Flash Flood Watch
The National Weather Service has issued a flash flood watch from 6PM tonight through Thursday afternoon. In the north Houston Area, it includes:
- Houston
- The Woodlands
- Coldspring
- Trinity
- Shepherd
- College Station
- Huntsville
- Conroe
- Livingston
- Madisonville
The watch extends much farther north and west. It includes the Dallas/Fort Worth Area, Oklahoma, Arkansas where NWS predicts up to six inches of rain.
Jeff Lindner, Harris County Meteorologist reports increasing risk of excessive rainfall along and west of US 59 and west of SH 288. A strong upper level storm system will combine with increasing moisture and a slow/stalling surface frontal boundary over SE TX tonight. The stalling boundary will produce training.
Lindner adds, “Heavy rainfall of 1-2 inches per hour looks possible and this could be maintained for several hours along/near the stalling front. Where the heaviest rains fall will be determine where the front slows and stalls and at this time areas from Wharton and Fort Bend into western Harris and then northward into Montgomery County have the highest chances.”
“Widespread rainfall amounts of 2-4 inches with isolated totals of 5-6 inches will be possible,” says Lindner. “We need to watch for flooding.”
Areas At Highest Risk of Flooding
While grounds west of I-45 are especially dry, Lindner predicts that the entire San Jacinto basin (west, east, and mainstem) and Trinity basins will be affected – especially in the longer term as water works its way downstream.
Northwest and western Harris County will likely see the highest totals. Responses on the creeks in those areas are likely early Thursday.
Lindner believes most watersheds will be able to handle incoming rainfall up to 4.0 inches. Should western Harris County get more, minor flooding would be possible. Especially along the lower end of South Mayde Creek, the upper end of Little Cypress Creek, the upper end of Spring Creek, and the lower end of Keegans Bayou.
As of noon on Wednesday, the SJRA shows Lake Conroe at 199.41, slightly below its normal level.
The City of Houston began lowering Lake Houston at noon Wednesday as a precautionary measure. Property owners should secure property along the shoreline. Lake levels can be monitored in real time by visiting the Coastal Water Authority website.
Heavy rainfall will end Thursday afternoon.
PRECAUTIONARY ACTIONS
A Flash Flood Watch means that conditions may develop that lead to Flash Flooding. Flash Flooding is a very dangerous situation. You should monitor forecasts and be prepared to take action should Flash Flood Warnings be issued. See:
- Harris County Flood Warning System (harriscountyfws.org)
- Houston TranStar (houstontranstar.org)
- National Weather Service Houston/Galveston Forecast Office (weather.gov/hgx).
Do not enter or cross flowing water or water of unknown depth.
Posted by Bob Rehak on 12/30/2020 based on information from the National Weather Service and HCFCD
1219 Days since Hurricane Harvey
