Tropical Storm Alvin has developed off the coast of western Mexico, marking the first named storm of the Northern Hemisphere this year. Located 670 miles south-southeast of Baja California, it has maximum sustained winds of 40 mph and is moving northwest at 10 mph. While no coastal warnings are in effect, the storm may bring rain and gusty winds to the west-central Mexico coastline. Forecasters predict Alvin could strengthen before weakening as it moves over cooler waters. The eastern Pacific hurricane season began on May 15, with an average of 15 named storms expected this year.