At 10 a.m. CDT, the National Hurricane Center (NHC) downgraded Tropical Storm Beta to a tropical depression. The NHC also cancelled the tropical storm and storm surge warnings that were in effect. However, flash flood warnings remain in effect for large parts of the seven-county Houston region, especially the southern part. A flash flood watch remains in effect for the entire region.
RadarScope split image. Left half shows track of active storms as of 9:06AM CDT. Right half shows total rainfall accumulation for Beta. Note band of extreme rainfall near Sugar Land and sharp drop-off near Kingwood.
Flash Flood Warnings and Watches
A flash flood warning means that flooding is in progress. A Flash Flood Watch means that conditions may develop that lead to Flash Flooding.
Source: National Weather Service. Updated at 10:29 a.m. 9/22/2020. Reddish area = Flash flood warning. Green = Flash flood watch.
Lake Conroe/Lake Houston Within Banks
Neither Lake Conroe, nor Lake Houston have yet been adversely affected by Beta.
The level of Lake Conroe stands at 199.63 feet. Normal conservation pool equals 201.
According to the Coastal Water Authority, Lake Houston is at:
Tropical Storm Beta moved inland last night around 10 p.m. The center is now near Victoria and moving toward the northwest near 3 mph. The National Hurricane Center predicts Beta will weaken and stall today, but will then begin to move slowly toward the Houston Area tonight. They expect forward speed to increase Wednesday through Friday.
At the moment, maximum sustained winds are near 40 mph with higher gusts. Tropical-storm-force winds extend outward up to 105 miles from the center. A sustained wind of 39 mph and a gust to 47 mph were recently reported at Victoria, Texas. But at the moment, my wind gage is reading ZERO here in Kingwood.
Yesterday’s Heaviest Rains Narrowly Missed Lake Houston Area
Yesterday’s heaviest rainfall narrowly missed us. While the Lake Houston Area received around an inch of rain, the southwest corner of Loop 610 received 11.64 inches due to a training feeder band.
The main threat today to the Lake Houston Area is having a similar feeder band train over us.
Below are the two-day storm totals so far for Beta in Harris County.
For the middle and upper Texas coast, additional rainfall of 6 to 12 inches with isolated storm totals up to 20 inches is expected.
Significant flash and urban flooding is occurring south and west of the Lake Houston Area and will continue today.
RadarScope image as of 6:30 a.m. CDT on 9/22/2020. Center of storm located over Victoria in lower left.
Minor river flooding is likely. Rainfall totals of 3 to 5 inches are expected northward into the ArkLaTex region and east into the Lower Mississippi Valley through the end of the week.
Track
Steering currents around the storm are now collapsing, and Beta is expected to meander during the next 12-24 hours. By this time tomorrow, however, a mid-level trough over west Texas should begin moving eastward and scoop Beta up. That will cause the storm to move toward the east-northeast near or just inland of the upper Texas coast through 36 hours.
After that time, Beta will likely turn northeastward, moving farther inland across Louisiana and Mississippi before dissipating in about 4 days. Beta should weaken to a tropical depression in about 24 hours before it reaches the Lake Houston Area. It will become a remnant low in 2-3 days.
Tornadoes
A tornado or two could occur today near the upper Texas and southwestern Louisiana coasts.
Surf
Swells generated by a combination of Beta and a cold front over the northern Gulf of Mexico will continue along the coasts of Louisiana and Texas during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
Winds
It is unlikely we will see tropical storm strength winds in the Lake Houston Area.
Winds will increase today as Beta moves in our direction. But Beta is barely at tropical storm strength now and is weakening. The most likely arrival time for the heaviest winds: tonight at 8 p.m.
Flash-Flooding Potential
A flash flooding event is in progress over Harris County. “Numerous roadways are flooded. Avoid travel.
Jeff Lindner, Harris County Meteorologist
At this time (8am Tuesday, 9/22/2020), the main problem areas are south and west of Houston near the coast. However, that could change as the storm moves toward us.
Channel Status in Harris County. Green means “within banks.” Yellow means “flooding possible.” Red means “flooding likely.”
