Light to moderate snow will continue into Saturday over the Great Lakes, Central Appalachians, and Northeast. This weekend into next week, a series of atmospheric rivers will bring gusty winds, periods of heavy rain, and mountain snow to northern California and the Pacific Northwest. Colder temperatures are in store for the weekend from the Great Lakes to East Coast. Read More >
24 Hr. Hazards
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Day 1
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Severe Thunderstorm Arrival Tool
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Tornado
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Hail
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Thunderstorm Wind Gust
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Severe Thunderstorms
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Lightning
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Flooding
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Fire Weather
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Grassland Fire Weather Index
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Fog
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Non Thunderstorm Winds
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Excessive Heat
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Snow & Sleet
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Ice Accumulation
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Frost & Freeze
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Excessive Cold
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Coastal Flood
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Swim Risk
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Marine Hazard
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Freezing Spray
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Risk Level
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Definition
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None
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Severe thunderstorms are not expected today or tonight.
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Later Today or Tonight
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Severe thunderstorms will be possible later today or tonight .
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Next 6 hours
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Severe thunderstorms will be possible in the next 6 hours.
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Next 3 hours
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Severe thunderstorms will be possible in the next 3 hours.
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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
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Definition
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None
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No tornado risk.
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Limited
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Probability of a tornado within 25 miles of a point: less than 10 percent.
Be aware of where your closest interior shelter is located. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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No risk of hail.
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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No thunderstorm wind risk.
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition Severe Thunderstorm Risk Day 2 to 7
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None
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No risk of severe thunderstorms.
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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No lightning risk
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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No Flooding risk.
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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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. |
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Limited
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Open burning is usually safe with the proper precautions.
Burning should be done in the early morning and late evening to avoid windier and drier conditions from midday through mid-afternoon. Residents should always check on local ordinances that prohibit open burning under any conditions. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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Very strong winds, well in excess of Red Flag Criteria combined with moderate to low humidity.
Fires will spread very quickly with spot fires common. Fire control is extremely difficult due to very strong winds. |
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Risk Level
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Definition
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Low-Moderate
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Favorable to marginal weather conditions with moderate to high moisture content of grasses and other dry organic material on the ground, indicating that the probability of a fast moving fire is low to a slight potential. Outdoor burning under these conditions can usually be performed with reasonable safety precautions, but should be monitored. Difficulty of fire suppression: Headfire can generally be stopped by road and tracks in low conditions and with water under moderate conditions.
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High
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Unfavorable weather conditions and low moisture content of grasses and other dry organic material on the ground, indicating that there is a high potential for fire to spread. Outdoor burning should be restricted to early morning or evening hours when wind speeds are usually lower and the relative humidity is higher. Burning is still favorable for well-planned burns by experienced land management personnel. Difficulty of fire suppression: Headfire attack generally successful with water.
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Very High
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Very poor weather conditions and very low moisture content of grasses and other dry organic material on the ground, indicating that dangerous burning conditions exist. Fires will spread rapidly and show erratic behavior. Outdoor burning is not recommended other than for experienced land management personnel. Difficulty of fire suppression: Direct headfire attack will become increasingly difficult. Spot fires are more likely.
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Extreme (GFDI 50-75)
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Extreme weather conditions and very low moisture content of grasses and other dry organic material on the ground, indicating that critical burning conditions exist. All fires have the potential to become large and spread quickly and become erratic with extreme fire behavioral characteristics. Difficulty of fire suppression: Direct attack on a headfire will generally fail. Back burn from a secure good line with adequate manpower and equipment. Flanks may become more difficult to control in shifting or erratic winds. Spot fires are likely.
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Extreme (GFDI > 75)
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Extreme grassland fire weather conditions that are rarely experienced in our area. Very high winds and low humidity with very dry cured grasses. Any fire that starts will spread rapidly and almost impossible to control. Fire suppression: Direct attack will likely fail, especially in heavy fuel loads.
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Risk Level
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Definition
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None
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No risk of fog.
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Limited
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Fog with visibilities less than or equal to 1 mile.
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Elevated
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Fog with visibilities less than or equal to 1/2 mile.
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Significant
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Fog with visibilities less than or equal to 1/4 mile.
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Extreme
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Fog with near zero visibilities.
