Tuesday, August 28, 2007

Dean visits the Southwest

After coming ashore last week, Hurricane Dean moved into central Mexico and has since reignited the Southwest Monsoon. Injecting copious tropical moisture into the region, the storm can now be blamed for floods in Las Vegas and a soggy week in Albuquerque.

Of course, the remnants of Dean are only part of the explanation for a resurgence of the monsoon rains. A low pressure "disturbance" off southern California, coupled with the persistent dome of high pressure over the lower Mississippi Valley, are producing southerly winds over northern Mexico and the Four Corners region, pushing the moisture northward. In addition, a cold front has moved into Colorado from the northwest and southwest winds ahead of the front are bringing Dean's gift to the southern Rockies and Front Range cities.

Though hurricanes often devastate coastal areas and spawn destructive inland tornados, they can also bring beneficial rains to drought-plagued regions. Pros and cons can be listed for all of nature's forces; we tend to judge them based on how they affect our personal lives.