Weather Forecast Offices (WFOs) issue SVRs to provide the public and emergency managers with advance notice of damaging wind gusts and large hail. WFOs will issue SVRs when there is radar or satellite indication and/or reliable reports of wind gusts equal to or in excess of 50 knots (58 mph) and/or hail size of one inch (U.S. quarter-size) diameter or larger. WFOs may issue SVRs for a convective squall with little or no lightning that otherwise meet or exceed hail or wind warning criterion.

SVRs have valid time issuances of 30 to 60 minutes. For thunderstorms that are expected to remain severe beyond the valid time of the original warning, WFOs will issue a new warning.

SVRs will follow a standard bullet-style format with brief points of information, including:

• Type of warning (i.e., damaging wind and/or hail)
• Expiration time of the warning
• Locations used to identify threatened areas (i.e., larger towns, familiar landmarks, states, counties, mileage markers)
• Basis for warning; forecast impacts including hail sizes and wind gusts
• torm motion, in some instances pathcasts (during instances of when a forecaster has high confidence in the movement of hazardous weather)
• Call-to-Action statements (Precaution / Preparedness Actions)

SVRs will also, at times, include the following:

• The possibility of tornadoes if a Tornado Watch is in effect
• Recent credible reports of severe hail, wind gusts, or damage due to hail or wind

If a severe thunderstorm moves over coastal waters, then a Special Marine Warning will be issued.

Flash flood warnings are issued when flooding is imminent or likely. This product will be reserved for those short-term events which require immediate action to protect life and property, such as dangerous small stream or urban flooding and dam or levee failures. The geographic area covered, which is defined by a polygon, may be all or a portion of one or more counties, a river/stream basin, or any other type of definable area (e.g., a specific valley).

A flash flood warning will be issued for a geographical area defined by a polygon in a WFOs CWFA when:

• Flash flooding is reported; and/or
• A dam or levee failure is imminent or occurring; and/or
• A sudden failure of a naturally-caused stream obstruction (including debris slide, avalanche, or ice jam) is imminent or occurring, and/or
• Precipitation capable of causing flash flooding is indicated by radar, rain gages, and/or satellite; and/or
• Precipitation as indicated by radar, rain gages, satellite and/or other guidance is capable of causing debris flows, particularly (but not only) in burn areas; and/or
• Local monitoring and prediction tools indicate flash flooding is likely; and/or
• A hydrologic model indicates flash flooding for locations on small streams, or
• A previously issued flash flood warning needs to be extended in time, or
• Flash flooding is imminent or occurring in a geographical area currently not under a valid flash flood warning.

Flash flood warnings use a bullet format and will include:

• The immediate cause followed by the geographic areas of concern.
• Basis for the warning and expected impacts.
• Pathcast i.e., forecast timing of the flood with specific locations to be affected and the most flood-prone areas.
• Call-to-action statements will focus on avoiding flood dangers and not include instructions on how to escape from vehicles caught in flood waters.

Examples of situations which warrant the inclusion of flash flood emergency language in flash flood warnings may include but are not limited to:

• Declared states of emergency and confirmation of rapidly rising flood waters are placing or will place people in life-threatening situations.

• Water has rapidly risen or will rapidly rise to levels where people who are ordinarily in safe locations during previous flash flood events are now placed in life-threatening situations.

• Multiple swift water rescue teams have been or are being deployed in response to flash flooding of an exceptional magnitude.

• Stream gages, where available, indicate flood waters have risen rapidly to at least major levels or if gages are not available, flood waters have risen to levels rarely if ever seen.

• Total failure of a major high hazard dam that would have a catastrophic impact on the downstream communities.

Special Weather Statements (SPS) provide the public with information concerning ongoing or imminent weather hazards, which require a heightened level of awareness or action. Although typically used for hazards within 6 hours of product issuance, the SPS may also be used to heighten the awareness of a major event forecast to occur beyond 6 hours. The criteria are dependent on the situation for which the SPS is issued. Issuance criteria guidelines by weather hazard are as follows:

Threat	Description
Developing Hazardous Convective Weather	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.
Sub-Severe Thunderstorms	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: Sustained winds or gusts of 40 to 57 mph (lower values may be used at forecaster’s discretion) Hail less than 1 inch in diameter Frequent to continuous lightning Funnel clouds not expected to become a tornado threat
Other Short-Term Hazards	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: “black ice” short-duration heavy snow bands lake-effect snow bands that briefly reduce visibility heavy rainfall that is not expected to cause flooding heat indices or wind chill near “advisory” level for an hour or two local areas of blowing dust where wind is below advisory criteria
Major Events Forecast to Occur Beyond 6 Hours	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.

Severe Weather Statements (SVSs) provide the public and emergency managers with updated information for specific Severe Thunderstorm and Tornado Warnings. Updated information includes reports of observed severe weather. They also inform the public and emergency managers when all or portions of a warning have been canceled or have expired.

