Eric Berger

In brief: Light to moderate showers are moving into Houston from the southwest this morning, and this more or less will be the pattern over the next two days. There’s a chance for some heavier rain on Friday afternoon or evening, but overall the threat for significant flooding in Houston and surrounding suburbs is fairly low. After Friday, our weather turns warmer for awhile.

Rain status

For a few days now we’ve been discussing the impending arrival of a disturbance in the upper atmosphere, and its potential to drop buckets of rainfall over the region. There has been a see-saw battle between global and regional weather models. Now that the rains have finally begun, the contours of this system and its impacts are finally coming into focus. Essentially, instead of seeing mostly heavy rainfall in the Houston region, we are likely to see mostly light to moderate showers over the next two days.

The one exception to this is locations southwest of the Houston metro area, including Jackson, Matagorda,
Wharton, and Colorado counties that have already received 1 inch of rainfall. Some locations within these counties may eventually pick up 4 to 6 inches of rainfall with higher totals. This is certainly enough to cause some street flooding issues. So areas southwest of Houston could get soggy. But as for Houston itself, we are probably looking at rain accumulations of 0.5 to 2 inches between now and Friday night.

I am going to leave the Stage 1 flood alert in place for areas south of Interstate 10 out of an abundance of caution, because at this time there should not be significant flooding or mobility disruptions in Houston and its suburbs.

Thursday

We are seeing light to moderate showers moving in from the southwest this morning, and these should be fairly persistent for much of the day. Expect on-and-off rain, with overall mostly light accumulations. Certainly there could be a few isolated thunderstorms with some heavier rain, but I don’t expect widespread issues. With cloudy skies, high temperatures today are likely to peak in the mid-70s with easterly winds of about 10 mph and higher gusts. There may be a lull in the rain this evening (or not) before more widespread showers return after midnight.

Friday

I expect Friday to be similar. If there is a time when we may see more dynamic weather, including heavier rain, it probably will come on Friday afternoon or during the early evening hours. I don’t have great confidence yet, but it’s possible that some sort of line of storms will push through the area from west to east during the evening commute, and disrupt the start to the weekend. We’ll keep an eye on that. Some rain chances will linger Friday night but generally, by Saturday morning, the upper-level system will have moved on.

Saturday and Sunday

The weekend should see partly sunny and warmer skies. Look for highs in the mid-80s on both days, and sultry springtime lows only dropping to around 70 degrees. With dewpoints in the upper 60s, it will definitely feel pretty humid after winter in Houston. It’s good for the skin, I guess.

Next week

Most of next week should see additional warm and humid weather with highs generally in the mid- to upper-80s and warm nights. We may briefly see some drier air on Monday night and Tuesday with a weak front, but it will not be much to write home about. Some kind of front may push through next weekend to bring cooler weather by Sunday or Monday, but since that’s 10 days out our overall confidence is fairly low.

In brief: Houston has no weather concerns today, and most of Thursday should be fine. But beginning Thursday evening, and during the overnight hours, the region faces the threat of heavy rainfall. But for now, it’s only a threat, as our overall confidence is low. We’ve put a Stage 1 flood alert in place for areas along and south of Interstate 10.

Wednesday

Houston’s high temperature reached 89 degrees on Tuesday at Bush Intercontinental Airport, the city’s official measuring station. Because there will be more clouds today, highs will likely top out in the mid-80s, but with dewpoints in the low 60s it will feel more humid outside. Winds will generally be light, from the southeast. The humidity party continues tonight, when lows will only drop into the upper 60s for most locations. There will also be a slight chance of some rain showers after midnight.

Thursday and Friday

I’d love to provide you with some concrete answers about what to expect with the potential for heavy rainfall to end the work week, but they’re in short supply. Here’s what we do know. Most of Thursday, in Houston, should be fine. If there is heavy rainfall during the daytime, it likely will occur to the southwest of Houston, closer to Matagorda Bay than Houston and its suburbs.

Beginning Thursday evening, and lasting through Friday afternoon, the environment over Houston will become more favorable for heavy rainfall with an atmospheric disturbance and plenty of moisture to work with. But does that mean you’re going to get 4 inches of rain on top of your house? No, it does not. Much of our guidance continues to indicate that the heaviest rains will fall to the west or, more likely, southwest of the Houston region.

We are just now coming into the forecasting range of higher-resolution weather models. These are trending much drier than the global models (which have shown a few inches of rain over the Houston metro area on Thursday night and Friday). By contrast, the higher resolution models are much spottier in terms of showers and accumulations. So which is correct? Well, normally in such situations I would side with the higher-resolution models, but they absolutely missed on Sunday night’s storms that moved through Houston.

The bottom line is that the region faces the potential for heavy rainfall to end the week, but the bust factor is high. Yesterday I called for a total of 1 to 4 inches of rainfall across Houston, and I think that’s still a good forecast range. This type of rain would be enough to cause some street flooding, but not much more. We will continue to watch things closely for you.

Saturday and Sunday

We remain pretty confident that any rain showers, such as they are, should end Friday night or early Saturday. This should leave us with a couple of warmer, at least partly sunny weekend days. Look for highs in the mid-80s with plenty of humidity. Some of the more intrepid among you might try to take that first dip in the pool, even. That’s because nighttime temperatures won’t provide much cooling, dropping only to around 70 degrees.

Next week

Do you like the warmer temperatures and humidity? Well, you’re in luck. After Monday and Tuesday, when a weak front may briefly bring some drier air, most of next week should bring days in the mid- to upper-80s with plenty of humidity. Perhaps we’ll see a stronger front by the following weekend. We’ll see.

