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Experimental product!

Risk Level - Legend
None
Limited
Elevated
Significant
Extreme
Risk - Limited
Risk - Elevated
Risk - Significant
Risk - Excessive
Click tabs to switch between Graphical and Text:
Click on risk level to display risk map and proper legend
Severe Weather Arrival Tool
Risk
Level
Risk
Level
Tornado
Fog
Hail
 
Non - Thunderstorm Winds
 
Thunderstorm Wind Gusts
Excessive Heat
Flooding
Snow and Sleet
Lightning
Ice Accumulation
Severe Thunderstorm
Arrival Tool
Frost and Freeze
Fire Weather
Excessive Cold
 
Risk Level
Definition
None
No tornado risk.
Limited
Probability of a tornado within 25 miles of a point:
less than 10 percent.
Elevated
Probability of a tornado within 25 miles of a point:
Equal to or greater than 10 percent.
Significant
Probability of a tornado within 25 miles of a point:
Equal to or greater than 15 percent.
Extreme
Probability of a  tornado within 25 miles of a point:
Equal to or greater than 45 percent.
 
Risk Level
Definition
None
No risk of fog.
Limited
Patchy fog with visibility reduced mainly along river valleys and other low lying areas. Only localized visibility down to around 1/4 mile.
A Dense Fog Advisory is usually not issued in these cases.
Elevated
Areas of fog, including patchy dense fog. Expect visibility in most areas down to 3/4 to 1/2 mile, but up to half of the coverage area may see 1/4 mile or less visibility at times.
A Dense Fog Advisory may be issued in some cases
Significant
Widespread fog is forecast, including the likelihood of dense fog. Expect over half of the coverage area to see 1/4 mile or less visibility for three or more hours.
A Dense Fog Advisory will likely be issued in most cases
Extreme
Not Assigned.
 
Risk Level
Definition
None
No risk of hail.
Limited
Probability of severe hail (1" or greater) within 25 miles of a point:
up to 15%
Elevated
Probability of severe hail (1" or greater) within 25 miles of a point:
Equal to or greater than 15%
Significant
Probability of severe hail (1" or greater) within 25 miles of a point:
Equal to or greater than 30%
Extreme
Probability of severe hail (1" or greater) within 25 miles of a point:
Equal to or greater than 45%
 
Risk Level
Definition
None

Sustained winds < 25 mph
and
Wind gusts < 40 mph.

Limited
Sustained winds 25-29 mph
or
Wind gusts 40-44 mph.
Elevated
Sustained winds 30-39 mph
or
Wind gusts 45-57 mph.
Significant
Sustained winds 40-49 mph
or
Wind gusts 58-64 mph.
Extreme
Sustained winds > 50 mph
or
Wind gusts > 65 mph.
 
Risk Level
Definition
None
No thunderstorm wind risk.
Limited
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point:
Up to 15%
Elevated
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point:
Equal to or greater than 15%
Significant
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point:
Equal to or greater than 30%
Extreme
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point:
Equal to or greater than 45%
 
Risk Level
Definition
None
Maximum Apparent Temperature < 100
Limited
Maximum Apparent Temperature 100 to 104
Elevated

Maximum Apparent Temperature 105 to 109
OR
Maximum Apparent Temperature greater than or equal to 100 for 4 consecutive days.

Significant

Maximum Apparent Temperature 110 to 114
OR
Maximum Apparent Temperature greater than or equal to 105 for 4 consecutive days.

Extreme
Maximum Apparent Temperature greater than or equal to 115
OR
Maximum Apparent Temperataure greater than or equal to 105 for 5 consecutive days.
Note:
Apparent Temperature is defined as:
  Wind Chill Temperature during the cold season.
  Heat Index Temperature during the warm season.
 
Risk Level
Definition
None
No Flooding risk.
Limited
Risk of localized flash flooding of small streams and low water crossings, and minor flooding of poor drainage or urban areas.
Elevated

Risk of flash flooding of several low water crossings, roads, and small streams,
or
Minor River Flooding.

Significant

Risk of flash flooding of numerous roads, low water crossings, and small streams,
or
Moderate river flooding.

Extreme
Risk of widespread flash flooding of low water crossings, roads, and small streams.
or
Major river flooding.
 
Risk Level
Definition
None
No snow or sleet.
Limited
Snow and/or sleet with less than 2 inch of accumulation expected.
Elevated
Snow and/or sleet with 2 to 5.9 inches of accumulation expected.
Significant
Snow and/or sleet with 6 to 11.9 inches of accumulation expected.
Extreme
Snow and/or sleet with greater than or equal to 12 inches of accumulation expected.
 
Risk Level
Definition
None
No lightning risk
Limited
Thunderstorms expected to be isolated to scattered in coverage. 
Atmospheric conditions support cloud to ground lightning strikes in and near thunderstorms.
Elevated
Thunderstorms expected to be numerous in coverage.
  Atmospheric conditions support cloud to ground lightning strikes in and near thunderstorms.
Significant
Widespread thunderstorms are expected.
  Atmospheric conditions support cloud to ground lightning strikes in and near thunderstorms.
Extreme
Not Assigned.
 
