Warnings     |     Watches     |      Advisories

 

Warnings
Conditions are occurring or imminent.
Tornado
A severe thunderstorm has developed and has either produced a tornado or radar has indicated intense low level rotation in the presence of atmospheric conditions conducive to tornado development.
Severe Thunderstorm
A severe thunderstorm has developed, capable of producing hail greater than 1 inch in diameter and/or 50 knot (58 mph) wind speeds.
Flood
Long duration areal or river flooding is occurring or is imminent, which may result from excessive rainfall, rapid snow melt, ice jams on rivers, or other similar causes.
Flash Flood
Excessive rainfall producing thunderstorms have developed, leading to short duration flash flooding. A warning may also be issued if a dam break has occurred.
Blizzard
35 mph or greater wind speeds, considerable falling or blowing snow, and visibilities frequently below a quarter mile are expected to prevail for 3 hours or more.
Winter Storm
Snow amounts of 6 inches or more in 12 hours or 8 inches or more in 24 hours are expected.  These may or may not be accompanied by wind or other phenomena. A warning may also be issued if conditions will be approaching blizzard criteria, even if snow amounts are not expected to reach the aforementioned thresholds.
Ice Storm
Ice accumulations of a quarter inch or more.
Excessive Heat
In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport reaches 105° or greater for 1 day, or the maximum heat index reaches 100° or greater and the overnight low temperature is no cooler than 75° for 2 days in a row. In addition, the Heat Watch/Warning System must recommend a warning. A warning may also be issued if advisory criteria are expected for 4 days in a row.
Outside Hennepin and Ramsey counties: Maximum heat index reaches 105° or greater and a minimum heat index of 75° or greater for at least 48 hours. A warning may also be issued if advisory criteria are expected for 4 days in a row.
Hard Freeze
Widespread temperatures below 28° are expected during the growing season.
Freeze
Widespread temperatures below freezing are expected during the growing season.
Wind Chill
Widespread wind chill readings of -35° with wind speeds of 5 to 10 mph or greater are expected.  See below for criteria for all of Minnesota.
High Wind
Synoptic scale gradient winds (i.e. – those not associated with thunderstorms) or mesoscale winds associated with wake lows are expected to reach speeds of 40 mph or greater, sustained for at least 1 hour, or 58 mph or greater gusts.

 

Watches
Conditions are favorable or expected but not occurring or imminent.
Tornado
Atmospheric conditions are favorable for the development of severe thunderstorms capable of producing tornadoes.
Severe Thunderstorm
Atmospheric conditions are favorable for the development of severe thunderstorms (i.e. – producing hail at least 1 inch in diameter and/or 50 knot [58 mph] or greater wind speeds).
Flood
Atmospheric and hydrologic conditions are favorable for long duration areal or river flooding.
Flash Flood
Atmospheric and hydrologic conditions are favorable for short duration flash flooding and/or a dam break is possible.
Blizzard
35 mph or greater wind speeds, considerable falling or blowing snow, and visibilities frequently below a quarter mile are expected to prevail for 3 hours or more.
Winter Storm
Severe winter storm conditions are expected to occur, including heavy snow, significant ice or sleet accumulations, and any of the above accompanied by strong winds that may lead to significant visibility reductions.
Excessive Heat
In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport is expected to reach 105° or greater for 1 day, or the maximum heat index is expected to reach 100° or greater and an overnight low temperature no cooler than 75° for 2 days in a row. In addition, the Heat Watch/Warning System must recommend a watch.
Outside Hennepin and Ramsey counties: Maximum heat index reaches 105° or greater and a minimum heat index of 75° or greater for at least 48 hours.
Freeze
Widespread temperatures below freezing are expected during the growing season.
Wind Chill
Widespread wind chill readings of -35° with wind speeds of 5 to 10 mph or greater are expected.  See below for criteria for all of Minnesota.
High Wind
Synoptic scale gradient winds (i.e. – those not associated with thunderstorms) with speeds of 40 mph or greater, sustained for at least 1 hour, or 58 mph or greater gusts are expected.

 

Advisories
Special Weather Statement
A thunderstorm has developed and is capable of producing hail and gusty winds that approach but do not reach those contained in a severe thunderstorm, such as pea sized hail and 40 to 50 mph winds.
Flood Advisory
Thunderstorms have produced heavy rainfall that may result in ponding of water on roadways and in low-lying areas, as well as rises in small stream levels, none of which pose an immediate threat to life and property.
Winter Weather
Any one or combination of the following winter weather elements is expected during an event:  three to six inches of snow, light sleet accumulation, light ice and snow or sleet accumulation, or significant visibility reductions due to light snow and/or blowing snow.
Freezing Rain
Light ice accumulation is expected.
Heat
In Hennepin and Ramsey counties: Maximum heat index at Minneapolis/St. Paul International Airport is expected to reach 105° or greater for 1 day, or the maximum heat index is expected to reach 100° or greater and an overnight low temperature no cooler than 75° for 2 days in a row.
Outside Hennepin and Ramsey counties:  Maximum heat index reaches 100° and/or the maximum temperature reaches 95° or higher.
Frost
Widespread temperatures of 33 to 36 degrees are expected during the growing season.
Wind Chill
Widespread wind chill readings of -25° to -35°, are expected, accompanied wind speeds of 5 to 10 mph or greater.  See below for criteria for all of Minnesota.
Wind
Sustained winds of 30 to 39 mph are expected to last for at least 1 hour.
Dense Fog
Widespread visibilities of a quarter mile or less are expected.
Freezing Fog
Very light ice accumulation is expected from freezing fog.

 

Wind Chill Warning Criteria

Wind Chill Advisory Criteria

 


  • National Weather Service
  • Twin Cities, MN Weather Forecast Office
  • 1733 Lake Drive West
  • Chanhassen, MN 55317-8581
  • 952-361-6670
  • Page Author: MPX Webmaster
  • Web Master's E-mail: w-mpx.webmaster@noaa.gov
  • Page last modified: November 5th 2009 6:37 PM
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