Heavy rainfall from scattered thunderstorms is expected across the Southwest, Intermountain West, and Plains. Isolated dry thunderstorms may initiate additional fires across the west. The coastal Carolinas may experience flash floods in the coming days due to repeated thunderstorms. Additionally, a wave of intense summer heat will hit the Southern Plains and central Gulf Coast States this week. Read More >
Within each of the program-area specific tabs are a list of products incorporated into the operations of and issued by the NWS Boston Weather Forecast Office (WFO). Inclusive are simply the descriptions of the products themselves.
If you are looking for the actual products, please consult our product webpage.
If you are looking for product criteria, please consult our product criteria webpage.
Variable | Description |
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Maximum ... day, month, season, year, all time Minimum ... day, month, season, year, all time Lowest Maximum ... day, month, season, year, all time Highest Minimum ... day, month, season, year, all time |
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Highest ... all time Lowest ... all time |
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Highest speed .... all time Highest gust ... all time |
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Largest hail size, all time Most / Least Precipitation ... day, month, season, year, all time Snowfall / Snow Depth ... day, month, season, year, all time |
Weather Hazard | Description |
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Convective weather hazards include large hail, damaging winds, and tornadoes. WFOs should include Storm Prediction Center Categorical Convective Outlook information for Day 1, Day 2, and Day 3 Risks (Slight, Moderate and High) of organized severe convective weather. WFOs may include information on strong (less than severe) convection. |
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Winter weather hazards include wind chill, freezing fog, significant snow, freezing rain, sleet, or a mixture of these weather phenomena. |
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Non-precipitation weather hazards include strong winds, excessive heat, extreme cold, blowing dust/sand, freezing temperatures during the growing season, and dense fog. |
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Fire weather hazards include extremely dry conditions, strong gusty winds, and dry thunderstorms. While mentioning active Fire Weather Watches and Red Flag Warnings for Days 1 and 2, SPC Fire Weather Outlooks (Day 1 and Day 2) may also be incorporated. |
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Any and all flood hazards (coastal marine, inland, river) are incorporated including those impacts associated with a tropical cyclone. WFOs may include information on small stream flood situations and life threatening flood prone areas. |
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Marine hazards include high winds, high seas, high surf, rip-currents, coastal flooding, and waterspouts. High risk of rip-currents and accompanying information can be included in the Day 1 portion of the HWO. Marine hazards that do not directly affect the coastline (i.e., Small Craft Advisories), may be omitted from the HWO. |
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Day 1 Tropical Cyclone Watches and Warnings issued by the National Hurricane Center (NHC) will be headlined, though users will be strongly urged to consult Hurricane Local Statements to obtain detailed information concerning potential hazards such as strong winds, storm surge, and excessive rainfall. Days 2 through 7 will be consistent with official guidance and products issued by the NHC/WPC. WFOs will not reference tropical cyclone activity beyond the time period addressed by official tropical cyclone products (currently 5 days). |
Threat | Description |
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WFOs may issue SPSs to heighten public awareness about ongoing or imminent hazardous convective weather expected to continue/dissipate, or expand/decrease in geographical coverage within the next hour or two. |
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WFOs should issue an SPS for strong thunderstorms that approach, or are expected to approach, severe convective criteria. General criteria for a sub-severe thunderstorm is considered to be one or a combination of the following events:
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WFOs may issue SPSs for high-impact events to supplement information contained in other hazardous weather products, providing high-resolution details when possible. Examples include but are not limited to:
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WFOs may issue SPSs to heighten awareness of major events forecast to occur beyond 6 hours. Priority should be given to ongoing or imminent events such as those listed above. |
