Home > Local Offices > Mobile, AL > All Posts > What do all of our products mean?
By Wyatt Huber (Meteorologist In Charge)
Posted on Sat, Oct 19, 2024 at 6:18 AM CDT
It likely comes to mind what all of the products we issue are, and what they mean. This blog post will summarize what products/alerts we issue, and what the criteria for them are.
FORECAST PRODUCTS
Public Local Forecast (PLF): This product is the weather forecast for the next 5 to 7 days. It is issued for six "zones", which are groups of counties. These zones may change depending on incoming weather.
Public Forecast Discussion: This text product details the weather synopsis, analyses, forecasts, and reasoning.
LocalCast: This graphical product is used to show areal extent of specific weather conditions, such as rain, snow, wind, t-storms, etc.
Short Term Update: This product details the current and forecasted weather conditions for the next few hours. Generally used during weather conditions that may cause an inconvienience, but below any advisory criteria. It will include counties affected, and it may be accompanied by a LocalCast issuance.
Hazardous Weather Discussion: This product details potential hazardous weather concerns during the next 5-to-7-day period. Usually only used preceeding a significant weather or hydrological event.
Storm Assessment Report: This text product details the impacts that occured after a storm, and may include forecast critique.
Public Weather Bulletin: A PWB is issued when any weather event does NOT meet any of the alert criteria listed below, but still poses an inconvenience or minor threat. Can also be used for events that do not currently have their own product, such as poor air quality, dense smoke, or blowing dust. It will also be used for the first frost/freeze signifying the end of the growing season, or any frosts/freezes during the beginning of the growing season or after an extended, anomously warm period during the non growing season.
ALERTS
USA Weather Inc. issues numerous alerts/statements for different hazardous weather conditions. This is a listing of all alerts that may be issued within the Mobile Local Forecast Office (LFO), and the criteria that is required for issuance.
Alert: An "alert" is issued when hazardous weather conditions are expected within 24 to 36 hours.
Statement: A "statement" is issued when hazardous weather conditions are possible within 48 hours.
Extremely Hazardous Situation (EHS): An alert may be tagged as an "Extremely Hazardous Situation (EHS)" if it poses an exeptionally significant threat to life and property. An EHS alert will incorperate enhanced impact wording and stronger preperation messages.
Blizzard Alert: Blizzard conditions are expected within 36 hours. In order for a winter storm to be classified as a blizzard, it MUST have winds or gusts over 35 mph, visibility of less than 1/4 of a mile from falling/blowing snow, and it must last for 3 consecutive hours. These conditions are extremely rare in the deep south, and any Blizzard Alert issued will be tagged "EHS".
Blizzard Statement: Blizzard conditions are possible within 48 hours.
Blowing Snow Alert: Falling and/or blowing snow is expected to reduce visibility, but not meeting blizzard criteria.
Coastal Flood Alert: Coastal flooding of low-lying areas, roadways, and in severe cases, homes are expected. This may be accompanied with large, breaking waves and beach erosion. Will be tagged "EHS" if the flood threat is "high" or "catastrophic".
Coastal Flood Statement: Coastal flooding is possible within 48 hours.
Dense Fog Alert: Widespread (not isolated/localized) fog reduces visibility to under 1/2 of a mile. Also can be issued for freezing fog with any low visibility due to the potential for icy roadways and bridges.
Extreme Cold Alert:
ALL INLAND COUNTIES: Air temperatures under 20 degrees are expected. Will be tagged EHS for air temperatures 10 degrees or less.
ALL COASTAL COUNTIES: Air temperatures under 25 degrees are expected. Will be tagged EHS for air temperatures 15 degrees or less.
Extreme Heat Alert: Heat indicies over 108, or air temperature over 103. Will be tagged EHS for heat indicies over 113, or air temperatures over 105.
Fire Danger Alert: The combination of low humidity under 30%, winds over 15 mph, and widespread dry fuels will result in the potential for dangerous fire weather conditions. Will be tagged EHS if these conditions are exceptionally severe, and any fire may rapidly/erratically spread.
Fire Danger Statement: Dangerous fire weather conditions are possible.
