National Weather Service - Marquette, MI -
|
||
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.
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. |
Risk Level - Legend
|
||||
None
|
Limited
|
Elevated
|
Significant
|
Extreme
|
![]() |
![]() |
![]() |
![]() |
![]() |
Note: To display hazard maps, click on any of the risk level indicators below.
|
||||||||
![]() |
||||||||
Risk
|
Level
|
Risk
|
Level
|
|||||
Tornado
|
Fog
|
|||||||
Hail
|
Non - Thunderstorm Winds
|
|||||||
Thunderstorm Wind Gusts
|
Excessive Heat
|
|||||||
Flooding
|
Snow and Sleet
|
|||||||
Lightning
|
Ice Accumulation
|
|||||||
Spotter Outlook
|
Frost and Freeze
|
|||||||
Fire Weather
|
Excessive Cold
|
|||||||
Coastal Flooding
|
Swim Risk
|
|||||||
High Surf
|
Marine Hazard
|
|||||||
Freezing Spray
|
![]() |
||||||
Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Level
|
||||||
Severe Thunderstorms
|
||||||
Lightning
|
||||||
Flooding
|
||||||
Fire Weather
|
||||||
Fog
|
||||||
Non - Thunderstorm Winds
|
||||||
Excessive Heat
|
||||||
Snow and Sleet
|
||||||
Ice Accumulation
|
||||||
Frost and Freeze
|
||||||
Excessive Cold
|
||||||
Coastal Flooding
|
||||||
Swim Risk
|
||||||
High Surf
|
||||||
Marine Hazard
|
||||||
Freezing Spray
|
Spotter Activation
|
Definition
|
|
![]() |
No
|
Spotters will not be needed for severe weather activation today or tonight.
|
![]() |
Yes
|
Spotters may be needed later in the day or tonight. Any reports of severe or hazardous weather would be appreciated. Spotter Reports can be submitted here: MQT Storm Reports |
Hail Risk
|
![]() |
|
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% |
![]() |
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 45% |
![]() |
Extreme
|
Probability of severe hail (1" or greater) within 25 miles of a point:
Equal to or greater than 60% |
Hail is a form of precipitation that occurs when updrafts in thunderstorms carry raindrops upward into extremely cold areas of the atmosphere where they freeze into ice.
There are two ideas about hail formation. In the past, the prevailing thought was that hailstones grow by colliding with supercooled water drops. Supercooled water will freeze on contact with ice crystals, frozen rain drops, dust or some other nuclei. Thunderstorms that have a strong updraft keep lifting the hailstones up to the top of the cloud where they encounter more supercooled water and continue to grow. The hail falls when the thunderstorm's updraft can no longer support the weight of the ice or the updraft weakens. The stronger the updraft the larger the hailstone can grow.
Recent studies suggest that supercooled water may accumulate on frozen particles near the back-side of the storm as they are pushed forward across and above the updraft by the prevailing winds near the top of the storm. Eventually, the hailstones encounter downdraft air and fall to the ground.
Hailstones grow two ways: by wet growth or dry growth processes. In wet growth, a tiny piece of ice is in an area where the air temperature is below freezing, but not super cold. When the tiny piece of ice collides with a supercooled drop, the water does not freeze on the ice immediately. Instead, liquid water spreads across tumbling hailstones and slowly freezes. Since the process is slow, air bubbles can escape resulting in a layer of clear ice.
Dry growth hailstones grow when the air temperature is well below freezing and the water droplet freezes immediately as it collides with the ice particle. The air bubbles are "frozen" in place, leaving cloudy ice.
Hailstones can have layers like an onion if they travel up and down in an updraft, or they can have few or no layers if they are "balanced" in an updraft. One can tell how many times a hailstone traveled to the top of the storm by counting the layers. Hailstones can begin to melt and then re-freeze together - forming large and very irregularly shaped hail.
We really only have estimates about the speed hail falls. One estimate is that a 1cm hailstone falls at 9 m/s, and an 8cm stone, weighing .7kg falls at 48 m/s (171 km/h). However, the hailstone is not likely to reach terminal velocity due to friction, collisions with other hailstones or raindrops, wind, the viscosity of the wind, and melting. Also, the formula to calculate terminal velocity is based on the assumption that you are dealing with a perfect sphere. Hail is generally not a perfect sphere!
Hail size is estimated by comparing it to a known object. Most hail storms are made up of a mix of sizes, and only the very largest hail stones pose serious risk to people caught in the open.