Rip-Current Risk | Description |
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Wind and/or wave conditions are not expected to support the development of Rip Currents. However, Rip Currents can sometimes occur, especially in the vicinity of groins, jetties, reefs and piers. Know how to swim and heed the advice of the beach patrol. |
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Wind and/or wave conditions support stronger or more frequent Rip Currents. Only experienced surf swimmers should enter the water. |
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Wind and/or wave conditions support dangerous Rip Currents. Rip Currents are life-threatening to anyone entering the surf. |
Coastal Hazard | Description |
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Issued 12 to 48 hours in advance, informing users of coastal flooding that may have significant impacts. |
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Informing users that coastal flooding which poses a serious threat to life and property is occurring, imminent, or highly likely in the first 12 to 24 hours. |
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Informing users that minor flooding, such as minor tidal overflow, is occurring or is possible within 12 hours. |
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When breaking wave action poses a threat to life and property within the surf zone (the surf zone is the narrow area of water between high tide level on the beach and seaward side of the breaking waves). |
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When breaking wave action results in an especially heightened threat to life and property within the surf zone. |
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Usually mentioned when concurrent with another coastal hazard (particularly high surf), but when not coincident, an Informational Statement may be used. Informational statements may be used to describe hazards that do not meet Advisory, Watch, or Warning criteria, as well as hazards that do not have Advisory, Watch, or Warning criteria (e.g. rip currents, oil spill). |
Rip-Current Risk | Description |
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Wind and/or wave conditions are not expected to support the development of Rip Currents. However, Rip Currents can sometimes occur, especially in the vicinity of groins, jetties, reefs and piers. Know how to swim and heed the advice of the beach patrol. |
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Wind and/or wave conditions support stronger or more frequent Rip Currents. Only experienced surf swimmers should enter the water. |
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Wind and/or wave conditions support dangerous Rip Currents. Rip Currents are life-threatening to anyone entering the surf. |
Concept | Description |
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An outlook is used to indicate that a hazardous marine weather event may develop. It is intended to provide information to those who need considerable lead time to prepare for the event. Marine outlooks are issued with a Hazardous Weather Outlook (HWO) and/or a Marine Weather Statement (MWS). |
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A watch is used when the risk of a hazardous marine weather event has increased, but its occurrence, location, and/or timing is still uncertain. It is intended to provide enough lead time so those who need to set their plans in motion can do so. |
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A warning is used when a hazardous marine weather event is occurring, is imminent, or has a very high probability of occurrence. A warning is used for conditions posing a threat to life or property. |
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An advisory is used for less serious conditions that cause significant inconvenience and, if caution is not exercised, could lead to situations that may threaten life and/or property. |
Watch-Type | Description |
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Conditions are favorable for a gale force wind event to meet the Gale Warning criteria of sustained winds or frequent gusts* of 34 knots to 47 knots in the next 12 to 48 hours. |
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Conditions are favorable for a storm force wind event to meet Storm Warning criteria of sustained winds or frequent gusts* of 48 knots to 63 knots in the next 12 to 48 hours. |
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Conditions are favorable for a hurricane force wind event to meet or exceed Hurricane Force Wind Warning criteria of sustained winds or frequent gusts* of 64 knots or greater in the next 12 to 48 hours. |
