A serious flash flood threat remains in place over all of SE TX and much of eastern TX into Thursday.
According to Harris County Meteorologist Jeff Lindner, “After the storms from yesterday, deeper moisture has been pushed toward the coastline and offshore, but will rapidly return today.
A slow moving line of thunderstorms moved through the area on Monday producing generally 1 to 4 inches of rain across the area with localized areas of 6 to 8 inches in Liberty, eastern Montgomery, and northeastern Harris County.
The National Weather Service says that a lull in the precipitation occurred overnight, but the chance for heavy rainfall returns this morning as an upper level disturbance moves through the area. An additional 1 to 3 inches of rain with locally higher totals will be possible today. A stronger upper level disturbance will bring yet another round of heavy rain Wednesday into Thursday with additional rainfall totals of 2 to 4 inches of rain with again locally higher totals possible. Storm total rainfall by Thursday morning will average between 4 and 8 inches with isolated totals possibly exceeding 10 inches. The flood threat will be strongly dependent on where the rain falls and how quickly it falls.
Today-Tonight
Scattered showers and thunderstorms will develop with heating today. But it continues to be hard to pinpoint where storms may develop. By this afternoon, storms will likely begin to approach southeast Texas from the west and northwest. They may also possibly approach again from the northeast or north into the evening and overnight hours. See the satellite photo below.
Satellite image as of about 8 a.m. Houston time this morning.
Wednesday-Early Thursday
An upper level trough will transport extreme moisture into the region along with the jet stream. Models many possible scenarios from slow moving lines to quickly approaching complexes from the west. Regardless, the overall pattern favors heavy rainfall, flash flooding, and severe weather.
Rainfall Amounts
Lindner expects additional rainfall totals of 4-6 inches over the next 48 hours with isolated totals of 10-12 inches. Much of what falls is going to come in short intense bursts of rainfall, he says, and not spread out evenly over time.
The National Weather Service gives our eastern and northern counties a moderate risk of flash flooding today. The risk area should enlarge tomorrow across the entire region.
Excessive rainfall outlook for today
Excessive rainfall outlook for Wednesday and Thursday.
The orange areas indicate moderate risk. That means a 20-50% chance of excessive rainfall.
River, Stream Report
Run-off continues across the region this morning from the heavy rainfall yesterday. Cedar Bayou upstream of US 90 remains high, but has crested and is slowly falling. Spring Creek is rising as upstream run-off from northern Waller County moves into the mainstem of the creek. Not flooding is expected, but the creek will be elevated through the day. West Fork of the San Jacinto River is rising due to inflow from Spring and Cypress Creeks and will crest later this morning.
Both the SJRA and Coastal Water Authority are releasing water from Lake Conroe and Lake Houston preemptively. However, both lakes remain a few inches above their normal levels at the moment.
Additional rainfall over the next few days will quickly run-off resulting in new rises on area creeks, bayous, and rivers. Some flooding of creeks, bayous, and rivers will be possible.
Forecasted Rainfall Next 72 Hours
Predicted accumulations through Friday. Source: National Weather Service
As I write this, the rain has started already this morning. Let’s hope the rain is spread out enough that the creeks can handle it. As predicted, so far it’s coming down in sporadic bursts mixed with light drizzle.
Posted by Bob Rehak on 5/18/2021 based on information provided by the NWS, HCFCD, and Donald Brown
1358 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/image009.jpg?fit=662%2C495&ssl=1495662adminadmin2021-05-18 08:56:082021-05-18 09:07:36Tuesday AM Rain Outlook: Heating Up, Flash Flood Watch Remains in Effect
Had Harris County Flood Control not recently excavated parts of Bens Branch and Taylor Gully, both streams would have likely come out of their banks today. The skies opened up and dumped 4.98 inches on my rain gage in a little more than two hours. That’s about a 10-year rain according to the new Atlas 14 statistics below.
Atlas 14 Rainfall Statistics for the Kingwood Area.
Photos from Around Kingwood
At 5 pm both streams were near the tops of their banks but well within them. That might not have been the case just a couple months ago before the flood control district widened and deepened them to restore their original conveyance. Parts of Ben’s Branch were down to a two year level of service. That’s means they would flood in a two-year rain…obviously less than today’s.
Bens Branch at Kingwood Drive at approximately 5pm on 5/17/2021after receiving 4.88 inches of rain in about 2 hours.
