Meteorologists with the National Weather Service Brownsville-Rio Grande Valley issued their latest forecast Wednesday afternoon for the “beneficial rainfall” that was expected to begin falling on the Valley later in the day and lasting into early Friday.
Wednesday’s forecast was largely unchanged from Monday’s and Tuesday’s, warning of a possibility for isolated strong to severe thunderstorms Wednesday night and Thursday complements of a cold front moving in late Wednesday.
Total estimated rainfall amounts for the event were between 1 to 3 inches for the ranchlands north of the Valley and 1 to 2 inches for the Valley itself.
Brownsville was on the low side of the estimates, with 0.5 to 1 inch predicted, while the rest of the Valley might see as much of 1.5 inches, according to the NWS.
Still, the agency warned — again — that “nuisance flooding and isolated flash flooding may occur with these rain showers.”
“As of (Wednesday), the Weather Prediction Center has portions of the northern ranchlands in a Slight Risk of Excessive Rainfall, while the Rio Grande Valley is still in a Marginal Risk valid for Thursday,” meteorologists said. “The Storm Prediction Center has all of deep South Texas/Rio Grande Valley in a Marginal Risk for severe weather for Thursday as well.”
One of the two windows of opportunity for heavier rain and strong to severe thunderstorms during the event was the arrival of the cold front Wednesday night, with nuisance flooding in poor drainage areas, including street flooding, a possibility along arroyos and small creeks in the Brooks and Kenedy ranch region and in what NWS called “Brush Country and Rio Grande Plains.”
Wednesday night was said to have the best chance for strong to severe thunderstorms, with the possibility of small hail and winds of up to 50 or 60 mph accompanying the storms, meteorologists said.
The second rainy window, Thursday afternoon through early Friday morning, will see “a series of disturbances” rolling over the region. Strong to severe thunderstorms may result, as may additional nuisance flooding, though the rain is expected to taper off Friday during the day, according to the forecast.
The threat of hail larger than 1 inch in diameter, winds in excess of 60 mph, flooding and lightning were toward the low end of the probability scale for Wednesday and Thursday, while there was virtually no chance of tornadoes, NWS said.
Meteorologists’ medium level of confidence in the likelihood of a heavy rainfall event remained unchanged Wednesday, while confidence that strong to severe thunderstorms would occur was medium to low.
The station again advised residents to clean debris from drainage ditches, clean-outs and canals as a precaution.