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Conditions are favorable for a heavy freezing spray event to meet local Heavy Freezing Spray Warning criteria in the next 12 to 48 hours. |
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Conditions are favorable for a hazardous seas event to meet or exceed Hazardous Seas Warning criteria in the next 12 to 48 hours. |
Warning-Type | Description |
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Sustained surface winds, or frequent gusts* in the range of 34 knots to 47 knots inclusive, either predicted or occurring, and not directly associated with a tropical cyclone. |
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Sustained surface winds, or frequent gusts* in the range of 48 knots to 63 knots inclusive, either predicted or occurring, and not directly associated with a tropical cyclone. |
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Sustained winds, or frequent gusts* of 64 knots or greater, either predicted or occurring, and not directly associated with a tropical cyclone. |
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An accumulation of freezing water droplets on a vessel at a rate of 2 cm per hour or greater caused by some appropriate combination of cold water, wind, cold air temperature, and vessel movement. |
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Wave heights and/or wave steepness values meeting or exceeding locally defined warning criteria. |
Advisory-Type | Description |
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Light to moderate accumulation of ice is expected on vessels. |
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Sustained wind speeds or frequent gusts of 25 to 33 knots and/or seas or waves 5 feet and greater. |
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Wind speeds are lower than small craft advisory criteria, yet waves or seas are potentially hazardous due to wave period, steepness, or swell direction. |
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Waves in or near bars are hazardous to mariners due to the interaction of swell, tidal or river currents in relatively shallow water. |
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When wave heights and/or wave steepness are lower than Small Craft Advisory criteria, yet wind speeds are potentially hazardous. |
Scheduled Issuance | Valid Period | 30-Hour | Issuance Window |
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0000 UTC | 0000 to 0000 UTC | 0600 UTC | 2320 to 2340 UTC |
0300 UTC (AMD) | 0300 to 0000 UTC | 0600 UTC | |
0600 UTC | 0600 to 0600 UTC | 1200 UTC | 0520 to 0540 UTC |
0900 UTC (AMD) | 0900 to 0600 UTC | 1200 UTC | |
1200 UTC | 1200 to 1200 UTC | 1800 UTC | 1120 to 1140 UTC |
1500 UTC (AMD) | 1500 to 1200 UTC | 1800 UTC | |
1800 UTC | 1800 to 1800 UTC | 0000 UTC | 1720 to 1740 UTC |
2100 UTC (AMD) | 2100 to 1800 UTC | 0000 UTC |
Watch Type | Watch Description |
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Active Watches | WFOs will issue updated WCNs to continue, cancel or extend in time or area portions of one or more active convective watches in their geographic area of responsibility |
New Watches | WFOs will also issue updated WCNs to include new watches issued within their geographic area of responsibility while existing watches remain in effect |
Watch Extensions | CONUS WFOs will collaborate with SPC and affected WFOs on counties, parishes, independent cities or marine zones added to the initial watch area, or extensions to the expiration time of the initial convective watch area |
Watch Replacements | CONUS WFOs will collaborate with SPC and adjacent WFOs when counties, parishes, independent cities or marine zones are transferred from an existing convective watch to a new convective watch (e.g. watch replacement) |
Watch Editing Consistency | WFOs will ensure modifications to the convective watch area are consistent with modifications made by adjacent WFOs |
WCN Issuance Times | WCNs will be issued by H+55 so that changes will be reflected in the WOU issued by SPC after the top of the hour |
Watch Cancellation /Expiration | The final WCN for a particular convective watch will cancel or allow expiration of all remaining counties, parishes, independent cities and/or marine zones in the watch for their geographic area of responsibility |
Overview Header | Overview Header Description |
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.NEW INFORMATION… | Will concisely list what is new. If applicable, state "NO SIGNIFICANT CHANGES". |
.AREAS AFFECTED… | Provides details of which counties/parishes or cities are included in the HLS. |
.WATCHES / WARNINGS… | Includes watches and warnings in effect and counties/parishes to which they apply. |
.STORM INFORMATION… | Discusses present location, movement, and winds. Forecast trend information may also be provided. |