See data on the problem areas below.
Harris County Flood Control District – Hydrologic Operations Division Rain and Channel Status Report at 09/22/2020 07:30 AM ============================================
Maximum Rainfall the last 1hr 1.56 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard 1.4 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue 1.24 inches – Gage 370 @ 370 Sims Bayou @ SH 288 1.16 inches – Gage 190 @ 190 Clear Creek @ SH 288 1.04 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road
Maximum Rainfall the last 6hrs 5.72 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road 5.0 inches – Gage 2265 @ 2265 Buffalo Bayou @ Piney Point Rd 4.56 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue 4.6 inches – Gage 2260 @ 2260 Buffalo Bayou @ San Felipe Drive 4.48 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard 4.4 inches – Gage 2270 @ 2270 Buffalo Bayou @ West Beltway 8 4.44 inches – Gage 2255 @ 2255 Briar Branch @ Campbell Road 4.52 inches – Gage 420 @ 420 Brays Bayou @ South Main Street
Maximum Rainfall the last 24hrs 11.04 inches – Gage 180 @ 180 Clear Creek @ Mykawa Road 11.0 inches – Gage 370 @ 370 Sims Bayou @ SH 288 10.88 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard 10.56 inches – Gage 445 @ 445 Willow Water Hole @ Landsdowne Drive 10.36 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road 10.12 inches – Gage 175 @ 175 Clear Creek @ Pearland Parkway 10.12 inches – Gage 380 @ 380 Sims Bayou @ Hiram Clark Rd 9.96 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue 9.92 inches – Gage 150 @ 150 Clear Creek @ Country Club Drive 9.84 inches – Gage 145 @ 145 Clear Creek @ Dixie Farm Road 9.8 inches – Gage 190 @ 190 Clear Creek @ SH 288 9.6 inches – Gage 460 @ 460 Brays Bayou @ Gessner Road 9.4 inches – Gage 105 @ 105 Marys Creek @ Winding Road 9.44 inches – Gage 360 @ 360 Sims Bayou @ Martin Luther King Road 8.68 inches – Gage 135 @ 135 Clear Creek @ FM 2351 8.56 inches – Gage 465 @ 465 Brays Bayou @ Beltway 8 8.36 inches – Gage 115 @ 115 Cowart Creek @ Baker Road 8.28 inches – Gage 140 @ 140 Turkey Creek @ FM 1959
Stream Water Surface Elevation Data
Out of Banks: Gage 110 @ Clear Creek @ I-45 Gage 120 @ Clear Creek @ FM 528 Gage 130 @ Clear Creek @ Bay Area Boulevard Gage 135 @ Clear Creek @ FM 2351 Gage 145 @ Clear Creek @ Dixie Farm Road Gage 175 @ Clear Creek @ Pearland Parkway Gage 180 @ Clear Creek @ Mykawa Road Gage 610 @ Taylors Bayou @ Shoreacres Boulevard Gage 2150 @ South Mayde @ Greenhouse Road
Near Bankfull: Gage 100 @ Clear Lake 2nd Outlet @ SH 146 Gage 140 @ Turkey Creek @ FM 1959 Gage 150 @ Clear Creek @ Country Club Drive Gage 160 @ Beamer Ditch @ Hughes Road Gage 170 @ Clear Creek @ Nassau Bay Gage 190 @ Clear Creek @ SH 288 Gage 200 @ Taylor Lake @ Nasa Road 1 Gage 410 @ Brays Bayou @ Lawndale Street Gage 420 @ Brays Bayou @ South Main Street Gage 430 @ Brays Bayou @ Stella Link Road Gage 440 @ Brays Bayou @ Rice Avenue Gage 460 @ Brays Bayou @ Gessner Road Gage 480 @ Keegans Bayou @ Roark Road Gage 710 @ San Jacinto River @ Rio Villa Gage 720 @ San Jacinto River @ US 90 Gage 740 @ Lake Houston @ FM 1960 Gage 1610 @ Greens Bayou @ Normandy Street Gage 1720 @ Cedar Bayou @ SH 146 Gage 2115 @ Langham Creek @ Clay Rd Gage 2210 @ Buffalo Bayou @ Turning Basin Gage 2253 @ Buttermilk Creek @ Moorberry Lane Gage 2255 @ Briar Branch @ Campbell Road Gage 2265 @ Buffalo Bayou @ Piney Point Rd
Key Messages
Posted by Bob Rehak on 9/22/2020 at 8am based on data from Jeff Lindner, Harris County Meteorologist, the National Hurricane Center, Harris County Flood Warning System and RadarScope
1120 Days After Hurricane Harvey and 369 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/Screen-Shot-2020-09-22-at-6.20.22-AM.jpg?fit=1200%2C638&ssl=16381200adminadmin2020-09-22 08:07:012020-09-22 08:23:09Beta Stalling Onshore Around Victoria; Will Start Moving Toward Houston Tonight
As of 10:00 a.m. Monday morning, the National Hurricane Center (NHC) still shows the center of Tropical Storm Beta located offshore. The latest forecasts from the NHC predict that Beta will move onshore near Matagorda Bay, then move up the coastline toward League City.
