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Experimental Enhanced Hazardous Weather Outlook

Product Suite Last Updated:     Saturday May 25, 2019     08:16 PM
 
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Severe Thunderstorm Risk
Current Time - 7 AM
24 Hr. Hazards
Day 1
Spotter Outlook
 
 
 
 
 
 
Tornado
 
 
 
 
 
 
Hail
 
 
 
 
 
 
Thunderstorm Wind Gust
 
 
 
 
 
 
Severe Thunderstorms
Lightning
Flooding
Fire Weather (RFTI)
Fog
Non Thunderstorm Winds
Excessive Heat
Snow & Sleet
Ice Accumulation
Frost & Freeze
Excessive Cold
 
Spotter Outlook         Severe Thunderstorm Safety Tips
 
Risk Level
Definition
None
Severe thunderstorms are not expected today or tonight.
Severe Thunderstorms Possible
Severe thunderstorms will be possible today or tonight and spotters may be needed.
The Spotter Outlook is a resource for municipalities, counties, and SKYWARN storm spotters to plan for possible storm spotter activation on the current calendar day.
Tornado Risk Legend         Tornado Safety Tips
 Risk Level
Definition
None
No tornado risk.
Limited
Probability of a tornado within 25 miles of a point: less than 10 percent.
Be aware of where your closest interior shelter is located.
Elevated
Probability of a tornado within 25 miles of a point: Equal to or greater than 10 percent.
Be prepared to move to the closest strong interior shelter if you are in a vulnerable location: outdoors, in a motor vehicle, mobile home, or other vulnerable structure.
Significant
Probability of a tornado within 25 miles of a point: Equal to or greater than 30 percent.
Plan to move to your closest strong interior shelter if you are in a vulnerable location: outdoors, in a motor vehicle, mobile home, or other vulnerable structure.
Extreme
Probability of a  tornado within 25 miles of a point: Equal to or greater than 45 percent.
Plan to move to your closest strong interior shelter if you are in a vulnerable location: outdoors, in a motor vehicle, mobile home, or other vulnerable structure.
Hail Risk Legend         Severe Thunderstorm Safety Tips
 
Risk Level
Definition
None
No risk of hail.
Limited
Risk of sub-severe hail (less than 1")
or
Probability of severe hail (1" or greater) within 25 miles of a point: less than 15%
Be aware of potential need to move vehicles, people, and animals for protection.
Elevated
Probability of severe hail (1" or greater) within 25 miles of a point: Equal to or greater than 15%
Be prepared to move vehicles, people, and animals for protection.
Significant
Probability of severe hail (1" or greater) within 25 miles of a point: Equal to or greater than 45%
Plan to move vehicles, people, and animals for protection.
Extreme
Probability of severe hail (1" or greater) within 25 miles of a point: Equal to or greater than 60%
Plan to move vehicles, people, and animals for protection.
Thunderstorm Wind Gust Risk Legend         Severe Thunderstorm Safety Tips
 
Risk Level
Definition
None
No thunderstorm wind risk.
Limited
Risk for sub-severe wind gusts (less than 58 mph)
or
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point: Less than 15%
Be prepared to secure unsecured property to prevent wind damage.
Elevated
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point: Equal to or greater than 15%
Be prepared to secure unsecured property to prevent wind damage. Prepare to move to an interior shelter.
Significant
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point: Equal to or greater than 45%
Plan to secure unsecured property to prevent wind damage. Plan to move to an interior shelter.
Extreme
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point: Equal to or greater than 60%
Plan to secure unsecured property to prevent wind damage. Plan to move to an interior shelter.
Severe Thunderstorm Legend         Severe Thunderstorm Safety Tips
 
Risk Level
Definition Severe Thunderstorm Risk Day 2 to 7
None
No risk of severe thunderstorms.
Limited
Risk for severe thunderstorms with the
Probability of severe thunderstorms* within 25 miles of a point: Less than 15%
Review weather safety tips and emergency kit.
Elevated
Probability of severe thunderstorms* within 25 miles of a point: Equal to or greater than 15%
Review weather safety tips and emergency kit. Identify closest safe shelter.
Significant
Probability of severe thunderstorms* within 25 miles of a point: Equal to or greater than 45%
Review weather safety tips and emergency kit. Identify closest safe shelter.
Extreme
Probability of severe thunderstorms* within 25 miles of a point: Equal to or greater than 60%
Review weather safety tips and emergency kit. Identify closest safe shelter.
Lightning Legend         Lightning Safety Tips
 
