Tag Archive for: flash flood warning

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.

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:

Lake Level41.41 ft.
Normal Pool42.4 ft.
Source: Coastal Water Authority

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

Thursday AM River, Lake Report for Lake Houston Area; Flash Flood Warning In Effect

The National Weather Service just issued a FLASH FLOOD WARNING FOR OUR AREA. Extreme rainfall rates of 3-6 inches per hour could lead to extensive and rapid onset flash flooding. This flash flooding will be possible over the Humble, Kingwood, Huffman, Crosby areas if a line of thunderstorms progresses slightly more to the SSE over the next few hours.

Given saturated grounds and already high water levels in E/NE Harris County these sort of rainfall totals would result in significant run-off and flash flooding.

Travel is strongly discouraged in the Flash Flood Warning and Flash Flood Emergency areas.

Overnight, the remnants of TS Imelda continued to shift north. The heaviest rainfall occurred north and east of Houston. The East Fork of the San Jacinto is at flood stage at Splendora and New Caney. The NWS has issued multiple flood warnings for that area.

A band of intense rainfall with rates of 3-5 inches per hour continues from Conroe to Porter to Liberty to Winnie.

Conroe Airport recorded 5.16 inches of rain in the last hour. 

This band of intense rainfall will move into the NE portions of Harris County over the next hour impacting areas around Kingwood, Humble, Huffman, and Crosby.

Flash flood warnings for much of the NE Houston, SE Montgomery County and W Liberty County that had been due to expire this morning have been extended to this evening.

Intense rainfall rates will result in rapid onset urban flash flooding. It is already in progress in SE Montgomery County. 

Source: National Weather Service via SJRA.net

West Fork and Lake Conroe Well Within Banks

Overnight, the West Fork of the San Jacinto at the SH99 (Grand Parkway) received another three inches of rain.

Lewis Creek on Lake Conroe received two inches in the last couple of hours.

Lake Conroe is now at its seasonal lowering target of 199 feet (actual reading is 198.88). Until now, the lake had been about a half a foot lower than its target due to evaporation. Despite the rain, Lake Conroe is still two feet below its normal level of 201 feet. That means an additional two feet of buffer remains before the lake reaches its normal level. Another two feet remains beyond that before the lake would have to open its gates.

The West Fork at US59 is at 43.5 feet, a little up, but still six feet from coming out of its banks.

Source: Harris County Flood Warning System

Currently Lake Conroe is still releasing 0 cubic feet per second. I.e., NOTHING.

East Fork Getting Hammered

Over on the East Fork, it’s a much different story. The storm has hammered that area all night.

  • Caney Creek at FM2090 received 12 inches in the last 24 hours and almost 6 inches in the last six hours. And 4.5 inches between 6 and 7 am.
  • The East Fork at New Caney has risen 18 feet since yesterday and will continue rising. It is currently at 62.78 feet.
  • FM1485 is now under water and closed.
  • Peach Creek at Splendora rose 10 feet since yesterday.
  • The East Fork at 2090 received more than 14 inches of rain in the last 24 hours, more than 8 of those inches falling overnight. As a result, the stream rose another six feet since 2 a.m. Flooding is now likely.
Source: Harris County Flood Warning System
Source: Harris County Flood Warning System

Lake Houston Up Slightly

Lake Houston is at 42.78 feet. Normal is 42.38. As East Fork rains descend into the lake, we can expect a rise. How much depends on the amount of rain this morning across the region.

The remnants of Tropical Depression Imelda should continue to drift slowly north today as extremely warm and moist air flows into Southeast Texas.

This moisture will feed the development of slow moving and training thunderstorms with rainfall rates of 3 to 5 inches per hour.

A persistent swath of storms across Eastern Montgomery, Liberty and Chambers county should wobble north then south early this morning.

Storms should continue to expand and develop further to the west as far out as the College Station by mid to late morning. Eventually a band of rainfall should develop and amounts across the band of 3-5 inches should be common with isolated amounts near 10 inches while outside of the band heavy rainfall may be more scattered in nature with amounts of only 1 to 2 inches.

The heavy rains will not only cause street flooding but with the elevated river and bayou levels more river flooding is likely to occur. The flash flood watch may need to be extended this evening. The flood threat may begin to shift further north tonight toward the Madisonville and Huntsville and Crockett areas.

Worst to East; Consider Yourself Lucky

As bad as this sounds, it could be worse. Areas east of us received an incredible 17.24 inches of rainfall in 6 hours near HWY 124 with a storm total nearing 28 inches. Catastrophic flooding is in progress along I-10 between Winnie and Beaumont.

Protective Actions

DO NOT Travel. Wait until the threat of high water has passed. 

