Month: August 2022

Good evening. Just a quick update to say that we’re expecting shower and thunderstorm activity during the overnight hours to be more widespread than previously thought, and that this threat will persist into Tuesday. The greatest risk for heavy rainfall continues to be north of Interstate 10, so we’re issuing a Stage 1 flood alert for parts of the metro area along and north of this freeway. Areas south and west of Houston may also see some heavy rain, but the biggest threat appears to be further inland, to the north.

The problem is that a slow-moving boundary is sagging into the region from the northwest this evening, and it’s finding an environment fairly conducive for additional showers and thunderstorms tonight. In meteorology speak, we’re likely to see the convergence of boundaries that efficiently produce upward motion in the atmosphere. Given the overall tropical air mass, some storms could produce rainfall rates of 2 inches per hour, or higher, which will quickly back up streets. Some parts of the Houston metro area could see an additional 2 to 4 inches of rain overnight, into Tuesday morning, with higher isolated totals. The potential for heavy rainfall, again focused north of Interstate 10, will likely continue on Tuesday.

Here’s the truth: We’re not entirely sure what will happen. We know the ingredients are there for heavy rainfall tonight. It could be a bust, or some location in San Jacinto County could pick up 6 or 8 inches. What we can say for sure is that the atmosphere has potential for heavy rains tonight, and we wanted to call your attention to it. We’ll be back with a full update in the morning.

As Eric covered this morning, we’re watching rain chances here in the Houston area for the midweek period, as some rainfall rates may lead to street flooding in parts of the area, especially north of I-10. But we wanted to also catch you up on what’s happening elsewhere in Texas, as we know many of you travel to and fro or have friends and relatives across the Lone Star State. Here’s a quick rundown of what’s happened and what to expect.

DFW Metroplex flooded

Incredible amounts of rain fell on the Dallas and Fort Worth Metroplex overnight and into today, with some parts of Dallas and Tarrant Counties seeing 12 to 16 inches of rain in 24 hours. DFW Airport is approaching its single day rainfall record, and at worst it will finish as the second wettest day there on record.

Many roadways are flooded, and if they aren’t, they are littered with flooded cars. Travel is discouraged to Dallas or Fort Worth the rest of today. Tomorrow seems like a better day for that, though you may encounter heavy rainfall between Houston and Dallas. So whatever your plans are, please use caution and budget in patience and pad.

City of Dallas rain total map
Tarrant County rain total map

Next round of flooding concerns

For folks in Dallas, the good news is that rain should ease up a lot this evening as the frontal boundary that has helped focus the rains has sagged south of the city. They will have a chance to clean up. Rainfall should begin to pick up in intensity a bit farther south though, and tonight’s focus could be Hill Country or the San Antonio and Austin areas.

In fact, Hill Country and parts of San Antonio, Austin, and Waco are being highlighted by the National Weather Service Weather Prediction Center (WPC) this afternoon for potential 2 to 3 inch hourly rainfall rates.

In addition to this, areas of northeast Texas may be targeted with heavy rainfall as well, and the flooding threat will extend to places like Texarkana and Tyler. Tyler is under a Flash Flood Warning as of this writing. Flood Watches include those locations, down to Lufkin and east past Shreveport, LA.

Look for flood watches and warnings to shift through the week as the rainfall threat shifts.

Tuesday and Wednesday’s risks

Both Tuesday and Wednesday will see rain drop closer to Houston. We aren’t expecting the level of tremendous rain rates and flooding as seen in Dallas, but we’ll want to watch things closely over the next few days, as model precision in handling rain rates through these types of events is rather poor. As of now, the primary risk of flooding rains will extend from just northeast of San Antonio across northern parts of Houston into Louisiana tomorrow.

Then on Wednesday we’ll deal with residual rain chances in Houston and most flooding risks in Louisiana.

Will this end the drought?

Yes and no. Drought is complicated. The amount of rainfall needed to officially end the drought in Texas is 10 to 15 inches over a wide swath of the state. Other than the Dallas area, we aren’t seeing those kinds of totals over a wide enough area.

Drought is a little more complex than just needing a certain amount of rain, however. There are longer-term droughts, like the one Texas is in, which impacts agriculture, deep soil moisture, water supply, etc. Then there is short-term drought, which we also have had this summer. That leads to all of the above but also things like wildfire risk. This rain will absolutely help, if not end the short-term drought in much of eastern Texas. It will help the long-term drought as well, but we will need more rain in the coming weeks in order for that to be effective. I spoke a bit about this on Texas Standard this morning.

Why is this so bad so fast?

There’s a saying that droughts end in floods for a reason. Texas is a state of extremes, becoming further exacerbated in a warming climate. In this case, a persistent weather pattern that plagued us with drought and heat all summer finally flipped, simultaneous to a bunch of added moisture from the Southwest monsoon (which itself may have been energized somewhat by the old tropical disturbance that flooded parts of South Texas over a week ago), as well as added moisture from this weekend’s PTC 4 that went into Mexico. All of this hit a sagging cold front, and someone will get slammed in that instance.

In a timely turn of events, new research has come out showing how dry soil can exacerbate flooding issues with heavy rain. You can read about that here.

The bottom line: Texas has a history of droughts ending with floods. That’s sort of what’s happening here. While this may not necessarily be the “end” of drought for all of Texas, it will be for some of the state. Please use caution and stay aware of rain risks over the next few days as it all moves through.

