Matt Lanza

In brief: Quiet weather, (hopefully) less haze and smoke, and lower humidity will welcome us today and most of Saturday. Scattered to numerous showers and storms will bring a heavy rain chance back to the area on Sunday and Monday. We will be watching for flooding risks again to the north of Metro Houston.

I just want to start with a quick thank you to all that replied to our call for assistance earlier this week for our partners at the University of Houston working on weather messaging research. Nearly 200 of you responded, which is both amazing — and overwhelming! The small team of researchers at UH is working hard to get to everyone who replied. They should have more than enough response now to hopefully generate some interesting and useful results. Once again, you’re all awesome, so thank you!

Heavy rain update

While most of Houston saw little to no rain last night, areas to the north and west were clobbered with large hail or heavy downpours. There was another 1 to 4 inches of rain on the northern end of Lake Livingston. At this point, it does not appear that will do much to the Trinity River situation (which continues to slowly drop). But we’ll await updated forecasts later today. Meanwhile, the Brazos will begin to crest from north to south this weekend into next week.

The crest should reach Rosharon by about Monday and then West Columbia by Tuesday, with minor to moderate flooding, which primarily affects the lowlands and perhaps a couple roads near the river. This is not currently expected to get worse.

Today

Update (10:05 AM): Some showers have developed across Wharton and Jackson Counties and will spread eastward through the morning. Brief heavy rain is possible, and a shower can’t be ruled out in Houston either.

Good news today. Air quality should improve. Yes, the last couple days have seen smoke from a lot, I mean a *lot* of agricultural fires in Mexico and Central America. It has degraded air quality and everyone’s mood. With a breeze today pointed offshore, that should hopefully push a lot of this smoke back south of here. Hopefully last night’s rain helped too. I won’t promise a super clean air quality day, but we are starting off much better than yesterday already.

Will this end our streak of 90 degree-free days? Probably not. But it may be close. Drier air heats up more efficiently than humid air, and there may be just enough to push some of us over 90 today, particularly south of I-10. Maybe bet on Hobby Airport and not Bush Airport.

Saturday

This should be a mostly quiet day. Maybe a sprinkle or shower. But otherwise clouds, sun, still not terribly humid or hot. Morning lows will be in the 60s to near 70, with daytime highs in the mid-80s.

Mother’s Day & Monday

The word to your mother will be rain this year. Unfortunately we continue to see a soggy picture being painted for Sunday. I don’t think the entire day will be a washout everywhere, but an umbrella will be a required accessory for church or brunch or wherever your plans take you. Scattered to numerous showers and thunderstorms are likely on both Sunday and Monday. For the majority of metro Houston, most of the rain should be manageable. Some ponding or a stronger storm or two are possible. At this time, we don’t expect much worse than that. Again, that’s for most of Houston.

That said, atmospheric moisture is near the top of the charts for this time of year, which means that we could be talking about heavy rainfall rates in spots. If those rains end up north of I-10 in vulnerable areas up in Montgomery, northeast Harris, or Liberty Counties and points north, we may have flooding issues again. For now, let’s call it 1 to 3 inches of additional rain, with lower amounts possible south and higher amounts possible north. Keep tabs on the forecast this weekend. We will have at least one more update later tomorrow or Sunday morning with the latest.

Rest of next week

Quieter weather should follow for Tuesday or Wednesday before more storm chances return perhaps Wednesday night or Thursday. We have an opportunity to hit 90 on Tuesday, but then our next realistic chance won’t come until next weekend.

In brief: Morning rain has thus far been manageable, but repeated rounds of thunderstorms along and on either side of I-10 will likely cause ponding and street flooding in spots this morning and afternoon. Flood Watches remain in effect through evening.

Happening now

One round of heavy rain and storms has exited to our east. Rain totals from that round were manageable in the Houston area and most points north to Conroe. A couple flash flood warnings were needed north of Lake Livingston and back into Huntsville, where totals approached two inches. Now, we’re seeing a west-east line of storms from northern & central Harris County back past Columbus.

Rest of today

This line of storms will likely “train” west to east through the morning and early afternoon. This means repeated rounds of storms basically within 20 miles of either side of I-10. For now, there are enough gaps in between downpours to keep things mostly just annoying and not troublesome. If that continues like that the rest of today, we’ll be fine; yes there will be roadway ponding or localized street flooding but probably nothing much worse.