Taylor Gully at approximately same time taken from the Maple Bend Bridge in Woodstream Forest. Photo by Nicole Black-Rudolph. Finished in the nick of time. Note the construction equipment still in the right corner of the frame.
Photo by Jeff Miller around same time. This shows Taylor Gully at the bridge over Rustic Elms, farther upstream toward Woodridge Village.
Video by Paul Campbell at approximately 3pm on 5/17/21. Shows the level of Ben’s Branch behind his apartment in Kingwood Town Center, also recently excavated by HCFCD.
Street flooding on West Lake Houston Parkway near Kingwood Drive at 5pm. I saw scenes like this all over Kingwood this afternoon while trying to return from a lunch in the Woodlands.
Forecast for Remainder of Evening
As of 5:30 pm, Jeff Lindner, Harris County Meteorologist said, “Heavy rainfall continues to progress WSW across the area while a second area of heavy rainfall is moving SE across western Montgomery, N Waller, and NW Harris County. This area to the northwest is the remains of a line of thunderstorms from central Texas.”
“Rainfall amounts have averaged 2-3 inches over the northern half of Harris County with 4-6 inches over the Humble, Kingwood, Crosby, and Huffman areas,” said Lindner. “Significant street flooding has occurred over the northeast and northern portions of the county into Liberty and Montgomery Counties. While the activity is continuing to progress through the area, recent radar and HCFCD gage rainfall sensors indicate the hourly rainfall rates have weakened into the .50-1.5 inch range which is significantly lower than the 3-4 inches per hour recorded earlier this afternoon.”
“Street flooding will continue into the early evening hours and slowly subside over the area, while creeks and bayous continue to respond to the heavy rainfall. At this time all creeks and bayous are well within banks.”
More Yet to Come
Heavy rainfalls like this afternoon’s should continue through Thursday when the chances start to diminish through the weekend. Runoff should increase as grounds are now thoroughly saturated. Stay cautious. I almost drove into the water that rose to the bumper of that semi above. It didn’t look that deep but obviously could have stalled my Tahoe. Remember, if water gets over your tailpipe, it will cause your engine to stall. Game over.
Posted by Bob Rehak on May 17, 2021 based on personal observation and information supplied by HCFCD, Jeff Miller, Paul Campbell, and Nicole Black-Rudolph
1357 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/20210517-RJR_6615.jpg?fit=1200%2C800&ssl=18001200adminadmin2021-05-17 18:05:152021-05-17 18:10:21Street Flooding Rampant Throughout Kingwood, Streams Near Capacity
The National Weather Service has produced a 3-day excessive rainfall map that show all of SE Texas under a moderate risk for flash flooding this week. “Moderate” means we have a 20-50% chance of exceeding flash-flooding guidance. Flash flooding occurs when short-duration, high-intensity rains exceed the drainage capacity in areas.
Issued Monday at 3AM Houston time by the National Weather Service.
Jeff Lindner, Harris County’s meteorologist, sees heavy rainfall and flash flood threats increasing through the week. “A flash flood watch will likely be required for portions of the area later today,” he said.
Chance of Thunderstorms 70% and Increasing
The National Weather Service predicts a 70% chance of thunderstorms for the Lake Houston Area through Tuesday night. The chance increases to 80% for Wednesday and Thurday. The chances decrease to 70% for Friday, 60% for Saturday and 40% for Sunday.
It is difficult to predict exact amounts of rainfall for any specific location, such as Lake Houston, that far in advance. However, conditions are in place to produce heavy rainfall. The main threat for today is slow moving storms that could produce street flooding this afternoon. But chances increase tomorrow, Wednesday and Thursday.
“This pattern will support heavy rainfall and flash flooding especially during the mid-week period. But really every day this week has potential,” says Lindner.
Space City Weather likens the conditions in place to those that produced the May 2019 floods in Kingwood.
Rainfall Amounts
Since yesterday, there has been no change. Models suggest a fairly high limit on potential totals. “As seen yesterday, this air mass is capable of excessive short term rainfall amounts. Widespread amounts of 4-8 inches will be likely over much of the area over the next 5 days with isolated totals of 10-12 inches or more. Short duration rainfall rates of 2-4 inches per hour will be possible leading to rapid urban flash flooding,” says Lindner.
Grounds in the Houston area are already wet and water supply lakes near full capacity. As of this morning, the City has started lowering Lake Houston by one foot. The SJRA is not releasing water from Lake Conroe.
