According to the National Hurricane Center (NHC), recent satellite imagery suggests that a low-level circulation is forming associated with the disturbance over the Gulf of Mexico. The NHC has upgraded the chances of tropical formation from 20 percent to 40 percent overnight. However, shower and thunderstorm activity remains disorganized and the flood threat from the storm is minimal.
Overnight, NHC upgraded the chances for tropical development of the disturbance along the Texas Coast from 20% to 40%.
Conditions Marginally Conducive to Tropical Development
NHC says conditions are marginally conducive for development. A short-lived tropical depression or storm could form before the disturbance moves inland over the northwestern Gulf coast tonight.
NOAA predicts three day rainfall totals for the Houston area to range from 1-3 inches. Note the circular formation in the system.
Regardless of development, the system could produce heavy rainfall over portions of southeastern Texas and southwestern Louisiana during the next few days.
Jeff Lindner, Harris County’s meteorologist says, “There has been very little thunderstorm activity near the feature overnight with dry air wrapping in from the west.”
Lindner cites two forecast models that continue to attempt to close off the system nears the coast. “However, given the appearance this morning, this potential continues to be modest.”
Regardless of any development…impacts will be minimal, says Lindner. High rain chances in the forecast are a function of moisture levels over the central Gulf of Mexico which will be pushed westward over the next 24-36 hours and into southeast Texas.
Scattered showers and thunderstorms will develop with heating today and progress NW/WNW across the area.
Jeff Lindner, Harris County Meteorologist
Expect heavy rainfall under any areas of training cells. The National Weather Service has the eastern portions of the area under a slight risk for flash flooding today.
However, the scattered nature of the showers and thunderstorms should keep rainfall amounts manageable for most – generally in the 1-3 inch range today into Saturday.
If the system over the Gulf develops into a tropical storm or depression near the coast later today or tonight, expect an increase in the potential for thunderstorm training, especially in areas east of Houston.
River and Lake Report
The break most of us had from heavy rains yesterday let many rivers and streams recover. Lake Conroe remains a little more than a half foot above normal and continues releasing water at the rate of 2,665 cubic feet per second.
Lake Conroe level as of 7:30 am on Friday, May 21, 2021
And Lake Houston remains a little more than a foot above normal.
From Coastal Water Authority as of 5/21/2021 at 7:30 am.
Peach Creek at FM2090 is out of its banks but falling.
However, the East Fork at FM2090 and FM1485 is in danger of coming out of its banks.
Overall, the flood threat remains low for most of us with these few exceptions.
Posted by Bob Rehak on 5/21/2021, ten days from the official start of hurricane season, based on information from NHC, NWS, and HCFCD
1361 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/image003.gif?fit=800%2C561&ssl=1561800adminadmin2021-05-21 08:14:212021-05-21 08:14:25More Rain on Way, but Flood Threat Minimal for Most
After four days of heavy rains, today looked like a respite. This morning’s predictions mentioned another inch or two on Friday and Saturday. But then this the National Hurricane Center posted this within the last few minutes: a warning about what could turn into the season’s first tropical depression. And hurricane season doesn’t officially start for another ten days.
20% chance of formation for yellow area in next two to five days
20% Chance Before Official Start of Season
According to Jeff Lindner, Harris County Meteorologist, “The old complex of thunderstorms that moved off the Texas coast yesterday has festered over the west-central Gulf of Mexico today. While the satellite images look impressive, there appears to be no closed low pressure system at the surface and instead a surface trough extending across the region. Thunderstorms have been weakening this afternoon and there is no new development.”
Radar this morning showed storm festering in Gulf with a stationary trough drawing moisture up through Texas and Lousiana.
“So far this evening,” continued Lindner, “there is a large area of dry air to the west of the feature in the Gulf. The dry air will likely become entrained over time. However, some models show additional development for this feature as it moves generally toward the NW or NNW in the general direction of the Texas and Louisiana coastlines.”
NHC suggests the yellow feature has a 20% chance of developing into a tropical cyclone over the next 2 days.
This feature could help to enhance rainfall amounts over SE Texas this weekend, but any additional impacts beyond that at this time appear to be minimal, according to Lindner.
Take some time getting to know them know. During an actual storm, power outages and crowded bandwidth may make leisurely learning difficult.