The NHC also advises that the storm has picked up speed. Yesterday, they estimated 3 mph; today 7 mph.
No one seems to predict that the storm will intensify before landfall.
“Dry air continues to work into and wrap around the large wind field of Beta yielding the disorganized precipitation field with the system.”
Lake Houston Area is the blue dot in the center of the swirl. Red line is predicted path of Beta.Source: Weather Live.
Main Threat: Storm Surge
At this time, Beta’s main threat is to the coastline through storm surge. “Tides are currently running 4.0-4.5 feet in Clear Lake and across coastal sections of Harris County with several sites near the Gulf beaches running 4.0-4.5 feet. Coastal flooding is ongoing and will continue for much of the day. Several roadways are underwater along the coast and around Galveston Bay,” says Lindner.
Lindner continues, “As Beta makes landfall along the middle Texas coast later today, the storm will begin to slow and then turn ENE toward the upper TX coast. It will slowly weaken along the way. This track will keep onshore flow along the upper Texas coast tonight and Tuesday. Tides will remain high into the high tide tonight. Impacts along the coast will continue through the day and into tonight and likely Tuesday.”
Wind Forecast
The most likely arrival time of tropical storm force winds, if we get them, is later tonight.
Tropical storm force winds already cover a large part of the mid-Texas coast.
The storm will weaken as it moves toward the Houston Area and turn into a tropical depression. The further north you live from the coastline, the less intense winds will be.
Depending on where you live in Houston, you have a 30% to 100% chance of experiencing topical storm force winds. The Lake Houston Area is on the low end of that range. The National Weather Service predicts that the Lake Houston Area has a chance of seeing 39-57 mph winds. But Spaces City Weather advises that Beta is “not a significant wind threat.”
However, note that tropical-storm-force winds currently extend outward up to 175 miles (280 km) from the center of the storm.
Galveston has reported sustained winds of 39 mph and a gust of 43 mph during the past couple of hours.
Rainfall
Dry air has worked into the circulation of Beta, according to Lindner. “This has resulted in a more disorganized and scattered rainfall pattern. However, the system is still capable of heavy rainfall especially near the center later today and in bending structures east of the center for the next 48 hours.”
Models show several banding features developing during the next 48 hours over SE TX, But little consensus exists on where the heaviest rainfall totals may be.
Lindner advises that, “Given that much of the area will reside on the eastern side of a the tropical system, we should keep some level of concern of heavy rainfall and flooding in place through the next 48 hours.”
Lindner predicts that widespread rainfall amounts of 4-8 inches will be possible for areas along and south of I-10 with isolated totals of 10-12 inches under any training feeder bands. Totals to the north of I-10 will likely average 3-5 inches with isolated totals of 6-7 inches.
However, the NHC predicts slightly less rain. See the map below.
