After three years of La Niña, signs point to the start of El Niño with cooler-than-normal temperatures off the Pacific Coast of North America. Jeff Lindner, Harris County’s meteorologist, says an El Niño could fully develop in the next few months. Here are El Niño implications for the Gulf Coast.
Cooler, Wetter, Fewer Hurricanes
In the south-central United States, major impacts during an El Niño event consist of:
above-normal precipitation, particularly during winter
below-normal temperatures, also during winter
a less active hurricane season, with fewer named storms
In general, stronger winds from the west during El Niño tend to inhibit development of storms trying to approach from the east. Meteorologists call that process “wind shear.” See red arrow in second map below.
While most organizations have expressed growing confidence in the development of an El Niño, a few have noted above-average ocean temperatures in the eastern Atlantic that introduce uncertainty and which could actually yield greater activity, particularly if a weaker El Niño event materializes. See below.
Note cooling sea surface temps off coast ofwestern U.S. and warming temps off coast of western South America and Africa. Source: NOAA SST Anomaly Charts.
South America has had cooler-than-normal waters off its west coast for the last three years, but now those same waters have warmed for the last 3-5 months. And the cooler waters have shifted north of the western coast of the U.S. and Canada.
Jeff Lindner, Harris County’s meteorologist says, “We need to see these conditions hold for a few months for the official declaration of El Niño. Lindner says conditions could likely intensify into a strong El Niño by late this summer or early fall.
El Niño Typically Brings Wetter Weather to Gulf Coast
He also notes that sea surface temperature anomalies of this magnitude can shift weather patterns across the globe.
Locally, Lindner says, “El Nino tends to support wetter and cooler conditions during our fall, winter, and spring months. There is less influence during summer.”
“The threat for heavy rainfall and flooding is generally higher during El Niño periods.”
Jeff Lindner, Harris County Meteorologist
According to Lindner, La Niña tends to correlate with the opposite influences – warmer, drier conditions for Texas or even drought…as many areas have experienced during the most recent La Niña event that started in early 2020.
Not all El Niño events are the same. Other global weather patterns can enhance or interfere with the effects of El Niño.
Lindner believes that the speed with which El Niño conditions form this summer will likely determine the fate of the Atlantic basin hurricane season. “A quicker onset would tend to significantly reduce Atlantic basin activity while an onset more toward early fall may allow a slightly busier and “front loaded” season,” he says.
El Niño patterns tend to favor reduced Caribbean hurricane activity and a higher chance of more sub-tropical development over the mid-Atlantic.
During El Niño years, says Lindner, tropical storms and hurricanes tend to form “in close” in the northern Gulf and off the southeast U.S. coast as tropical waves move into more favorable conditions.
Less Drought Likely
As El Nino develops this summer into the fall, it is likely that Texas and the southern plains will transition toward a wetter pattern. That should lessen or eliminate the ongoing drought across portions of Texas. Lindner expects to see significant improvements by late fall into the winter.
Posted by Bob Rehak on 5/4/2023based on a press release by Harris County Meteorologist Jeff Lindner
2074 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/05/ssta.daily_.current.png?fit=1787%2C1085&ssl=110851787adminadmin2023-05-04 16:11:532023-05-04 16:27:44El Niño Implications for Gulf Coast
The stormwater-detention basin at the Laurel Springs RV Resort is supposed to have, according to the construction permit plans, a dry bottom. However, the basin almost always retains water, despite the fact that it should empty within 48 hours of a 100-year rain. A 100-year rain is 17.3 inches in the Lake Houston Area.
The pond retains so much water for so long – after even minor rains – that the resort has posted “No Swimming” signs.
As a tribute to the presence of water, the pond has even attracted nesting ducks, which can be an aviation hazard so close to Bush Intercontinental Airport.
Reason for Dry-Bottom Requirement
The Resort falls within a defined radius of Houston Bush Intercontinental Airport and the City wants to discourage birds from nesting there, especially large birds that can damage aircraft. Hence the requirement on the permit plans. (See more below.)
