In brief: Strong showers and thunderstorms are moving through Houston on Saturday afternoon, creating some flash flooding. The good news is that this mess should exit the area over the next couple of hours. Until then be weather aware.

Hi everyone, just a quick update to note that the “afternoon” round of storms we advertised in this morning’s post is now moving through central Houston. This band of showers and thunderstorms is producing heavy rainfall, and we’re seeing some flash flooding consistent with the Stage 2 alert we have put into place for this weekend.

The good news is that these storms are progressing fairly well to the east-northeast, and should gradually clear the entire metro area by around sunset if not before. Accordingly if you have dinner reservations or other plans later this evening you should feel free to go out. Once these storms end we anticipate a quiet evening and overnight period.

As for Sunday, we expect scattered showers and thunderstorms (probably better chances closer to the coast) but nothing as organized as what we experienced today. Memorial Day probably will have less coverage still, with more sunshine. We will break this all down for you in an update on Sunday morning.

In brief: Storms are rumbling through Houston during the pre-dawn hours on Saturday, and this is the first of a handful of disturbances we can expect this weekend. Rain chances are a bit lower on Sunday, and we are hopeful that by Memorial Day we’ll see a fair bit of sunshine.

Good morning. Like some of you, I imagine, I was awoken before 5 am by storms rumbling into the Houston area from the west. This pre-sunrise activity is the first of a series of disturbances expected to propagate across the region over the next 24 to 36 hours. We still have some uncertainty about the timing for heaviest rainfall, but I am increasingly hopeful that we will see improving conditions by Memorial Day. Thus, if you were hoping to have a pool day, or a beach day, or otherwise celebrate the holiday outdoors in hopes of a little sunshine, all is not lost.

But first, we have some storms to deal with.

The current area of showers and thunderstorms is producing fairly heavy rainfall, and there is also the threat of some severe weather, including small hail and damaging wind gusts. The period between now (5:45 am) and around 9 or 10 am this morning should be treated with caution due to the potential for severe weather as well as pockets of heavy rainfall (we’ve seen rainfall rates of 2 to 3 inches).

So what happens after this round of storms? I think we’ll see a break in activity from the mid-morning to the early afternoon hours. But then, as the atmosphere has time to recharge and we experience daytime heating, another disturbance will approach from the southwest. This will likely spread into Houston during the afternoon or evening hours. Whether it is intense as the storms this morning is not entirely clear—the atmosphere may still be a bit worked over. Some of our high resolution modeling indicates these storms will be strongest along and south of Interstate 10.

We are likely to see more disturbances on Sunday, although timing them is difficult, and it’s not clear how strong they will be. Anyway, expect a healthy rain chance in the vicinity of 60 or 70 percent. By later on Sunday we may be able to lift our Stage 2 flood alert, which is indicative of the waning potential for street flooding and flash flooding.

In contrast to the first part of the holiday weekend, we now think there’s a decent chance of partly sunny (maybe mostly sunny) skies on Memorial Day, with rain chances at or below 50 percent. In other words, most of the day should be fine to celebrate outdoors. Highs will likely be in the vicinity of the mid-80s on Monday, so fairly warm but not in any meaningful way will it be hot.

If the storms this evening look to become fairly strong, we’ll be back with a short update this afternoon. If not, we’ll see you on Sunday morning.

In brief: While rain totals across the Houston area have been rather variable (ranging from less than an inch in some spots to over 8 inches in far southern Brazoria County), we expect everyone to participate in rain and storm chances this weekend, especially from Saturday night into Monday. Flash flooding remains a distinct possibility, and our Stage 2 flood alert will remain up through at least Monday.

Rainy pattern check-up

We’re a few days into this relatively significant change to a rainy pattern, and so far, so good for the most part. We’re going to maintain the Stage 2 flood alert through the holiday weekend. I think the rains we saw Wednesday down in Brazoria County (7 inches) exemplify what this setup is capable of.

So far, the northern half of the area has seen a relatively pedestrian 1 to 2 inches (even less in spots), while the southern half has seen 1 to 4 inches on average, with pockets of 5 to 8 inches. We expect another 1 to 4 inches on average over the next week across the entire area. Isolated higher and a couple lower amounts are indeed possible.

For those concerned about the situation in Corpus Christi, Lake Texana has seen about 3 inches of rain, while Lake Corpus Christi has seen about 4 inches of rain so far. Areas upstream of those lakes have received anywhere from 2 to 4 inches as well. By no means does this “save” Corpus Christi from a very bad situation, but it obviously helps buy some time. And any help is great news down there right now.

