A strong upper level low continues to spin over northern Mexico this morning. This system is outside of the United States upper air network. That means there is a certain guessing aspect with the forecast. We’ve seen a couple surprises over the past few days thanks to the lack of an upper air network over Mexico. To have such a strong upper level low in the Tropic of Cancer is extremely rare. The heaviest rain overnight has been in Far East Texas but much more so in Louisiana. They’re in a downright emergency with some locations approaching 20 inches of rain since yesterday. Many roads are completely flooded or just washed out and many neighborhoods are underwater. Regional radar at the time of this writing shows pockets of moderate to heavy rain moving north across the Houston Metro and in Southeast Texas. Light to moderate rain is moving north across the San Antonio metro north into North Texas and Northeast Texas.
Areas of rain will continue today across the eastern half of Texas. An isolated severe thunderstorm may occur along or south of a warm front. The Storm Prediction Center has highlighted a level 1 risk of severe weather to account for that possibility. The likelihood of severe weather is low, but not zero. A brief, weak tornado or damaging wind gust near 60 MPH would be the main threats.
It won’t be raining all the time today across the eastern half of Texas. When not raining clouds will remain widespread with dreary conditions. Rain chances increase again tonight across the eastern two-thirds of Texas as a new surface low develops in South Texas. That low will help push a warm front north into Central Texas. We’ll have to watch for an isolated severe weather threat tonight along and south of that warm front. Rain and storm chances will continue on Friday and Friday Night before tapering down on Saturday.
The official rain forecast from the Weather Prediction Center indicates an additional one half inch to three inches of rain may fall by Saturday morning in the eastern two thirds of Texas. These totals are regionalized and with the expectation of variations on a local scale. Any additional rain in East Texas will cause flooding so we’ll be watching for that. Hopefully we can get some good rain totals in the Hill Country, Big Country, and western North Texas with tonight’s rain chances.