A retired airline pilot, who lives nearby and knows the dangers of bird strikes all too well, sent me the two photos below. The first shows seven ducklings in the Resort pond. The next shows a “No Swimming” sign next to the walking trail around the pond.
Seven ducklings enjoying the waters of the Laurel Springs RV Resort. No adults seen at this time.Sign warning customers not to swim indicates permanence of water.
Construction Permit Plans Note Restriction
Because of this pond’s location near IAH, the FAA and City of Houston stipulate that the stormwater detention basin should have a dry bottom within 48 hours after a “design storm.” The requirement helps discourage birds, especially geese and other large waterfowl, from taking up residence close to the airport. That’s an important consideration, especially during the migration season, which we are in right now.
Reference to “design storm”means a 100-year event. In this location, that means 17.3 inches of rain in 24 hours.
A retired airline captain who lives near the RV resort keeps calling this to my attention.
I first posted about this in May of last year and was told that the Resort hadn’t hooked up electricity to its pumps yet. Six months later, the pumps still weren’t working.
Now, a full year later, we have a brood of ducklings in the pond and a no-swimming sign that shouldn’t be necessary if the drainage worked properly.
No Rain in Past 48 Hours, Little Rain in Past Week
It hasn’t rained in the last 48 hours, according to the official gage at US59 gage about a half mile from the basin.
And in the last week, we have received only .72 inches of rain. That occurred in two events more than 24 hours apart.
That’s about one sixth of a 1-year rain according to Atlas-14 standards below. It’s also less than one twenty-fourth of a 100-year rain stipulated by the FAA.
Atlas-14 Rainfall standards used as the basis for designing detention basins.
Here’s what the pond looked like today – five days after after the last rain – which could have been pumped out within hours.
Laurel Springs RV Resort Detention basin should be dry but obviously isn’t.
Two Bird Strikes Force United Flights Down at IAH Last Week
CNN reported last week that two bird strikes within 20 minutes of each other forced United flights to return to Intercontinental. CNN said that this year alone the FAA has already reported about 2,000 bird strikes, and 85% involved commercial airliners. Most bird strikes are waterfowl, although admittedly larger than the ducklings above.
Something to think about next time you fly.
Posted by Bob Rehak on 5/3/2023 based on pictures from a reader
2073 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/05/No-Swimming.jpg?fit=1200%2C822&ssl=18221200adminadmin2023-05-03 13:05:012023-05-03 14:06:45“No Swimming” in Dry-Bottom Pond!
Harris County Flood Control District’s (HCFCD) Woodridge Village Excavation and Removal contract with Sprint Sand & Clay continues progressing nicely. The volume excavated last month shows a continued rebound in activity after a dip last year when the housing market slowed.
As of the end of April, Sprint has completed approximately 23% of its 500,000-cubic-yard contract. More important, excavation could meet Atlas-14 detention requirements by the end of 2023.
Sprint excavated an estimated 11,000 cubic yards in April – more than double the monthly minimum. That brings the total to date to approximately 115,000 cubic yards.
Photos Reveal Excavation in New Direction
Here’s what the status of Woodridge Village excavation looked like on 5/1/2023. For the last year, Sprint has focused on lengthening the basin. Now it is focusing on widening it, too. Note the work taking place in the upper left quadrant of the photo below.
Looking northeast. Looking southwest toward Kingwood Park High School.Looking east at current area of excavation.
Typically, HCFCD gives E&R contractors some general boundaries and says, “Start digging.” Sprint makes its money by selling the dirt on the open market. There’s virtually no cost to taxpayers. And usually the bigger the hole in the ground, the better. So, according to a former flood control executive, if Sprint goes beyond 500,000 cubic yards, no one will complain. It reduces flood risk free of charge.
Partially as a result of insufficient stormwater detention capacity, up to 600 homes downstream in Kingwood flooded twice in 2019.
After HCFCD bought the property, it hired Sprint to get a head start on Woodridge Village excavation of additional detention capacity while it worked out exact plans for a regional detention basin and Taylor Gully.