As long as the rainfall spreads out over the next 48 hours, most of the creeks and bayous can handle the expected rainfall amounts, Lindner says. But should any training develop, flash flooding would be possible.
Watches and Warnings in Effect
A Storm Surge Warning is in effect for Port Aransas, Texas to Rockefeller Wildlife Refuge, Louisiana. That includes Copano Bay, Aransas Bay, San Antonio Bay, Matagorda Bay, Galveston Bay, Sabine Lake, and Lake Calcasieu.
A Tropical Storm Warning is in effect for Port Aransas Texas to Morgan City Louisiana. That includes the Lake Houston Area.
A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.
Lindner, the NHC and NWS all warn that tornadoes remain a threat with this storm. Especially, tonight and Tuesday.
Track
Yesterday, models predicted that Beta would track up US59 toward the Humble/Kingwood Area. However, today, forecasters think the storm will track closer to the coast. They put it on a line toward League City.
Wind shear will keep Beta’s track close to the coastline, but it will also affect the cyclone’s intensity along with land interaction. The closer the cyclone stays near the Gulf of Mexico, the more likely that bands of convection containing tropical-storm-force winds will continue to roll onshore the Texas coast through 36-48 hours.
Summary
Flash, urban, and isolated minor river flooding is possible, but the danger is “slight.”
Net: Beta is still a threat. But it may be less of one than yesterday. That’s because of the dry air folding into the system and wind sheer which seem to be weakening it somewhat. Be hopeful, but cautious. Expect several inches of rain and high winds in the next two days with both tapering off Wednesday.
Posted by Bob Rehak on 9/21/2020 at noon based on data from NHC, NWS, Jeff Lindner, Space City Weather and Weather Live
1119 Days after Hurricane Harvey and 368 since Imelda
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2020/09/Screenshot-2020-09-21-at-11.37.19-AM-scaled.jpg?fit=1183%2C2560&ssl=125601183adminadmin2020-09-21 11:46:032020-09-21 11:52:04Beta Moving Ashore Today Then Likely Tracking Slightly South of Houston
Beta Downgraded to Tropical Depression
At 10 a.m. CDT, the National Hurricane Center (NHC) downgraded Tropical Storm Beta to a tropical depression. The NHC also cancelled the tropical storm and storm surge warnings that were in effect. However, flash flood warnings remain in effect for large parts of the seven-county Houston region, especially the southern part. A flash flood watch remains in effect for the entire region.
Flash Flood Warnings and Watches
A flash flood warning means that flooding is in progress. A Flash Flood Watch means that conditions may develop that lead to Flash Flooding.
Lake Conroe/Lake Houston Within Banks
Neither Lake Conroe, nor Lake Houston have yet been adversely affected by Beta.
The level of Lake Conroe stands at 199.63 feet. Normal conservation pool equals 201.
According to the Coastal Water Authority, Lake Houston is at:
USGS shows that even though the lake has received about 1.75 inches of rainfall to date…
…the lake level has been dropping, no doubt due to a preemptive release.
Posted by Bob Rehak at 10:50 on 9/22/2020 based on NHC, NWS, and RadarScope data
1120 Days since Hurricane Harvey and 369 since Imelda
Beta Stalling Onshore Around Victoria; Will Start Moving Toward Houston Tonight
Tropical Storm Beta moved inland last night around 10 p.m. The center is now near Victoria and moving toward the northwest near 3 mph. The National Hurricane Center predicts Beta will weaken and stall today, but will then begin to move slowly toward the Houston Area tonight. They expect forward speed to increase Wednesday through Friday.
At the moment, maximum sustained winds are near 40 mph with higher gusts. Tropical-storm-force winds extend outward up to 105 miles from the center. A sustained wind of 39 mph and a gust to 47 mph were recently reported at Victoria, Texas. But at the moment, my wind gage is reading ZERO here in Kingwood.
Yesterday’s Heaviest Rains Narrowly Missed Lake Houston Area
Yesterday’s heaviest rainfall narrowly missed us. While the Lake Houston Area received around an inch of rain, the southwest corner of Loop 610 received 11.64 inches due to a training feeder band.