Eric and I have been wary about things this week because, frankly, most model guidance has struggled. But in general, things seem to be doing what was expected. So, thunderstorms this morning on both sides of I-10. Look for these to continue into early afternoon. Some scattered activity may pop up north of Harris County this afternoon, and we’ll watch for localized downpours up that way. The NWS Flood Watch continues through evening, and our Stage 2 flood alert will continue with that as well. If, for some reason this band of storms shifts farther to the north, it will not take a lot to begin flash flooding. And if for some reason, the rains over Houston remain heavy with fewer breaks, we could see more widespread street flooding. So that’s why we’ll maintain that Stage 2.

Editor’s Note: The National Weather Service Weather Prediction Center issued a discussion while I was editing this post, suggesting that heavier rain over the Houston area was likely through afternoon and could lead to more widespread street flooding. We’ll continue to watch this through the day.

Totals, as you can see from above should be generally 1 to 2 inches, with isolated higher amounts possible. Lower amounts toward the coast and perhaps to the north. Obviously, it’s been pretty rough this week in terms of forecasts and impacts, so continue to monitor the situation, and we’ll post later if anything seriously changes.

Conditions should improve this evening.

Monday and beyond

We finally begin to unwind this disrespectful weather pattern. Temperatures will begin to heat up, and we still expect low to mid-90s into midweek. Rain chances won’t be zero, but they’ll be much lower than they’ve been in recent days.

Even though the rain will quiet down, river flooding will continue this week. One river we have not discussed much is the Brazos. Things have been fine there, but the river is likely to continue rising all week and may even approach moderate flood levels by late in the week.

Beyond Friday, it’s a bit uncertain still, but assuming the river hits 68 feet or so, we’ll begin to see the flood plain get inundated, requiring the relocation of cattle. We’ll monitor this in the coming days; thankfully there’s time to prepare.

In brief: A few showers are possible today, but for the most part Saturday should be an okay day. Another round of storms and potential heavy rain arrives tonight and Sunday which could renew street flooding in spots. Quieter, hotter weather arrives next week.

For the latest flood gauge information, visit the National Weather Service or Harris County Flood Control websites.

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The East Fork of the San Jacinto has crested at New Caney but will only slowly fall.

To the south, the West Fork of the San Jacinto at Humble is expected to crest on Sunday and remain in major flood until at least Monday or Tuesday.

The San Jacinto will continue in major flood downstream as well, with very fast flow passing barges near I-10 which could lead to some loss of mooring.

Unfortunately, the Trinity in Liberty County is going to remain just shy of record levels for several days, allowing major flooding to continue.

Please continue to heed the advice of local officials and never drive around barricades.

Saturday morning & afternoon

The good news this morning is that radar is vacant around Houston for the first time in some time. There are a few storms passing through the Beaumont-Port Arthur area up toward Jasper, but they’re moving offshore or into Louisiana. I would expect the morning to be fine in most areas.

With daytime heating, scattered showers and a few thunderstorms should begin to develop this afternoon. These will be hit and miss; some people will see downpours, others will be dry. I expect these will move along at a decent pace. The belief is that both the movement and the actual rain rates with these will be a bit lower than we’ve seen in recent days. The best chance for this will be north of I-10 after 12 to 2 PM, which isn’t great news for areas dealing with river flooding, but hopefully they don’t add much to problems. We should make the low to mid-80s today.

Tonight & Sunday morning

Here’s why Flood Watches remain in effect. Storms this afternoon in Central and West Texas will slide east with a disturbance and likely congeal into a well organized area of rain and thunderstorms. This should arrive in our area tonight, after 12 to 2 AM or so. There are still questions regarding how this plays out. Some model guidance shows less organization to the storms and more scattered type activity. Other data suggests it will push through at a good clip. And yet other data has sort of a repetitive scenario, where we see multiple rounds of storms, much like occurred on Friday and Thursday.