From SJRA.net as of Monday 5/17/21 at 9am.
Lindner says that rises on area watersheds are likely given the widespread nature of this event. “It is certainly possible some watersheds will experience flooding at some point this week. Which watersheds potentially get hit the hardest remains uncertain…but the risk for flooding will be increasing,” he says.
Posted by Bob Rehak on Monday morning at 9 am, 5/17/21 based on information by HCFCD, NWS, and Space City Weather
1357 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/image002.gif?fit=800%2C561&ssl=1561800adminadmin2021-05-17 09:16:192021-05-17 09:16:28Monday AM: All SE Texas Now Under Moderate Risk for Flash Flooding This Week
Tuesday AM Rain Outlook: Heating Up, Flash Flood Watch Remains in Effect
A Flash Flood Watch remains in effect through Thursday morning.
A serious flash flood threat remains in place over all of SE TX and much of eastern TX into Thursday.
According to Harris County Meteorologist Jeff Lindner, “After the storms from yesterday, deeper moisture has been pushed toward the coastline and offshore, but will rapidly return today.
A slow moving line of thunderstorms moved through the area on Monday producing generally 1 to 4 inches of rain across the area with localized areas of 6 to 8 inches in Liberty, eastern Montgomery, and northeastern Harris County.
The National Weather Service says that a lull in the precipitation occurred overnight, but the chance for heavy rainfall returns this morning as an upper level disturbance moves through the area. An additional 1 to 3 inches of rain with locally higher totals will be possible today. A stronger upper level disturbance will bring yet another round of heavy rain Wednesday into Thursday with additional rainfall totals of 2 to 4 inches of rain with again locally higher totals possible. Storm total rainfall by Thursday morning will average between 4 and 8 inches with isolated totals possibly exceeding 10 inches. The flood threat will be strongly dependent on where the rain falls and how quickly it falls.
Today-Tonight
Scattered showers and thunderstorms will develop with heating today. But it continues to be hard to pinpoint where storms may develop. By this afternoon, storms will likely begin to approach southeast Texas from the west and northwest. They may also possibly approach again from the northeast or north into the evening and overnight hours. See the satellite photo below.
Wednesday-Early Thursday
An upper level trough will transport extreme moisture into the region along with the jet stream. Models many possible scenarios from slow moving lines to quickly approaching complexes from the west. Regardless, the overall pattern favors heavy rainfall, flash flooding, and severe weather.
Rainfall Amounts
Lindner expects additional rainfall totals of 4-6 inches over the next 48 hours with isolated totals of 10-12 inches. Much of what falls is going to come in short intense bursts of rainfall, he says, and not spread out evenly over time.
The National Weather Service gives our eastern and northern counties a moderate risk of flash flooding today. The risk area should enlarge tomorrow across the entire region.
The orange areas indicate moderate risk. That means a 20-50% chance of excessive rainfall.
River, Stream Report
Run-off continues across the region this morning from the heavy rainfall yesterday. Cedar Bayou upstream of US 90 remains high, but has crested and is slowly falling. Spring Creek is rising as upstream run-off from northern Waller County moves into the mainstem of the creek. Not flooding is expected, but the creek will be elevated through the day. West Fork of the San Jacinto River is rising due to inflow from Spring and Cypress Creeks and will crest later this morning.
Both the SJRA and Coastal Water Authority are releasing water from Lake Conroe and Lake Houston preemptively. However, both lakes remain a few inches above their normal levels at the moment.
Additional rainfall over the next few days will quickly run-off resulting in new rises on area creeks, bayous, and rivers. Some flooding of creeks, bayous, and rivers will be possible.
Forecasted Rainfall Next 72 Hours
Photo of White Oak Creek from Yesterday
As I write this, the rain has started already this morning. Let’s hope the rain is spread out enough that the creeks can handle it. As predicted, so far it’s coming down in sporadic bursts mixed with light drizzle.
Posted by Bob Rehak on 5/18/2021 based on information provided by the NWS, HCFCD, and Donald Brown
1358 Days since Hurricane Harvey
Street Flooding Rampant Throughout Kingwood, Streams Near Capacity
Had Harris County Flood Control not recently excavated parts of Bens Branch and Taylor Gully, both streams would have likely come out of their banks today. The skies opened up and dumped 4.98 inches on my rain gage in a little more than two hours. That’s about a 10-year rain according to the new Atlas 14 statistics below.