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.
Be aware for thunderstorms in your area.
Elevated
Thunderstorms expected to be numerous in coverage.
  Atmospheric conditions support cloud to ground lightning strikes in and near thunderstorms.
Be prepared to take immediate shelter from thunderstorms and lightning.
Significant
Widespread thunderstorms are expected.
  Atmospheric conditions support cloud to ground lightning strikes in and near thunderstorms.
Plan to take immediate shelter from thunderstorms and lightning.
Extreme
Thunderstorms are expected with nearly continuous cloud to ground lightning strikes in and near thunderstorms.
Plan to stop all outdoor activity and move to shelters. Remain in shelters until all danger of wind and lightning has passed.
Flooding Legend         Flooding Safety Tips
 
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.
Be aware of flood prone areas and potential to change your driving course if roadways flood.
Elevated
Risk of flash flooding of several low water crossings, roads, and small streams,
or
Minor River Flooding.
Be prepared to move away from flood prone areas. If you observe flooded roadways, be prepared to change your driving course.
Significant
Risk of flash flooding of numerous roads, low water crossings, and small streams,
or
Moderate river flooding.
Plan to move away from flood prone areas. If you observe flooded roadways, change your driving course or stay off roads completely.
Extreme
Risk of widespread flash flooding of low water crossings, roads, and small streams.
or
Major river flooding.
Plan to move away from flood prone areas. If you observe flooded roadways, change your driving course or stay off roads completely.
Fire Weather Legend         Wildfire Weather Safety Tips
 
Risk Level
Definition
Limited-Elevated
The forecast combination of relative humidity and winds limit wildfire potential, except in record fuel dryness levels.
Critical-Low
Low critical fire weather conditions are forecast due to a combination of low relative humidity and wind. This along with critically dry fuel levels can increase the wildfire potential.
Critical-High
High-level critical fire weather conditions are forecast due to a combination of low relative humidity and wind. Moderately dry fuels can be over come by the weather resulting in an increased wildfire potential. When combined with unseasonably warm temperatures numerous fires can occur.
Extremely Critical
Extremely critical fire weather conditions exist due to low relative humidity and strong winds. This along with sufficiently dry fuels can lead to a high potential for dangerous wildfires, some large and hard to control and outbreaks can occur in this type of weather.
Historically Critical
Extremely critical fire weather conditions are rarely experienced. These weather conditions along with sufficiently dry fuels can result in outbreaks of fires, some long lived.
The Red Flag Threat Index (RFTI) is a simple index derived from expected relative humidity and wind speed values to quantify the severity of critical fire weather condition. In general, lower relative humidities and higher winds contribute to higher RFTI calculations. Do more details about the RFTI, please refer to the Modified RFTI primer.
 
Red Flag Threat Index Legend         Wildfire Weather Safety Tips         Red Flag Threat Index
 
Risk Level
Definition
Limited-Elevated
The forecast combination of relative humidity and winds limit wildfire potential, except in record fuel dryness levels.
Critical-Low
Low critical fire weather conditions are forecast due to a combination of low relative humidity and wind. This along with critically dry fuel levels can increase the wildfire potential.
Critical-High
High-level critical fire weather conditions are forecast due to a combination of low relative humidity and wind. Moderately dry fuels can be over come by the weather resulting in an increased wildfire potential. When combined with unseasonably warm temperatures numerous fires can occur.
Extremely Critical
Extremely critical fire weather conditions exist due to low relative humidity and strong winds. This along with sufficiently dry fuels can lead to a high potential for dangerous wildfires, some large and hard to control and outbreaks can occur in this type of weather.
Historically Critical
Extremely critical fire weather conditions are rarely experienced. These weather conditions along with sufficiently dry fuels can result in outbreaks of fires, some long lived.
The Red Flag Threat Index (RFTI) is a simple index derived from expected relative humidity and wind speed values to quantify the severity of critical fire weather condition. In general, lower relative humidities and higher winds contribute to higher RFTI calculations. Do more details about the RFTI, please refer to the Modified RFTI primer.
 
Fog Legend         Fog Safety Tips
 
Risk Level
Definition
None
No risk of fog.
Limited
Fog with visibilities less than or equal to 1 mile.
Elevated
Fog with visibilities less than or equal to 1/2 mile
Significant
Fog with visibilities less than or equal to 1/4 mile.
Extreme
Fog with near zero visibilities.
Non Thunderstorm Wind Legend         Wind Safety Tips     Boating Safety Tips
 
Risk Level
Definition
None

Sustained winds < 20 mph
and
Wind gusts < 30 mph.

