Excessive Rainfall Threat from Beta Spreads Inland
As of mid-day Sunday, all of East Texas now faces some level of excessive rainfall and flash flood risk from Tropical Storm Beta.
The projected path of the storm has shifted inland, so rainfall will reach father north. The latest track now takes the storm on a path right up US59 from Sugar Land to Humble and Kingwood. However, Beta likely be a tropical depression by the time it reaches the north side.
Six to 15 Inches of Rain Now Predicted
According to the local National Weather Service office and the National Hurricane Center, most of the Houston region can expect 6 to 15 inches with the highest totals closer to the coast.
Harris, Montgomery and Liberty Counties (and the whole Houston region) face a high to moderate threat of flooding rains. The first rainbands from Beta have already started to move onshore today, but the heaviest rain will not occur until Monday into Tuesday.
North Houston Under Moderate Flooding Rain Threat
Flash Flood Watch in Effect
The entire region is under a flash flood watch. Coastal areas also face storm surge and tropical storm warnings.
Slow Moving Storm Will Produce Prolonged Rains
Beta is meandering slowly at about 3 mph northwest toward the coastline west of Houston and will then curl back over Houston. It should move inland sometime Monday or Monday night and turn from a storm into a depression by the time it reaches Houston.
However, Beta could dump rain on us from later today all the way through Wednesday.
40-50% Chance of Tropical Storm Force Winds Reaching North Houston
The North Houston Area has a 40-50% chance of seeing tropical storm force winds from Beta.
If the high winds reach this far inland, they would likely arrive Monday evening. Winds extend outward from the center for 195 miles as of Sunday morning.
Feeder Bands Extend Outward 190 Miles
In fact, at 11 a.m. Sunday morning, the first feeder band was approaching the eastern side of Houston, as you can see in the radar image below.
This image shows how the wind and rain from Beta could remain with us for days as the storm’s center wanders around the Gulf.
These feeder bands reach out 190 miles. That is roughly the distance from Houston to San Antonio. So Beta will produce long-duration rainfall from the middle Texas coast to southern Louisiana.
Flash, Urban, and River Flooding Likely
The National Weather Service warns that coastal flooding will remain a threat through midweek with the worst of the storm surge anticipated on Monday and Tuesday.
Elsewhere impacts from the excessive rain include:
- Rainfall flooding may prompt evacuations and rescues.
- Rivers and tributaries may rapidly overflow their banks.
- Small streams, creeks, canals, and ditches may become dangerous rivers.
- Flood control systems and barriers may become stressed.
- Flood waters may cover escape routes.
- Streets and parking lots may become rivers of moving water with underpasses submerged.
- Driving conditions may become dangerous.
- Many roads and bridges may close with some weakened or washed out.
Lake-Level Situation
According to the SJRA, Beta has the potential to dump up to 8 inches of rain in Montgomery County.
SJRA is operating under standard protocols for a severe weather event and will be onsite at Lake Conroe throughout the duration of Tropical Storm Beta.
Lake Conroe remains 18 inches low, and based on the current forecast, no reservoir releases are expected.
SJRA
Real-time information on lake level can be found on the SJRA homepage at the “Lake Operations and Rainfall Dashboard” link.
At of this writing, Lake Houston is down a foot compared to its normal pool level (41.38 vs 42.4). You can monitor Lake Houston levels via the Coastal Water Authority website.
Monitor Downstream River Levels
You can monitor stream and river levels in near-real time at Harris County Flood Warning System. Make sure you check out the inundation mapping feature.
Posted by Bob Rehak on 9/20/2020 based on information from the National Weather Service and National Hurricane Center
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