Emergency Management Agency
Vermilion County, Illinois

Ted Fisher, Director
2507 Georgetown Road
Danville, IL 61832
Phone:  (217) 443-6010
Fax: (217) 443-6653
 

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Non-Precipitation Watches, Advisories & Warnings
 
High Wind Watch
Issued when conditions are favorable for a widespread storm system to produce sustained wind of 40 mph or higher for at least one hour and/or wind gusts (not from thunderstorms) around 60 mph or higher which may cause damage to trees, limbs, power lines and some structures in the next 12 to 48 hours.
 
Excessive Heat Watch
Issued when conditions are favorable for an excessive heat event for at least two consecutive days in the next 24 to 72 hours.
 
Freeze Watch
Issued when conditions are favorable for widespread temperatures at or below freezing during the local growing season.
 
Fire Weather Watch
Issued when dry vegetation and conditions favoring extreme fire danger are expected 12 to 72 hours in the future.
 
Wind Advisory

Issued when sustained winds of 30 to 39 mph are expected for 1 hour or longer, OR for wind gusts of 45 to 60 mph for any duration within the next 12 to 36 hours.

 
Heat Advisory
Issued when maximum daytime heat index values are expected to reach or exceed 105F.
 
Frost Advisory
Issued when nighttime minimum temperatures are expected to range from 33F to 36F in the local growing season, resulting in the development of widespread frost.
 
Dense Fog Advisory
Issued when widespread fog is expected to reduce visibilities to 1/4 mile or less, causing a hazard to motorists.
 
Freezing Fog Advisory
Issued when light fog (visibility greater than 0.25 mile) combines with temperatures of 32F or colder to produce a hazardous formation of ice on roadways and/or bridges (also known as Black Ice).
 
High Wind Warning
Issued when sustained winds of 40 mph or more are expected for 1 hour or longer, or for wind gusts (not from thunderstorms) around 60 mph or higher which may cause damage to trees, limbs, power lines and some structures in the next 24 hours.
 
Excessive Heat Warning
Issued when maximum daytime heat index values are expected to reach or exceed 110F on at least two consecutive days AND nighttime heat index values of 75F or higher.  An Excessive Heat Warning can also be issued for at least four consecutive days of Heat Advisory criteria, since the effects of heat are usually cumulative.
 
Freeze Warning
Issued when widespread nighttime low temperatures are expected to reach 32F or lower in the local growing season. They are usually issued to highlight the first few freezes of the fall or unusually late freezes in the spring.
 
Red Flag Warning  (Fire Weather Warnings)
Issued when dry vegetation, sustained winds of 20 mph or higher, and minimum relative humidity drops to 25% or less  are all expected within 24 hours, resulting in an extreme fire danger.