Limited
Sustained winds 20-29 mph
or
Wind gusts 30-44 mph.
Be aware that unsecured property may need to be secured from potential wind damage.
Elevated
Sustained winds 30-39 mph
or
Wind gusts 45-57 mph.
Be prepared to secure unsecured property from potential wind damage.
Significant
Sustained winds 40-49 mph
or
Wind gusts 58-64 mph.
Plan to secure unsecured property from potential wind damage and move people and animals to interior shelters
Extreme
Sustained winds > 50 mph
or
Wind gusts > 65 mph.
Secure unsecured property from potential wind damage and move people and animals to interior shelters.
Excessive Heat Legend         Excessive Heat Safety Tips
 
Risk Level
Definition
None
Maximum Apparent Temperature < 98
Limited
Maximum Apparent Temperature 98 to 107
Sunstroke, muscle cramps and/or heat exhaustion possible with prolonged exposure. Be aware to stay hydrated and seek air conditioned locations if needed. Identify air conditioned locations to move to.
Elevated
Maximum Apparent Temperature 108 to 113.
OR
Maximum Apparent Temperature greater than or equal to 100 for 4 consecutive days.

Sunstroke, muscle cramps and/or heat exhaustion likely with prolonged exposure. Be prepared to stay hydrated and seek air conditioned locations if needed.
Significant
Maximum Apparent Temperature 114 to 116
OR
Maximum Apparent Temperature greater than or equal to 108 for 4 consecutive days.


Sunstroke, muscle cramps and/or heat exhaustion likely with prolonged exposure. Stay hydrated and seek air conditioned locations if needed.
Extreme
Maximum Apparent Temperature greater than or equal to 117
OR
Maximum Apparent Temperataure greater than or equal to 110 for 4 consecutive days.

Sunstroke, muscle cramps and/or heat exhaustion likely. Stay hydrated and seek air conditioned locations if needed.
Note:
Apparent Temperature is defined as:
  Wind Chill Temperature during the cold season.
  Heat Index Temperature during the warm season.
Snow and Sleet Legend         Winter Weather Safety Tips
 
Risk Level
Definition
None
No snow or sleet.
Limited
Snow and/or sleet with less than 1 inch of accumulation expected.
Be aware of locally hazardous travel conditions on bridges, overpasses, and untreated or secondary roads.
Elevated
Snow and/or sleet with 1 to 1.9 inches of accumulation expected.
Be prepared to reduce travel speed for hazardous travel conditions especially on bridges, overpasses, untreated and secondary roads.
Significant
Snow and/or sleet with 2 to 5.9 inches of accumulation expected.
Plan for hazardous travel conditions. Avoid travel if possible.
Extreme
Snow and/or sleet with greater than or equal to 6 inches of accumulation expected.
Travel will be dangerous and may be impossible. Avoid travel unless it is an emergency.
Ice Accumulation Legend         Winter Weather Safety Tips
 
Risk Level
Definition
None
No freezing rain or drizzle.
Limited
Very light freezing rain or drizzle with up to a thin glaze, OR Freezing Fog.
Be aware of locally hazardous travel conditions on bridges, overpasses, and untreated or secondary roads.
Elevated
Freezing rain or drizzle with accumulation less than 1/4 inch.
Be prepared to reduce travel speed for hazardous travel conditions especially on bridges, overpasses, untreated and secondary roads.
Significant
Freezing rain with accumulation of 1/4 inch to less than 1 inch.
Plan for hazardous travel conditions. Powelines and trees may be damaged resulting in localized to scattered power outages. Avoid travel if possible and prepare for possible power outages.
Extreme
Freezing rain with accumulation of greater than or equal to 1 inch.
Travel will be dangerous and may be impossible. Powerlines and trees likely damaged resulting in widespread power outages. Avoid travel unless it is an emergency and prepare for extended power outages.
Frost and Freeze Legend
 
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.
Be aware that vegetation may need to be protected.
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.
Be prepared to protect vegetation.
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.
Protect vegetation.
Extreme
Hard freeze (less than or equal to 28 degrees F) during the growing season with catastrophic damage to unprotected vegetation.
Protect vegetation when watches and warnings are issued.
Excessive Cold Legend         Extreme Cold Safety Tips
 
Risk Level
Definition
None
Minimum apparent temperature greater than or equal to 32 degrees F.
Limited
Minimum apparent temperature 25 to 31 degrees F.
Frostbite and hypothermia may occur with prolonged exposure without proper clothing. Be aware to have proper clothing for exposure and limit or eliminate exposure if possible.
Elevated
Minimum apparent temperature 13 to 24 degrees F.
Frostbite and hypothermia could occur within 30 minutes without proper clothing. Be prepared to have proper clothing for exposure and limit or eliminate exposure if possible.
Significant
Minimum apparent temperature 7 to 12 degrees F.
Frostbite and hypothermia will likely occur within minutes without proper clothing. Have proper clothing for exposure and limit or eliminate exposure.
Extreme
Minimum apparent temperature less than or equal to 6 degrees F.
Frostbite and hypothermia will occur within minutes without proper clothing. Have proper clothing for exposure and limit or eliminate exposure.
Note:
Apparent Temperature is defined as:
  Wind Chill Temperature during the cold season.
  Heat Index Temperature during the warm season.
 

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.