Alert Summary for All Northern CA Counties
NOAA's National Weather Service|
Current Alert Summary for Northern CA Counties
Last update: September 21, 2020, 11:40 AM
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Updates every 10 Minutes
National Weather Service Description of Alerts -
(What Does It All Mean?)
- WEATHER WARNING -
A warning is issued when a hazardous weather or hydrologic event is occurring, imminent or likely. A warning means weather conditions pose a
threat to life or property. People in the path of the storm need to take protective action.
The generic term, Winter Storm Warning, is used for a combination of two or more of the following winter weather events; heavy snow, freezing rain,
sleet and strong winds. Heavy snowfall amounts are imminent and the criteria for amounts varies significantly over different county warning areas.
- WEATHER ADVISORY -
An advisory is issued when a hazardous weather or hydrologic event is occurring, imminent or likely. Advisories are for less serious
conditions than warnings, that cause significant inconvenience and if caution is not exercised, could lead to situations that may threaten life
The generic term, Winter Weather Advisory, is used for a combination of two or more of the following events; snow, freezing rain or freezing
drizzle, sleet, and/or blowing snow. Moderate snowfall amounts are imminent and the criteria for amounts varies significantly over different
county warning areas.
- WEATHER WATCH -
A watch is used when the risk of a hazardous weather or hydrologic event has increased significantly, but its occurrence, location or timing
is still uncertain. It is intended to provide enough lead time so those who need to set their plans in motion can do so. A watch means that
hazardous weather is possible. People should have a plan of action in case a storm threatens and they should listen for later information and
possible warnings especially when planning travel or outdoor activities. A Winter Storm Watch mean that hazardous winter weather conditions
including significant accumulations of snow and/or freezing rain and/or sleet are possible generally within the next 36 hours.
- SPECIAL WEATHER STATEMENT -
A special weather statement is a form of weather advisory. There is no set criteria for special weather statements. A special weather statement
may be issued by the NWS for hazards that have not yet reached warning or advisory status or that do not have a specific code of their own, such
as widespread funnel clouds. They are also occasionally used to clear counties from severe weather watches. A common form of special weather
statement is a "Significant Weather Advisory."
- SHORT TERM FORECAST -
The short term forecast may include any current or recent past conditions that form a basis for, or an enhancement to, the forecast. Detail in the
short term forecast will depend on radar coverage, satellite imagery and other remote sensing capabilities. The short term forecast is not a
vehicle to initiate or cancel warnings watches or advisories, but in a severe weather event, will be used to describe to where severe weather
and/or flash flood producing rains are moving.