In brief: Houston faces a couple of warm (almost hot?) days before clouds and rain chances increase to end the week. The period of Thursday night into Friday looks to be the wettest time, and there is the potential for several inches of rainfall, especially south and west of Houston. To that end we are instituting a Stage 1 flood alert for areas along and south of Interstate 10 on Thursday and Friday.

Tuesday

Take a little extra time as there is a fair bit of fog this morning on roadways. It should clear out by mid-morning at the latest, leaving sunny skies. This combination of sunshine and a warm flow will allow high temperatures to spike this afternoon into the upper 80s, with some west and southwest parts of Houston likely reaching 90 degrees. This will be aided by dewpoints in the upper 50s, so while it will be quite warm, it won’t be super humid by Houston standards (that’s dewpoints in the 70s). Given the calm winds, there is also the potential for high ozone levels in the atmosphere today. Low temperatures tonight will drop into the mid-60s for most locations.

Wednesday

Expect a healthy chance of fog again on Wednesday morning. As moisture levels in the atmosphere increase, we’ll see more clouds on Wednesday. This should help to limit high temperatures in the mid-80s, with another warm night.

Thursday and Friday

We are continuing to watch an evolving situation with the potential for heavy rainfall to end the week. And I know many of you are as well, with the Texas Children’s Houston Open golf tournament at Memorial Park Golf Course running from Thursday through Sunday. The good news is that, I think, the weekend should be OK. But what of Thursday and Friday?

An upper-level disturbance will lift into the area beginning Thursday and find high atmospheric moisture levels to work with. This is a fairly potent system in that it has the potential to drop 6 to 10 inches of rain somewhere in Texas later this week. However, at this time the majority of our guidance now indicates that the best chance for the highest amounts will be southwest of Houston, near the Matagorda Bay area, or perhaps further south. But that does not mean the Houston area is out of the woods as uncertainty remains.

Rain chances will start to increase on Thursday, but the potential for heavy rainfall appears to be highest on Thursday night and Friday. As for our expectations in Houston, my best guess at this point is that we will see widespread accumulations between 1 and 4 inches, with higher isolated totals. The chances for higher accumulations appear to be greater closer to the coast. For that reason, we are instituting a Stage 1 flood alert for areas in Houston along and south of Interstate 10 on Thursday and Friday. Please note we may continue to modify this as better data becomes available.

The bottom line is that you should prepare for the possibility of some disruptive rainfall on Thursday night and Friday, but it is by no means a certainty. Expect temperatures in the 70s, with cloudy skies when it is not raining, and plenty of humidity.

Saturday and Sunday

As the upper low lifts north of the area, rains should end on Friday night or Saturday morning, and we should be left with partly sunny skies for the weekend. Expect highs both days in the low- to mid-80s with a fair bit of humidity. So if you have outdoor activities, at this point, they look fine. Nights will be warm and muggy, in the upper 60s for most locations.

Next week

Most of next week looks fairly warm and muggy as well, with highs likely in the 80s somewhere and warm nights as we get into April.

In brief: Some areas of Houston got hit by Sunday night’s storms, and others did not. We will now experience a few days of calmer weather this week before the chance for heavy rainfall on Thursday and Friday of this week. The details of that forecast remain hazy, but it’s something to watch.

Rainfall needed

For central and northwest areas of the Houston region, Sunday night’s storms brough some much needed rainfall, with one or more inches in an area roughly between Highway 290 and I-45 North. Much of the rest of the metro area got significantly less. That could change during the second half of this week, with the combination of an upper-level system and plenty of moisture in the atmosphere bringing a healthy chance of rain to the forecast. It is still too early to say whether this is a case in which most of Houston receives about 1 inch of rain, or whether some areas are at risk of 4 to 6 inches. We will be watching it closely.

Monday

Last night’s storms were prompted by a weak front sagging into the area, and this has helped push lows down to near 60 degrees this morning for much of Houston. This is likely to be the “coldest” we get for the next week at least. Highs today will reach the lower 80s, with mostly sunny skies and mostly calm winds. The onshore flow will return later this afternoon or this evening, so lows are unlikely to fall below the low 60s tonight.

Tuesday

This will be a warm—borderline hot—day as we see mostly sunny skies and a warm southerly flow. Expect high temperatures in the upper 80s with a few locations possibly hitting 90 degrees. Some slightly drier air (dewpoints in the upper 50s) will help the air warm more rapidly. Winds will generally be light, perhaps at 5 mph from the east. Lows on Tuesday night will drop into the mid-60s.

Wednesday

A few more clouds on Wednesday should help to limit high temperatures in the mid-80s. After Wednesday the region will not see much (any?) sunshine until at least Saturday. Expect another mild night in the mid-60s.

Thursday and Friday

The period of Thursday afternoon through Friday night should bring a high chance of rain as an upper-level system moves into the region. In terms of most impactful rains, with the potential for street flooding, we’re probably looking at late Thursday night into Friday afternoon, but those details will have to wait. These will be cloudy days, with highs mostly in the upper 70s, and muggy evenings. The global models are indicating the potential for a heavy pocket of rainfall, with several inches of rain during this period. However it still is not clear whether this will line up north of the Houston metro area, or more directly over the city and its suburbs. For now I think it’s best to say that we’re going to see some rain during the second half of the work week, and there’s the distinct potential for heavy rainfall and street flooding. We may need to break out the Space City Weather flood scale, but I’m going to hold off on that decision until Tuesday’s post.

Saturday, Sunday, and beyond

At this point it looks like things will begin to clear up by Saturday, so if you have some outdoor plans this weekend all is not lost. Both days this weekend should see partly sunny skies with highs in the lower 80s, give or take. We cannot rule out some showers each day, but the overall odds appear fairly low. A weak front may arrive by Monday, or so, to bring us some slightly cooler nights. We’ll see!