Good morning. After scattered showers and thunderstorms this weekend, the potential for more organized storms returns to Houston this week, especially areas north of Interstate 10. Most of the region will see 1 to 4 inches of rain through Friday, although isolated areas beneath the heaviest storms could see 6 or more inches. Please note that we’re not looking at continuous rainfall this week, by any means. Monday, in particular, should see a fair bit of sun.

These rains, which will likely reach their maximum coverage on Wednesday, are due to a very moist atmosphere and a series of disturbances in the atmosphere. The overall pattern will support slow-moving storms, which is a concern due to the potential for high rainfall rates. At this time we’re not expecting significant or widespread flooding in the greater Houston area, however stronger and slow-moving storms will likely flood some roadways this week.

Monday

Showers today will be fairly scattered in nature, and due to at least partly sunny skies I think we’ll see a warm day with high temperatures pushing into the mid-90s for much of the area. Rain chances are likely about 40 percent for much of the day. However, late this afternoon or evening we should see a line of storms moving through our northern areas, such as Montgomery and Walker counties, in association with a boundary. This line of storms should steadily weaken, before (probably) dying around around Interstate 10. Things should quiet down overnight.

Tuesday

The potential for more widespread rainfall increases on Tuesday, with coverage of 50 to 60 percent of the area. Chances will be highest north of Interstate 10, in places such as Montgomery County. With more clouds, expect highs to peak around 90 degrees.

Wednesday

This is the day we expect the most widespread rain in the metro area, with chances of around 80 percent. We still don’t have great confidence in the timing of storms on Wednesday, but should be able to offer some better guidance in tomorrow’s post. Highs for most of the area should remain in the upper 80s.

Thursday and Friday

As the atmosphere starts to dry out some, rain chances should fall back to around 50 percent or so to end the work week. Look for highs of around 90 degrees, with partly sunny skies.

Saturday, Sunday, and beyond

I think the pattern will revert to more typical conditions for late summer this weekend, with partly to possibly mostly sunny skies, and highs climbing back into the low 90s. Rain chances are not zero, but likely will not be higher than 30 percent, or so, and will be driven by the afternoon sea breeze. If you were expecting us to fall into a high-pressure dominated hot weather pattern next week, don’t. All indications are we’re going to see healthy rain chances through the end of the month, with moderate highs in the low 90s.

Tropics

We are now officially in the heart of hurricane season for Texas, and the entire Atlantic basin. For us, this period runs for about the next six weeks, when the state is most vulnerable to hurricanes, and the Gulf of Mexico at its warmest to support them. So far, it has been a quiet year in terms of Accumulated Cyclone Energy, a measurement of the duration and intensity of tropical systems. The Atlantic basin has seen just 13 percent of its average cyclone energy through this week, according to hurricane scientist Brian McNoldy.

The tropics are waking up, however. A tropical wave that recently moved off of Africa has a chance of developing this week as it traverses the Atlantic, although it will have to combat a fair amount of dry air over the next several days so it may dissipate. Behind this wave there are more, so we should expect to see activity continue to tick up. But the good news is that the season is slower than anticipated so far, and there’s no reason to think any of these systems are going to track near the Gulf of Mexico any time soon.

Good morning. I’m jumping in with a quick weekend update due to the ongoing wet pattern. We don’t have any concerns about significant, widespread flooding right now. However, these storms will bear a lot of moisture, and some will produce high rainfall rates that can quickly lead to flash flooding in Houston’s streets. This is a concern for today, and for the next week or so.

In terms of the overall picture, after a torrid start to summer Houston is in the midst of a stark pattern change due to an unsettled atmosphere that is producing lots of clouds, cooler daytime temperatures, and widespread showers. How about this for a stark contrast? Friday’s high temperature at Bush Intercontinental Airport was just 77 degrees (a record low maximum temperature for August 19). The region has not recorded a daily high that low since April 19. This pattern is likely to hold through most of next week, although daytime highs will not be that cool.

Saturday and Sunday

We’re going to see rainfall on both weekend days across much of the region, probably with 60 or 70 percent coverage, and the best chances coming between about 10 am and 6 pm CT on both days with daytime heating. Accumulations will be on the order of 0.5 to 1.0 inch of rain for most, but a handful of locations could see 2, 3 or even more inches of rain beneath the heaviest storms that will have high rainfall rates. Otherwise, expect high temperatures generally in the upper 80s, with partly to mostly cloudy skies.

Next week

The pattern, if anything, turns wetter during the coming week for Houston and much of Texas as high pressure is gone and the state sees a series of atmospheric disturbances pass through. The best chance of rain will come for parts of north and east Texas, where upwards of 10 inches is possible through Friday. This is almost certainly going to cause flooding issues for parts of the Dallas metro area over to places like Texarkana. Closer to home, I think much of the area will pick up 2 to 5 inches of rain from Monday through Friday of next week. Highs most days will be in the mid- to upper-80s. These days will be partly to mostly cloudy, with limited chances for sunshine until Friday most likely.

Tropics

The National Hurricane Center has designated a tropical disturbance in the southern Gulf of Mexico “Potential Tropical Cyclone Four,” and it should move into the northern coast of Mexico, and South Texas, during the next 24 hours. Whether it organizes sufficiently before then to become a tropical depression or storm is largely moot, as it is principally a rainmaker, likely to bring several inches of rain to those areas. The Upper Texas coast may see some ancillary moisture from this system that will support rain on Sunday or Monday, but we don’t see any serious, direct effects.