Flash Flood Alert: Heavy rainfall has resulted in flash flooding. Will be tagged EHS if the flooding is exceptionally severe and produces a significant threat to life/property.
Flash Flood Statement: Heavy rainfall is expected, and flash flooding may result.
Flood Alert: Extended periods of rainfall has resulted in areal flooding. Will be tagged EHS if the flooding is exceptionally severe and produces a significant threat to life/property.
Flood Statement: Extended periods of rainfall is expected, and areal flooding may result.
Heavy Snow Alert: Snowfall accumulations of 2" or greater are expected over purple counties, or 1" or greater over blue counties.
High Wind Alert: Non-convective, sustained winds of 40 to 49 mph and/or gusts of 55 to 69 mph are expected to last for one hour or greater. May be tagged EHS if wind speeds 50 mph or higher and/or gusts are 70 mph or higher.
High Wind Statement: High wind speeds are possible within 48 hours.
Hurricane Alert: Hurricane-Force Winds of 74 mph, but not exceeding 111mph in association with a landfalling hurricane are expected within the next 24 hours. Will be tagged EHS if the maximum winds are expected to exceed 111 mph in association with a major hurricane.
Hurricane Statement: Hurricane-Force Winds of 74 mph in association with a landfalling hurricane are expected within the next 48 hours.
Ice Alert: Accumulating freezing rain is expected. Will be tagged EHS if the freezing rain accumulations exceed 1/4 of an inch.
Ice Statement: Freezing rain accumulations are possible within 48 hours.
PLT Wind Alert: Potentially life-threatening winds of 111 mph or greater are expected within an hour due to the eyewall of a major hurricane or are imminent due to a derecho.
Severe Thunderstorm Alert: A convective thunderstorm has the potential to produce damaging winds between 60 to 75 mph and/or large hail between 1 to 2.5 inches. Will be tagged EHS if winds reach or exceed 80 mph and/or hail exceeds 2.5".
Snow Alert: Snow accumulations between 1/2 of an inch and 2 inches over inland counties OR any snow accumulations up to an inch are expected over coastal counties.
Strong Storm Alert: A convective thunderstorm has the potential to produce gusty winds between 40 to 59 mph and/or small hail under 1 inch. Can also be issued for the potential of fair-weather waterspouts moving inland, and can also mention the potential of landspouts.
Tornado Alert: Doppler Radar has indicated a severe thunderstorm with strong rotation capable of producing a tornado, or a confirmed tornado has been reported by the general public, law enforcement, broadcast media, etc. Will be tagged EHS if there is a confirmed large and violent tornado, and confidence it will continue.
Tropical Storm Alert: Tropical-Storm-Force Winds of 40 mph, but not exceeding 74 mph are expected within the next 24 hours in association with a landfalling tropical cyclone.
Tropical Storm Statement: Tropical-Storm-Force Winds of 40 mph, but not exceeding 74 mph are expected within the next 48 hours in association with a landfalling tropical cyclone.
Wind Alert: Sustained winds between 25 to 39 mph and/or gusts of 35 to 54 mph are expected.
Wind Chill Alert:
ALL INLAND COUNTIES: Wind chill temperatures under 10 degrees are expected. Will be tagged EHS for wind chill temperatures 0 degrees or less.
ALL COASTAL COUNTIES: Wind chill temperatures under 15 degrees are expected. Will be tagged EHS for wind chill temperatures 5 degrees or less.
Winter Storm Alert: Any combination of snow accumulations, freezing rain accumulations, or sleet accumulations are expected. Will be tagged EHS if snow accumulations exceed 2" purple counties or 1" in blue counties, and/or freezing rain accumulations exceed 1/4 of an inch, or sleet accumulations exceed 1/2 of an inch areawide. This is ONLY issued if there will be multiple precipitation types; otherwise, the respective alert is to be used. EHS will be tagged if one of the precipitation types meets criteria.
Winter Storm Statement: Any combination of snow, sleet, or freezing rain accumulations are possible within 48 hours. This is to be used if: multiple precipitation types are expected OR heavy snow alert criteria may be met.
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