Storms are absolutely hauling their way into the Houston area tonight, faster than most of us expected earlier today. Good news, as you’ll see below. But they are intense. Rain is falling at a rate of 3 to 4 inches per hour on average in that intense red portion of the line bowing across Rosenberg, Cinco Ranch, and Cypress at 9:45 P.M.
Intense storms with torrential rains were moving into the Houston area at 9:45 P.M. Tuesday (RadarScope)
These types of rain rates will almost certainly produce street flooding across many parts of the region through Midnight, spreading east and south.
In addition, there have been multiple tornado warnings issued with these storms, including one storm that may have well produced a tornado just north of Brookshire earlier. Stay alert and aware, and seek shelter if a tornado warning is issued in your area. As of this writing, there is a tornado warning for the northwest side of the city through 10:15 P.M. Even with no tornado, strong, damaging winds are possible.
So, some good news about all this at least: That the storms are moving quickly is positive because, while it’s going to rain much of tonight, the super-intense, “floody” 2 to 4+ inch per hour rates will be short-lived over a given area. We can manage a steady rain. It’s when you get that overly intense stuff for more than an hour or two that things get out of hand.
Beyond tonight? Truthfully, I don’t have a great feel on what to expect tomorrow at this point. I think some of that will depend on how these storms evolve over the next several hours, and what happens back to our west overnight. Some models redevelop storms in parts of the area. Others give us a nice break between storm chances. It’s a tough call right now, so you’ll need to be fairly flexible and adjust with the forecast tomorrow. We do know that there will be more storms, but how intense and exactly where they hit matters a lot, and we just aren’t sure yet.
Eric will have an update on what’s happening here after midnight tonight.
Ok everyone, take a deep breath. The greater Houston region has experienced a nice reprieve from heavy rainfall today. That’s the good news. The bad news is that our atmosphere has recharged, and we are about to experience the worst of this potential flooding evening tonight and on Wednesday. The timing of all this remains in flux, but what follows is our best assessment for now.
Tuesday night
A pretty serious block of showers and thunderstorms are massing just to the west of Houston this afternoon, and we expect them to move toward our region this evening and during the overnight hours. These storms are being juiced by a slow-moving upper-level low pressure system, and they will have plenty of moisture to work with tonight.
We think most of Houston and the surrounding counties will see 2 to 5 inches of rainfall between now and sunrise on Wednesday, with higher isolated totals. These storms will be capable of producing intense rainfall rates above 2 inches per hour, which will quickly back up streets. Almost certainly some part of our region will see 10 inches of rainfall, or more, during the overnight hours. For now we are maintaining a Stage 2 flood alert, but this threat may need to be adjusted upward later this evening.
Although rainfall is the primary threat, some of these thunderstorms may bring severe weather as well. The National Weather Service has published a tornado warning that will remain in effect for the western half of our region until at least 9 pm CT tonight.
(National Weather Service)
Wednesday
It looks like tonight’s storms may work over the atmosphere, and if this happens we would expect to see a break in storms on Wednesday morning, possibly lasting into the afternoon hours. After this point it’s really difficult to say what will happen with confidence, but I think it’s reasonable to expect another round of storms Wednesday evening or during the overnight hours. Where this sets up, and whether it’s as intense as Tuesday night, is something I just don’t really feel comfortable predicting.
Thursday and beyond
We think the focus of these storms will begin to swing eastward on Thursday. For the overall event, most areas will probably see an additional 4 to 8 inches of rainfall, on average, from now through Thursday. This means some areas will see more, and it is in those locations we are most concerned about flooding.
The map below shows NOAA’s best guess for rain accumulation totals from now through Thursday night, but this should not be taken as gospel.
Matt and I will be continuing to work this event, and will update again by around 10pm CT Tuesday night.
Good morning. We’re now approaching the half-way point of a multi-day heavy rainfall event that began Sunday and should wrap up on Thursday. We remain at a Stage 2 alert on our flood scale, which means the Houston region is likely to see flash flooding. The bottom line is that this air mass has produced explosive rainfall events the last two days (southwest, and then east of Houston) along the Texas coast, so it bears watching closely.
Tuesday
Although we should see showers and thunderstorms in Houston today, they may be less organized than on Monday. The primary threat for widespread, heavy rainfall is likely to lie north and east of the Houston metro area, where the atmosphere remains somewhat more unsettled. This area, north of Montgomery County and east of Harris County, is shown on the “excessive rainfall outlook” prediction below from NOAA for Tuesday and Tuesday night. Unfortunately, the area of “moderate” risk, denoted in red, could affect the Beaumont and Lake Charles areas that were hammered by heavy rainfall on Monday. Highs today will be in the mid-80s, with mostly cloudy skies.
Excessive rainfall outlook for Tuesday. (Pivotal Weather)
Wednesday and Wednesday night
We continue to believe that the period from Wednesday morning through Thursday morning will bring the heaviest rainfall to most parts of Houston. This is because of vigorous atmospheric lift, and a setup that allows a regenerative flow of moisture from the Gulf of Mexico. During this time frame we think rainfall totals will average 2 to 6 inches across the region. Our main concern, of course, is higher bullseyes that drop in bursts and lead to flooding. This will will definitely be possible given the moist and unstable air mass overhead.
