Here comes another hurricane.

Omar could bring up to 20 inches of rain across Puerto Rico and the Northern Leeward islands — and life-threatening flash floods and mud slides — when it arrives over the next 24-36 hours, according to the National Hurricane Center.

Omar is the 15th tropical storm of the season; a typical hurricane season brings 10 storms, according to Reuters. This season ends November 30.

Right now, Omar is a Category 1 hurricane with winds near 80 miles per hour (130 kilometers per hour). Forecasters say it could become a category 2 hurricane with winds up to 96 miles per hour (154 kilometers per hour) by the time it hits the northern Caribbean, producing coastal storm surges, swells and large waves that could erode beaches.

A hurricane warning — meaning the storm is expected in the next 24 hours — is in effect for the U.S. Virgin Islands, Vieques and Culebra. A hurricane watch — with stormy weather possible over the next 36 hours — is in effect for Puerto Rico.

Satellite image of Hurricane Omar by NOAA