For now, a widespread half-inch seems reasonable for Houston and points south, with 1 to 2 inches north of Houston. There will almost certainly be higher amounts, with the most likely areas being north of Houston. In those spots, 2 to 5 inches of rain could fall on top of already saturated ground, leading to rapid street flooding. This would be mostly a concern in the northern part of Harris, Montgomery, and Liberty Counties and points north. If you have outdoor Sunday plans, it would be best to have an indoor backup plan available.

In addition to rain, some storms could be strong with a couple perhaps producing some modest hail or strong winds.

Monday & next week

We expect the pattern to begin to transition beginning Monday into the forecast heat for next week. While a few showers or storms are possible, significant weather is not expected on Monday. The main story will be heat next week, building through the week.

Heat will build up to “major” levels, as classified by the National Weather Service, with low to mid-90s likely for highs by Wednesday and/or Thursday. Given that this will be our first real heat of the season, give your body some extra time to adjust. We’re not used to it just yet. We’ll have more tomorrow, or later today if necessary on the rain.

In brief: Flash flood warnings are in effect for Montgomery, far northern Harris, and Liberty Counties this morning, as an additional 1 to 4 inches of rain has fallen. River flooding will continue in those areas as well, with numerous evacuation orders and road closures in effect. Major rain should hopefully exit this morning with more intermittent, scattered downpours through the day. Additional storm chances exist tonight and especially Sunday before the heat sets in next week.

A flash flood warning is in effect north of Houston through 8 AM, as another batch of heavy rain fired up overnight dropping 1 to 4 inches of rain between southern Montgomery, northeast Harris, and northern Liberty Counties.

This is not where we wanted to see the rain this morning. We do expect that this will actually move along at a better clip than yesterday’s rain did. Hopefully that leads to some quicker improvement, but all this water will help further swell the river systems up there. You can view flood gauge information on rivers, creeks, and bayous at the National Weather Service or at Harris County Flood Control. Please follow the advice of your local officials, and never drive around barricades.

A Flood Watch remains in effect along and north of I-10, extended through Saturday, and we will maintain our Stage 1 flood alert for Houston.

The San Jacinto and Trinity Rivers remain the two most serious issues at this time. There will continue to be rises and damaging flooding within both systems. Additionally, the Navasota River is expected to crest at record levels north of Bryan. That feeds the Brazos, and we’re likely to see high water or minor flooding begin in that river too as we head into next week. Thankfully, we aren’t expecting a whole lot worse in that system. A lot happening, and we’ll keep you posted on any significant changes with at least one more update later today.

Today

The rest of this morning is expected to see this very heavy stuff north of Houston exit east and be replaced by more in the way of scattered thunderstorms.

If we can pop more in the way of scattered storms, yes, that will lead to isolated heavy downpours, but more often than not it wouldn’t rain over one place hard for more than 15-20 minutes at a time. Even a few rounds of that is more manageable than the deluge and 2 to 6 inch per hour rates we’ve seen this week. We’ll continue watching and keep you posted. Have an umbrella and an indoor backup plan anywhere in the area today just in case. Highs will range from the upper-70s in places it rains persistently to low-80s. Showers should diminish in coverage this evening.

Saturday

Do we expect more showers and storms to fire up overnight tonight and Saturday morning? It’s NBA playoff season, so in the words of Marv Albert, “Yes!” Unfortunately we will probably see additional rains in saturated and flood-impacted areas north of Houston. There is a chance that this ends up being a little less rain than today, so hopefully that’s the case. Otherwise, sun, clouds, and 80s.

Sunday

The back half of the weekend looks to remain unsettled. Another wave of storms could pass through the area in the morning or afternoon hours, especially north of I-10, again. Rainfall could again be heavy, and right now I am a little more concerned about Sunday than Saturday in terms of rain and impacts. Outside of any storms, expect clouds, some sun, and highs in the 80s.

Next week

I wouldn’t be shocked to see one more round of showers or storms on Monday or Tuesday, but then the heat cranks up. Expect upper 80s on Monday, low-90s by Tuesday, and low to mid-90s on Wednesday and Thursday.

It will feel uncomfortably hot, given this is first real heat of the summer season, so take it easy. Morning lows will generally be in the mid-70s. We may see rain chances return toward the weekend but for now that’s mostly speculation, and I wouldn’t be changing any Mother’s Day plans at this time.