The following guidelines apply to the issuance of SVSs by Weather Forecast Offices (WFOs):

• Cancellations – WFOs will issue a SVS to provide notice a SVR or TOR has been canceled for all or portions of the warned area
• Updates – WFOs will issue SVSs at least once during the valid time of a SVR or TOR
• Corrections – WFOs will issue a SVS to notify users of erroneous counties included in the original SVR or TOR have been removed
• Expirations – WFOs may issue a SVS to provide notice that a SVR or TOR has expired

The following Guidelines apply to the issuance of SVSs by WFOs:

• WFOs will issue SVSs to address the status of severe weather warnings
• WFOs will not use SVSs to expand in area or extend the valid time of TORs and SVRs
• If the threat of severe weather clears a significant portion of the SVR or TOR during the warning period, forecasters will update the warned area

SVSs will follow free-text format that shall include the following:

• Type of warning (i.e., damaging wind and/or hail)
• Expiration time of the warning
• Locations used to identify threatened areas (i.e., larger towns, familiar landmarks, states, counties, mileage markers)
• Basis for warning; forecast impacts including a tornado, hail sizes and/or wind gusts
• Storm motion, in some instances pathcasts (during instances of when a forecaster has high confidence in the movement of hazardous weather)
• Concise Call-to-Action statements (Precaution / Preparedness Actions)

SVSs will also, at times, include the following:

• The possibility of tornadoes if a Tornado Watch is in effect
• Recent credible reports of a tornado, severe hail, wind gusts, or damage due to a tornado, hail and/or wind

In exceedingly rare situations within a SVS, WFOs may use the terminology of “Tornado Emergency” and will use specific “Impacted Locations” such as cities, towns, and/or well-known landmarks. This can also include “Surrounding Areas”. Use of such terminology is appropriate for the tornadic situation if all of the following criteria are met:

• Severe threat to human life is imminent or ongoing

• Catastrophic damage is imminent or ongoing

• Reliable sources confirm the tornado either visually and/or radar imagery strongly suggests the existance of a damaging tornado (i.e., debris ball signature)

Flood advisories for forecast points provide information on elevated river/stream flows as indexed by observations and/or forecasts at specific locations, when such events warrant notification of the public in a product less urgent than a warning. Flood advisories may be issued for forecast points in an HSA when:

• Elevated stream flow (excluding rivers and streams which are above flood stage or to exceed flood stage) warranting public notification occurs or is more than 80% likely to occur at one or more locations.
• One or more forecast points are already covered by an existing advisory, but an advisory needs to be issued for additional forecast points.
• Providing updated hydrometeorological information on a previously issued advisory.

An optional general overview/synopsis section may be provided at the top of the product which will contain at least one of the following:

• General Overview Headline – One or more headlines summarizing the current flood situation, affected locations/areas including the list of rivers and forecast points impacted, and the expected duration (if known).
• General Synopsis – a brief, non-technical description of the flood situation and contributing hydrometeorological factors.

This is followed by the segmented follow-up information section for each of the forecast points which will include the following:

• Headline summarizing the current situation (optional).

• The action lead-in phrase providing the immediate cause for the flood advisory followed by a list of iver/stream and/or forecast point names impacted.

• Event beginning and end times, when appropriate.

• Basis for warning and expected impacts.

• Call-to-action statements will focus on avoiding flood dangers and not include instructions on how to escape from vehicles caught in flood waters (for continuation segments).

An areal advisory provides information on elevated river/stream flow or ponding of water in a geographic area, when such an event warrants notification of the public in a product less urgent than a warning.

Five types of areal advisories are issued under the flood statement identifier:

• Urban and Small Stream Flood Advisories
• Arroyo and Small Stream Flood Advisories
• Small Stream Flood Advisoriess
• Flood Advisories
• Hydrologic Advisories

Areal advisories will be issued for a geographical area defined by a polygon in a WFO’s CWFA when:

• Elevated stream flow or ponding of water occurs or is more than 80% likely to occur which warrants public notification.
• An advisory needs to be issued for a geographical area currently not under a valid flood advisory.
• Updated hydrometeorological information needs to be provided on an existing advisory.

An optional general overview/synopsis section may be provided at the top of the product which will contain at least one of the following:

• General Overview Headline – One or more headlines summarizing the current flood situation, affected locations/areas impacted, and the expected duration (if known).
• General Synopsis – a brief, non-technical description of the flood situation and contributing hydrometeorological factors.

This is followed by the segmented follow-up information section for each of the forecast points which will include the following:

• Action lead-in phrase for the cause of the flooding followed by the geographic area of concern.

• Type of advisory (i.e., Urban and Small Stream)

• Event beginning and end times, when appropriate.

• Basis for the advisory and expected impacts.

• Call-to-action statements will focus on avoiding flood dangers and not include instructions on how to escape from vehicles caught in flood waters (for continuation segments).

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.

Wind chill temperatures reaching or exceeding locally defined warning criteria.

Conditions are favorable for wind chill temperatures to meet or exceed local Wind Chill Warning criteria.

Wind chill temperatures reaching or exceeding locally defined advisory criteria, but remaining below warning criteria.

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.

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.