As of 4am Saturday, 9/19/20 (the 1-year anniversary of Imelda), the National Hurricane Center issued:
Hurricane Watches for Texas coast from Port Aransas to High Island
Tropical Storm Watches east of High Island into Louisiana and from Port Aransas to the Rio Grande
Storm Surge Watches from Port Mansfield, TX to Cameron, LA including all inland bays.
Discussion
There is an increasing risk of heavy rainfall and flooding along the northwest Gulf Coast Sunday through at least the middle of next week. Beta is forecast to move slowly toward and along or offshore of the coast through that time and create life-threatening storm surge.
Lake Friday, a USAF mission found a stronger tropical storm with winds of 60mph and a fairly large area of 40-50mph winds. Ships and oil platforms in the north-central Gulf of Mexico have reported winds above 40mph. The wind field is starting to expand toward the north.
Track:
Beta is moving NNE at 12mph. Faster than expected. Beta will turn west around mid-day Saturday and decrease forward speed into early next week. This will bring Beta toward the middle Texas coast.
As Beta approaches the mid TX coast, weakening high pressure to the north will turn the storm toward the north and northeast. However, forecasters have lower-than-normal confidence as to when all this will happen.
The current National Hurricane Center forecast track is near the center of consensus for major global models, but shifts in this track will remain possible both toward the north or south.
Intensity:
Beta intensified despite wind shear. As Beta moves over very warm western Gulf of Mexico waters, intensification will likely continue for the 24-48 hours. NHC now forecasts Beta to become an 80mph hurricane. As Beta begins to turn northeast and skirt the middle and upper TX coast, the storm may weaken. Some uncertainty remains in the intensity forecast.
Tropical storm force winds will likely begin to arrive along the middle TX coast Sunday evening and spread northward into Matagorda Bay and along the upper TX coast by Monday. Hurricane conditions could reach the Matagorda Bay region on Tuesday.
Impacts
Storm Surge:
Water level rises along the upper TX coast will begin on Saturday and worsen Sunday into Monday due to the expansion of the tropical-storm-force wind field. This large wind field will also develop large swells over the NW Gulf of Mexico by Sunday into Monday with swells reaching 15-25 feet. On Sunday into Monday, expect 4-8 feet waves breaking on beaches. These large swells will lead to wave run up on top of elevated tides.
Large waves will accompany the higher tides. The prolonged nature of the event will result in significant beach erosion and damage to fragile dunes.
Expect inundation of low lying roads near the coast. Once the water begins to rise on Saturday evening, some low lying areas may remain flooded into the middle of next week.
Jeff Lindner, Harris County Meteorologist
Ferry operations at both the Galveston-Bolivar and the Lynchburg sites may be impacted.
For SE Harris County:
From Saturday night into next week, coastal flooding will be possible in El Lago, Nassau Bay, Shoreacres, Seabrook and portions of Baytown near Goose Creek and Cedar Bayou.
This includes all areas around:
Clear Lake
Along Taylor’s Bayou in Shoreacres and Taylor Lake Village
Around the San Jacinto Monument and Lynchburg Ferry landing
In Seabrook areas along and east of Toddville Rd and in the waterfront area east of HWY 146.
The lower San Jacinto River at Rio Villa and other low lying areas south of US HWY 90.
Low lying areas in Galena Park and Jacinto City near the Houston Ship Channel
Lower portions of Greens and Hunting Bayous south of I-10.
Most flooding will happen in streets, low marsh lands, roads near Galveston Bay and around Clear Lake and some subdivisions streets.
Wave action from ENE/E winds across Galveston Bay of 2-4 feet will be possible on top of these tides along the west side of Galveston Bay and 1-3 feet in Clear Lake which may damage docks, bulkheads, and moored vessels.
Rainfall
Rainfall will strongly depend on the track of Beta. Small changes could result in significant differences in rainfall amounts. Heaviest rains will likely be near the coast and offshore.
Any deviation of the track northward would bring the heavy rainfall further inland, likewise any south or east shift in the track would keep the heaviest rains off the coast.
Coast: 8-12 inches
Coastal counties: 6-8 inches
South of I-10: 4-6 inches
South of Hwy 105: 3-5 inches
North of Hwy 105: 1-3 inches
HCFCD models suggest that basin average rainfall totals of at least 6 inches would fill smaller creeks and bayous in Harris County (Willow Waterhole, Keegans Bayou, Willow Creek, Upper Little Cypress Creek).