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Risk Level
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Definition
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None
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Sustained winds < 20 mph |
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Limited
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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. |
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Elevated
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Sustained winds 30-39 mph
or Wind gusts 45-57 mph. Be prepared to secure unsecured property from potential wind damage. |
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Significant
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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 |
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Extreme
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Sustained winds > 50 mph
or Wind gusts > 65 mph. Secure unsecured property from potential wind damage and move people and animals to interior shelters. |
Risk Level
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Definition
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None
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Maximum Apparent Temperature < 95
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Limited
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Maximum Apparent Temperature 95 to 104
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. |
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Elevated
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Maximum Apparent Temperature 105 to 109
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. |
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Significant
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Maximum Apparent Temperature 110 to 114
OR Maximum Apparent Temperature greater than or equal to 105 for 4 consecutive days. Sunstroke, muscle cramps and/or heat exhaustion likely with prolonged exposure. Stay hydrated and seek air conditioned locations if needed. |
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Extreme
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Maximum Apparent Temperature greater than or equal to 115
OR Maximum Apparent Temperataure greater than or equal to 105 for 5 consecutive days. Sunstroke, muscle cramps and/or heat exhaustion likely. Stay hydrated and seek air conditioned locations if needed. |
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Risk Level
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Definition
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None
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No snow or sleet.
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Limited
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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. |
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Elevated
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Snow and/or sleet with 1 to 5.9 inches of accumulation expected.
Be prepared to reduce travel speed for hazardous travel conditions especially on bridges, overpasses, untreated and secondary roads. |
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Significant
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Snow and/or sleet with 6 to 11.9 inches of accumulation expected.
Plan for hazardous travel conditions. Avoid travel if possible. |
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Extreme
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Snow and/or sleet with greater than or equal to 12 inches of accumulation expected.
Travel will be dangerous and may be impossible. Avoid travel unless it is an emergency. |
Risk Level
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Definition
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None
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No freezing rain or drizzle.
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Limited
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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. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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No danger of frost or freeze causing damage to vegetation.
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Limited
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Patchy frost during the growing season with minor damage to unprotected vegetation.
Be aware that vegetation may need to be protected. |
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Elevated
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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. |
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Significant
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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. |
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Extreme
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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. |
Risk Level
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Definition
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None
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Minimum apparent temperature greater than or equal to 10 degrees F.
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Limited
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Minimum apparent temperature -9 to 9 deg 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. |
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Elevated
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Minimum apparent temperature -10 to -24 deg. 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. |
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Significant
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Minimum apparent temperature -25 to -34 deg. F.
Frostbite and hypothermia will likely occur within minutes without proper clothing. Have proper clothing for exposure and limit or eliminate exposure. |
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Extreme
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Minimum apparent temperature less than or equal to -35 degrees F
Frostbite and hypothermia will occur within minutes without proper clothing. Have proper clothing for exposure and limit or eliminate exposure. |
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Risk Level
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Definition
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None
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No Coastal Flooding risk.
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Limited
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Winds >= 30mpg and Wave Heights >= 8 feet.
These conditions could lead to isolated areas of beach erosion and coastal flooding. |
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Elevated
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Winds >=35 mph and Wave Heights >=11 feet.
These conditions could lead to scattered areas of beach erosion and coastal flooding. |
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Significant
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Winds >=40 mph and Wave Heights >=14 feet.
These conditions could lead to significant beach erosion and coastal flooding. |
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Extreme
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Winds >= 45 mph and Wave Heights >= 17 feet.
These conditions could lead to widespread beach erosion and coastal flooding. |
Risk Level
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Definition
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None
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No Swim Risk.
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Limited
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A limited risk of swimming hazards imply that large waves and strong currents are not expected along the shore. However, dangerous currents can still form near river mouths and shoreline structures, such as piers or breakwalls, even during low wave heights.
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Elevated
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An elevated risk of swimming hazards imply that large waves and strong currents are likely along the shore. Only experienced swimmers should consider entering the water. Stay away from river mouths and shoreline stuctures.
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Significant
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A significant risk of swimming hazards imply dangerous waves and currents are expected along the shore. Swimming conditions may be life threatening to anyone entering the water.
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Extreme
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The Swim Risk grids are only generated during the swimming season, generally from mid June through the end of September. |
Risk Level
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Definition
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None
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No High Surf Risk.
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Limited
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Wave height >= 2 feet and Wave Period > 3 seconds.
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Elevated
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Wave Height >= 4 feet and Wave Period > 4 seconds.
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Significant
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Wave Height >= 6 feet and Wave Period > 5 seconds.
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Extreme
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Wave Height > 8 feet.
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Risk Level
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Definition
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None
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No Marine Hazards Risk.
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Limited
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Winds >= 15 knots and/or Waves >= 2 feet.
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Elevated
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Winds >= 23 knots and/or Waves >= 4 feet.
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Significant
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Winds >= 34 knots and/or Waves >= 9 feet.
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Extreme
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Winds >= 48 knots and/or Waves >= 14 feet.
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Risk Level
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Definition
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None
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No Freezing Spray Risk.
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Limited
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Moderate Freezing Spray Expected.
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Elevated
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Significant
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Heavy Freezing Spray Expected.
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Extreme
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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.