Tropical Storm Priscilla could bring heavy rain and a “significant” risk of flash flooding to the southwestern United States through this weekend, forecasters warn.

The National Hurricane Center on Friday said Tropical Storm Jerry was dropping torrents of rain on the Caribbean’s northern Leeward Islands while Subtropical Storm Karen formed in the

Downgraded from a powerful hurricane, Tropical Storm Priscilla has lost its punch in the eastern Pacific Ocean near the coast of Mexico's Baja California peninsula. But the storm still carries plenty of moisture and is now bearing down on the southwestern U.S., where flood warnings already were posted Thursday.

Most Atlantic tropical systems form much farther south—in the tropical Atlantic, Gulf of Mexico or Caribbean—where warm sea surface temperatures and humid air foster cyclogenesis. The current system, however, is forming in cooler northern waters and under increasing wind shear, making tropical development rare but not impossible.

MIAMI -- MIAMI (AP) — Tropical Storm Raymond, the third system now off the coast of Mexico, forms in the eastern Pacific Ocean.