Weather buffs could soon be treated to a rare event: the Fujiwhara Effect. That’s when one tropical storm collides with another. Topical Storm Philippe is being overtaken by the newly formed Tropical Storm Rina. See the satellite image below taken around 12:30 PM CDT.
12:20 pm Houston timeTwo hours and forty minutes later.
Will They Merge?
I asked Harris County Meteorologist Jeff Lindner what happens in such a case. His response:
“Generally speaking the weaker system will rotate around the stronger system. This is known as the Fujiwhara Effect.”
Harris County Meteorologist Jeff Lindner
Wikipedia offers a great description of this rare event and some of the parameters necessary for it to occur.
“The effect occurs,” says Wikipedia, when two nearby cyclonicvortices move around each other and close the distance between the circulations of their corresponding low-pressure areas. The effect is named after Sakuhei Fujiwhara, the Japanese meteorologist who initially described the effect. Binary interaction of smaller circulations can cause the development of a larger cyclone, or cause two cyclones to merge into one. … Tropical cyclones typically interact within 870 mi. of each other.”
These storms are already within that radius. At this hour (3:30 PM CDT on 9/28/23), the centers of Philippe and Rina are 631 miles apart, but their outer bands are already interacting as you can see in the photos above. And the effect will likely become stronger.
Philippe (left) is moving at 2 mph and Rina at 10 mph. So they will come even closer.
Cones of Uncertainty
The two maps below show projected tracks for the next few days. But remember, the center of the storm has an equal chance of passing through any point within the cone of uncertainty.
Here’s the cone for Philippe.
Here’s the cone for Rina.
Pick a spot on the grid and compare the projected locations over time.
Wikipedia says, “Rotation rates accelerate when tropical cyclones close within 400 mi of each other. Systems typically merge when they are within 190 mi of one another.”
So we have at least a few days to watch these two and a developing Fujiwhara effect if any.
At an 8 mph closing rate, two storms 631 miles apart would take about 2.5 days to get within 190 miles of each other.
How to See if They Merge
Mergers are fairly rare, according to Wikipedia. But these two could tango. So watch to see if they merge over the next few days. Exact predictions are difficult, because of the uncertainty associated with storm tracks.
However, you can check their progress and proximity visually by looking at the satellite images on NOAA’s National Hurricane Center website. Select from several different options within the “Atlantic-Wide View”: Geo-Color, Visible, Short Wave IR, Infrared, and Water Vapor.
Regardless of what happens, NOAA does not predict that these storms will come anywhere close to Texas. So sleep easy.
Posted by Bob Rehak on 9/28/23
2221 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/09/20230928-Twin-Spin.jpg?fit=1100%2C660&ssl=16601100adminadmin2023-09-28 15:52:012023-09-28 15:53:36Will We See Fujiwhara Effect? Twin Spin in Atlantic
When I say “dig a little deeper” to improve flood mitigation, I’m speaking metaphorically, of course.
On September 17, 2023, Jim Blackburn, a lawyer and professor of environmental law in the Rice University engineering department, published an article in the Houston Chronicle. He titled it, “What Houston’s next mayor needs to do about flooding.”
Both Prof. Blackburn and the Chronicle labeled the article “opinion.” That’s fortunate because in some areas, Blackburn made assertions contradicted by facts. In most other areas, he made high-level recommendations without any specifics.
For example, among other things, Prof. Blackburn argues that Houston’s next mayor should:
Build more mitigation projects for Halls and Greens Bayou Watersheds, which he says haven’t received their fair share.
Address climate change with better planning and engineering tools.
Speed up buyouts.
Let’s examine each and why we all need to dig a little deeper if we want to improve flood mitigation.
Halls and Greens Bayou Watersheds
Both Halls and Greens watersheds HAVE received mitigation projects. Many. And more than their fair share. You can see it in spending data and on the ground. However, Harris County Flood Control District has delivered the projects, not the City of Houston.
HCFCD and its partners have spent more than $390 million on Greens and Halls mitigation improvements since 2000. Greens has received more dollars than any other watershed except Brays (where Rice is). And tiny Halls ranks third in dollars per capita among all watersheds.
Professor Blackburn and his graduate students need to dig a little deeper. They should get out more and smell the construction dust. For example, here is a new Halls Bayou detention basin, one of many built in the watershed during the last 10 years.
New Halls Bayou Detention Basin west of Keith Weiss Park, photographed in March 2022.