Damage from hail approaches $1billion in the US each year. Much of the damage inflicted by hail is to crops. Even relatively small hail can shred plants to ribbons in a matter of minutes. Vehicles, roofs of buildings and homes, and landscaping are the other things most commonly damaged by hail.
Hail has been known to cause injury to humans, and occasionally has been fatal. The most deadly hailstorm on record occurred in India on April 30, 1988, killing 246 people and 1600 domesticated animals.
A large hailstone can cause serious injury. A hailstone the diameter of a baseball falls at a speed comparable to that of a pitched baseball - on the order of 100 mph! It's like being hit by a "beanball" thrown by a major league pitcher.
(The above information is from the National Severe Storms Laboratory)
Tornado Risk
|
![]() |
|
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 30 percent. |
![]() |
Extreme
|
Probability of a tornado within 25 miles of a point:
Equal to or greater than 45 percent. |
The probabilities shown are a combination of forecast uncertainty and the magnitude of the threat.
Because of the difficulty in forecasting severe thunderstorms and tornadoes, the trend in the probability is as important as the numbers themselves.
Remember that any probabilities shown in this graphic indicates that forecasters are concerned about a severe weather threat and you should be ready for a warning to be issued in your area sometime during the Day 1 period regardless of how high or low the probability is.
Tornado and Severe Thunderstorm Watches and Warnings ALWAYS take precedence over the information contained in the Risk Analysis Graphics.
What can you do before Severe Weather Strikes?
- Develop a plan for you and your family at home, work, school, and when outdoors.
- Identify a safe place to take shelter.
- Have frequent drills.
- Know the county in which you live or visit. The National Weather Service in Springfield issues warnings with a reference to county names.
- Keep a highway map nearby to follow storm movement from weather bulletins.
- Have a NOAA Weather Radio with a warning alarm tone and battery back-up to receive warnings.
- Listen to radio and television for weather information.
- Check the weather forecast before leaving for extended periods outdoors. Watch for signs of approaching storms.
- If severe weather threatens, check on people who are elderly, very young, or physically or mentally disabled.
Tornado Safety Rules
- In a home or building, move to a pre-designed shelter such as a basement.
- If an underground shelter is not available, move to a small interior room or hallway on the lowest floor and get under a sturdy piece of furniture. Put as many walls as possible between you and the outside.
- Stay away from windows.
- Get out of automobiles.
- Do not try to outrun a tornado in your car; instead leave your car immediately for safe shelter.
- If caught outside or in a vehicle, lie flat in a nearby ditch or depression and cover your head with your hands.
- Be aware of flying debris. Flying debris from tornadoes causes most fatalities and injuries.
- Mobile homes, even if tied down, offer little protection from tornadoes. You should leave a mobile home and go to the lowest floor of a sturdy nearby building or a storm shelter.
Thunderstorm Wind Gust Risk
|
![]() |
|
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% |
![]() |
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 45% |
![]() |
Extreme
|
Probability of severe wind gusts (58 mph or greater) within 25 miles of a point:
Equal to or greater than 60% |
Damaging wind from thunderstorms is much more common than damage from tornadoes. In fact, many confuse damage produced by "straight-line" winds and often erroneously attribute it to tornadoes. Wind speeds can reach up to 100 mph (161 kph) with a damage path extending many miles.
Downdrafts are generated when rain-cooled, more dense air sinks inside a thunderstorm. Also some of the strong winds aloft are carried down with the downdraft by a process called "momentum transfer". As precipitation begins to fall, it drags some of the air with it. This "precipitation drag" initiates a downdraft. The downdraft is intensified by evaporative cooling as drier air from the edges of the storm mix with the moist air within the storm.
These processes lead to a rapid downward rush of air. As the air impacts the ground it is forced to spread out laterally causing the gusty winds associated with thunderstorms. Occasionally, thunderstorms will produce intense downdrafts that create damage as the wind spread out along the ground.
Downbursts are divided into two catagories; macrobursts and microbursts. A macroburst is more than 2½ miles (4 km) in diameter and can produce winds as high as 135 mph (215 kph). Microbursts are smaller and produces winds as high as 170 mph (270 kph).
In wet, humid environments, macrobursts and microbursts will be accompanied by intense rainfall at the ground. If the storm forms in a relatively dry environment, however, the rain may evaporate before it reaches the ground and these downbursts will be without precipitation, known as dry microbursts.
