Tag Archive for: rain

Up to 6″ of Rain Possible by Weekend

The second half of this week will likely be very wet. The National Weather Service’s (NWS) Weather Prediction Center forecasts widespread rain totaling 4″ with isolated areas getting 5- 6″ between Wednesday and Sunday.

Seven-day forecasted rain totals, predicted as of Monday morning 4/3/2023.

However, the rain will come in several waves and be spread out. The sporadic nature of the rainfall plus dry ground will minimize the risk of flash flooding. But some forecasters are already warning of possible street flooding, especially where storms cluster or train.

Timing of Rainfall

An upper level storm system will slow and eventually stall over the Houston area from Wednesday-Saturday. Scattered showers and thunderstorms will accompany the frontal passage on Wednesday.

As the front slows and lingers just off the upper Texas coast, both the Gulf and Pacific will feed moisture into our area along the boundary. Moisture values will approach the maximum levels for early April by Thursday and Friday.

As the cold front transforms into a coastal trough along the coast or just inland, periods of widespread showers and thunderstorms will be possible Thursday and Friday.

Given the stalled system, repeat cell training will be possible which may quickly produce areas of heavy rainfall.

Jeff Lindner, Harris County Meteorologist

Runoff Will Increase As Ground Becomes Saturated

While it will not rain the entire period, several rounds of showers and thunderstorms will be likely. Expect 1-2 inches per day. And remain alert for cell clustering or training which could trigger street flooding.

Grounds are now very dry over the region and much of the rainfall should soak in. However, grounds will eventually become saturated and when they do, run-off will increase and so will the risk of street flooding.

Severe Weather Threat Low

At this time, the risk of severe weather remains low. The Weather Prediction Center rates our chances of flash flooding from excessive rainfall at less than 15% for both Wednesday/Thursday and Thursday/Friday. But monitor forecasts closely this week.

Posted by Bob Rehak on 4/3/2023

2043 Days since Hurricane Harvey

Houston in Bullseye: NWS Predicting Another 4-6 Inches of Rain in Next 5 Days

The National Weather Service released this map around 7 a.m. Houston time this morning. It shows Houston in the bullseye with another 4 to 6 inches of rain predicted in the next five days. Jeff Lindner, Harris County Meteorologist, warns that flash flood watches may be needed by Friday into the weekend.

Houston Area is in the Bullseye and could receive another 4-6 inches of rain in the next five days.

Atmosphere Moisture Levels Support 1-3 Inches Per Hour Later Today

Yesterday’s active weather pushed down toward the coast overnight. The local air mass stabilized by Thursday morning. But afternoon heating and a rapid influx of Gulf moisture favor the development of numerous thunderstorms later today over the region.

Moisture levels in the atmosphere support heavy rainfall with hourly rainfall rates of 1-3 inches per hour possible under the strongest cells. Lindner notes that we saw this yesterday evening throughout the Lake Houston area.

Heaviest Rains Expected Friday

However, the main storm system will begin to move slowly into southwest and west TX on Friday. It will dominate local weather through the weekend, according to Lindner, as several disturbances rotate around around it and feed off the near-continuous stream of rich Gulf moisture over the area.

Expect widespread showers and thunderstorms Friday through the weekend with frequent rounds of heavy rainfall.

Jeff Lindner, Harris County meteorologist

Upper level winds will support cell training over the area this weekend. Flash flooding will be a concern. 

Rainfall Amounts, Impacts

Additional rainfall amounts of 4-6 inches will be possible over the next 5 days. Much of this will fall during periods of heavy rainfall. Isolated totals could be significantly higher under any areas of sustained training. Hourly rainfall rates of 1-3 inches will be possible, which could support rapid street flooding.

Ground Still Saturated

Grounds are still saturated from heavy rainfall in May. And some watersheds are still elevated from the rainfall yesterday evening. Rainfall over the next several days will likely generate run-off into local watersheds resulting in rises. Any areas of sustained heavy rainfall will increase the threat for channel flooding given the delicate groundwater situation currently in the area.

Posted by Bob Rehak on June 3, 2021, based on info from the NWS and HCFCD

1074 Days since Hurricane Harvey

Overnight Rains Could Add to This Afternoon’s Woes

A strong line of thunderstorms with high winds, torrential rains and possible tornadoes swept through the Lake Houston area this afternoon. It left widespread power outages, snarled traffic, flooded streets, and swollen creeks and ditches. People still suffering PTSD from Harvey were re-traumatized by the sound of news helicopters and water creeping up their front steps. More heavy rains tonight will add to the area’s woes, even as people are still cleaning up from this afternoon’s flooding.

Examples of Damage Reported

Among the damage reported:

  • Several flooded homes in Bear Branch and Woodland Hills near creeks or ditches
  • Flooded locker rooms at Kingwood High School
  • Trees down and blocking Kingwood Drive at rush hour
  • Power lines down on Kingwood Drive
  • Knee-high water on Kingwood Drive at Town Center
  • Kingwood Drive traffic rerouted up Valley Manor
  • New pad sites for the retail expansion of the HEB center under water
  • Street flooding from one end of Kingwood to the other

Streets Designed as Part of Flood Retention System

Note: the streets in Kingwood are DESIGNED as part of the flood retention system. When rainfall rates exceed what creeks, ditches and bayous can handle, water backs up into streets. and drainage swales.