Two other important sites for this area are the San Jacinto River Authority for Lake Conroe releases/levels and the Coastal Water Authority for Lake Houston levels. At this hour, the Lake Conroe is holding steady while releasing 2665 cubic feet per second. Lake Houston is still rising slightly with the flood gates wide open.
Lake Conroe Dashboard as of 7:30 PM on 5/20/21
Lake Houston as of 7:30PM , 5/20/21.
Posted By Bob Rehak on 5/20/21 Based on Information by NWS, NHC, HCFCD, SJRA, and Coast Water Authority
1360 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/two_atl_5d0-1.png?fit=900%2C665&ssl=1665900adminadmin2021-05-20 19:36:472021-05-20 19:49:12Could This Be the Start of Hurricane Season?
Today, the Lake Houston Area may finally get a breather from non-stop storms that blanketed the area for the previous three days. That doesn’t mean that we won’t get more rain. And it doesn’t mean flooding is not possible. It just means streams and bayous may get a chance to drain.
According to Jeff Lindner, Harris County Meteorologist, “Light rainfall continues mainly south of I-10 across the area.”
RadarScope Pro as of 10:54AM Houston time shows a large complex of storms to Houston’s south and west. They are moving north but have been dissipating as they move past the I-10 corridor for most of the morning.
Says Lindner, “A complex of thunderstorms is moving well into the NW Gulf. Another moving offshore of south Texas will likely keep southeast Texas stable today with only passing light or moderate rain showers and those will mainly focus south of I-10. Additional showers and thunderstorms will be possible on Thursday and Friday with continued high moisture levels over the area. However, the activity looks more scattered in nature and not as organized or intense as the last 48 hours.”
Additional rainfall amounts of 1-3 inches can be expected over the next 48 hours with the higher totals likely focused south of I-10.
Jeff Lindner, Harris County Meteorologist
Rainfall In This Event Almost Half of Year’s Total So Far
My digital rain gage indicates that we’ve received almost as much rain in the last three and a half days as we have year to date. That’s 138 days.
Here’s a breakdown:
Year to date: 23.64 inches
March: 1.95 inches
April: 4.01 inches
May to date: 11.38 inches
May 16: 1.22
May 17: 5.57
May 18: 1.64
May 19 so far: 1.22
According to the National Weather Service, the normal cumulative precipitation for May (up to the 19th) is 3.12 inches. And the normal yearly precipitation through today is 16.42 inches. Before this is all over, we could skew those averages a bit. We’ve exceeded the monthly average to date by a factor of two in the last two days!
Two-day rainfall totals for most Harris County gages as of 5/19/2021 at 10AM.
Run-off
Run-off continues from the rainfall over the last 48 hours with widespread totals of 3-5 inches over much of the area and an isolated amount of 8.56 inches in the Huffman area. Here’s how that is affecting local rivers and streams.
Rivers and Stream
Creeks in the northwestern portion of Harris County remain elevated and in some cases near bankfull. So do the middle and upper portions of Cedar Bayou and the West and East Forks of the San Jacinto River. Creeks in the northwestern portion of Harris County will crest and slowly fall this afternoon while rises will continue along the West and East Forks of the San Jacinto River. Peach Creek at 2090 is flooding.
East Fork at New Caney should experience minor to moderate flooding in next five days.
West Fork at 59 should experience minor flooding in low lying areas by Saturday.
Peach Creek at FM290 is already out of its banks according to the Harris County Flood Warning System.As of 11 am, elevation was 99.1. A ten-year flood at this gage is 99.3.
Lake Report
Lake Conroe is at 201.64 feet (normal is 201) at this writing and and releasing 2,665 cubic feet per second. Notice that they no longer have a box for seasonal lowering. They now call that COH (City of Houston) Diversion. It’s not that they have discontinued the seasonal lowering; they’ve just changed the way they account for it, according to Jace Houston, SJRA’s general manager. When the Lake is above 201 and water is inbound as it is now, SJRA is allowed to release water without it coming from the City of Houston’s portion.
When the flood threat has passed, if and when the City calls to resume seasonal lowering, the rate will show up in the COH diversion box. SJRA seems to be trying to lay responsibility for any inconvenience to Lake Conroe boaters at the feet of the City of Houston, which has already been dismissed from the Lake Conroe Association lawsuit.
Meanwhile, Lake Houston is up about a quarter foot so far this morning, despite the flood gates being wide open.