Below are the two-day storm totals so far for Beta in Harris County.
Rainfall Predictions
For the middle and upper Texas coast, additional rainfall of 6 to 12 inches with isolated storm totals up to 20 inches is expected.
Minor river flooding is likely. Rainfall totals of 3 to 5 inches are expected northward into the ArkLaTex region and east into the Lower Mississippi Valley through the end of the week.
Track
Steering currents around the storm are now collapsing, and Beta is expected to meander during the next 12-24 hours. By this time tomorrow, however, a mid-level trough over west Texas should begin moving eastward and scoop Beta up. That will cause the storm to move toward the east-northeast near or just inland of the upper Texas coast through 36 hours.
After that time, Beta will likely turn northeastward, moving farther inland across Louisiana and Mississippi before dissipating in about 4 days. Beta should weaken to a tropical depression in about 24 hours before it reaches the Lake Houston Area. It will become a remnant low in 2-3 days.
Tornadoes
A tornado or two could occur today near the upper Texas and southwestern Louisiana coasts.
Surf
Swells generated by a combination of Beta and a cold front over the northern Gulf of Mexico will continue along the coasts of Louisiana and Texas during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
Winds
It is unlikely we will see tropical storm strength winds in the Lake Houston Area.
Winds will increase today as Beta moves in our direction. But Beta is barely at tropical storm strength now and is weakening. The most likely arrival time for the heaviest winds: tonight at 8 p.m.
Flash-Flooding Potential
At this time (8am Tuesday, 9/22/2020), the main problem areas are south and west of Houston near the coast. However, that could change as the storm moves toward us.
See data on the problem areas below.
Harris County Flood Control District – Hydrologic Operations Division
Rain and Channel Status Report at 09/22/2020 07:30 AM
============================================
Maximum Rainfall the last 1hr
1.56 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard
1.4 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue
1.24 inches – Gage 370 @ 370 Sims Bayou @ SH 288
1.16 inches – Gage 190 @ 190 Clear Creek @ SH 288
1.04 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road
Maximum Rainfall the last 6hrs
5.72 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road
5.0 inches – Gage 2265 @ 2265 Buffalo Bayou @ Piney Point Rd
4.56 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue
4.6 inches – Gage 2260 @ 2260 Buffalo Bayou @ San Felipe Drive
4.48 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard
4.4 inches – Gage 2270 @ 2270 Buffalo Bayou @ West Beltway 8
4.44 inches – Gage 2255 @ 2255 Briar Branch @ Campbell Road
4.52 inches – Gage 420 @ 420 Brays Bayou @ South Main Street
Maximum Rainfall the last 12hrs
8.4 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road
8.28 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard
8.0 inches – Gage 370 @ 370 Sims Bayou @ SH 288
7.76 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue
7.4 inches – Gage 445 @ 445 Willow Water Hole @ Landsdowne Drive
7.28 inches – Gage 180 @ 180 Clear Creek @ Mykawa Road
7.2 inches – Gage 360 @ 360 Sims Bayou @ Martin Luther King Road
6.96 inches – Gage 460 @ 460 Brays Bayou @ Gessner Road