The amount of rain we received today was not great. But the intensity was off the charts. In about a half hour at my house, we received almost two inches. That’s between 3 and 4 inches per hour. Here’s an example: the swale beside my house.

Valley Manor just north of Kingwood Drive at 4PM on 5.3.19. Two neighbors across the street reports water on their front steps. One said water started to come through her front door. The family is still repairing from Harvey. Her entire family is traumatized.
This is the ditch adjacent to the retail expansion of the H-E-B center. Photo courtesy of Mark Micheletti.
Kingwood Drive west of Town Center. Photo courtesy of Clay Crawford.
Kingwood Drive at Town Center.Photo courtesy of Clay Crawford. I heard that the entrance to Fosters Mill was also under water.
Video of street in Riverchase by John Knoerzer.

Rainfall Totals for Friday Storm

Rainfall totals for last 24 hours as of 10PM 5.3.19. Note higher totals upstream from Lake Houston area.

River Report: Minor Flooding Possible on West Fork

Harris County Flood Warning System’s Real Time Inundation Mapping shows most streams within their banks. But note the warning for Humble at US59. While the river is 2 feet below the top of bank as of 10PM, it could easily go out of bank tonight.

More Storms on Way

As of 9PM a severe thunderstorm watch is still in effect for much of southeast Texas until 3PM Saturday.. A large line of strong to severe thunderstorms has developed from E of Austin to NW of San Antonio and is moving ESE/SE at 15-20mph. Expect an average 1-2 inches with the line passage. Isolated total up to 3 inches be common. Creeks and bayous should be able to handle that amount of rainfall, according to Jeff Lindner of Harris County Flood Control.

NOAA forecast clearly shows the line of strong thunderstorms that should hit us overnight.

Here is an updated radar image as of 12:01 AM Saturday morning.

Image courtesy of RadarScope, an amazing app!

Expect minor flooding at 59 and River Grove Park, that could be exacerbated by the mouth bar and other sediment still in the river.

This does not account for any local effects to the mouth bar.

Hoping you stay dry!

Posted by Bob Rehak on 5/3/19 around midnight

613 Days since Hurricane Harvey

Impact of March 28/29 Rain and Lower Lake Level on Kingwood

Beginning March 27, 2018, the City of Houston lowered the level of Lake Houston in anticipation of flash flooding. The storm hit Kingwood in the afternoon of the 28th and was over by the morning of the 29th According to Harris County Flood Control rain gages, we received 2.64 inches of rain at the Kingwood Country Club and 3.36 inches at the US59 bridge. Areas upstream received as much as 5.5 inches. An average across the watershed was close to 4.

Thank you, Dave Martin and Sylvester Turner!

Mayor Sylvester Turner and Council Member Dave Martin should be congratulated on their decision to lower Lake Houston. Some low-lying areas like River Grove Park flooded. However, as of this writing, I’m not aware of any homes that flooded. Surely there would have been major property damage, given all the siltation from Hurricane Harvey, had the lake been at its normal level.

How the rain affected different parts of Kingwood

The underpass at the 59 bridge was closed due to high water early in the morning on the 29th.  This is a perennial choke point. It has gotten worse since Harvey.

At Scenic Shores in Kings Point, the river was well within its banks thanks to the decision to lower the lake.

How much was it lowered? 2.5 feet according to the Coastal Water Authority.

Below is a photo taken last night in Kingwood Greens. It shows vast expanses of sand before the rain started. There were no reports of flooding in Kingwood Greens today, again, thanks in large part to the decision to lower the lake before the storm.

In Kings Lake Estates on the south side of the San Jacinto River, across from Kingwood Greens, the water got close. A resident sent this pic.

The homeowner above stated, “I am literally stunned how high the water is at my property right now even though the lake level was extremely low only 24 hours ago….and only after a modest rain storm last night.” To underscore the need to begin dredging immediately, he added, “This has NEVER happened before with such a minor rain event!”

Worst Flooding At River Grove Park

River Grove still has that massive sand bar blocking the drainage ditch. Water backed up behind that and flooded the park – for the second time within a month! See four images below.

As of 2:30 PM on March 29th, the disc golf course, playing fields, boat dock area and boardwalk at River Grove were totally under water. Additionally, about a third of the parking lot was under water and the flood level was continuing to rise.

All in all though, we lucked out with this storm largely because of the decision to lower the lake. Without that, flooding would have been much worse.

Anxiously Awaiting Dredging

Yesterday, the county approved money to begin dredging this area. Hopefully that will help cure the flooding woes at River Grove and give us a great margin of safety elsewhere.

As bad as these pictures look, about three weeks ago, on one-fifth the amount of rain that we received last night, the flooding was far worse. Before Harvey and the giant sand blockage at the base of the drainage ditch, River Grove could take twice as much rain without this much flooding.

As the resident who owned the gazebo above said, “With no major dredging, Kingwood residents better start praying every single day that we don’t get a tropical storm or even minor hurricane. We need dredging SOON!”

Posted by Bob Rehak on March 29, 2018

212 days since Hurricane Harvey