.SITUATION OVERVIEW… | Concisely describes, in general terms, the tropical cyclone’s meteorological hazards (peak values, generalized onset/duration times and locations) and projected forecast track in relation to the WFO’s CWA/MAOR. |
.PRECAUTIONARY / PREPAREDNESS ACTIONS… |
May contain general protective action information as well as an overview of significant protective actions underway within the CWA/MAOR such as recommendations, announcements, or evacuation information for the general public provided by local or state officials. |
.NEXT UPDATE… | Provides a quick sentence stating the approximate time when the next HLS will be issued. |
Segment Header | Segment Description |
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…HEADLINE(s)… | |
…NEW INFORMATION… | New and vital information specific to the segment. If present, New Information will always be the first section header. |
…PRECAUTIONARY / …PREPAREDNESS ACTIONS… |
The protective actions outlined in the overview block precautionary/preparedness actions section may be expanded upon here to provide further detail for a specific area of concern if necessary. This section will contain mainly significant protective actions issued by local and state officials. |
…PROBABILITY TROPICAL STORM / HURRICANE CONDITIONS… |
Information on probability of hurricane/typhoon/tropical storm conditions. |
…WINDS…or …WINDS AND SEAS… |
Information about the potential impacts of forecast winds such as the anticipated time of onset, approximate duration and cessation (in general terms, i.e., "afternoon") of tropical storm/hurricane/typhoon force winds, peak winds and gusts. Wind speed values will be expressed in appropriate ranges relative to the magnitude of the storm (40 to 50 mph instead of 45 mph). |
…STORM SURGE AND STORM TIDE… |
Information about the potential impacts of forecast storm surge and storm tide. This includes the anticipated time of onset, approximate duration and cessation (in general terms, i.e., "afternoon") of the storm surge and storm tide, as well as peak heights. Heights should be expressed in appropriate ranges relative to the magnitude of the surge and tide (8 to 12 feet above ground level). WFOs will reference storm surge and storm tide relative to height above ground level (inundation). WFOs may use other vertical datum references such as Mean Sea Level (MSL) and/or Mean Lower Low Water (MLLW). |
…INLAND FLOODING… | Highlight the threat of flash flooding and rapid inundation relative to the zone or zone group as a result of heavy rain. |
…TORNADOES… or …TORNADOES AND WATERSPOUTS… |
Highlight the threat of tornadoes or waterspouts relative to the zone or zone group. |
…OTHER… | The section is optional. WFOs may address other hazards specific to their area for the event (e.g., rip currents, mudslides). |
Segment Header | Segment Description |
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Wind data | If the observed peak gusts are greater than 33 knots, highest sustained surface wind speed (knots) and duration (1-, 2- 8-, or 10-minute average which ever applies), peak gust (knots), and date/times of occurrence in UTC are reported. All descriptions associated with the station making the observation will also be provided as either Official or Unofficial Observations. Wind speeds may be corrected based on instrument type and speed range if known. Any all all data should be included only when deemed reliable based on the particular facts and circumstances. |
Pressure data | Lowest sea level pressure (millibars) and date/time of occurrence (UTC) are reported as well as any and all descriptive information concerning the sources. |
Storm total rainfall | Amount (inches) and duration (dates) are reported from any and all locations where significant rainfall observations are available (typically 3-inches or more). Anything less is reported as a needed- or requested-basis. |
Inland flooding | Date/times (UTC) and counties/parishes/independent cities of occurrence are reported, along with a brief worded summary, as appropriate. |
Maximum storm surge and storm tide |
Reports are made so in referencing storm tide to appropriate datums (North American Vertical Datum of 1988) understood by local authorities. Some areas may still be using the National Geodetic Vertical Datum of 1929 (NGVD) or Mean Lower Low Water (MLLW). Storm tide is reported in feet above the datum, and storm surge/wind waves in feet above the normal, predicted (astronomical) tide level. Location and date/time (UTC) of occurrence is provided where possible. Storm surges greater than 1 foot are included, as well as storm-tides 1 foot or greater above the normal astronomical tide. Tides of 1 foot or greater above normal, with tides of less than 1 foot above normal are reported as needed or as requested. Extent of beach erosion as appropriate is included. The National Ocean Service’s Center for Operational Oceanographic Products and Services (NOS CO-OPS) will provide a final report of storm surge and storm tide information from NOS tide gauges to WFOs within 4 days following the issuance of the final HLS. |