6.56 inches – Gage 175 @ 175 Clear Creek @ Pearland Parkway
6.48 inches – Gage 380 @ 380 Sims Bayou @ Hiram Clark Rd
6.44 inches – Gage 465 @ 465 Brays Bayou @ Beltway 8
6.32 inches – Gage 2265 @ 2265 Buffalo Bayou @ Piney Point Rd
6.04 inches – Gage 470 @ 470 Brays Bayou @ Belle Park Drive
6.2 inches – Gage 420 @ 420 Brays Bayou @ South Main Street
Maximum Rainfall the last 24hrs
11.04 inches – Gage 180 @ 180 Clear Creek @ Mykawa Road
11.0 inches – Gage 370 @ 370 Sims Bayou @ SH 288
10.88 inches – Gage 435 @ 435 Willow Water Hole @ Willowbend Boulevard
10.56 inches – Gage 445 @ 445 Willow Water Hole @ Landsdowne Drive
10.36 inches – Gage 430 @ 430 Brays Bayou @ Stella Link Road
10.12 inches – Gage 175 @ 175 Clear Creek @ Pearland Parkway
10.12 inches – Gage 380 @ 380 Sims Bayou @ Hiram Clark Rd
9.96 inches – Gage 440 @ 440 Brays Bayou @ Rice Avenue
9.92 inches – Gage 150 @ 150 Clear Creek @ Country Club Drive
9.84 inches – Gage 145 @ 145 Clear Creek @ Dixie Farm Road
9.8 inches – Gage 190 @ 190 Clear Creek @ SH 288
9.6 inches – Gage 460 @ 460 Brays Bayou @ Gessner Road
9.4 inches – Gage 105 @ 105 Marys Creek @ Winding Road
9.44 inches – Gage 360 @ 360 Sims Bayou @ Martin Luther King Road
8.68 inches – Gage 135 @ 135 Clear Creek @ FM 2351
8.56 inches – Gage 465 @ 465 Brays Bayou @ Beltway 8
8.36 inches – Gage 115 @ 115 Cowart Creek @ Baker Road
8.28 inches – Gage 140 @ 140 Turkey Creek @ FM 1959
Stream Water Surface Elevation Data
Out of Banks:
Gage 110 @ Clear Creek @ I-45
Gage 120 @ Clear Creek @ FM 528
Gage 130 @ Clear Creek @ Bay Area Boulevard
Gage 135 @ Clear Creek @ FM 2351
Gage 145 @ Clear Creek @ Dixie Farm Road
Gage 175 @ Clear Creek @ Pearland Parkway
Gage 180 @ Clear Creek @ Mykawa Road
Gage 610 @ Taylors Bayou @ Shoreacres Boulevard
Gage 2150 @ South Mayde @ Greenhouse Road
Near Bankfull:
Gage 100 @ Clear Lake 2nd Outlet @ SH 146
Gage 140 @ Turkey Creek @ FM 1959
Gage 150 @ Clear Creek @ Country Club Drive
Gage 160 @ Beamer Ditch @ Hughes Road
Gage 170 @ Clear Creek @ Nassau Bay
Gage 190 @ Clear Creek @ SH 288
Gage 200 @ Taylor Lake @ Nasa Road 1
Gage 410 @ Brays Bayou @ Lawndale Street
Gage 420 @ Brays Bayou @ South Main Street
Gage 430 @ Brays Bayou @ Stella Link Road
Gage 440 @ Brays Bayou @ Rice Avenue
Gage 460 @ Brays Bayou @ Gessner Road
Gage 480 @ Keegans Bayou @ Roark Road
Gage 710 @ San Jacinto River @ Rio Villa
Gage 720 @ San Jacinto River @ US 90
Gage 740 @ Lake Houston @ FM 1960
Gage 1610 @ Greens Bayou @ Normandy Street
Gage 1720 @ Cedar Bayou @ SH 146
Gage 2115 @ Langham Creek @ Clay Rd
Gage 2210 @ Buffalo Bayou @ Turning Basin
Gage 2253 @ Buttermilk Creek @ Moorberry Lane
Gage 2255 @ Briar Branch @ Campbell Road
Gage 2265 @ Buffalo Bayou @ Piney Point Rd
Key Messages
Posted by Bob Rehak on 9/22/2020 at 8am based on data from Jeff Lindner, Harris County Meteorologist, the National Hurricane Center, Harris County Flood Warning System and RadarScope
1120 Days After Hurricane Harvey and 369 since Imelda
Beta Moving Ashore Today Then Likely Tracking Slightly South of Houston
As of 10:00 a.m. Monday morning, the National Hurricane Center (NHC) still shows the center of Tropical Storm Beta located offshore. The latest forecasts from the NHC predict that Beta will move onshore near Matagorda Bay, then move up the coastline toward League City.
The NHC also advises that the storm has picked up speed. Yesterday, they estimated 3 mph; today 7 mph.