A derecho is a widespread and long lived windstorm that is associated with a band of rapidly moving showers or thunderstorms. The word "derecho" is of Spanish origin, and means straight ahead. A derecho is made up of a "family of downburst clusters" and by definition must be at least 240 miles in length.
Derechos are associated with a band of showers or thunderstorms that are often "curved" in shape. These bowed out storms are called "bow echoes". A derecho can be associated with a single bow echo or multiple bow echoes. The bow echoes may vary in scale and may die out and redevelop during the course of derecho evolution.
Winds in derecho can exceed 100 mph. For example, a derecho in northern Wisconsin on July 4, 1977 produced winds of 115 mph. The winds associated with derechos are not constant and may vary considerably along the derecho path.
(information above from NWS Jet Stream Publication)
Flooding Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
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, |
![]() |
Significant
|
Risk of flash flooding of numerous roads, low water crossings, and small streams, |
![]() |
Extreme
|
Risk of widespread flash flooding of low water crossings, roads, and small strams.
or Major river flooding. |
Except for heat related fatalities, more deaths occur from flooding than any other hazard. Why? Most people fail to realize the power of water. For example, six inches of fast-moving flood water can knock you off your feet.
While the number of fatalities can vary dramatically with weather conditions from year to year, the national 30-year average for flood deaths is 127. That compares with a 30-year average of 73 deaths for lightning, 68 for tornadoes and 16 for hurricanes.
National Weather Service data also shows:
Most flash floods are caused by slow moving thunderstorms, thunderstorms that move repeatedly over the same area or heavy rains from tropical storms and hurricanes. These floods can develop within minutes or hours depending on the intensity and duration of the rain, the topography, soil conditions and ground cover.
Flash floods can roll boulders, tear out trees, destroy buildings and bridges, and scour out new channels. Rapidly rising water can reach heights of 30 feet or more. Furthermore, flash flood-producing rains can also trigger catastrophic mud slides.
Occasionally, floating debris or ice can accumulate at a natural or man-made obstruction and restrict the flow of water. Water held back by the ice jam or debris dam can cause flooding upstream. Subsequent flash flooding can occur downstream if the obstruction should suddenly release.
Lightning Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
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
|
Thunderstorms are expected with nearly continuous cloud to ground lightning strikes in and near thunderstorms.
|
How lightning forms
Lightning results from the buildup and discharge of electrical energy between positively and negatively charged areas. Rising and descending air within a thunderstorm separates these positive and negative charges. Water and ice particles also affect charge distribution.
A cloud-to-ground lightning strike begins as an invisible channel of electrically charged air moving from the cloud toward the ground. When one channel nears an object on the ground, a powerful surge of electricity from the ground moves upward to the clouds and produces the visible lightning strike.
Lightning Safety and Impact Prevention
- Lightning causes an average of 80 fatalities and 300 injuries each year.
- Lightning occurs with ALL thunderstorms, making all thunderstorms dangerous!
- Around 100,000 thunderstorms occur each year in the United States.
- Most lightning fatalities and injuries occur when people are caught outdoors during a thunderstorm.
- The air near a lightning strike is rapidly heated to 50,000 degrees F or hotter than the surface of the sun! The rapid heating and cooling of the air near the lightning channel causes a shock wave that results in thunder.
30/30 Lightning Safety Rule
Go indoors if, after seeing lightning, you cannot count to 30 before hearing thunder. Stay indoors for 30 minutes after hearing the last clap of thunder.
Other Lightning Safety Rules
- Postpone outdoor activities if thunderstorms are imminent. This is your best way to avoid being caught in a dangerous situation.
- Move to a sturdy building or car. Do not take shelter in sheds, under isolated trees, or in convertible automobiles. Stay away from tall objects such as towers, fences, telephone poles and power lines.
- If lightning is occurring and a sturdy shelter is not available, get inside a hard top automobile and keep the windows up. Avoid touching any metal.
- Utility lines and metal pipes can conduct electricity. Unplug appliances not necessary for obtaining weather information. Avoid using the telephone or any electrical appliances. Use phones only in an emergency.
- Do not take a bath or shower during a thunderstorm.
- Turn off air conditioners. Power surges from lightning can cause serious damage.
If Caught Outdoors and No Shelter is Nearby...
- Find a low spot away from trees, fences, and poles. Make sure the place you pick is not subject to flooding.
- If you are in the woods, take shelter under shorter trees.
- If you are boating or swimming, get to land and find shelter immediately!
