Thursday, July 1, 2010

Alex Update - Rain Impact Areas



There has not been a whole lot of change from the update posted yesterday. Rainfall continues to be our main impact from Hurricane Alex. Hurricane Alex will likely make landfall tonight over northeast Mexico south of Brownsville. Like we saw yesterday, the counterclockwise circulation of Alex is bringing large amounts of moisture onto the coast and pushing it into South Central Texas.

Daytime heating will likely trigger storms again late this morning into the afternoon and evening hours. As was seen near the San Antonio airport Monday, and in Austin yesterday afternoon, some of the storms will produce torrential rainfall in a short amount of time...these can be rates of 2 inches per hour or more. These rainfall rates and the tropical nature of the atmosphere have increased the potential for flash flooding over the area. For this reason...the National Weather Service has issued a Flash Flood Watch for all of South Central Texas through 7 pm on Thursday.
Bands of showers and thunderstorms wi ll produce 2-4 inches of rain over the next several days with isolated totals of 6+ inches possible, mainly over southern areas. Just in the past two days, they have had cars stranded in water and even some rescues had to be made.

Please remember...Turn Around Dont Drown.

Winds will only be an issue in the vicinity of these showers and thunderstorms. Typically with a strong thunderstorm it is not uncommon to get wind gusts of 40-50 mph. We do not expect any sustained tropical storm force winds as the circulation of Alex will remain too far south.
Any wind damage that does occur will be very isolated and limited to strong thunderstorms.

Because the circulation of Alex is forecast to hit south of Brownsville, the tornado threat will likely remain over Deep South Texas. We also can't rule out the possible threat of a tornado, but the main threat area will be well south of San Antonio.

The unstable and moist atmosphere will stick around for several days...even after Alex makes landfall tonight. For this reason...scattered showers and thunderstorms will remain in the forecast over the holiday weekend. Rain chances of 30-40 percent should mean however that activity will be scattered and most scheduled events can go on with possible brief interruptions from the weather. Areas along the Rio Grande from Del Rio southward will have to watch Alex closely as there is a chance for significant rains over the mountains of Mexico. In the past, these type of events have led to flood events along the Rio Grande.

Please check the latest information on forecasts, watches, and warnings by going to the website at www.srh.noaa.gov/ewx A picture depicting the rain and flooding threats that are possible is included.

Be aware. Be informed. Be prepared.

Riverwalker

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