Sprint has excavated approximately 71 acre feet so far. That brings the current detention capacity to 342 acre feet.
But HCFCD will ultimately need approximately 385 acre feet of stormwater detention capacity to meet Atlas-14 requirements and it hopes to build even more as a safety hedge against future needs should they increase.
If Sprint excavates the entire 500,000 cubic yards in its contract, that would bring the total stormwater detention capacity up to 580 acre feet. In tabular form, the steps look like this:
Acre Feetof Stormwater Detention
% of Ultimate
Site Had When Purchased from Perry Homes
271
47%
Has as of 5/1/23
342
59%
Atlas 14 Requires
385
66%
If Sprint Excavates All 500K Cubic Feet
580
100%
Calculations based on original construction plans, HCFCD monthly reports, Atlas-14 Requirements and Sprint contract.
Calculations in the last column assume that Sprint excavates all 500,000 cubic yards. But Sprint’s contract calls for excavating UP TO 500,000 cubic yards.
A lot of flexibility exists for both parties in an E&R contract. If the demand for dirt dries up and excavation slows, HCFCD and Sprint could modify the E&R contract to complete a smaller detention basin sooner. But I assume it would still meet Atlas 14 requirements at a minimum.
Based on April performance, Sprint is currently excavating approximately 6 acre feet per month.
If demand for dirt holds, excavation should reach Atlas-14 requirements near the end of 2023.
Still Much More Work to Do
But simply excavating the dirt isn’t the end of the job. Harris County still needs to slope the sides, plant grass, and tie the new basin into the site’s existing stormwater-detention-basin network.
An engineering team is currently working on drawing up final construction plans. Simultaneously, they are looking at how Woodridge Village excavation will impact Taylor Gully needs.
At the moment, no one knows exactly how this project will end. There are simply too many variables. The site could contain one giant stormwater detention basin or several smaller ones.
HCFCD often employs a phased approach with large projects, such as Woodridge/Taylor Gully. Consider for instance, Willow Water Hole on South Post Oak at Highway 90. Or the Lauder Basin on Greens Bayou south of Beltway 8 North.
A phased approach enables residents to start reaping partial benefits sooner, with an eye toward maximizing future risk reduction as circumstances and funding allow.
Posted by Bob Rehak on 5/2/2023
2072 Days since Hurricane Harveyand 1329 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/05/20230501-DJI_0671.jpg?fit=1200%2C799&ssl=17991200adminadmin2023-05-02 15:13:082023-05-02 18:17:05Woodridge Village Excavation Approaching Atlas-14 Requirement
El Niño Implications for Gulf Coast
After three years of La Niña, signs point to the start of El Niño with cooler-than-normal temperatures off the Pacific Coast of North America. Jeff Lindner, Harris County’s meteorologist, says an El Niño could fully develop in the next few months. Here are El Niño implications for the Gulf Coast.
Cooler, Wetter, Fewer Hurricanes
In the south-central United States, major impacts during an El Niño event consist of:
In general, stronger winds from the west during El Niño tend to inhibit development of storms trying to approach from the east. Meteorologists call that process “wind shear.” See red arrow in second map below.
CSU Predicts Below-Normal Hurricane Season This Year
Colorado State University hurricane researchers predict a slightly below-average Atlantic hurricane season in 2023, citing the likely development of El Niño as a primary factor.
While most organizations have expressed growing confidence in the development of an El Niño, a few have noted above-average ocean temperatures in the eastern Atlantic that introduce uncertainty and which could actually yield greater activity, particularly if a weaker El Niño event materializes. See below.
South America has had cooler-than-normal waters off its west coast for the last three years, but now those same waters have warmed for the last 3-5 months. And the cooler waters have shifted north of the western coast of the U.S. and Canada.
Jeff Lindner, Harris County’s meteorologist says, “We need to see these conditions hold for a few months for the official declaration of El Niño. Lindner says conditions could likely intensify into a strong El Niño by late this summer or early fall.
El Niño Typically Brings Wetter Weather to Gulf Coast
He also notes that sea surface temperature anomalies of this magnitude can shift weather patterns across the globe.