Basin average amounts of 7-8 inches would fill Clear Creek, Hunting Bayou, Armand Bayou, Cypress Creek, Halls Bayou, Greens Bayou, White Oak Bayou, Buffalo Bayou, Cedar Bayou, and various smaller tributaries.
Addicks and Barker Reservoirs are currently empty.
Winds:
Tropical storm force winds may start Sunday evening around Matagorda Bay. Sustained 40mph winds likely spread northward along the upper TX coast on Monday including Galveston Bay.
Hurricane conditions will be possible near Matagorda Bay on Tuesday and across portions of coastal Matagorda, Brazoria, and Galveston Counties into Wednesday.
Across Harris County wind will increase into the 25-35mph range on Monday and possibly 40-50mph range on Tuesday into Wednesday with higher gusts, especially near Galveston Bay.
Posted by Bob Rehak on 9/19/2020at 4ambased on data from the National Hurricane Center and Harris County Meteorologist Jeff Lindner.
1117 Days since Hurricane Harvey and 1 Year since Tropical Storm Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/image003.gif?fit=800%2C561&ssl=1561800adminadmin2020-09-19 04:20:102020-09-19 04:23:40Hurricane Watch for Port Aransas to High Island
Preparations for Prolonged Coastal Flooding and Potential Inland Rainfall Flooding Should Beginnow for Tropical Storm Beta.
As of 4PM CDT Friday, the National Hurricane Center predicts that storm surge, tropical storm and/or hurricane watches will likely be required for portions of the western Gulf coast tonight or on Saturday.
Forecast Track
Tropical Storm Beta is moving toward the north-northeast near 9 mph (15 km/h). This general direction should last through Saturday. Late Saturday or Saturday night, the storm should begin a slow westward drift into early next week. After that, Beta should recurve to the northeast.
Cone of uncertainty for TS Beta. Every point within the cone has an equal chance of receiving a hit from the center of the storm.
Don’t Focus on Exact Track Yet
Do not focus on the exact forecast track for Tropical Storm Beta, especially at days 3 to 5, as a high degree of uncertainty remains.
Regardless the forecast track, the center of Beta will approach western coast of the Gulf of Mexico Sunday night and Monday. Even if we don’t take a direct hit from Beta…
…Houston will likely be on the wet/dirty side of the storm.
10-20% Chance of Tropical Storm Winds for Houston
The Houston Area currently has a 10-20% chance of receiving tropical-storm force winds starting Sunday.
Probability of Houston receiving winds greater than 40 mph is 10-20%.Those winds could arrive as early as Sunday morning.
Maximum sustained winds have already increased to near 40 mph (65 km/h) with higher gusts. Beta could reach near hurricane strength Sunday or Sunday night. Tropical-storm-force winds extend outward up to 105 miles (165 km) from the center.
Key Messages
According to the National Hurricane Center:
Beta should strengthen and possibly become a hurricane, while moving slowly over the western Gulf of Mexico during the next few days.
There is an increasing risk of heavy rainfall and flooding along the northwest Gulf Coast Sunday through at least the middle of next week as Beta is forecast to move slowly toward and along or offshore of the coast through that time. For additional information, see products from your local National Weather Service office.
Beta could affect the Houston Area much of next week.
Impacts
Tides/Storm Surge:
Strong ENE/E winds will push sea water toward the coast. Expect seas to build into the 8-15 foot range and waves to run up along the coast.
Expect at least 4.0-5.0 feet seas above the barnacle level. They could even reach near 6.0 feet. Impacts begin around 4.5 ft at several locations along the upper TX coast.
Low lying roadways near the coast will likely flood at times of high tide and some locations could become isolated. Significant beach erosion is likely with elevated tides and large wave action lasting for several days and coastal infrastructure could be damaged. The expected tides on Sunday will likely be 1.5-2.5 feet higher than those experienced with Laura and Hanna.
DO NOT get caught off guard with the expected water level rise along the coast. Understand that low lying coastal roads may be inundated for a long period of time
Rainfall:
Squalls will increase in frequency and intensity into Sunday night and Monday and begin to spread farther inland. There will be a sharp cut off in the higher rainfall amounts from south to north over the area with amounts of 10-12 inches likely near the coast and even higher offshore. However, College Station will probably only see 1-3 inches.