Severe Thunderstorm Risk
Day 1 risks are covered by individual risks of Tornado, Hail and Thunderstorm Wind Gusts |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition Severe Thunderstorm Risk Day 2 to 7
|
|
![]() |
None
|
No risk of severe thunderstorms.
|
![]() |
Limited
|
Risk for sub-severe wind gusts (less than 58 mph), sub-severe hail (less than 1" in diameter)
or Probability of severe thunderstorms* within 25 miles of a point: Less than 15% |
![]() |
Elevated
|
Probability of severe thunderstorms* within 25 miles of a point:
Equal to or greater than 15% |
![]() |
Significant
|
Probability of severe thunderstorms* within 25 miles of a point:
Equal to or greater than 45% |
![]() |
Extreme
|
Probability of severe thunderstorms* within 25 miles of a point:
Equal to or greater than 60% |
Severe Thunderstorm Safety and Impact Prevention
The Severe Thunderstorm risk level is based on the probability of being in a Severe Thunderstorm Warning in an area.
The probability of a Severe Thunderstorm Warning in an area is forecast based on :
Because of the difficulty in forecasting severe thunderstorms and tornadoes, the trend in the probability is as important as the numbers themselves.
Remember that any probabilities shown in this graphic indicates that forecasters are concerned about a severe weather threat and you should be ready for a warning to be issued in your area sometime during the Day 1 period regardless of how high or low the probability is.
Tornado and Severe Thunderstorm Watches and Warnings ALWAYS take precedence over the information contained in the Enhanced Graphical Hazardous Weather Outlook (HWO) Graphics.
What can you do before Severe Weather Strikes?
- Develop a plan for you and your family at home, work, school, and when outdoors.
- Identify a safe place to take shelter.
- Have frequent drills.
- Know the county in which you live or visit. The National Weather Service in Springfield issues warnings with a reference to county names.
- Keep a highway map nearby to follow storm movement from weather bulletins.
- Have a NOAA Weather Radio with a warning alarm tone and battery back-up to receive warnings.
- Listen to radio and television for weather information.
- Check the weather forecast before leaving for extended periods outdoors. Watch for signs of approaching storms.
- If severe weather threatens, check on people who are elderly, very young, or physically or mentally disabled.
A "Severe Thunderstorm" is defined as a thunderstorm that produces a wind speed at or above 58 MPH or, hail 1 inch in diameter or larger.
A Severe Thunderstorm Watch is issued for large area or, state, for a period of time (usually about 6 hours in length) in advance of a projected severe weather event. This would be on a day when atmospheric conditions favor the development of a number of Severe Thunderstorms. These
watches will likely be followed by Severe Thunderstorm Warnings throughout the life of the watch.
A Severe Thunderstorm Warning is issued for a particular polygon area when a severe thunderstorm is either imminent within that polygon or is occurring in that polygon. A Severe Thunderstorm Warning is not always preceded by a Severe Thunderstorm Watch especially in the Summer-time when thunderstorm development is not as well organized and is more isolated.
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
|
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. |
![]() |
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 moderate to 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 June 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. |
Fire Weather Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
NOAA's National Weather Service provides daily fire weather forecasts, fire weather warning products, and forecasts designed to assist wildland Fire Agencies' assessment of fire danger every day of the year. Most NWS Weather Forecast Offices provide fire forecasts twice a day and provide warnings in close partnership with local, state and Federal fire control agencies. Every year, fire weather forecasting experts provide over 8,000 Red Flag Warnings and Fire Weather Watches for protection of the public and safety of fire fighters on the ground. Also, Weather Forecast Staff provide vital, site-specific spot forecasts for wildfire, prescribed fire projects, all-hazards incidents, marine incidents and search and rescue. Spot forecast requests have been increasing tremendously, with the NWS now providing over 19,000 Spots every year.
Spotter Outlook
|
![]() |
|
Spotter Activation
|
Definition
|
|
![]() |
No
|
Spotters will not be needed for severe weather activation today or tonight.
|
![]() |
Yes
|
Spotters may be needed later in the day or tonight. Any reports of severe or hazardous weather would be appreciated. Spotter Reports can be submitted here: MQT Storm Reports |
The routine act of simply driving a vehicle is probably the most dangerous activity storm spotters engage in. When you take the normal everyday risks associated with driving, and add to that the additional risks storm spotters face, such as driving in bad weather, being distracted by the storm, using the radio or cell phone, etc, it becomes apparent that mobile spotters need to take extra care to be safe.