Today through tomorrow afternoon

Right now, weather modeling is suspiciously calm today and much of Saturday across the area. Obviously, showers and thunderstorms are still possible. But I would suspect most places stay dry as the best “oomph” for storms remains south or offshore in the Gulf. We’ll probably see clouds and sun. Highs may nudge back up into the middle or even some upper-80s after a couple days of lower 80s. There will be plentiful humidity to go along with that.

Saturday night through Monday

If we’re going to get smacked by rainfall, Saturday evening through Memorial Day would be the timeframe I’d be watching closest. A rather vigorous disturbance in the middle and upper atmosphere is going to swing into the Houston area on Saturday evening. This should provide the trigger necessary to get storms off and running. It’s impossible to really say exactly how things are going to setup right now, but expect increasing thunderstorm chances after about 4 PM on Saturday into Saturday night across the Houston area.

We’ll then need to watch for repeated development of storms and the risk for flash flooding, including in areas that have not seen much rain so far. With moisture in the atmosphere much higher than normal, any storms will be capable of dropping 2 to 4 inches of rain in an hour or so. Any “training” or repeating thunderstorms over the same area means those totals could add up quickly, hence the concern for some localized flooding and our Stage 2 flood alert. More to come on this throughout the weekend as we get more clarity on timing and locations impacted.

Next week

The area will remain under the influence of an unsettled weather pattern and above normal atmospheric moisture. I would expect this on again/off again type rain and storm stuff to continue through much of next week, though perhaps at a slightly slower pace. Either way, what we can say with fairly high confidence right now is that any sustained, strong early summer heat is not in the cards through at least early June.

In brief: A round of storms moving into the region today should impact areas south of Houston, including southern Brazoria County which has already been hard-hit by rainfall. Storms should be more scattered in nature on Friday before the likelihood of widespread heavy rainfall ramps up over Memorial Day Weekend.

Rains recap

Since the beginning of these late May storms on Tuesday, most of the Houston area has picked up 1 to 3 inches of rainfall, which has been manageable. However areas south of Houston, particularly in southern Brazoria County near Angleton and Lake Jackson, have had a far wetter time of it. Some of these locations have already received 6 to 8 inches of rainfall. Unfortunately for these locations, it appears that rainfall on Thursday will be mostly concentrated over areas south of Interstate 10.

Thursday

A check of the radar this morning shows a large mass of showers off to the southwest of Houston near Victoria Port Lavaca. These showers and thunderstorms should slowly move to the northeast, toward the metro area this morning. Our latest high-resolution guidance suggests these storms will largely remain confined to areas south of Interstate 10 as they move through during the morning hours, and likely exit to the east by early afternoon. Rain accumulations of 1 to 3 inches will be possible for coastal areas, but I’m hopeful that much of the heavier rain will fall just offshore.

For the rest of the Houston area rain showers and thunderstorms should be more scattered later this afternoon. Skies will be mostly cloudy with high temperatures in the upper 70s to lower 80s. (I have to say that afternoon temperatures on Wednesday afternoon were very comfortable for late May in Houston). Rain chances should be low overnight, with lows around 70 degrees.

Friday

This is looking like a day during which showers and thunderstorms are more scattered in nature rather than organized into a broader system; which is to say rain chances will be a bit lower than the weekend at about 50 percent. With mostly cloudy skies we can probably expect highs in the vicinity of 80 degrees.

Memorial Day Weekend

The upper-air pattern will become more amenable to supporting widespread showers and heavy rainfall this weekend as a low pressure system allows the passage of multiple disturbances over the region. Rain chances will be near 100 percent on Saturday and Sunday, and perhaps only a little bit lower on Monday. Most of the area is likely to pick up an additional 3 to 6 inches of rain this weekend, with higher isolated totals leading to at least street flooding, and possibly some flash flooding. For this reason we are maintaining our Stage 2 flood alert through the holiday weekend.

It’s still a little too early to have precise details about timing, but basically you should be prepared for some disruptions at any point this weekend. Certainly roads should be passable most of the time, but these are the conditions that support some impacts to mobility where rainfall is heaviest and/or prolonged. Basically we want you to be alert to the possibility of flooding, but not fear widespread mayhem.

High temperatures should remain in the low- to mid-80s this weekend with plenty of humidity, and nights not cooling down much. Saturday looks to be mostly cloudy, but we could see some breaks in the sky on Sunday and Monday when it’s not raining.

Next week

I don’t have great confidence in the forecast for next week. Daily rain chances continue to look healthy, perhaps in the vicinity of 50 percent or so, but at this point I think (and hope) amounts will be trending downward after Monday. Highs remain in the 80s, probably.