Harris County Meteorologist Jeff Lindner predicts 4-6 inches over Harris County.
These rainfall amounts will likely change
Winds:
Tropical storm force winds could arrive by Sunday evening and slowly spread NE Monday and Tuesday. It is possible that some locations could see 24-48 hours of sustained tropical storm force winds with the slow movement of the system.
Posted by Bob Rehak on 9/18/2020 based on input from the National Hurricane Center and Jeff Lindner, Harris County Meteorologist
1116 Days after Hurricane Harvey and 365 Days after Tropical Storm Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/205430_5day_cone_no_line_and_wind.png?fit=897%2C736&ssl=1736897adminadmin2020-09-18 17:36:062020-09-18 17:36:17Tropical Storm Beta Likely to Dump 4-6 Inches on Harris County, 10-12 Inches Near Coast
Month after month, I fly up and down the West Fork of the San Jacinto. More often than not, the confluence of Spring Creek and the West Fork (just west of I-69) looks like this.
West Fork (top) shows much more silt despite more flow coming from Spring Creek (left).
What Spring Creek Looked Like on Same Day
On this day (Friday, September 11), we took off from Intercontinental Airport and flew north over Spring Creek. Spring Creek looked like this.
Spring Creek north of Intercontinental Airport. Note how you can see the sandy bottom.
The difference in the water clarity is readily apparent. Yet in the 2000 Brown & Root study the authors said that Cypress and Spring Creeks contributed far more sediment. See Page 14. Sand miners, still quote and re-quote that study every chance they get.
What Accounts for Difference
So what accounts for the difference between the study and current visual observations? Mainly:
Upstream development
Sand mining
Storms that fall over one watershed, but not the other, on any given day
Twenty years after the Brown & Root study:
The heaviest development has shifted north into the West Fork watershed
Sand mining has expanded exponentially on the West Fork
Storms continue to fall over one or both watersheds.
Brown & Root’s findings on this one narrow issue (source of sediment) no longer reflect current conditions and visual observations.
The result is what you see above. Upstream from the sand mines, water flowed clearly on the West Fork, as it did on Spring Creek. Downstream, the West Fork looked like a sewer. The pictures below show some of the reasons.
Unless, otherwise noted, all the photos below were taken on 9/11/2020.
LMI River Bend mine. Not recent repair of breach and drainage ditch filled with silty water.Same ditch goes under mine entrance. From there, the silty water goes into woods and then the West Fork.At the LMI Moorehead mine, I spotted this pump.At the same mine, this pipe and what looks like a fire hose send silty water into surrounding wetlands when the level in the pond at the right gets high enough.One of the places where silty water enters the river.Zooming out, you can see the source in the background.Another mine where silty water leaks out of pitsThe water collects in the woods and eventually flows into the West Fork.
The Result
This is the end result. The West Fork (top) is far more silty than flow from Spring and Cypress Creeks (left).
A Sampling of Previous Flyovers
West Fork (right), Spring Creek (left). Photo taken on 10/2/19.West Fork (right), Spring Creek (left). November 4, 2019West Fork (right), Spring Creek (Left). February 13, 2020West Fork (top), Spring Creek (left). March 6, 2020.
I’m sure that when Brown & Root did its survey twenty years ago that Spring and Cypress Creeks contributed more sediment to Lake Houston. Today, however, I believe the West Fork contributes more.
It’s important to get this right if the community is to develop strategies that reduce the long term rate of sedimentation and save dredging dollars.
Posted by Bob Rehak on 9/18/2020
1116 Days after 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/2020/09/20200911-RJR_0948.jpg?fit=1200%2C800&ssl=18001200adminadmin2020-09-18 15:48:392020-09-18 15:48:59West Fork or Spring Creek: Which Contributes More Sediment to Lake Houston?
Hurricane Watch for Port Aransas to High Island
As of 4am Saturday, 9/19/20 (the 1-year anniversary of Imelda), the National Hurricane Center issued:
Discussion
There is an increasing risk of heavy rainfall and flooding along the northwest Gulf Coast Sunday through at least the middle of next week. Beta is forecast to move slowly toward and along or offshore of the coast through that time and create life-threatening storm surge.