Here are some suggestions to help you stay safe when spotting from your vehicle:
If you are close enough to a storm to hear thunder, you are close enough to be struck by lightning. Lightning can strike with no warning - the first bolt could be the one that gets you.
Here are some tips to stay safe from lightning while spotting:
Floods kill more people than any other weather hazard. Most people that are killed drown in their vehicles. Remember -- Turn Around, Don't Drown!
Here are some tips to stay safe from flash flooding while spotting:
Mobile spotters should be extra cautious when operating around any thunderstorm, and even more cautious when dealing with a severe storm.
Here are some tips to stay safe from severe weather while spotting:
In order from the greatest hazard to spotters to the least: being on the road, lightning, flooding, hail and wind, and then tornadoes. The slides below add a little more detail to these hazards.
Fog Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
No risk of fog.
|
![]() |
Limited
|
There is a potential for Fog that could reduce visibility to a 1/4 mile.
|
![]() |
Elevated
|
Patchy Dense Fog with visibilities less than a 1/4 mile.
|
![]() |
Significant
|
Areas of Dense Fog with visibilities less than a 1/4 mile.
|
![]() |
Extreme
|
Widespread Dense Fog with visibilities less than a 1/4 mile.
|
Atmospheric conditions that are typical for fog development :
Fog Safety and Impact Prevention
- The air near the ground cools more quickly than the air just above the ground setting up a temperature inversion. If the air temperature cools to the dew point temperature, fog will normally form in light wind and clear sky conditions.
Some Important Safety Notes on Dense Fog
- Remember to drive with your low beam headlights on. High beams will reflect off of the fog creating a "white wall" effect.
- Allow extra time to get to your destination as travel speeds will likely be much slower than normal.
- In dense fog, visibilities can change quite rapidly which creates additional driving hazards. Low lying areas and locations near bodies of water may often times have lower visibilities than surrounding locations.
Non - Thunderstorm Wind Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
|
|||||||
Risk Level
|
Definition
|
|
![]() |
None
|
Sustained winds < 20 mph |
![]() |
Limited
|
Sustained winds 20-29 mph
or Wind gusts 30-44 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. |
Driving Safety Tips in High Wind
1) Be aware of the vehicles around you. High winds are usually more problematic for high profile vehicles such as RV's, trucks, buses, campers and those towing trailers.
2) Reduce your speed and correct your steering, especially when moving from a protected area to an unprotected area, or when meeting large vehicles.
Other Information and Safety Tips for High Wind
Gusts larger than 30 mph can cause lightweight items such as empty trash cans to be blown around and may cause some rough waters on area lakes. Boaters should use extreme caution.
Gusts larger than 40 mph can cause medium weight objects to be blown around and can create dangerous boating conditions on area lakes.
Gusts larger than 50 mph can cause buildings and trees to become damaged. Small boats can become capsized. High profile vehicles can be blown off the road.
Extreme Heat Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
Maximum Apparent Temperature < 90
|
![]() |
Limited
|
Maximum Apparent Temperature 90 to 99
|
![]() |
Elevated
|
Maximum Apparent Temperature 100 to 104 |
![]() |
Significant
|
Maximum Apparent Temperature 105 to 109 |
![]() |
Extreme
|
Maximum Apparent Temperature greater than or equal to 110
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. |
A National Problem
Heat kills by taxing the human body beyond its abilities. In a normal year, about 175 Americans succumb to the demands of summer heat. Among the large continental family of natural hazards, only the cold of winter-not lightning, hurricanes, tornadoes, floods, or earthquakes-takes a greater toll. In the 40-year period from 1936 through 1975, nearly 20,000 people were killed in the United States by the effects of heat and solar radiation. In the disastrous heat wave of 1980, more than 1,250 people died.
And these are the direct casualties. No one can know how many more deaths are advanced by heat wave weather-how many diseased or aging hearts surrender that under better conditions would have continued functioning.
North American summers are hot; most summers see heat waves in one section or another of the United States. East of the Rockies, they tend to combine both high temperature and high humidity although some of the worst have been catastrophically dry.
NOAA’s National Weather Service Heat Index Program
How Heat Affects the Body Human
Elderly persons, small children, chronic invalids, those on certain medications or drugs (especially tranquilizers and anticholinergics), and persons with weight and alcohol problems are particularly susceptible to heat reactions, especially during heat waves in areas where a moderate climate usually prevails.
Slow down. Strenuous activities should be reduced, eliminated, or rescheduled to the coolest time of the day. Individuals at risk should stay in the coolest available place, not necessarily indoors.