Locally, Lindner says, “El Nino tends to support wetter and cooler conditions during our fall, winter, and spring months. There is less influence during summer.”
According to Lindner, La Niña tends to correlate with the opposite influences – warmer, drier conditions for Texas or even drought…as many areas have experienced during the most recent La Niña event that started in early 2020.
Not all El Niño events are the same. Other global weather patterns can enhance or interfere with the effects of El Niño.
Lindner believes that the speed with which El Niño conditions form this summer will likely determine the fate of the Atlantic basin hurricane season. “A quicker onset would tend to significantly reduce Atlantic basin activity while an onset more toward early fall may allow a slightly busier and “front loaded” season,” he says.
El Niño patterns tend to favor reduced Caribbean hurricane activity and a higher chance of more sub-tropical development over the mid-Atlantic.
During El Niño years, says Lindner, tropical storms and hurricanes tend to form “in close” in the northern Gulf and off the southeast U.S. coast as tropical waves move into more favorable conditions.
Less Drought Likely
As El Nino develops this summer into the fall, it is likely that Texas and the southern plains will transition toward a wetter pattern. That should lessen or eliminate the ongoing drought across portions of Texas. Lindner expects to see significant improvements by late fall into the winter.
Posted by Bob Rehak on 5/4/2023 based on a press release by Harris County Meteorologist Jeff Lindner
2074 Days since Hurricane Harvey
“No Swimming” in Dry-Bottom Pond!
The stormwater-detention basin at the Laurel Springs RV Resort is supposed to have, according to the construction permit plans, a dry bottom. However, the basin almost always retains water, despite the fact that it should empty within 48 hours of a 100-year rain. A 100-year rain is 17.3 inches in the Lake Houston Area.
The pond retains so much water for so long – after even minor rains – that the resort has posted “No Swimming” signs.
As a tribute to the presence of water, the pond has even attracted nesting ducks, which can be an aviation hazard so close to Bush Intercontinental Airport.
Reason for Dry-Bottom Requirement
The Resort falls within a defined radius of Houston Bush Intercontinental Airport and the City wants to discourage birds from nesting there, especially large birds that can damage aircraft. Hence the requirement on the permit plans. (See more below.)
A retired airline pilot, who lives nearby and knows the dangers of bird strikes all too well, sent me the two photos below. The first shows seven ducklings in the Resort pond. The next shows a “No Swimming” sign next to the walking trail around the pond.
Construction Permit Plans Note Restriction
Because of this pond’s location near IAH, the FAA and City of Houston stipulate that the stormwater detention basin should have a dry bottom within 48 hours after a “design storm.” The requirement helps discourage birds, especially geese and other large waterfowl, from taking up residence close to the airport. That’s an important consideration, especially during the migration season, which we are in right now.
Wet-bottom ponds attract ducks and geese that create a hazard for aircraft taking off, landing or circling. This requirement is clearly marked on the Resort’s detention and mitigation plan approved by the City of Houston on 12/2/2020.
A retired airline captain who lives near the RV resort keeps calling this to my attention.
I first posted about this in May of last year and was told that the Resort hadn’t hooked up electricity to its pumps yet. Six months later, the pumps still weren’t working.
Now, a full year later, we have a brood of ducklings in the pond and a no-swimming sign that shouldn’t be necessary if the drainage worked properly.
No Rain in Past 48 Hours, Little Rain in Past Week
It hasn’t rained in the last 48 hours, according to the official gage at US59 gage about a half mile from the basin.
And in the last week, we have received only .72 inches of rain. That occurred in two events more than 24 hours apart.
That’s about one sixth of a 1-year rain according to Atlas-14 standards below. It’s also less than one twenty-fourth of a 100-year rain stipulated by the FAA.
Here’s what the pond looked like today – five days after after the last rain – which could have been pumped out within hours.
Two Bird Strikes Force United Flights Down at IAH Last Week
CNN reported last week that two bird strikes within 20 minutes of each other forced United flights to return to Intercontinental. CNN said that this year alone the FAA has already reported about 2,000 bird strikes, and 85% involved commercial airliners. Most bird strikes are waterfowl, although admittedly larger than the ducklings above.