As of noon on 5/19/21
How Lake Houston Levels have varied during the last 7 days. Graph shows up to noon on 5/19.
As of this morning, here’s how White Oak Creek looks from the back yard of Woodstream Forest resident.
Photo from a video courtesy of Donald and Kristi Brown. Taken on 5/19/2021.
Posted by Bob Rehak on 5/19/2021 at Noon based on information from the NWS, HCFCD, Coastal Water Authority and SJRA
1359 Days since Hurricane Harvey
https://i0.wp.com/reduceflooding.com/wp-content/uploads/2021/05/White-Oak-Creek-by-Donald-Brown-in-Woodstream.jpg?fit=1200%2C676&ssl=16761200adminadmin2021-05-19 12:39:192021-05-19 15:12:11A Breather: Rain Mainly South of I-10 For Most of Day
More Rain on Way, but Flood Threat Minimal for Most
According to the National Hurricane Center (NHC), recent satellite imagery suggests that a low-level circulation is forming associated with the disturbance over the Gulf of Mexico. The NHC has upgraded the chances of tropical formation from 20 percent to 40 percent overnight. However, shower and thunderstorm activity remains disorganized and the flood threat from the storm is minimal.
Conditions Marginally Conducive to Tropical Development
NHC says conditions are marginally conducive for development. A short-lived tropical depression or storm could form before the disturbance moves inland over the northwestern Gulf coast tonight.
Regardless of development, the system could produce heavy rainfall over portions of southeastern Texas and southwestern Louisiana during the next few days.
Jeff Lindner, Harris County’s meteorologist says, “There has been very little thunderstorm activity near the feature overnight with dry air wrapping in from the west.”
Lindner cites two forecast models that continue to attempt to close off the system nears the coast. “However, given the appearance this morning, this potential continues to be modest.”
Regardless of any development…impacts will be minimal, says Lindner. High rain chances in the forecast are a function of moisture levels over the central Gulf of Mexico which will be pushed westward over the next 24-36 hours and into southeast Texas.
Expect heavy rainfall under any areas of training cells. The National Weather Service has the eastern portions of the area under a slight risk for flash flooding today.
However, the scattered nature of the showers and thunderstorms should keep rainfall amounts manageable for most – generally in the 1-3 inch range today into Saturday.
If the system over the Gulf develops into a tropical storm or depression near the coast later today or tonight, expect an increase in the potential for thunderstorm training, especially in areas east of Houston.
River and Lake Report
The break most of us had from heavy rains yesterday let many rivers and streams recover. Lake Conroe remains a little more than a half foot above normal and continues releasing water at the rate of 2,665 cubic feet per second.
And Lake Houston remains a little more than a foot above normal.
Rivers and streams have largely recovered from heavy rains earlier this week. Harris County’s Flood Warning System shows that the San Jacinto West Fork at 59 is falling and within its banks.
Peach Creek at FM2090 is out of its banks but falling.
However, the East Fork at FM2090 and FM1485 is in danger of coming out of its banks.
Overall, the flood threat remains low for most of us with these few exceptions.
Posted by Bob Rehak on 5/21/2021, ten days from the official start of hurricane season, based on information from NHC, NWS, and HCFCD
1361 Days since Hurricane Harvey
Could This Be the Start of Hurricane Season?
After four days of heavy rains, today looked like a respite. This morning’s predictions mentioned another inch or two on Friday and Saturday. But then this the National Hurricane Center posted this within the last few minutes: a warning about what could turn into the season’s first tropical depression. And hurricane season doesn’t officially start for another ten days.
20% Chance Before Official Start of Season
According to Jeff Lindner, Harris County Meteorologist, “The old complex of thunderstorms that moved off the Texas coast yesterday has festered over the west-central Gulf of Mexico today. While the satellite images look impressive, there appears to be no closed low pressure system at the surface and instead a surface trough extending across the region. Thunderstorms have been weakening this afternoon and there is no new development.”
“So far this evening,” continued Lindner, “there is a large area of dry air to the west of the feature in the Gulf. The dry air will likely become entrained over time. However, some models show additional development for this feature as it moves generally toward the NW or NNW in the general direction of the Texas and Louisiana coastlines.”
This feature could help to enhance rainfall amounts over SE Texas this weekend, but any additional impacts beyond that at this time appear to be minimal, according to Lindner.