Then, there’s this new detention basin along Greens Bayou at Cutten Road under construction in 2021. Again, it’s one of at least a half dozen built in the last ten years along Greens.
One portion of the massive Cutten Road stormwater detention basin on Greens Bayou
I compile flood-mitigation funding by watershed through quarterly FOIA requests. I also cross-check the data by photographing construction from the air.
Of the top five watersheds above, four have a majority of low-to-moderate income residents; only Cypress Creek does not. Those five watersheds have received 60% of all funding going back to 2000, compared to 40% for the other 18 watersheds put together.
From high to low in the graph above, spending varies by 130X. Such data shows that many watersheds have been historically deprived – in the name of “equity.” But those deprived tend to be on the more affluent end of the spectrum.
Address Climate Change with Better Planning and Engineering Tools
Next, Professor Blackburn wants to address climate change with better planning and engineering tools. It’s hard to see what more the next Mayor of Houston could do in this regard.
Professor Blackburn asserts that we need to “understand our changed rainfall patterns and integrate that knowledge into every aspect of the City’s thinking.”
Since Harvey, the City has already adopted NOAA’s new Atlas-14 rainfall-probability statistics and incorporated them into its regulations. So, design professionals are already working on new, updated assumptions.
Professor Blackburn, a reputed expert, doesn’t define how climate is changing, but asserts that professionals should consider the changing patterns. He believes they should engineer “streets, sewage treatment plants, underground and above-ground stormwater systems, floodplains and general drainage flow patterns” with the unspecified climate patterns in mind.
It’s hard to argue against progress. But the real issue, in my opinion, is that leaders in many surrounding cities and counties have not yet uniformly adopted NOAA’s Atlas 14 standards. Perhaps the next Mayor could jawbone them into sending less water downstream.
The Mayor could also discourage large increases in impervious cover under proposed programs such as the Houston Planning Commission’s so-called Livable Places. Livable Places would disproportionately increase flood risk for low-income and minority neighborhoods because of the program’s linkage to mass transit.
Speed Up Buyouts
Blackburn believes that buyouts should happen faster after a flood – before people rebuild. Most people agree that the process needs streamlining. But how?
Experts have proposed multiple improvements. However, none has gained traction across the board with local, State, and Federal lawmakers.
For instance, after Harvey, Harris County Flood Control executives pitched plans in Austin for a QBF (Quick Buyout Force). Instead of waiting for:
The President to declare a disaster
Congress to vote funds
FEMA to design rules for disaster relief
The State to adopt them
Local agencies to identify eligible recipients and solicit applications
Local, State and Federal authorities to review and approve the applications, and
Money to flow through the pipeline…
…HCFCD argued for pre-approval of guidelines and to have a pot of funds available before disaster strikes, kind of like a savings account for a rainy day. Money could then be used immediately. Local agencies would later reimburse the Federal government for money they didn’t use.
Houston’s next Mayor could throw his/her influence behind such a plan or a suitable alternative.
Unfortunately, Prof. Blackburn doesn’t recommend a plan. Nor does he dissect each issue and give us the benefit of his wisdom. With all the brainpower and resources at his disposal, he could make a genuine contribution to the community. Perhaps his future opinion pieces will elucidate how we should improve beyond simply preparing for the future.
Collectively, we all need to dig a little deeper to improve flood mitigation. We need to start with facts and get down to specifics.
Posted by Bob Rehak on 9/27/2023
2220 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/2023/09/image-1.png?fit=936%2C618&ssl=1618936adminadmin2023-09-27 06:45:282023-09-27 18:25:07For Better Flood Mitigation, Let’s Dig a Little Deeper
9/25/23 – Approximately 425,000 people live in the 204 square mile Cypress Creek watershed which has severe repetitive flooding. At a press conference this morning, County, State and Federal officials announced $50 million in funding for a massive complex of stormwater detention basins on Cypress Creek at T.C. Jester Blvd. to help protect those people.
The basins will span approximately 150 acres on both sides of T.C. Jester and include 1200-acre feet of planned stormwater detention capacity, wet bottoms, and recreational trails.
Approximate boundaries of three detention basins – one will go west of TC Jester and two more east.White area is existing basin.
Altogether, the stormwater detention capacity in this area will increase approximately 75X.
Google Earth calculation of existing and planned ponds
The existing pond covers approximately 2 acres and the new areas will cover more than 150.
Looking E over T.C. Jester. Existing 2-acre basin in foreground was site of press conference. Wooded area beyond will become two new detention basins.
