“Extreme wind warning”的意思、由来-开放百科全书

An extreme wind warning (SAME code EWW) is an alert issued by the National Weather Service for areas are experiencing or could experience 100 knots (115 mph, 185 km/h, 51 m/s) within an hour due to the landfall of a powerful hurricane.^[1] EWWs are intended to provide guidance to the general public at a county or sub-county level of winds that could pose a significant threat of casualties. Their issuance is intended to cover as precise of an area as possible and can be issued no prior than two hours before the onset of extreme winds.^[2]

The motivation to create a short-fused warning for extreme winds began after Hurricane Charley and Hurricane Jeanne struck Florida in 2004. During the passage of Charley across the state, strong winds prompted the National Weather Service weather forecast office in Melbourne, Florida to issue a special bulletin advising immediate action due to the onset of life-threatening winds by embedding the bulletin within a tornado warning, thus giving the bulletin higher visibility and urgency. The forecast office also issued similar "tornado" warnings as the strong winds of Jeanne moved ashore from the east later that year.^[3] The nonconventional usage of tornado warnings for extreme hurricane winds was praised by emergency management, citing it as an ingenious method of protecting lives.^[3] In December 2004, the Melbourne forecast office briefed attendees at an annual NOAA Hurricane Conference on their use of the special tornado warning, advocating and eventually reaching consensus for a specialized official National Weather Service product for extreme winds.^[4]

The new warning was standardized in its experimental stages in 2005, so weather forecast offices continued to use special tornado warnings to broadcast the threat of severe wind during the landfalls of Hurricanes Dennis, Katrina, Rita, and Wilma. The wind and temporal thresholds that eventually became a part of extreme wind warnings were also used as thresholds for these special tornado warnings in 2005.^[2] The warnings, termed Extreme Tropical Cyclone Destructive Wind Warnings, advised residents to take sturdy shelter in the interior portions of well-built structures. During Katrina, the weather services serving the Jackson and New Orleans and Baton Rouge, Louisiana issued 19 warnings. Public response to these warnings was mixed, praising their specificity but finding their placement within tornado warnings confusing, particularly when they were issued near traditional tornado warnings. The advice of taking interior low-level shelter given in the wind warnings also contradicted the advice given in Hurricane Local Statements of taking interior shelter in elevated floors for storm surge-prone areas. NOAA/NWS recommendations called for the development of an extreme wind warning independent from tornado warnings and increased outreach for the warning.^[3]

The following year, extreme wind warnings continued to be packaged within special tornado warnings for public evaluation,^[5] and the warning became its own official independent product by the 2007 Atlantic hurricane season,^[6] though no hurricane would trigger an extreme wind warning for nearly another decade. Despite the newly independent warning system, until the 2015 Atlantic hurricane season, the Emergency Alert System continued to broadcast EWWs as tornado warnings (using the TOR event code).^[3] On the morning of October 7, 2016, the nearby passage of Category 3 Hurricane Matthew just off of Cape Canaveral prompted the first issuance of an extreme wind warning.^[7]

Examples

This Extreme Wind Warning was issued by the National Weather Service in Melbourne during the passage of Hurricane Matthew.

BULLETIN - EAS ACTIVATION REQUESTEDEXTREME WIND WARNINGNATIONAL WEATHER SERVICE MELBOURNE FL526 AM EDT FRI OCT 7 2016THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A* EXTREME WIND WARNING FOR... NORTHEASTERN BREVARD COUNTY IN FLORIDA...* UNTIL 715 AM EDT* AT 521 AM EDT...SURFACE OBSERVATIONS AND DOPPLER RADAR INDICATEDEXTREME WINDS... ASSOCIATED WITH THE EYEWALL OF HURRICANE MATTHEWWERE ABOUT TO MOVE ONSHORE CAPE CANAVERAL INCLUDING PORT CANAVERALAND MOVING NORTH-NORTHWEST AT 15 MPH. THIS IS AN EXTREMELYDANGEROUS AND LIFE-THREATENING SITUATION!PRECAUTIONARY/PREPAREDNESS ACTIONS...FREQUENT DESTRUCTIVE WIND GUSTS TO AROUND 115 MPH WILL SPREAD ACROSSTHE CAPE CANAVERAL AREA...PRODUCING SWATHS OF TORNADO-LIKE DAMAGE.A WIND GUST OF 100 MPH WAS RECENTLY RECORDED AT THE TIP OF CAPECANAVERAL.

This Extreme Wind Warning was issued by the National Weather Service in Corpus Christi in association with Hurricane Harvey prior to landfall.

BULLETIN - EAS ACTIVATION REQUESTEDExtreme Wind WarningNational Weather Service Corpus Christi TX456 PM CDT FRI AUG 25 2017The National Weather Service in Corpus Christi has issued a* Extreme Wind Warning for... Southwestern Calhoun County in south Texas... Aransas County in south central Texas... East central Nueces County in south central Texas... Eastern San Patricio County in south central Texas... Central Refugio County in south central Texas...* Until 700 PM CDT* At 454 PM CDT, National Weather Service Doppler radar indicated extreme winds, associated with the eyewall of Hurricane Harvey, were moving onshore 17 miles east of Key Allegro, or 18 miles east of Rockport, moving northwest at 25 mph. This is an extremely dangerous and life-threatening situation!PRECAUTIONARY/PREPAREDNESS ACTIONS...Widespread destructive winds of 115 to 145 mph will spread acrossCalhoun County, Aransas County, Nueces County, San PatricioCounty, Refugio County, producing swaths of tornado-like damage.TAKE COVER NOW! Treat these imminent extreme winds as if a tornadowas approaching and move immediately to the safe room in yourshelter. Take action now to protect your life!

This Extreme Wind Warning was issued by the National Weather Service in San Juan, Puerto Rico in association with Hurricane Irma.

BULLETIN - EAS ACTIVATION REQUESTEDExtreme Wind WarningNational Weather Service San Juan PR1116 AM AST WED SEP 6 2017The National Weather Service in San Juan has issued a* Extreme Wind Warning for... Saint John in Virgin Islands... Saint Thomas in Virgin Islands...* Until 115 PM AST* At 1114 AM AST, National Weather Service Doppler radar indicated extreme winds, associated with the eyewall of Major Hurricane Irma, about to move over St John, moving west at 20 mph. This extreme winds will affect St John and St Thomas through 100 PM AST. This is an extremely dangerous and life-threatening situation!PRECAUTIONARY/PREPAREDNESS ACTIONS...TAKE COVER NOW! Treat these imminent extreme winds as if a tornadowas approaching and move immediately to the safe room in yourshelter. Take action now to protect your life!The safest place to be during a major landfalling hurricane is in areinforced interior room away from windows. Get under a table orother piece of sturdy furniture. Use mattresses, blankets or pillowsto cover your head and body. Remain in place through the passage ofthese life-threatening conditions.

This Extreme Wind Warning was issued by the National Weather Service in San Juan in association with Hurricane Maria prior to landfall.

BULLETIN - EAS ACTIVATION REQUESTEDExtreme Wind WarningNational Weather Service San Juan PR538 AM AST WED SEP 20 2017The National Weather Service in San Juan has issued a* Extreme Wind Warning for... Trujillo Alto Municipality in Puerto Rico... Rio Grande Municipality in Puerto Rico... San Juan Municipality in Puerto Rico... Aguas Buenas Municipality in Puerto Rico... