Floods

Monitoring Potential Flood Hazards

To help emergency managers and others prepare for floods, the USGS delivers a continuous source of streamflow information that provides the scientific basis for decision-making related to protection of life and property from water hazards. The USGS California Water Science Center maintains a network of nearly 500 streamgages that monitor hydrologic conditions throughout the State. Core data collected at streamgages are surface water levels that are used to determine the amount of water flowing in a river or stream. The USGS uses streamgage data to provide flood-warning alerts when surface water levels change rapidly, or reach flood-stage levels, which can signify potential hazardous conditions for downstream locations.

Winter Weather: La Nina

La Nina (translated from Spanish as "little girl") is a natural ocean-atmospheric phenomenon marked by cooler-than-average sea surface temperatures in the central Pacific Ocean near the equator. According to the National Oceanic and Atmospheric Administration, a wintertime La Nina climate pattern is in place for Winter 2017/2018, and there is a 50-percent chance it will affect the United States well into Spring 2018. Typically, La Nina climatic patterns include cooler, wetter weather in the northern United States, and warmer, drier weather in the southern states.

In California, La Nina usually brings drier and warmer conditions to Southern California. For Winter 2017/2017, NOAA's temperature and precipitation outlooks suggest climate patterns resembling those of a weaker La Nina. Less-than-normal precipitation over an extended period of time can contribute to water-supply problems and potential drought.

Related

Winter Weather in California Keeps CAWSC Field Crews Busy
Stormy weather: How the USGS goes to work monitoring its effects
Overview of the ARkStorm scenario
Anticipating the Environmental and Environmental-Health Implications of Extreme Storms: ARkStorm Scenario