National Weather Service United States Department of Commerce

Heat Building and Strong to Severe Storms

A building ridge of high pressure will produce possible record heat and extremely humid conditions over the next several days. The summer heat wave is already present in the south Plains, will expand across the Mid-Atlantic/Northeast and then shift into the Desert Southwest. Meanwhile, a cold front may trigger strong to severe storms w/ heavy rain from the Great Lakes to the south-central Plains Read More >

Experimental Enhanced Hazardous Weather Outlook

Product Suite Last Updated:     Sunday August 18, 2019     03:24 AM
 
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Severe Thunderstorm Risk
Current Time - 7 AM
24 Hr. Hazards
Day 1
Tornado
 
 
 
 
 
 
Hail
 
 
 
 
 
 
Thunderstorm Winds
 
 
 
 
 
 
Severe Thunderstorms
 
 
 
 
Lightning
Flooding
Fire Weather (RFTI)
Fog
Non Thunderstorm Winds
Snow & Sleet
Ice Accumulation
Frost & Freeze
Wind Chill
Definition
Severe thunderstorms are not expected today or tonight.
Severe thunderstorms will be possible later today or tonight .
Severe thunderstorms will be possible in the next 6 hours.
Severe thunderstorms will be possible in the next 3 hours.
Definition
No tornado risk.
Probability of a tornado is less than 10 percent.
Probability of a tornado is equal to or greater than 10 percent.
Probability of a tornado is equal to or greater than 30 percent.
Probability of a tornado is equal to or greater than 45 percent.
Definition
No risk of hail.
Risk of sub-severe hail (less than 1")
or
Probability of severe hail (1" or greater): Less than 15%
Probability of severe hail (1" or greater): Equal to or greater than 15%
Probability of severe hail (1" or greater): Equal to or greater than 45%
Probability of severe hail (1" or greater): Equal to or greater than 60%
Definition
No thunderstorm wind risk.
Risk for sub-severe wind gusts (less than 58 mph)
or
Probability of severe wind gusts (58 mph or greater): Less than 15%
Probability of severe wind gusts (58 mph or greater): Equal to or greater than 15%
Probability of severe wind gusts (58 mph or greater): Equal to or greater than 45%
Probability of severe wind gusts (58 mph or greater): Equal to or greater than 60%
Definition Severe Thunderstorm Risk Day 2 to 7
No risk of severe thunderstorms.
Probability of severe thunderstorms: Less than 15%
Probability of severe thunderstorms: Equal to or greater than 15%
Probability of severe thunderstorms: Equal to or greater than 45%
Probability of severe thunderstorms: Equal to or greater than 60%
Definition
No lightning risk
Thunderstorms expected to be isolated to scattered in coverage. 
Thunderstorms expected to be numerous in coverage.
Widespread thunderstorms are expected.
Thunderstorms are expected with nearly continuous cloud to ground lightning strikes in and near thunderstorms.
Definition
No Flooding risk.
Risk of localized flash flooding of small streams and low water crossings, and minor flooding of poor drainage or urban areas.
Risk of flash flooding of several low water crossings, roads, and small streams.
or
Minor River Flooding.
Risk of flash flooding of numerous roads, low water crossings, and small streams.
or
Moderate river flooding.
Risk of widespread flash flooding of low water crossings, roads, and small streams.
or
Major river flooding.
Definition
Open burning is usually safe with proper containers and precautions
Open burning is usually safe with the proper precautions.
Any open burning is discouraged
Open burning should not be attempted.>
Very strong winds, well in excess of Red Flag Criteria combined with moderate to low humidity.
Definition
Limited fire weather conditions.
Elevated fire weather conditions.
Critical fire weather conditions.
Significant fire weather conditions.
Extreme fire weather conditions.
Definition
No risk of fog.
Fog with visibilities less than or equal to 1 mile.
Fog with visibilities less than or equal to 1/2 mile
Fog with visibilities less than or equal to 1/4 mile.
Fog with near zero visibilities.
Definition
Sustained winds < 30 mph
and
Wind gusts < 40 mph.
Sustained winds 30-34 mph
or
Wind gusts 40-49 mph.
Sustained winds 35-39 mph
or
Wind gusts 50-57 mph.
Sustained winds 40-45 mph
or
Wind gusts 58-69 mph.
Sustained winds > 45 mph
or
Wind gusts > 70 mph.
Definition
Maximum Apparent Temperature < 95
Maximum Apparent Temperature 95 to 104
Maximum Apparent Temperature 105 to 109
Maximum Apparent Temperature 110 to 114
Maximum Apparent Temperature greater than or equal to 115
Definition
No snow or sleet.
Snow and/or sleet with less than 1 inch of accumulation expected.
Snow and/or sleet with 1 to 5.9 inches of accumulation expected.
Snow and/or sleet with 6 to 11.9 inches of accumulation expected.
Snow and/or sleet with greater than or equal to 12 inches of accumulation expected.
Definition
No freezing rain or drizzle.
Very light freezing rain or drizzle with up to a thin glaze,
OR Freezing Fog.
Freezing rain or drizzle with accumulation less than 1/4 inch. .
Freezing rain with accumulation of 1/4 inch to less than 1 inch.
Freezing rain with accumulation of greater than or equal to 1 inch.
Definition
No danger of frost or freeze.
Patchy frost.
Frost expected.
Freeze expected (less than or equal to 32 degrees F for 3 or more hours). .
Hard freeze (less than or equal to 28 degrees F).
Definition
Minimum apparent temperature greater than or equal to 0 degrees F.
Minimum apparent temperature 0 to -4 deg. F.
Minimum apparent temperature -5 to -14 deg. F.
Minimum apparent temperature -15 to -19 deg. F.
Minimum apparent temperature less than or equal to -20 degrees F .
 

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.