Dress for summer. Lightweight light-colored clothing reflects heat and sunlight, and helps your body maintain normal temperatures.
Put less fuel on your inner fires. Foods (like proteins) that increase metabolic heat production also increase water loss.
Drink plenty of water or other non-alcohol fluids. Your body needs water to keep cool. Drink plenty of fluids even if you don’t feel thirsty. Persons who (1) have epilepsy or heart, kidney, or liver disease, (2) are on fluid restrictive diets or (3) have a problem with fluid retention should consult a physician before increasing their consumption of fluids.
Do not drink alcoholic beverages.
Do not take salt tablets unless specified by a physician.
Spend more time in air-conditioned places. Air conditioning in homes and other buildings markedly reduces danger from the heat. If you cannot afford an air conditioner, spending some time each day (during hot weather) in an air conditioned environment affords some protection.
Don’t get too much sun. Sunburn makes the job of heat dissipation that much more difficult
*For more information contact your local American Red Cross Chapter. Ask to enroll in a first aid course.
Produced as a cooperative effort of NOAA’s National Weather Service, the Federal Emergency Management Agency, and the American Red Cross. NOAA/PA 85001
Snow and Sleet Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
Little (<1 inch) or No snow or sleet accumulation.
|
![]() |
Limited
|
Snow and/or sleet expected from "System Snow" to accumulate 1 to 2.9 inches |
![]() |
Elevated
|
Snow and/or sleet expected from "System Snow" to accumulate 3 to 5.9 inches |
![]() |
Significant
|
Snow and/or sleet expected from "System Snow" to accumulate 6 to 9.9 inches |
![]() |
Extreme
|
Snow and/or sleet expected from "System Snow" to accumulate more than 10 inches |
Heavy Snow
Heavy snow can immobilize a region and paralyze a city, stranding commuters, closing airports, stopping the flow of supplies, and disrupting emergency and medical services. Accumulations of snow can cause roofs to collapse and knock down trees and power lines. Homes and farms may be isolated for days and unprotected livestock may be lost. In the mountains, heavy snow can lead to avalanches. The cost of snow removal, repairing damages, and the loss of business can have severe economic impacts on cities and towns.
An avalanche is a mass of tumbling snow. More than 80 percent of midwinter avalanches are triggered by a rapid accumulation of snow, and 90 percent of those occur within 24 hours of snowfall. An avalanche may reach a mass of a million tons and travel at speeds up to 200 mph.
Injuries Due To Ice and Snow
• About 70% result from vehicle accidents
• About 25% occur in people caught out in a storm
• Most happen to males over 40 years old BLIZZARD: Winds of 35 mph or more with snow and blowing snow reducing visibility to less than ¼ mile for at least 3 hours.
BLOWING SNOW: Wind-driven snow that reduces visibility. Blowing snow may be falling snow and/or snow on the ground picked up by the wind.
SNOW SQUALLS: Brief, intense snow showers accompanied by strong, gusty winds. Accumulation may be significant.
SNOW SHOWERS: Snow falling at varying intensities for brief periods of time. Some accumulation is possible.
SNOW FLURRIES: Light snow falling for short durations with little or no accumulation.
Be Prepared!
Before the Storm Strikes
Freezing Rain Risk |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Freezing Rain: Rain that freezes when it hits the ground, creating a coating of ice on roads, walkways, trees, and power lines.
Ice Storm Warning: Heavy ice accumulation, generally greater than 1/4 of an inch thick, causing dangerous and damaging situations, such as downed utilitiy lines and icy roads.
Freezing Rain Advisory: Light ice coating on roads and highways, but no damage is expected to trees and power lines.
Have a winter storm survival kit in your home and vehicles, and be sure to receive the latest weather information from the NWS.
Be aware of carbon monoxide poisoning. Never use generators, grills, camp stoves, or other gasoline, propane, natural gas, or charcoal-burning devices inside your home, basement, garage, or camper-- or event outside near an open window.
Frost and Freeze Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
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.
|
The Frost and Freeze grids are only generated during the growing season, generally from mid May through the end of September. |
Additional Frost and Freeze Information
The National Weather Service in Marquette, MI will issue Frost Advisories and Freeze Warnings for the growing season. These products will be issued during the time frame of April 1st through October 1st.
Frost Advisories may be suspended earlier in the Autumn based on seasonal trends and surrounding Weather Service Office collaboration.