No one seems to predict that the storm will intensify before landfall.
Main Threat: Storm Surge
At this time, Beta’s main threat is to the coastline through storm surge. “Tides are currently running 4.0-4.5 feet in Clear Lake and across coastal sections of Harris County with several sites near the Gulf beaches running 4.0-4.5 feet. Coastal flooding is ongoing and will continue for much of the day. Several roadways are underwater along the coast and around Galveston Bay,” says Lindner.
Lindner continues, “As Beta makes landfall along the middle Texas coast later today, the storm will begin to slow and then turn ENE toward the upper TX coast. It will slowly weaken along the way. This track will keep onshore flow along the upper Texas coast tonight and Tuesday. Tides will remain high into the high tide tonight. Impacts along the coast will continue through the day and into tonight and likely Tuesday.”
Wind Forecast
The most likely arrival time of tropical storm force winds, if we get them, is later tonight.
Tropical storm force winds already cover a large part of the mid-Texas coast.
The storm will weaken as it moves toward the Houston Area and turn into a tropical depression. The further north you live from the coastline, the less intense winds will be.
Depending on where you live in Houston, you have a 30% to 100% chance of experiencing topical storm force winds. The Lake Houston Area is on the low end of that range. The National Weather Service predicts that the Lake Houston Area has a chance of seeing 39-57 mph winds. But Spaces City Weather advises that Beta is “not a significant wind threat.”
However, note that tropical-storm-force winds currently extend outward up to 175 miles (280 km) from the center of the storm.
Galveston has reported sustained winds of 39 mph and a gust of 43 mph during the past couple of hours.
Rainfall
Dry air has worked into the circulation of Beta, according to Lindner. “This has resulted in a more disorganized and scattered rainfall pattern. However, the system is still capable of heavy rainfall especially near the center later today and in bending structures east of the center for the next 48 hours.”
Models show several banding features developing during the next 48 hours over SE TX, But little consensus exists on where the heaviest rainfall totals may be.
Lindner advises that, “Given that much of the area will reside on the eastern side of a the tropical system, we should keep some level of concern of heavy rainfall and flooding in place through the next 48 hours.”
Lindner predicts that widespread rainfall amounts of 4-8 inches will be possible for areas along and south of I-10 with isolated totals of 10-12 inches under any training feeder bands. Totals to the north of I-10 will likely average 3-5 inches with isolated totals of 6-7 inches.
However, the NHC predicts slightly less rain. See the map below.
As long as the rainfall spreads out over the next 48 hours, most of the creeks and bayous can handle the expected rainfall amounts, Lindner says. But should any training develop, flash flooding would be possible.
Watches and Warnings in Effect
A Storm Surge Warning is in effect for Port Aransas, Texas to Rockefeller Wildlife Refuge, Louisiana. That includes Copano Bay, Aransas Bay, San Antonio Bay, Matagorda Bay, Galveston Bay, Sabine Lake, and Lake Calcasieu.
A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.
Lindner, the NHC and NWS all warn that tornadoes remain a threat with this storm. Especially, tonight and Tuesday.
Track
Yesterday, models predicted that Beta would track up US59 toward the Humble/Kingwood Area. However, today, forecasters think the storm will track closer to the coast. They put it on a line toward League City.
Wind shear will keep Beta’s track close to the coastline, but it will also affect the cyclone’s intensity along with land interaction. The closer the cyclone stays near the Gulf of Mexico, the more likely that bands of convection containing tropical-storm-force winds will continue to roll onshore the Texas coast through 36-48 hours.
Summary
Net: Beta is still a threat. But it may be less of one than yesterday. That’s because of the dry air folding into the system and wind sheer which seem to be weakening it somewhat. Be hopeful, but cautious. Expect several inches of rain and high winds in the next two days with both tapering off Wednesday.
Posted by Bob Rehak on 9/21/2020 at noon based on data from NHC, NWS, Jeff Lindner, Space City Weather and Weather Live
1119 Days after Hurricane Harvey and 368 since Imelda