Lake Friday, a USAF mission found a stronger tropical storm with winds of 60mph and a fairly large area of 40-50mph winds. Ships and oil platforms in the north-central Gulf of Mexico have reported winds above 40mph. The wind field is starting to expand toward the north.
Track:
Beta is moving NNE at 12mph. Faster than expected. Beta will turn west around mid-day Saturday and decrease forward speed into early next week. This will bring Beta toward the middle Texas coast.
As Beta approaches the mid TX coast, weakening high pressure to the north will turn the storm toward the north and northeast. However, forecasters have lower-than-normal confidence as to when all this will happen.
The current National Hurricane Center forecast track is near the center of consensus for major global models, but shifts in this track will remain possible both toward the north or south.
Intensity:
Beta intensified despite wind shear. As Beta moves over very warm western Gulf of Mexico waters, intensification will likely continue for the 24-48 hours. NHC now forecasts Beta to become an 80mph hurricane. As Beta begins to turn northeast and skirt the middle and upper TX coast, the storm may weaken. Some uncertainty remains in the intensity forecast.
Tropical storm force winds will likely begin to arrive along the middle TX coast Sunday evening and spread northward into Matagorda Bay and along the upper TX coast by Monday. Hurricane conditions could reach the Matagorda Bay region on Tuesday.
Impacts
Storm Surge:
Water level rises along the upper TX coast will begin on Saturday and worsen Sunday into Monday due to the expansion of the tropical-storm-force wind field. This large wind field will also develop large swells over the NW Gulf of Mexico by Sunday into Monday with swells reaching 15-25 feet. On Sunday into Monday, expect 4-8 feet waves breaking on beaches. These large swells will lead to wave run up on top of elevated tides.
Large waves will accompany the higher tides. The prolonged nature of the event will result in significant beach erosion and damage to fragile dunes.
Ferry operations at both the Galveston-Bolivar and the Lynchburg sites may be impacted.
For SE Harris County:
From Saturday night into next week, coastal flooding will be possible in El Lago, Nassau Bay, Shoreacres, Seabrook and portions of Baytown near Goose Creek and Cedar Bayou.
This includes all areas around:
Most flooding will happen in streets, low marsh lands, roads near Galveston Bay and around Clear Lake and some subdivisions streets.
Wave action from ENE/E winds across Galveston Bay of 2-4 feet will be possible on top of these tides along the west side of Galveston Bay and 1-3 feet in Clear Lake which may damage docks, bulkheads, and moored vessels.
Rainfall
Rainfall will strongly depend on the track of Beta. Small changes could result in significant differences in rainfall amounts. Heaviest rains will likely be near the coast and offshore.
HCFCD models suggest that basin average rainfall totals of at least 6 inches would fill smaller creeks and bayous in Harris County (Willow Waterhole, Keegans Bayou, Willow Creek, Upper Little Cypress Creek).
Basin average amounts of 7-8 inches would fill Clear Creek, Hunting Bayou, Armand Bayou, Cypress Creek, Halls Bayou, Greens Bayou, White Oak Bayou, Buffalo Bayou, Cedar Bayou, and various smaller tributaries.
Addicks and Barker Reservoirs are currently empty.
Winds:
Tropical storm force winds may start Sunday evening around Matagorda Bay. Sustained 40mph winds likely spread northward along the upper TX coast on Monday including Galveston Bay.
Hurricane conditions will be possible near Matagorda Bay on Tuesday and across portions of coastal Matagorda, Brazoria, and Galveston Counties into Wednesday.
Across Harris County wind will increase into the 25-35mph range on Monday and possibly 40-50mph range on Tuesday into Wednesday with higher gusts, especially near Galveston Bay.
Posted by Bob Rehak on 9/19/2020 at 4am based on data from the National Hurricane Center and Harris County Meteorologist Jeff Lindner.
1117 Days since Hurricane Harvey and 1 Year since Tropical Storm Imelda
Tropical Storm Beta Likely to Dump 4-6 Inches on Harris County, 10-12 Inches Near Coast
Preparations for Prolonged Coastal Flooding and Potential Inland Rainfall Flooding Should Begin now for Tropical Storm Beta.
As of 4PM CDT Friday, the National Hurricane Center predicts that storm surge, tropical storm and/or hurricane watches will likely be required for portions of the western Gulf coast tonight or on Saturday.