Photos from Around Kingwood
At 5 pm both streams were near the tops of their banks but well within them. That might not have been the case just a couple months ago before the flood control district widened and deepened them to restore their original conveyance. Parts of Ben’s Branch were down to a two year level of service. That’s means they would flood in a two-year rain…obviously less than today’s.
Forecast for Remainder of Evening
As of 5:30 pm, Jeff Lindner, Harris County Meteorologist said, “Heavy rainfall continues to progress WSW across the area while a second area of heavy rainfall is moving SE across western Montgomery, N Waller, and NW Harris County. This area to the northwest is the remains of a line of thunderstorms from central Texas.”
“Rainfall amounts have averaged 2-3 inches over the northern half of Harris County with 4-6 inches over the Humble, Kingwood, Crosby, and Huffman areas,” said Lindner. “Significant street flooding has occurred over the northeast and northern portions of the county into Liberty and Montgomery Counties. While the activity is continuing to progress through the area, recent radar and HCFCD gage rainfall sensors indicate the hourly rainfall rates have weakened into the .50-1.5 inch range which is significantly lower than the 3-4 inches per hour recorded earlier this afternoon.”
“Street flooding will continue into the early evening hours and slowly subside over the area, while creeks and bayous continue to respond to the heavy rainfall. At this time all creeks and bayous are well within banks.”
More Yet to Come
Heavy rainfalls like this afternoon’s should continue through Thursday when the chances start to diminish through the weekend. Runoff should increase as grounds are now thoroughly saturated. Stay cautious. I almost drove into the water that rose to the bumper of that semi above. It didn’t look that deep but obviously could have stalled my Tahoe. Remember, if water gets over your tailpipe, it will cause your engine to stall. Game over.
Posted by Bob Rehak on May 17, 2021 based on personal observation and information supplied by HCFCD, Jeff Miller, Paul Campbell, and Nicole Black-Rudolph
1357 Days since Hurricane Harvey
Monday AM: All SE Texas Now Under Moderate Risk for Flash Flooding This Week
The National Weather Service has produced a 3-day excessive rainfall map that show all of SE Texas under a moderate risk for flash flooding this week. “Moderate” means we have a 20-50% chance of exceeding flash-flooding guidance. Flash flooding occurs when short-duration, high-intensity rains exceed the drainage capacity in areas.
Jeff Lindner, Harris County’s meteorologist, sees heavy rainfall and flash flood threats increasing through the week. “A flash flood watch will likely be required for portions of the area later today,” he said.
Chance of Thunderstorms 70% and Increasing
The National Weather Service predicts a 70% chance of thunderstorms for the Lake Houston Area through Tuesday night. The chance increases to 80% for Wednesday and Thurday. The chances decrease to 70% for Friday, 60% for Saturday and 40% for Sunday.
It is difficult to predict exact amounts of rainfall for any specific location, such as Lake Houston, that far in advance. However, conditions are in place to produce heavy rainfall. The main threat for today is slow moving storms that could produce street flooding this afternoon. But chances increase tomorrow, Wednesday and Thursday.
“This pattern will support heavy rainfall and flash flooding especially during the mid-week period. But really every day this week has potential,” says Lindner.
Space City Weather likens the conditions in place to those that produced the May 2019 floods in Kingwood.
Rainfall Amounts
Since yesterday, there has been no change. Models suggest a fairly high limit on potential totals. “As seen yesterday, this air mass is capable of excessive short term rainfall amounts. Widespread amounts of 4-8 inches will be likely over much of the area over the next 5 days with isolated totals of 10-12 inches or more. Short duration rainfall rates of 2-4 inches per hour will be possible leading to rapid urban flash flooding,” says Lindner.
Grounds in the Houston area are already wet and water supply lakes near full capacity. As of this morning, the City has started lowering Lake Houston by one foot. The SJRA is not releasing water from Lake Conroe.
Lindner says that rises on area watersheds are likely given the widespread nature of this event. “It is certainly possible some watersheds will experience flooding at some point this week. Which watersheds potentially get hit the hardest remains uncertain…but the risk for flooding will be increasing,” he says.
Posted by Bob Rehak on Monday morning at 9 am, 5/17/21 based on information by HCFCD, NWS, and Space City Weather
1357 Days since Hurricane Harvey