Thanks to County, State and Federal Governments
The $50 million will come from three primary sources:
State Representative Sam Harless secured $12 million in State of Texas funding.
Harris County Flood Control District Executive Director Tina Petersen also reminded everyone of the money designated for Cypress Creek in the Flood Bond, which was considerable.
The GLO/HUD money has been requested but not yet confirmed although all indications are positive at this time. GLO Commissioner Dawn Buckingham has committed to making sure that people in all parts of Harris County benefit from the $750 million.
Timetable and Project Scope
HCFCD Director Dr. Petersen addressed the next steps in the projects. “A portion of the projects on the east side of T.C. Jester will start construction in the next 6 to 9 months. The remainder should go into construction no later than the end of 2024. So we’re going to see these projects move quickly. This type of progress would not have been possible without the critical funding that our Congressman and Representative secured “
The overall project includes three stormwater detention basins within a broader footprint. Two basin compartments are on the east side of T.C. Jester Boulevard and another is on the west side.
Excavation of the west side basin (see below) has already begun under an E&R (Excavation and Removal) Contract. A private contractor is removing the dirt, almost free of charge, then selling it at market rates to recoup costs and make a profit. An estimated 120,000 cubic yards of material has already been excavated to date.
Work to date on basin west of T.C. Jester. Looking N toward Cypresswood Drive.
The contractor began removing dirt in the general area to get a head start on construction, even before final design of the basin. The final design will begin soon.
Each basin will have a wet-bottom with maintenance berms, side slopes and high banks along the outside.
Construction for all basins should begin no later than Q4 2024. They have estimated 8-month construction timelines.
Extent of Benefits
The three stormwater detention basins will work together – taking stormwater from the main stem of Cypress Creek and holding it until water levels recede on the main stem.
The projects will also have recreational benefits such as hike and bike trails.
Director Petersen stated that the projects will primarily benefit the local area, i.e., benefits will not extend very far downstream. The 1200 acre feet will likely take several thousand homes out of the floodplain.
Even though those homes will be in the Cypress Creek area, 1200 acre feet being held back upstream is 1200 acre feet that won’t be in the living rooms of Lake Houston Area residents during the next big flood.
More to Come
Ramsey also pointed to more projects to come, though he didn’t elaborate. He said, “This is $50 million of the $100 million that will be spent over the coming months in the Cypress watershed. So hold on. We’re getting started. This isn’t the end. This is the beginning.”
Speakers at T.C. Jester Detention Basin Press Conference included U.S. Representative Dan Crenshaw, State Representative Sam Harless, Harris County Precinct 3 Commissioner Tom Ramsey P.E., and HCFCD Executive Director Dr. Tina Petersen.
Posted by Bob Rehak on 9/25/2023
2218 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2023/09/20230925-RJR_2415.jpg?fit=1100%2C733&ssl=17331100adminadmin2023-09-25 17:58:212023-09-25 22:11:13Funding Announced for Massive Detention-Basin Complex on Cypress Creek
Will We See Fujiwhara Effect? Twin Spin in Atlantic
Weather buffs could soon be treated to a rare event: the Fujiwhara Effect. That’s when one tropical storm collides with another. Topical Storm Philippe is being overtaken by the newly formed Tropical Storm Rina. See the satellite image below taken around 12:30 PM CDT.
Will They Merge?
I asked Harris County Meteorologist Jeff Lindner what happens in such a case. His response:
Wikipedia offers a great description of this rare event and some of the parameters necessary for it to occur.
“The effect occurs,” says Wikipedia, when two nearby cyclonic vortices move around each other and close the distance between the circulations of their corresponding low-pressure areas. The effect is named after Sakuhei Fujiwhara, the Japanese meteorologist who initially described the effect. Binary interaction of smaller circulations can cause the development of a larger cyclone, or cause two cyclones to merge into one. … Tropical cyclones typically interact within 870 mi. of each other.”
These storms are already within that radius. At this hour (3:30 PM CDT on 9/28/23), the centers of Philippe and Rina are 631 miles apart, but their outer bands are already interacting as you can see in the photos above. And the effect will likely become stronger.
Philippe (left) is moving at 2 mph and Rina at 10 mph. So they will come even closer.
Cones of Uncertainty
The two maps below show projected tracks for the next few days. But remember, the center of the storm has an equal chance of passing through any point within the cone of uncertainty.