Tornadoes | Times (UTC) and locations included, taken mainly from Local Storm Reports (LSRs) issued for the event, along with a brief description of damage, as appropriate. |
Storm impacts | Including deaths, injuries, dollar damages, number of people evacuated, etc., per county/parish/independent city as reported by emergency management, trusted media sources, etc. Please note: For data in sections (A, land observations), (B, marine observations), (C, storm total rainfall), and (F, tornadoes), latitude and longitude should be included. |
Watch Type | Watch Description |
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Blizzard Watch | Conditions are favorable for a blizzard event to meet or exceed Blizzard Warning criteria. This is no longer a separate product but rather incorporated into a Winter Storm Watch. |
Winter Storm Watch | Conditions are favorable for a winter storm event (Heavy Sleet, Heavy Snow, Ice Storm, Heavy Snow and Blowing Snow or a combination of events) to meet or exceed local Winter Storm Warning criteria. |
Wind Chill Watch | Conditions are favorable for wind chill temperatures to meet or exceed local Wind Chill Warning criteria. |
Warning Type | Warning Description |
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Blizzard Warning | Sustained wind or frequent gusts greater than or equal to 35 mph accompanied by falling and/or blowing snow, frequently reducing visibility to less than 1/4 mile for three hours or more. |
Winter Storm Warning | Winter weather event including 1) snow, ice, or sleet meeting or exceeding locally defined 12 and/or 24 hour warning criteria; or 2) a combination of snow, ice, or sleet and blowing snow with at least one of the precipitation elements meeting or exceeding locally defined 12 and/or 24 hour warning criteria. |
Ice Storm Warning | Ice accumulation meeting or exceeding locally defined warning criteria (i.e., higher thresholds for regions that are accustomed to ice events and lower thresholds for areas where lesser amounts can cause major problems; typical value is 1/4 inch or more). An ice storm is used to describe occasions when damaging accumulations of ice are expected during freezing rain situations. |
Wind Chill Warning | Wind chill temperatures reaching or exceeding locally defined warning criteria. |
Advisory Type | Advisory Description |
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Winter Weather Advisory | Winter weather event having one or more hazards (i.e., snow, snow and blowing snow, snow and ice, snow and sleet, or snow, ice and sleet) meeting or exceeding locally defined 12 and/or 24 hour advisory criteria for at least one of the precipitation elements, but remaining below warning criteria. |
Freezing Rain Advisory | Light ice accumulation (freezing rain and/or freezing drizzle) meeting or exceeding locally defined advisory criteria, but remaining below warning criteria. This is no longer a separate product but rather incorporated in a Winter Weather Advisory. |
Wind Chill Advisory | Wind chill temperatures reaching or exceeding locally defined advisory criteria, but remaining below warning criteria. |
Segment Type | Segment Description |
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Overview | The WSW overview section is optional. If included, it should contain at least an Overview Headline (a general headline statement that summarizes the hazardous weather threat, area affected and expected time of development) and/or an Overview Discussion (a brief, non-technical description of the developing winter storm event). |
Headline | Describes a hazardous winter weather event(s) and anticipated timing. |
Reasoning | In bullet-point format, includes winter weather element(s) prompting the watch, warning or advisory. Roughly one or two sentences, each point presents critical information for a winter weather event. Bullets can be locally or regionally defined in order to meet users needs, but should always include an impact. Bullet-types included can be any of the following: Hazard, Precipitation-Type, Quantitative Accumulations and/or Values, Timing, Location, Uncertainty, Temperatures, Winds, or others as appropriate. Any values provided will be generalized. |
Precautionary / Preparedness Actions | Brief (potential) impact or Call To Action (CTA) statements, safety rules describing what actions to take in preparing for a potential hazardous winter weather event. |
Winter Weather Type | Winter Weather Description |
