According to the National Hurricane Center (NHC), recent satellite imagery suggests that a low-level circulation is forming associated with the disturbance over the Gulf of Mexico. The NHC has upgraded the chances of tropical formation from 20 percent to 40 percent overnight. However, shower and thunderstorm activity remains disorganized and the flood threat from the storm is minimal.
Conditions Marginally Conducive to Tropical Development
NHC says conditions are marginally conducive for development. A short-lived tropical depression or storm could form before the disturbance moves inland over the northwestern Gulf coast tonight.
Regardless of development, the system could produce heavy rainfall over portions of southeastern Texas and southwestern Louisiana during the next few days.
Jeff Lindner, Harris County’s meteorologist says, “There has been very little thunderstorm activity near the feature overnight with dry air wrapping in from the west.”
Lindner cites two forecast models that continue to attempt to close off the system nears the coast. “However, given the appearance this morning, this potential continues to be modest.”
Regardless of any development…impacts will be minimal, says Lindner. High rain chances in the forecast are a function of moisture levels over the central Gulf of Mexico which will be pushed westward over the next 24-36 hours and into southeast Texas.
Expect heavy rainfall under any areas of training cells. The National Weather Service has the eastern portions of the area under a slight risk for flash flooding today.
However, the scattered nature of the showers and thunderstorms should keep rainfall amounts manageable for most – generally in the 1-3 inch range today into Saturday.
If the system over the Gulf develops into a tropical storm or depression near the coast later today or tonight, expect an increase in the potential for thunderstorm training, especially in areas east of Houston.
River and Lake Report
The break most of us had from heavy rains yesterday let many rivers and streams recover. Lake Conroe remains a little more than a half foot above normal and continues releasing water at the rate of 2,665 cubic feet per second.
And Lake Houston remains a little more than a foot above normal.
Rivers and streams have largely recovered from heavy rains earlier this week. Harris County’s Flood Warning System shows that the San Jacinto West Fork at 59 is falling and within its banks.
Peach Creek at FM2090 is out of its banks but falling.
However, the East Fork at FM2090 and FM1485 is in danger of coming out of its banks.
Overall, the flood threat remains low for most of us with these few exceptions.
Posted by Bob Rehak on 5/21/2021, ten days from the official start of hurricane season, based on information from NHC, NWS, and HCFCD
1361 Days since Hurricane Harvey