Non Precipitation Weather Terms

The following advisory terms are used to ALERT the public of weather situations that are not necessarily associated with precipitation, but need to be highlighted. The warning terms are used to WARN the public of non-precipitation events that could be a threat to life and/or property.


PRODUCT Description
DENSE FOG ADVISORY Used when dense fog covers a widespread area and reduces visibility to 1/4 mile or less, and frequently near zero.
FROST ADVISORY Issued during the growing season to indicate formation of widespread frost. Overnight lows in the lower or middle 30s accompanied by light winds will usually result in widespread frost.
FREEZE WARNING Issued during the growing season when temperatures at/near the ground are expected to drop well below freezing (32F) over a widespread area for a significant amount of time, regardless of whether frost forms or not. Adjectives such as 'killing' or 'hard' will be used as appropriate.
HEAT ADVISORY Issued for expected daytime heat indices above 105F and nighttime heat indices above 80F for two or more consecutive days.
EXCESSIVE HEAT WARNING Issued when the heat index is expected to equal or exceed 115F for 3 hours or longer. In these cases, the heat becomes dangerous for a large portion of the population.
WIND ADVISORY (also LAKE WIND ADVISORY) Wind Advisory issued when sustained winds of 30 mph or greater are expected to last for 1 hour or more, or for gusts of 45 to 57 mph for any duration. Lake Wind Advisory issued for area lakes when sustained winds of 30 mph or more are expected.
HIGH WIND WARNING Used when sustained winds of 40 mph or greater are expected to last for 1 hour or longer, or for non-thunderstorm winds of 58 mph or greater for any duration.
WIND CHILL WARNING Issued when wind chill temperatures are expected to reach -10°F or colder, with a minimum wind speed of about 10 mph.  (Test criteria for the 2002 / 2003 winter season.)
SHORT TERM FORECAST (NOWCAST) A short term forecast designed to give specific, detailed forecast information for the next 1 to 6 hours on a county-by-county basis. Non-severe advisory and warning information are contained in these forecasts which are routinely issued several times per day, and more often during busy weather periods. is the U.S. government's official web portal to all federal, state and local government web resources and services.