Turn Around, Don’t Drown®:  Do not drive through flooded areas.  If you see water covering the road, do not attempt to cross it.  Only a few inches of water can float a vehicle . If you find yourself in a dangerous situation where your vehicle is taking on water, get out of the vehicle, get to a higher position, and call 911.  

Monitor Official Sources for Current Information:  Harris County Flood Warning System (harriscountyfws.org), Houston TranStar (houstontranstar.org), and the National Weather Service Houston/Galveston Forecast Office (weather.gov/hgx).

Monitor Stream, Bayou, and Creek Conditions:  Rain may move repeatedly across the same area, causing creeks and bayous to rise and possibly exceed their banks.  Stay informed of current conditions and avoid traveling near creeks and bayous.

Avoid Traveling during Periods of Heavy Rain:  Rain can reduce visibility and prevent you from seeing the road ahead, which could lead to accidents.

Posted by Bob Rehak at 7:30 a.m. on 9/19/2019

751 Days after Hurricane Harvey

Flash Flood Warning Extended Again! Up to 10 Inches Already Today with More on Way

Update: Flash Flood Watch Extended until 8:00 PM or until cancelled.

For the second time in five days, the National Weather Service issued flash flood warnings. This means more street flooding. Move your vehicles to high ground.

Flash Flood Warning till 8:00 or Until Canceled

The National Weather Service has issued a Flash Flood Warning for portions of northeast Houston. It includes Lake Houston, Kingwood and northeastern Bush Intercontinental Airport, until 8:00 p.m.  

Area of Flash Flood Warning

Early this afternoon, Doppler radar and automated rain gauges indicated nearly stationary thunderstorms producing heavy rain across the warned area. By 1 PM, three to almost five inches of rain had fallen and worse was yet to come. By 5PM, storm totals were approaching 10 inches with one station near FM1485 reporting 11 inches. The good news: as of 6PM, although it is still raining, the storm appears to be moving east and lessening.

Stunning Accumulations for Day That Was Supposed to be Light

Just hours ago, I posted a City of Houston alert warning of 7-10 inches of rain possible this WEEK. We have already gotten more than that today and it’s not over! And this was supposed to be the lightest day this week! Here’s what it looked like on the streets this afternoon.

Video courtesy of Josh Alberson showing the land being cleared next to HEB for retail expansion along Kingwood Drive. Someone needs to rethink that idea!
New retail center called “The Docks” already under water. Photo courtesy of Josh Alberson.
Taylor Gully also coming out of its banks at the end of Dunham Road. Video courtesy of Josh Alberson.
This video shows the south end of Woodland Hills Drive near the soccer field road and Romerica property.
It shows tree and water blocking the road/evacuation route. Courtesy of Mohamad-Khaled Chaouki Jrab.
Kings Forest Pool House on Woods Estates Drive. Neighbor across the street reported more than 6″ on his rain gage.

House on Royal Circle in Kings Forest not far from pool house above. Photo courtesy of Cyndy Brown.


  • Kingwood College closed. Water was intruding through drains and windows. No power.
  • The creek by Deerwood Country Club is almost over Kingwood Drive.
  • 8″ to 9″ standing water reported in Memorial Hermann lot in HEB Center. See below.

Street by Strawbridge Methodist Church. Video courtesy of Josh Alberson.

Storm Total Accumulations

Here’s what the storm total accumulations looked like as of 5:15.

Bright purple area in center equals 8.5 inch accumulations; darker blue areas within it show 10 inch accumulations during the course of the afternoon.

River Report and Protective Actions

The San Jacinto river is forecasted to rise above flood stage by this evening and continue to rise to near 49.6 feet by tonight. The river will fall below flood stage by after midnight

At 49.3 feet, minor lowland flooding begins in the vicinity of the gage; the north side turnaround at US 59 begins to flood; and low points on Thelma Road, Aqua Vista Drive, and Riverview Drive begin to flood.

River Flooding Watch Area

People in the area should avoid the river as it rises. Residents near the river should make preparations in the event they are not able to leave their homes due to high water.   

Turn Around, Don’t Drown®:  Do not drive through flooded areas. If you see water covering the road, do not attempt to cross it.  Only takes a few inches of water to float a vehicle . If you find yourself in a dangerous situation where your vehicle is taking on water, get out of the vehicle, get to a higher position, and call 911. 

Monitor Official Sources for Current Information:  Harris County Flood Warning System (harriscountyfws.org), Houston TranStar (houstontranstar.org), the National Weather Service Houston/Galveston Forecast Office (weather.gov/hgx), and the National Weather Service West Gulf River Forecast Center (weather.gov/wgcrfc).

Posted by Bob Rehak on May 7, 2019 at 2PM and update at 4PM and 6pm

616 Days since Hurricane Harvey