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Blizzard | A blizzard means that the following conditions are expected to prevail for a period of 3 hours or longer: a). Sustained wind or frequent gusts to 35 miles an hour or greater and b). considerable falling and/or blowing snow, i.e., frequently reducing visibility below 1/4 mile. Although there is no set temperature requirement for blizzard conditions, the life-threatening nature of the low temperatures in combination with the other hazardous conditions of wind, snow, and poor visibility increases dramatically when the temperature falls below 20°F. |
Snow | Frozen precipitation in the form of (white or translucent) ice crystals that steadily falls for several hours or more. Qualifiers, such as occasional or intermittent, are used when a steady, prolonged (for several hours or more) fall is not expected. |
Blowing Snow | Blowing snow is snow lifted from the surface of the earth by the wind to a height of 6 feet or more above the surface (higher than drifting snow), and blown about in such quantities that horizontal visibility is reduced to less than 7 statute miles. Blowing snow is usually accompanied by drifting snow. |
Drifting Snow | Drifting snow is snow lifted from the surface of the earth by the wind to a height of less than 6 feet above the surface. Drifting snow may occur during or after a snowfall. Drifting snow is usually associated with blowing snow. |
Heavy Snow | Heavy Snow generally means: Snowfall accumulating to 4 inches or more in depth in 12 hours or less; or Snowfall accumulating to 6 inches or more in depth in 24 hours or less. |
Snow Flurries | Snow flurries are short duration (generally a few minutes) light snow showers with no measurable accumulation (trace category). |
Snow Showers | Snow showers are brief periods of snowfall in which intensity can be varied and may change rapidly. Some accumulation is possible. A snow shower in which light snow falls for a few minutes is typically called a snow flurry. |
Snow Squalls | Snow squalls are intense, but limited duration, periods of moderate to heavy snowfall, accompanied by strong, gusty surface winds and possibly lightning (generally moderate to heavy snow showers). Snow accumulation may be significant. Regional variation to this definition is expected. For example, close to the Great Lakes, snow squalls are usually locally intense, narrow bands of heavy snow that can extend over long distances, persist for many hours, and produce 6 inches or more of snow in 12 hours or less. |
Ice Storm | An ice storm is used to describe occasions when damaging accumulations of ice are expected during freezing rain situations. Significant accumulations of ice pull down trees and utility lines resulting in loss of power and communication. These accumulations of ice make walking and driving extremely dangerous. Significant ice accumulations are usually accumulations of 0.25 inch (one quarter of an inch) or greater. |
Sleet | Sleet is a type of precipitation consisting of transparent or translucent pellets of ice, 0.25 inch or less in diameter. These pellets of ice usually bounce when hitting hard ground and make a sound upon impact. |
Heavy Sleet | Heavy sleet is a relatively rare event defined as an accumulation of ice pellets covering the ground to a depth of 1/2 inch or more. |
Freezing Rain or Drizzle | Rain or drizzle that falls in liquid form but freezes upon impact with the ground or exposed objects. Small accumulations of ice can cause driving and walking difficulties while heavy accumulations produce extremely dangerous and damaging situations primarily by pulling down trees and utility lines. |
Wind Chill | The Wind Chill Temperature (WCT) is the air temperature at which the heat transfer rate and skin temperature would be the same in the absence of wind. The WCT represents the temperature the body feels when it is exposed to wind and cold. Prolonged exposure can lead to frostbite and hypothermia. |
Fire Weather Segment | Fire Weather Segment Description |
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Overview Headline(s) | General headline statement(s) that summarizes the Fire Weather threat, timing, reason for issuance, and area affected. |
Overview Discussion | an optional, brief, non-technical discussion of the focusing solely on the cause of the expected fire weather event. |
Headline | Describes the state of the RFW (issued, continued, canceled), the effective time of the event, critical weather element(s) causing the event, and the affected area. |
Bulleted Segments | Can include the Affected Area, Timing, Weather Element Forecast(s), Specific Impacts on fire threat and/or fire behavior. |
Precautionary / Preparedness Actions | Brief (potential) impact or Call To Action (CTA) statements, safety rules describing what actions to take in preparing for a potential hazardous fire weather event. |
Fire Weather Segment | Fire Weather Segment Description |
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Headlines | Required when RFWs and/or Fire Weather Watches are in effect. All headlines will include the warning type, location, reason for issuance, and effective time period. |