Something to think about next time you fly.
Posted by Bob Rehak on 5/3/2023 based on pictures from a reader
2073 Days since Hurricane Harvey
The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.
Woodridge Village Excavation Approaching Atlas-14 Requirement
Harris County Flood Control District’s (HCFCD) Woodridge Village Excavation and Removal contract with Sprint Sand & Clay continues progressing nicely. The volume excavated last month shows a continued rebound in activity after a dip last year when the housing market slowed.
As of the end of April, Sprint has completed approximately 23% of its 500,000-cubic-yard contract. More important, excavation could meet Atlas-14 detention requirements by the end of 2023.
Sprint excavated an estimated 11,000 cubic yards in April – more than double the monthly minimum. That brings the total to date to approximately 115,000 cubic yards.
Photos Reveal Excavation in New Direction
Here’s what the status of Woodridge Village excavation looked like on 5/1/2023. For the last year, Sprint has focused on lengthening the basin. Now it is focusing on widening it, too. Note the work taking place in the upper left quadrant of the photo below.
Typically, HCFCD gives E&R contractors some general boundaries and says, “Start digging.” Sprint makes its money by selling the dirt on the open market. There’s virtually no cost to taxpayers. And usually the bigger the hole in the ground, the better. So, according to a former flood control executive, if Sprint goes beyond 500,000 cubic yards, no one will complain. It reduces flood risk free of charge.
But where is all this headed and why?
Past, Current and Future Capacities
When Perry Homes sold the Woodridge Village property to HCFCD in 2021, it had five stormwater detention basins with a total storage capacity of 271 acre feet. But because Montgomery County issued construction permits based on pre-Atlas-14 requirements, the development was approximately 42% short of meeting current Harris County standards.
Partially as a result of insufficient stormwater detention capacity, up to 600 homes downstream in Kingwood flooded twice in 2019.
After HCFCD bought the property, it hired Sprint to get a head start on Woodridge Village excavation of additional detention capacity while it worked out exact plans for a regional detention basin and Taylor Gully.
Sprint has excavated approximately 71 acre feet so far. That brings the current detention capacity to 342 acre feet.
But HCFCD will ultimately need approximately 385 acre feet of stormwater detention capacity to meet Atlas-14 requirements and it hopes to build even more as a safety hedge against future needs should they increase.
If Sprint excavates the entire 500,000 cubic yards in its contract, that would bring the total stormwater detention capacity up to 580 acre feet. In tabular form, the steps look like this:
Calculations in the last column assume that Sprint excavates all 500,000 cubic yards. But Sprint’s contract calls for excavating UP TO 500,000 cubic yards.
A lot of flexibility exists for both parties in an E&R contract. If the demand for dirt dries up and excavation slows, HCFCD and Sprint could modify the E&R contract to complete a smaller detention basin sooner. But I assume it would still meet Atlas 14 requirements at a minimum.
Based on April performance, Sprint is currently excavating approximately 6 acre feet per month.
Still Much More Work to Do
But simply excavating the dirt isn’t the end of the job. Harris County still needs to slope the sides, plant grass, and tie the new basin into the site’s existing stormwater-detention-basin network.
An engineering team is currently working on drawing up final construction plans. Simultaneously, they are looking at how Woodridge Village excavation will impact Taylor Gully needs.
At the moment, no one knows exactly how this project will end. There are simply too many variables. The site could contain one giant stormwater detention basin or several smaller ones.
HCFCD often employs a phased approach with large projects, such as Woodridge/Taylor Gully. Consider for instance, Willow Water Hole on South Post Oak at Highway 90. Or the Lauder Basin on Greens Bayou south of Beltway 8 North.
A phased approach enables residents to start reaping partial benefits sooner, with an eye toward maximizing future risk reduction as circumstances and funding allow.
Posted by Bob Rehak on 5/2/2023
2072 Days since Hurricane Harvey and 1329 since Imelda