Where will these bullseyes occur? As you can see in the excessive rainfall outlook for Wednesday and Wednesday night, we just don’t have a great handle yet on where the heaviest bursts of rainfall will land along the Texas coast, and points inland. When we have more definitive information to share, we will share it.
Excessive rainfall outlook for Wednesday. (Pivotal Weather)
Thursday and Friday
Whatever mess develops on Wednesday and Wednesday night will carry over into Thursday morning. Conditions should begin to improve during the afternoon hours, but if you’re looking for a guarantee of that, we can’t provide it. After the worst passes, we should still see on-and-off light to moderate showers to end the work week. However, these should for the most part not produce heavy, flooding rains. Highs will be around 80 degrees both days.
Saturday and Sunday
Saturday should be a lot like Friday, which is to say mostly cloudy with a healthy chance of light to moderate rain. We don’t expect a washout, by any means, but keep an umbrella handy. Some sunshine may break through on Saturday before the sun sets, and Sunday should see clearing skies. Rain chances on Sunday should fall back to around the 10 percent range, and remain low for several days. You’ll be ready for some sunshine, right?
Our next update will come by or before 7pm CT today.
Good evening. The Houston area has been mostly fortunate through this rain event so far. We’ve managed to avoid very high impact rains, though we all finally got doused this afternoon and evening. Still, rain totals, while impressive were mostly manageable, aside from pockets of street flooding.
Rain totals for the past two days over the Houston metro area through 7 PM Monday. To view and zoom around yourself, visit harriscountyfws.org (Harris County Flood Control)
You can see that the highest totals for the event so far are in northeast Harris County, where over 6 inches fell in about 3 hours today just east of Huffman. All told, we’re lucky. After 13″ of rain fell in extreme southwestern Wharton County yesterday, it was Jefferson County, Liberty County, and the Lake Charles area that were hammered today.
Areas east of Houston pummeled
18.03″. That’s how much rain fell today near Fannett in Jefferson County, just off exit 838 of I-10. This is at least the third, if not fourth time this area has had houses flood — since Harvey.
Over 17" recorded near Fannett, TX. This area cannot catch a break. Some homes flooded for the 3rd time since 2017.
Southeast Texas is vulnerable to floods, but what has happened in the Beaumont-Port Arthur area in recent years is something different, and as someone who knows several folks in that area, completely exasperating.
Radar estimated totals were north of 8 inches from Liberty into Jefferson County in East Texas. Similar totals fell locally on Lake Charles, LA as well. (RadarScope)
And if that were not enough, the Lake Charles area, which has just barely had time to move on from Hurricanes Laura and Delta was battered today as well.
The combination of 15″ of rain and debris clogged waterways and drains in the wake of the aforementioned storms has led to water in homes and businesses in Lake Charles.
Lake Charles saw 10 to 15 inches of rain or more today, causing widespread flooding in that storm weary city, in addition to a few tornado warnings. (Calcasieu Parish Police Jury)
Repetitive disasters have become a hallmark of Southeast Texas and Louisiana, and it requires folks like us continuing to call attention to it without sugar coating it as “that’s just what happens here,” the linkages to climate change, and the reality that we need to continue to implement and expand mitigation measures. Or this will continue unabated.
Right now, we have just to get through this week.
Rest of tonight
Good news. The rain is tapering off from northwest to southeast as I type this, and we do not expect much, if any new development of storms overnight.
Tuesday
That said, we could see a cluster of storms find its way into the area by early morning Tuesday, as one model in particular (the HRRR) believes. I do think if we were to see that happen, it would be progressive, meaning a quick 1 or 2 inches of rain and then out. Granted, the ground is now saturated, so any rain of intense magnitude will be capable of producing flash flooding. But a quick moving system would be acceptable in this pattern. Additional storms will be possible later tomorrow afternoon or evening, though to be quite honest, the details are really fuzzy still. Tuesday will require a good bit of “nowcasting,” which means watching trends and making short-fused 12 to 18 hour forecasts at a time. Eric will update you in the morning.
Rest of the week
This week is a marathon, and we’re not sprinting to the finish. Wednesday and Thursday continue to look like active days with a combination of slower moving storms and saturated soils possibly combining to cause issues. We’ll remain in a Stage 2 flood alert unless something changes.
Just to underscore: As we’ve seen the last two days, these systems are relatively unpredictable with anything more than modest lead time. They are also capable of easily producing 2 to 4 inches of rain in an hour for more than one hour, and that will cause problems. So we know the potential for considerable heavy rain and flooding exists, particularly as soils saturate through the week. We still cannot tell you exactly where and when that will occur. We’ll continue to ask for your patience as we help you navigate the rest of this week. Stay safe.
Our next post will be Eric’s usual post on Tuesday morning.