Discussion | A brief, clear, non-technical description of weather patterns that influence the weather in the forecast area. The emphasis of the discussion will be on the first two days of the forecast period, though latter periods may be included if significant weather is expected to impact safety or operations, and there is reasonable confidence the weather will occur. |
Forecast Period | Consisting of a minimum of three 12-hour time periods with a general outlook section valid to Day 5. Days 6 and 7 are optional. |
Sky / Weather | Following the same guidelines for sky/weather and weather descriptors as those used in the Public Zone Forecasts (ZFP). |
Max or Min Temperatures |
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Max or Min Relative Humidity (RH) |
Minimum RH will be forecast during the daytime and the maximum RH during the nighttime with ranges of 5 to 10 percent. Qualitative descriptions (poor, moderate, good) of nighttime humidity recovery may be included. |
Wind | Indicate the prevalent direction and speed of the wind for each time period approximating a 20 foot, 10 minute average. Maximum gusts, erratic winds, and wind shifts will be mentioned when deemed significant. |
Extended (days 6, 7 optional) |
The extended period may be located at the end of the FWF and reflect an outlook for the entire FWF area, or optionally, an extended period may be located at the end of each zone segment and reflect an outlook for that particular segment. Extended periods will especially focus on the winds. |
Watch Type | Watch Description |
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Excessive Heat Watch | Conditions are favorable for an excessive heat event to meet or exceed local Excessive Heat Warning criteria in the next 24 to 72 hours. |
Freeze Watch | Conditions are favorable for a freeze event to meet or exceed Freeze Warning criteria in the next 12 to 48 hours during the locally defined growing season. |
High Wind Watch | Conditions are favorable for a high wind event to meet or exceed High Wind Warning criteria in the next 12 to 48 hours. |
Extreme Cold Watch | Experimental product. Conditions are favorable for an extreme cold event to meet or exceed local Extreme Cold Warning criteria. |
Warning Type | Warning Description |
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Excessive Heat Warning | Heat Index (HI) values forecast to meet or exceed locally defined warning criteria for at least two days. |
Extreme Cold Warning | This is an experimental product for temperatures that are expected to drop to critical thresholds (locally set) usually with little or no wind. |
Freeze Warning | Minimum shelter temperature is forecast to be 32°F or less during the locally defined growing season. |
High Wind Warning | Wind speeds forecast to meet or exceed locally defined warning criteria. (Typical values are sustained wind speeds of 40 mph or greater lasting for 1 hour or longer, or winds of 58 mph or greater for any duration). |
Advisory Type | Advisory Description |
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Air Stagnation Advisory | Atmospheric conditions stable enough to cause air pollutants to accumulate in a given area. Criteria developed in conjunction with the local or state EPA and the product issued at their request. |
Dense Fog Advisory | Widespread or localized fog reducing visibilities to 1/4 mile or less. |
Dense Smoke Advisory | Widespread or localized smoke reducing visibilities to 1/4 mile or less. |
Freezing Fog Advisory | Very light ice accumulation from freezing fog. |
Frost Advisory | Minimum shelter temperature forecast to be 33 to 36°F during the locally defined growing season, on nights with good radiational cooling conditions (e.g., light winds and clear skies). |
Heat Advisory | Heat Index values forecast to meet or exceed locally defined advisory criteria for one to two days. |
Wind Advisory | Sustained wind speeds of 30 to 39 mph lasting for 1 hour or longer or locally defined. |
Segment Type | Segment Description |
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Headline | Describes a hazardous non-precipitation weather event(s) and anticipated timing. |
Reasoning | In bullet-point format, includes non-precipitation weather element(s) prompting the watch, warning or advisory. Roughly one or two sentences, each point presents critical information for a non-precipitation weather event. Bullets can be locally or regionally defined in order to meet users needs, but should always include an impact. Bullet-types included can be any of the following: Hazard, Threats, Impact Locations, Timing, or others as appropriate. Any values provided will be generalized. |
Precautionary / Preparedness Actions | Brief (potential) impact or Call To Action (CTA) statements, safety rules describing what actions to take in preparing for a potential hazardous winter weather event. |