A freeze watch may also be issued for significant or unexpected freeze events generally in the Spring and Fall. This product would typically be issued 24 to 48 hours in advance of the freeze and would be replaced with a Freeze Warning.
The average date of the last killing frost in Spring is around Memorial Day, May 31st.
The average date of the first killing frost in Autumn varies greatly, the first killing frost can occur in the inland areas as early as mid-September and close the the Lake shore in mid-October.
Excessive Cold Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
Minimum apparent temperature greater than or equal to 0 degrees F.
|
![]() |
Limited
|
Minimum apparent temperature -9 to -1 deg F.
|
![]() |
Elevated
|
Minimum apparent temperature -10 to -24 deg. F
|
![]() |
Significant
|
Minimum apparent temperature -25 to -34 deg. F.
|
![]() |
Extreme
|
Minimum apparent temperature less than or equal to -35 degrees F
|
Note:
|
Apparent Temperature is defined as: | |
Wind Chill Temperature during the cold season. | ||
Heat Index Temperature during the warm season. |
Extreme Cold
Extreme cold often accompanies a winter storm or is left in its wake. Prolonged exposure to the cold can cause frostbite or hypothermia and become life-threatening. Infants and elderly people are most susceptible. What constitutes extreme cold and its effect varies across different areas of the United States. In areas unaccustomed to winter weather, near freezing temperatures are considered "extreme cold." Freezing temperatures can cause severe damage to citrus fruit crops and other vegetation. Pipes may freeze and burst in homes that are poorly insulated or without heat. In the north, below zero temperatures may be considered as "extreme cold."
FROSTBITE
Frostbite is damage to body tissue caused by that tissue being frozen. Frostbite causes a loss of feeling and a white or pale appearance in extremities, such as fingers, toes, ear lobes, or the tip of the nose. If symptoms are detected, get medical help immediately! If you must wait for help, slowly rewarm affected areas. However, if the person is also showing signs of hypothermia, warm the body core before the extremities.
HYPOTHERMIA: LOW BODY TEMPERATURE
Warning signs - uncontrollable shivering, memory loss, disorientation, incoherence, slurred speech,drowsiness, and apparent exhaustion.
Detection - Take the person's temperature. If below 95F (35C),immediately seek medical care! If medical care is not available, begin warming the person slowly. Warm the body core first. If needed, use your own body heat to help. Get the person into dry clothing, and wrap them in a warm blanket covering the head and neck. Do not give the person alcohol, drugs, coffee, or any hot beverage or food; warm broth is better. Do not warm extremities (arms and legs) first! This drives the cold blood toward the heart and can lead to heart failure.
WIND CHILL
The wind chill is based on the rate of heat loss from exposed skin caused by combined effects of wind and cold. As the wind increases, heat is carried away from the body at an accelerated rate, driving down the body temperature. Animals are also affected by wind chill.
Coastal Flooding Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
No Coastal Flooding risk.
|
![]() |
Limited
|
Winds >= 25 mph and Wave Heights >= 8 feet. These conditions could lead to isolated areas of beach erosion and coastal flooding. |
![]() |
Elevated
|
Winds >= 35 mph and Wave Heights >= 11 feet. These conditions could lead to scattered areas of beach erosion and coastal flooding.
|
![]() |
Significant
|
Winds >= 40 mph and Wave Heights >= 14 feet. These conditions could lead to significant beach erosion and coastal flooding.
|
![]() |
Extreme
|
Winds >= 45 mph and Wave Heights >= 18 feet. These conditions could lead to widespread beach erosion and coastal flooding. |
The combination of Wind and Waves could create Beach Erosion and Coastal Flooding. Use caution when near the lakeshore.
Swim Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
Low
|
A low risk of swimming hazards implies 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.
|
![]() |
Moderate
|
A moderate risk of swimming hazards implies 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.
|
![]() |
High
|
A high risk of swimming hazards implies dangerous waves and currents are expected along the shore. Swimming conditions may be life threatening to anyone entering the water. |
The Swim Risk grids are only generated during the swimming season, generally from mid June through the end of September. |
***Safety Information Coming Soon***
High Surf Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
No High Surf Risk.
|
![]() |
Limited
|
Wave height >= 2 feet and Wave Period > 3 seconds.
|
![]() |
Elevated
|
Wave Height >= 4 feet and Wave Period > 4 seconds. |
![]() |
Significant
|
Wave Height >= 6 feet and Wave Period > 5 seconds. |
![]() |
Extreme
|
Wave Height > 8 feet.
|
***Safety Information Coming Soon***
Marine Hazard Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
No Marine Hazards Risk.
