[WARC] Weather watch or warning definitions.

[Clare Jarvis]

SPRING/SUMMER WEATHER TERMS

      FLASH FLOOD WATCH Indicates that flash flooding is a possibility in or 
close to the watch area. Those in the affected area are urged to be ready to 
take action if a flash flood warning is issued or flooding is observed. 
      FLASH FLOOD WARNING Signifies a dangerous situation where rapid flooding 
of rivers, small streams, or urban areas is imminent or is occurring. Very 
heavy rain that falls in a short time period can lead to flash flooding, 
depending on local terrain, ground cover, degree of urbanization, degree of 
man-made changes to river banks, and initial ground or river condition. 
      RED FLAG WARNING A term used by fire-weather forecasters, to call 
attention to limited weather conditions of particular importance that may 
result in extreme burning conditions. A Red Flag Watch may be issued prior to 
the warning. The criteria for red flag events requires the combination of 
high to extreme fire danger and a critical fire weather pattern such as: dry 
lightning, low relative humidity, very dry and unstable air, and very strong/ 
shifting winds. 
      SEVERE THUNDERSTORM WATCH Conditions are favorable for the development 
of severe thunderstorms in and close to the watch area. Watches are usually 
in effect for several hours, with 6 hours being the most common. 
      SEVERE THUNDERSTORM WARNING Issued when a thunderstorm produces hail 3/4 
of an inch or larger in diameter and/or winds equal or exceed 58 mph. Severe 
thunderstorms can result in the loss of life and/or property. Information in 
this warning includes: where the storm was, what towns will be affected and 
the primary threat associated with the storm. A very severe tstm wrng is 
issued for sustained winds over 75 mph in the 7-county Minneapolis/St. Paul 
area. 
      SEVERE WEATHER STATEMENT Issued when the forecaster wants to follow up a 
warning with important information on the progress of severe weather 
elements. 
      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 
basis. Both severe and non-severe information is contained in these forecasts 
which are routinely issued several times per day, and more often during busy 
weather periods. 
      SPECIAL WEATHER STATEMENT Issued when the forecaster wants to pass 
information on to the public about developing or approaching weather that is 
not expected to be severe, but nonetheless is significant. 
      TORNADO WATCH Conditions are favorable for the development of tornadoes 
in and close to the watch area. Watches are usually in effect for several 
hours, with 6 hours being the most common. 
      TORNADO WARNING Tornado is indicated by radar or sighted by storm 
spotters. It is very important the warning include where the tornado was and 
what towns will be in its path. 
      URBAN AND SMALL STREAM FLOOD ADVISORY Alerts the public to flooding 
which is generally only an inconvenience (not life-threatening) to those 
living in the affected area. Issued when heavy rain will cause flooding of 
streets and low-lying places in urban areas. Also used if small rural or 
urban streams are expected to reach or exceed bankfull. Some damage to homes 
or roads could occur.