Risk Level
Definition
None
No freezing rain or drizzle.
Limited
Inconvenience to travel and other regular outdoor activities. Very light freezing rain or drizzle with up to a thin glaze OR Freezing Fog
Elevated
Significant inconvenience to travel and other regular outdoor activities. Minor ice accumulation could lead to a few small tree branches downed. Generally less than 1/4 inch of ice accumulation from freezing rain.
Significant
Major ice accumulations leading to at least minor damage to trees and power lines. Expect sporadic to scattered power outages. Ice accumulations averaging between 1/4 inch and 3/4 inch from freezing rain.
Extreme
*MAJOR ICE STORM* leading to widespread, significant tree and power line damage. Expect widespread and potentially prolonged power outages. Ice accumulations averaging greater than 3/4 inch from freezing rain.
 
Risk Level
Definition
None
No danger of frost or freeze causing damage to vegetation.
Limited
Patchy frost during the growing season with minor damage to unprotected vegetation.
Elevated
Frost expected during the growing season with damage to unprotected vegetation. 
This may include temperatures less than or equal to 32 degrees F for less than 3 hours.
Significant
Freeze expected (less than or equal to 32 degrees F for 3 or more hours) during the growing season with significant damage to unprotected vegetation.
Extreme
Hard freeze (less than or equal to 28 degrees F) during the growing season with catastrophic damage to unprotected vegetation.
NOTE: Grey-shaded areas are currently not in climatological active growing season. Beginning of growing season is defined here by historical median date of last 28-degree temperature in spring. Ending of growing season is defined by historical median date of first 28-degree temperature in fall.
 
Risk Level
Definition
None
Severe thunderstorms are not expected today or tonight.
Limited
Severe thunderstorms will be possible later today or tonight .
Elevated
Severe thunderstorms will be possible in the next 6 hours.
Significant
Severe thunderstorms will be possible in the next 3 hours.
The Severe Thunderstorm Arrival Tool is a resource for municipalities, counties, and SKYWARN storm spotters to plan for possible storm spotter activation on the current calendar day. Other interests can also use the Severe Thunderstorm Arrival Tool to determine the expected time frame for severe thunderstorm potential.
 
Risk Level
Definition
None
Open burning is usually safe with proper containers and precautions under low fire danger conditions. 
Residents should always check on local ordinances that prohibit open burning under any conditions.
Limited
Conditions usually safe for control burning in most situations, however open burning should only be performed with extra caution and monitoring, especially during the afternoon hours when winds are typically stronger and relative humidity is at its lowest.
Residents should always check on local ordinances that prohibit open burning under any conditions.
Elevated
Any open burning is discouraged due to increased wind and lower humidity - except by experienced fire personnel
Increasing winds and lower humidity contribute to drying fuels. Fires escape control more easily and containment is difficult for inexperienced fire personnel.
Approaching Red Flag conditions.
Significant
Open burning should not be attempted.
High winds and extended dry periods lead to extreme burning conditions. Open fires can quickly escape and are very difficult to control, even for experienced fire fighters. 
Conditions exceed minimum criteria for a Red Flag Warning in most cases.
Extreme
Very strong winds, well in excess of Red Flag Criteria combined with extremely low humidity.
Fires will spread very quickly with spot fires common. Fire control is extremely difficult due to very strong winds.
***These definitions are geared towards the general public and general emergency management and should not be confused with the standard National Fire Danger Rating System (NFDRS) adjectives used by wildland fire personnel.
The fire weather category for the Enhanced Hazardous Weather Outlook is based primarily on predicted wind, humidity and temperature, and does not account for fuel moisture from recent precipitation, snow cover and recently melted snow.  Appropriate adjustments to the fire environment must be made.
Fire weather hazard categories will normally be more restricted, generally in the "none" or "limited" categories from May 1st to September 30th due to normally predominant green and moist live vegetation.  This will be subject to change during unusual severe Spring and/or Summer drought.
 
Risk Level
Definition
None
Minimum apparent temperature greater than or equal to 5F.
Limited
Minimum apparent temperature -4 to 4F.
Elevated
Minimum apparent temperature -5 to -14F
Significant
Minimum apparent temperature -15 to -24F.
Extreme
Minimum apparent temperature less than or equal to -25F
Note:
Apparent Temperature is defined as:
  Wind Chill Temperature during the cold season.
  Heat Index Temperature during the warm season.
 
Risk Level
Definition Severe Thunderstorm Risk Days 2-7
None
No risk of severe thunderstorms.
Limited
At least some confidence in organized severe thunderstorm activity based on forecast meteorological conditions
Elevated
At least a moderate degree of confidence in organized severe thunderstorm activity based on forecast meteorological conditions. Significant severe thunderstorms would be possible in or near this region in this type of setup.
Significant
A fairly high degree of confidence in organized severe thunderstorm activity based on forecast meteorological conditions. ** At least a moderate degree of confidence in Significant severe thunderstorms including multiple tornadoes **
Extreme
At least a moderate degree of confidence of a **SEVERE WEATHER OUTBREAK** affecting the region, including numerous tornadoes, some of which long-lived and destructive
Risk
Level
Severe Thunderstorms
Lightning
Flooding
Fire Weather
Fog
Non - Thunderstorm Winds
Excessive Heat
Snow and Sleet
Ice Accumulation
Frost and Freeze
Excessive Cold
 

The Experimental Enhanced Hazardous Weather Outlook is an experimental product that will be posted to this page for evaluation. We encourage your comments or suggestions for improvements using the electronic survey provided. Your feedback will help us determine product utility, if modifications are needed, and whether the product should become part of our operational suite. | Product Description Document

The Experimental Enhanced Hazardous Weather Outlook is a decision support service that supports preparedness and response efforts prior to and during hazardous weather.  This service provides decision makers with convenient access to potential weather hazard information by graphically depicting the risk of weather hazards out through seven days.