|
![]() |
Limited
|
Winds >= 15 knots and/or Waves >= 2 feet.
|
![]() |
Elevated
|
Winds >= 23 knots and/or Waves >= 4 feet. |
![]() |
Significant
|
Winds >= 34 knots and/or Waves >= 9 feet. |
![]() |
Extreme
|
Winds >= 48 knots and/or Waves >= 14 feet.
|
Freezing Spray Risk
|
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
Risk Level
|
Definition
|
|
![]() |
None
|
No Freezing Spray Risk.
|
![]() |
Limited
|
Moderate Freezing Spray Expected
|
![]() |
Elevated
|
|
![]() |
Significant
|
Heavy Freezing Spray Expected |
![]() |
Extreme
|
|
***Enter Safety Information Here***
Radar & Satellite Links
|
Radar Analysis
|
Satellite Analysis
|
||||
Understanding the anticipated risk of weather hazards is important to making daily plans as well as carrying out preparedness activities prior to a hazardous weather event. The Enhanced Hazardous Weather Outlook (EHWO) depicts the risk of potential weather hazards through day 7 utilizing text, alert buttons and graphics. The EHWO should be utilized as a preparedness tool prior for hazardous weather events and a means of monitoring the severity and coverage during a hazardous weather event.
The Enhanced Hazardous Weather Outlook (EHWO) provides:
Hazardous Weather Buttons conveying risk levels for a given day
Spotter Outlook Graphic that portrays the need for spotter activation
Link to briefing pages that provide additional products and information for a given weather hazard
Risk Legend section that defines the risk levels
The EWHO integrates the text of the Hazardous Weather Outlook with the graphical representation of expected hazards. The graphical buttons depict the threat level for a given day. The button display provides a quick overview of potential hazard risk levels through day 7. More specific information about expected hazards can be obtained by clicking on the buttons. Additional links to radar, briefings pages, etc, are provided to compliment the hazards graphics.
Each days graphic represents a time frame from 12 UTC to 12 UTC
which is 7 am Eastern current day to 7 am Eastern the next day during standard time, and 8 am Eastern current day to 8 am Eastern the next day during daylight savings time. |
This section will describe how to navigate through our Enhanced Hazardous Weather Outlook(HWO) suite of pages.
The Video Briefing link will take you to one of our newest products. Our multi-media weather briefing will provide information concerning hazardous weather events within our service area. This briefing will provide graphics along with audio and will support the planning activities of emergency response partners and other key customers, as well as the general public, by conveying expected timing, location, reasoning and impacts associated with upcoming hazardous weather events. Remember that this product is experimental, only created for significant weather events, and is only updated when workload allows.
The Briefing Pages link will take you to a suite of weather briefing pages designed to provide you with an overview of weather information for specific types of weather events. These pages contain a set of graphics and text information that details weather parameters for specific weather events.
The Radar/Satellite link will display a menu under the header of the Enhanced HWO pages with links to satellite images along with local and regional radar links. After clicking on any of these links, the image will appear just below the menu.
The spotter outlook link will display the spotter outlook graphic under the Enhanced HWO header.
The HWO Text link will display the Hazardous Weather Outlook text product under the Enhanced HWO header.
On the right hand side on each of the Enhanced HWO pages will be the main menu for navigating your way through the suite of Enhanced HWO pages. Clicking on any of the risk level "buttons" will take you to that particular risk. The risk pages will display a map of our county warning area of responsibility with risk levels shading the map for each risk.
So if you wanted to see what the Flooding risk was for today across the Springfield, MO county warning area of responsibility, you would click on the "button" next to Flooding under the Day 1 through Tonight header.
Once you click on a risk "button", a specific risk page will be displayed. As in our above example, the Flooding risk for Day1 will be displayed. Directly below the header, a table with the Flooding risk will be displayed with risk "buttons" for each of the next 7 days. Clicking on any of these "buttons" will take you to that specific page.
There will also be a Risk Legend, and a Safety and Education tab. Clicking on the Risk Legend will describe what the different risk levels are intended to mean.
The Safety and Education Tab link will describe the risk, its impacts and safety information.
Example of a flooding risk table.
Navigating through Days 2 to 7 is done in the same manner described above for Day 1. Simply click on the risk "button" to go to that specific hazard.
To return back to the homepage for the National Weather Service in Marquette, MI, you can always click on the top of the page within the Marquette, MI text.
x::get_product,mqt,hwo,01::x