Here’s the cone for Philippe.
Here’s the cone for Rina.
Pick a spot on the grid and compare the projected locations over time.
Wikipedia says, “Rotation rates accelerate when tropical cyclones close within 400 mi of each other. Systems typically merge when they are within 190 mi of one another.”
So we have at least a few days to watch these two and a developing Fujiwhara effect if any.
At an 8 mph closing rate, two storms 631 miles apart would take about 2.5 days to get within 190 miles of each other.
How to See if They Merge
Mergers are fairly rare, according to Wikipedia. But these two could tango. So watch to see if they merge over the next few days. Exact predictions are difficult, because of the uncertainty associated with storm tracks.
However, you can check their progress and proximity visually by looking at the satellite images on NOAA’s National Hurricane Center website. Select from several different options within the “Atlantic-Wide View”: Geo-Color, Visible, Short Wave IR, Infrared, and Water Vapor.
Regardless of what happens, NOAA does not predict that these storms will come anywhere close to Texas. So sleep easy.
Posted by Bob Rehak on 9/28/23
2221 Days since Hurricane Harvey
For Better Flood Mitigation, Let’s Dig a Little Deeper
When I say “dig a little deeper” to improve flood mitigation, I’m speaking metaphorically, of course.
On September 17, 2023, Jim Blackburn, a lawyer and professor of environmental law in the Rice University engineering department, published an article in the Houston Chronicle. He titled it, “What Houston’s next mayor needs to do about flooding.”
Both Prof. Blackburn and the Chronicle labeled the article “opinion.” That’s fortunate because in some areas, Blackburn made assertions contradicted by facts. In most other areas, he made high-level recommendations without any specifics.
For example, among other things, Prof. Blackburn argues that Houston’s next mayor should:
Let’s examine each and why we all need to dig a little deeper if we want to improve flood mitigation.
Halls and Greens Bayou Watersheds
Both Halls and Greens watersheds HAVE received mitigation projects. Many. And more than their fair share. You can see it in spending data and on the ground. However, Harris County Flood Control District has delivered the projects, not the City of Houston.
HCFCD and its partners have spent more than $390 million on Greens and Halls mitigation improvements since 2000. Greens has received more dollars than any other watershed except Brays (where Rice is). And tiny Halls ranks third in dollars per capita among all watersheds.
Professor Blackburn and his graduate students need to dig a little deeper. They should get out more and smell the construction dust. For example, here is a new Halls Bayou detention basin, one of many built in the watershed during the last 10 years.
Then, there’s this new detention basin along Greens Bayou at Cutten Road under construction in 2021. Again, it’s one of at least a half dozen built in the last ten years along Greens.
I compile flood-mitigation funding by watershed through quarterly FOIA requests. I also cross-check the data by photographing construction from the air.
Photos such as those above support the spending reported below. However, neither the photos nor the spending data fit the current, popular political narrative about “historical disinvestment” in low-income minority neighborhoods.
Of the top five watersheds above, four have a majority of low-to-moderate income residents; only Cypress Creek does not. Those five watersheds have received 60% of all funding going back to 2000, compared to 40% for the other 18 watersheds put together.
From high to low in the graph above, spending varies by 130X. Such data shows that many watersheds have been historically deprived – in the name of “equity.” But those deprived tend to be on the more affluent end of the spectrum.
Address Climate Change with Better Planning and Engineering Tools
Next, Professor Blackburn wants to address climate change with better planning and engineering tools. It’s hard to see what more the next Mayor of Houston could do in this regard.
Professor Blackburn asserts that we need to “understand our changed rainfall patterns and integrate that knowledge into every aspect of the City’s thinking.”
Since Harvey, the City has already adopted NOAA’s new Atlas-14 rainfall-probability statistics and incorporated them into its regulations. So, design professionals are already working on new, updated assumptions.
Plus, NOAA is currently working on Atlas 15 which predicts future impacts of climate change. But NOAA won’t release those stats until 2027 at the earliest – after the next mayoral election.
Professor Blackburn, a reputed expert, doesn’t define how climate is changing, but asserts that professionals should consider the changing patterns. He believes they should engineer “streets, sewage treatment plants, underground and above-ground stormwater systems, floodplains and general drainage flow patterns” with the unspecified climate patterns in mind.
It’s hard to argue against progress. But the real issue, in my opinion, is that leaders in many surrounding cities and counties have not yet uniformly adopted NOAA’s Atlas 14 standards. Perhaps the next Mayor could jawbone them into sending less water downstream.
