Heavy Rainfall Threat in Coming Days

Jeff Lindner, Harris County Flood Control Meteorologist just issued a heavy rainfall warning. Lindner notes that the line of strong thunderstorms currently moving across the area will drop rainfall amounts of 1-3 inches.

The good news: the leading edge of this line is becoming detached from the outflow boundary. That suggests storms will weaken as they move southward. Rainfall rates which were 2-4 inches earlier over N Waller and Montgomery Counties have lessened to near 1-2 inches. The main threat now is short duration street flooding in areas with the heaviest rainfall.

Tonight’s Forecast 

Lindner points to extremely active radar out west along the Rio Grande. He says that’s where the next round of weather will be developing. He expects it to move quickly toward our area tonight. Models show this line of storms quickly reaching the area between midnight and 400 a.m. But at the speed it’s moving, he predicts only another 1-2 inches for most areas with this line.

Monday Prediction 

Continued high rain chances. The air may take much of the morning and early afternoon to recover from the early morning line of weather, but temperatures will only need to reach the low 80’s to trigger more storms. It will not take much heating to set things off, he warns. Storm motions could be fairly slow Monday afternoon and this could lead to excessive rainfall rates in a short period of time.

Tuesday-Thursday: Continued Threat 

Upper level disturbances remain parked over the state with rounds of storms at nearly any time. Heavy rainfall will continue to be a threat.

Rainfall Amounts Add Up Changing Nature of Threat 

Lindner concludes, “Moisture profiles certainly support heavy to excessive rainfall rates as seen today and if storms slow of train for a period of times totals could quickly add up. Grounds will saturate over time leading to increasing and eventually maximum run-off conditions…so the threat may grow from mainly street flooding to potential rises on area creeks, bayous, and rivers.”  

Lindner concedes that it’s hard to pinpoint any day or time or location that has a higher flood risk than another. “So we will just have to closely watch each convective episode and be prepared to react quickly,” he says.   

Impact of Today’s Rains on Elm Grove

Despite heavy rainfall this afternoon, Jeff Miller, an Elm Grove resident and frequent contributor, drove the streets of Elm Grove this evening. He notes that:

• Streets still seem clear as of 8 p.m.
• Taylor Gully is about half full, but water is flowing rapidly
• Water level is about 2 feet from the top of the twin culverts at the Rustling Elms bridge.

Miller sees the possibility of that culvert being overflowed as a danger.

Posted by Bob Rehak on 5/24/2020 with reporting from Jeff Miller and Jeff Lindner

999 Days since Hurricane Harvey, 248 since Imelda, and four years since the last Memorial Day Flood.