Forecast Track
Tropical Storm Beta is moving toward the north-northeast near 9 mph (15 km/h). This general direction should last through Saturday. Late Saturday or Saturday night, the storm should begin a slow westward drift into early next week. After that, Beta should recurve to the northeast.
Don’t Focus on Exact Track Yet
Do not focus on the exact forecast track for Tropical Storm Beta, especially at days 3 to 5, as a high degree of uncertainty remains.
Regardless the forecast track, the center of Beta will approach western coast of the Gulf of Mexico Sunday night and Monday. Even if we don’t take a direct hit from Beta…
10-20% Chance of Tropical Storm Winds for Houston
The Houston Area currently has a 10-20% chance of receiving tropical-storm force winds starting Sunday.
Maximum sustained winds have already increased to near 40 mph (65 km/h) with higher gusts. Beta could reach near hurricane strength Sunday or Sunday night. Tropical-storm-force winds extend outward up to 105 miles (165 km) from the center.
Key Messages
According to the National Hurricane Center:
Beta could affect the Houston Area much of next week.
Impacts
Tides/Storm Surge:
Strong ENE/E winds will push sea water toward the coast. Expect seas to build into the 8-15 foot range and waves to run up along the coast.
Expect at least 4.0-5.0 feet seas above the barnacle level. They could even reach near 6.0 feet. Impacts begin around 4.5 ft at several locations along the upper TX coast.
Low lying roadways near the coast will likely flood at times of high tide and some locations could become isolated. Significant beach erosion is likely with elevated tides and large wave action lasting for several days and coastal infrastructure could be damaged. The expected tides on Sunday will likely be 1.5-2.5 feet higher than those experienced with Laura and Hanna.
DO NOT get caught off guard with the expected water level rise along the coast. Understand that low lying coastal roads may be inundated for a long period of time
Rainfall:
Squalls will increase in frequency and intensity into Sunday night and Monday and begin to spread farther inland. There will be a sharp cut off in the higher rainfall amounts from south to north over the area with amounts of 10-12 inches likely near the coast and even higher offshore. However, College Station will probably only see 1-3 inches.
These rainfall amounts will likely change
Winds:
Tropical storm force winds could arrive by Sunday evening and slowly spread NE Monday and Tuesday. It is possible that some locations could see 24-48 hours of sustained tropical storm force winds with the slow movement of the system.
Posted by Bob Rehak on 9/18/2020 based on input from the National Hurricane Center and Jeff Lindner, Harris County Meteorologist
1116 Days after Hurricane Harvey and 365 Days after Tropical Storm Imelda
West Fork or Spring Creek: Which Contributes More Sediment to Lake Houston?
As the Lake Houston Area grapples with dredging, sedimentation surveys, sand trap studies and more, it’s important to understand where sediment comes from.
Month after month, I fly up and down the West Fork of the San Jacinto. More often than not, the confluence of Spring Creek and the West Fork (just west of I-69) looks like this.
What Spring Creek Looked Like on Same Day
On this day (Friday, September 11), we took off from Intercontinental Airport and flew north over Spring Creek. Spring Creek looked like this.
The difference in the water clarity is readily apparent. Yet in the 2000 Brown & Root study the authors said that Cypress and Spring Creeks contributed far more sediment. See Page 14. Sand miners, still quote and re-quote that study every chance they get.
What Accounts for Difference
So what accounts for the difference between the study and current visual observations? Mainly:
Twenty years after the Brown & Root study:
Twenty square miles of sand mines between I-45 and I-69 have widened the West Fork tremendously since then, exposing far more sediment to floodwater. Worse, the mines’ dikes often breach, allowing millions of gallons of sediment to flow downstream. Even worse yet, the mines often pump water over the side of their dikes into the river or surrounding streams and forests.
The result is what you see above. Upstream from the sand mines, water flowed clearly on the West Fork, as it did on Spring Creek. Downstream, the West Fork looked like a sewer. The pictures below show some of the reasons.
Unless, otherwise noted, all the photos below were taken on 9/11/2020.
The Result
A Sampling of Previous Flyovers
I’m sure that when Brown & Root did its survey twenty years ago that Spring and Cypress Creeks contributed more sediment to Lake Houston. Today, however, I believe the West Fork contributes more.
It’s important to get this right if the community is to develop strategies that reduce the long term rate of sedimentation and save dredging dollars.
Posted by Bob Rehak on 9/18/2020
1116 Days after 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.