the Houston metro area picked up at least some rainfall on Monday and Monday night, and much of the area received in excess of 1 inch. We will continue to see surging atmospheric moisture levels today, and accordingly the Houston-area radar will get another workout. The action is getting started earlier today than on Monday, with showers already having spread into much of the region.

Houston’s radar, shortly after sunrise on Tuesday. (RadarScope)

Basically we can expect fairly widespread showers and thunderstorms to persist through this morning, bringing an additional 1 to 2 inches of rainfall to most locations. It is possible that some locations see bullseyes of 3 or more inches of rainfall, which is why we have kept a Stage 1 flood alert in place for today and tonight. This means you should be aware of the potential for street flooding, and pay attention to the radar before venturing out. It also means that for most of the area most of the time, these showers are more of a nuisance than a serious hindrance to going about your business. Unless your business is house painting.

After this morning we expect there to be something of a reprieve this afternoon and this evening. An additional round of showers, likely not as intense nor as widespread, is possible on Wednesday.

Tuesday

As mentioned above, it’s raining. These showers and thunderstorms should be most widespread this morning before activity tapers off this afternoon to scattered, or possibly even isolated thunderstorms. Even when it’s not raining, skies should be mostly cloudy today, and high temperatures are likely to peak in the lower 80s. This is going to be one of the “coldest” days of the summer in Houston, with air temperatures for most of the day in the 70s. We don’t experience that often in the middle of the summer, so it’s a bit of silver lining to the rain. (Another silver lining is that next week looks rather hot and sunny, so the rains were getting now set us up nicely for that period). Showers will ease this afternoon and tonight should be mostly rain-free, with lows in the mid-70s.

High temperatures on Tuesday are very un-July like. (Weather Bell)

Wednesday

We’re going to see another chance of showers on Wednesday, including a few stronger thunderstorms. But instead of a 100 percent chance of rain, the overall likelihood is more like 50 percent, and storms should persist for less time. Skies should remain mostly cloudy, and this will help keep highs in the mid- to upper-80s.

Thursday

Skies will still be fairly cloudy on Thursday, although we probably will start to see some breaks in the clouds. This will allow highs to reach about 90 degrees. Could we squeeze out a few additional showers? Possibly, but by this point we’re likely to begin to see the influence of high pressure tamping down rain chances. Lows on Thursday night will only fall into the upper 70s.

Friday

Expect a partly sunny day with highs in the low- to mid-90s. Rain chances are pretty much gone.

Saturday and Sunday

The weekend looks set to bring us mostly sunny to sunny skies, with highs in the mid- to upper 90s. We have no weather concerns aside from the heat and of course the potential for sunburns from mid-morning through late afternoon.

Houston will see warmer-than-normal weather next week. (Pivotal Weather)

Next week

We are going to continue to see hot and sunny weather, with highs in the mid- to upper-90s for all locations but coastal areas, which will be a touch cooler. Rain chances are basically zero until the middle of the week, by which point we may see something like a 10 percent chance of showers. It’s late July in Houston, folks, and it’s going to feel like it.

With widespread showers and thunderstorms likely, we have a Stage 1 flood alert in place through Tuesday

In brief: Houston will see favorable conditions for widespread showers and thunderstorms today and Tuesday, and accordingly we have put a Stage 1 flood alert into place. On Wednesday we should transition to warmer and drier conditions. By this weekend, and into next week, we can expect hot and sunny conditions to prevail.

Stage 1 flood alert

Atmospheric moisture levels will surge today and Tuesday, and the absence of high pressure will support the development of widespread showers and thunderstorms. Generally, beginning later this morning, we expect rounds of storms to develop and slowly propagate through the region. Some of these storms may be slow moving. Although there will be some thunder and lightning, the primary threat will be heavy rainfall.

Space City Weather flood scale chart, showing flooding impacts and recommendations

Most of Houston will pick up 1 to 3 inches of rainfall over the next couple of days. These are manageable totals. However some locations, beneath slower moving storms, may see as much as 5 inches. For this reason we are putting a Stage 1 flood alert into place through Tuesday night. Essentially this means we are concerned about flooding on freeway frontage roads and low-lying streets.

Monday and Tuesday

Generally, we expect storms to develop offshore this morning and then move inland. By around noon, or the early afternoon, we should see showers and thunderstorms develop across the majority of the region. There may be a brief pause later this afternoon or evening before another round of showers later tonight. This pattern will likely repeat itself through Tuesday.

Skies will be mostly cloudy when it is not raining, and the storms should should help to limit high temperatures. Today will likely reach the upper 80s for most locations, with mid-80s possible on Tuesday. Except in stronger thunderstorms, winds will be light. Basically, you’ll want to be weather aware the next couple of days, and give yourself a little more time before venturing to work or running errands.

Wednesday

This will be a bit of a transition day, with some additional showers possible, but less coverage and intensity than previous days. High temperatures will likely be around 90 degrees, or a tick higher, for most of the region.

Thursday and Friday

Skies will turn partly to mostly sunny to end the work week, with rain chances falling to around 10 percent. Expect highs in the mid-90s.

NOAA rain accumulation forecast for now through Tuesday. Expect wide variations in totals. (Weather Bell)

Saturday and Sunday

Temperatures this weekend will be quite hot, with sunny skies. Expect highs in the mid- to upper-90s as high pressure builds in. If you have outdoor plans on Saturday and Sunday make sure they involve a lot of sunscreen. Rain chances are near zero so it will be good weather for the beach or a backyard pool.

Next week

I expect this hot and sunny pattern to prevail through at least the first half of next week. Our next chance of rain would probably not come before Thursday or Friday of next week, and even then, who knows? Bottom line is that rains over the next couple of days will be beneficial for our soils before a drier period settles in.

Coverage of Houston’s daily summer thunderstorms will slowly pick up this weekend

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 upper air map on Monday shows a strong upper level storm system moving east to west under a strong high pressure system over the Dakotas, leading to high rain chances across Texas. (WeatherFront)

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.

The eastern part of the Houston area is in a slight risk (level 2/4) for flash flooding risk on Monday. (NOAA WPC)

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.

As daily shower chances continue in Houston let’s check in on the Atlantic hurricane season

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.

Saharan dust (bright colors) extends across the entire Atlantic tropics. (Weather Bell)

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.

Accumulated Cyclone Energy to date for the Atlantic hurricane season. Red line shows year-to-date totals.(CyclonicWx.com)

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.

NOAA rain accumulation forecast for now through Tuesday. Some areas likely will see more rain than this. (Weather Bell)

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.