The Mayor could also discourage large increases in impervious cover under proposed programs such as the Houston Planning Commission’s so-called Livable Places. Livable Places would disproportionately increase flood risk for low-income and minority neighborhoods because of the program’s linkage to mass transit.
Speed Up Buyouts
Blackburn believes that buyouts should happen faster after a flood – before people rebuild. Most people agree that the process needs streamlining. But how?
Experts have proposed multiple improvements. However, none has gained traction across the board with local, State, and Federal lawmakers.
For instance, after Harvey, Harris County Flood Control executives pitched plans in Austin for a QBF (Quick Buyout Force). Instead of waiting for:
…HCFCD argued for pre-approval of guidelines and to have a pot of funds available before disaster strikes, kind of like a savings account for a rainy day. Money could then be used immediately. Local agencies would later reimburse the Federal government for money they didn’t use.
Houston’s next Mayor could throw his/her influence behind such a plan or a suitable alternative.
Unfortunately, Prof. Blackburn doesn’t recommend a plan. Nor does he dissect each issue and give us the benefit of his wisdom. With all the brainpower and resources at his disposal, he could make a genuine contribution to the community. Perhaps his future opinion pieces will elucidate how we should improve beyond simply preparing for the future.
Collectively, we all need to dig a little deeper to improve flood mitigation. We need to start with facts and get down to specifics.
Posted by Bob Rehak on 9/27/2023
2220 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.
Funding Announced for Massive Detention-Basin Complex on Cypress Creek
9/25/23 – Approximately 425,000 people live in the 204 square mile Cypress Creek watershed which has severe repetitive flooding. At a press conference this morning, County, State and Federal officials announced $50 million in funding for a massive complex of stormwater detention basins on Cypress Creek at T.C. Jester Blvd. to help protect those people.
The basins will span approximately 150 acres on both sides of T.C. Jester and include 1200-acre feet of planned stormwater detention capacity, wet bottoms, and recreational trails.
The existing pond covers approximately 2 acres and the new areas will cover more than 150.
Thanks to County, State and Federal Governments
The $50 million will come from three primary sources:
Harris County Flood Control District Executive Director Tina Petersen also reminded everyone of the money designated for Cypress Creek in the Flood Bond, which was considerable.
The GLO/HUD money has been requested but not yet confirmed although all indications are positive at this time. GLO Commissioner Dawn Buckingham has committed to making sure that people in all parts of Harris County benefit from the $750 million.
Timetable and Project Scope
HCFCD Director Dr. Petersen addressed the next steps in the projects. “A portion of the projects on the east side of T.C. Jester will start construction in the next 6 to 9 months. The remainder should go into construction no later than the end of 2024. So we’re going to see these projects move quickly. This type of progress would not have been possible without the critical funding that our Congressman and Representative secured “
The overall project includes three stormwater detention basins within a broader footprint. Two basin compartments are on the east side of T.C. Jester Boulevard and another is on the west side.
Excavation of the west side basin (see below) has already begun under an E&R (Excavation and Removal) Contract. A private contractor is removing the dirt, almost free of charge, then selling it at market rates to recoup costs and make a profit. An estimated 120,000 cubic yards of material has already been excavated to date.
The contractor began removing dirt in the general area to get a head start on construction, even before final design of the basin. The final design will begin soon.
Each basin will have a wet-bottom with maintenance berms, side slopes and high banks along the outside.
Construction for all basins should begin no later than Q4 2024. They have estimated 8-month construction timelines.
Extent of Benefits
The three stormwater detention basins will work together – taking stormwater from the main stem of Cypress Creek and holding it until water levels recede on the main stem.
The projects will also have recreational benefits such as hike and bike trails.
Director Petersen stated that the projects will primarily benefit the local area, i.e., benefits will not extend very far downstream. The 1200 acre feet will likely take several thousand homes out of the floodplain.
Even though those homes will be in the Cypress Creek area, 1200 acre feet being held back upstream is 1200 acre feet that won’t be in the living rooms of Lake Houston Area residents during the next big flood.
More to Come
Ramsey also pointed to more projects to come, though he didn’t elaborate. He said, “This is $50 million of the $100 million that will be spent over the coming months in the Cypress watershed. So hold on. We’re getting started. This isn’t the end. This is the beginning.”
Posted by Bob Rehak on 9/25/2023
2218 Days since Hurricane Harvey