The Atlantic Basin's first tropical storm of the 2011 season, Arlene, will push into Mexico Thursday with locally gusty thunderstorms and flooding rainfall.
Clusters of thunderstorms continue to rotate slowly around a center of low pressure located in the southwest Gulf of Mexico, in the middle of the Bay of Campeche Wednesday midday.
According to Tropical Weather and Hurricane Expert Dan Kottlowski, "Overall, Arlene is poorly organized for a tropical storm, but if thunderstorms are able to wrap around the center, the system could intensify somewhat prior to landfall Thursday near Tampico, Mexico."
The main threat from Arlene will be torrential rainfall falling on the parched, rocky and rugged landscape of northeastern Mexico forward into the weekend. Locally, a foot of rain can fall, according to International Weather Expert Meteorologist Jim Andrews. The team of AccuWeather meteorologists do not believe Arlene poses much of a wind threat to coastal areas and offshore oil rigs in the region due to the expected modest strength of the system up until the time of landfall. There will be a buildup of waves in the region with the potential for an uptick in rip currents throughout the Gulf of Mexico region through the end of the week. As a result, bathers and small craft operators should treat the situation with respect.
There is substantial risk to lives and property from flash flooding, mudslides and washouts in Mexico in the path of Arlene, even though the system will weaken after landfall. Arlene will move in a general west-northwest path into the weekend. However, the a real coverage of the downpours is rather large and care should be taken to focus not just on flooding problems near the storm center. Pockets of torrential rainfall can extend over 100 miles away.
Some rain will reach into southern Texas. While there is the risk of some flash and urban flooding this far away, odds are the benefits would outweigh problems, provided there are no serious incidents or loss of life.
It is also possible some sort of moisture will feed to the northwest, perhaps reaching into parts of fire-ravaged Arizona and New Mexico. That moisture could be merely in the form of higher humidity or perhaps isolated showers and thunderstorms. Mainly dry thunderstorms over the Southwest U.S. now into the weekend would bring a problem from fire-starting lightning strikes rather than beneficial rain.
In order to determine how much, if any, rain reaches the desert Southwest of the U.S., we will have to see exactly how Arlene's moisture tracks and holds together while traversing Mexico. High mountains in northern Mexico along the way may screen out much of that moisture before hand. It is the same mountains that will enhance and squeeze out the rainfall in northeastern Mexico, perhaps leading to disastrous flooding.