Preparedness
This should serve to all that hurricane season begins in ten days. Don’t be caught unprepared. My Links page has many sites with helpful tips. You may also want to take this opportunity to bookmark the National Weather Service, National Hurricane Center, and Harris County Flood Warning System. They offer round the clock updates.
Take some time getting to know them know. During an actual storm, power outages and crowded bandwidth may make leisurely learning difficult.
Two other important sites for this area are the San Jacinto River Authority for Lake Conroe releases/levels and the Coastal Water Authority for Lake Houston levels. At this hour, the Lake Conroe is holding steady while releasing 2665 cubic feet per second. Lake Houston is still rising slightly with the flood gates wide open.
Posted By Bob Rehak on 5/20/21 Based on Information by NWS, NHC, HCFCD, SJRA, and Coast Water Authority
1360 Days since Hurricane Harvey
A Breather: Rain Mainly South of I-10 For Most of Day
Today, the Lake Houston Area may finally get a breather from non-stop storms that blanketed the area for the previous three days. That doesn’t mean that we won’t get more rain. And it doesn’t mean flooding is not possible. It just means streams and bayous may get a chance to drain.
According to Jeff Lindner, Harris County Meteorologist, “Light rainfall continues mainly south of I-10 across the area.”
Says Lindner, “A complex of thunderstorms is moving well into the NW Gulf. Another moving offshore of south Texas will likely keep southeast Texas stable today with only passing light or moderate rain showers and those will mainly focus south of I-10. Additional showers and thunderstorms will be possible on Thursday and Friday with continued high moisture levels over the area. However, the activity looks more scattered in nature and not as organized or intense as the last 48 hours.”
Rainfall In This Event Almost Half of Year’s Total So Far
My digital rain gage indicates that we’ve received almost as much rain in the last three and a half days as we have year to date. That’s 138 days.
Here’s a breakdown:
According to the National Weather Service, the normal cumulative precipitation for May (up to the 19th) is 3.12 inches. And the normal yearly precipitation through today is 16.42 inches. Before this is all over, we could skew those averages a bit. We’ve exceeded the monthly average to date by a factor of two in the last two days!
Run-off
Run-off continues from the rainfall over the last 48 hours with widespread totals of 3-5 inches over much of the area and an isolated amount of 8.56 inches in the Huffman area. Here’s how that is affecting local rivers and streams.
Rivers and Stream
Creeks in the northwestern portion of Harris County remain elevated and in some cases near bankfull. So do the middle and upper portions of Cedar Bayou and the West and East Forks of the San Jacinto River. Creeks in the northwestern portion of Harris County will crest and slowly fall this afternoon while rises will continue along the West and East Forks of the San Jacinto River. Peach Creek at 2090 is flooding.
Lake Report
Lake Conroe is at 201.64 feet (normal is 201) at this writing and and releasing 2,665 cubic feet per second. Notice that they no longer have a box for seasonal lowering. They now call that COH (City of Houston) Diversion. It’s not that they have discontinued the seasonal lowering; they’ve just changed the way they account for it, according to Jace Houston, SJRA’s general manager. When the Lake is above 201 and water is inbound as it is now, SJRA is allowed to release water without it coming from the City of Houston’s portion.
When the flood threat has passed, if and when the City calls to resume seasonal lowering, the rate will show up in the COH diversion box. SJRA seems to be trying to lay responsibility for any inconvenience to Lake Conroe boaters at the feet of the City of Houston, which has already been dismissed from the Lake Conroe Association lawsuit.
Meanwhile, Lake Houston is up about a quarter foot so far this morning, despite the flood gates being wide open.
If rain during the rest of today remains light, SJRA may be able to avoid flooding people upstream and downstream, just as they did on May 1st, when the areas upstream from Lake Conroe received 8-10 inches of rain.
Flash Flood Watch Remains in Effect Through Thursday Morning
In the meantime, a flash flood watch remains in effect for the Houston region through tomorrow morning. Chance of precipitation is 60% this afternoon, going up to 90% this evening. NWS predicts up to 1.25 inches of rain today and up to .75 tomorrow for the Kingwood area.
As of this morning, here’s how White Oak Creek looks from the back yard of Woodstream Forest resident.
Posted by Bob Rehak on 5/19/2021 at Noon based on information from the NWS, HCFCD, Coastal Water Authority and SJRA
1359 Days since Hurricane Harvey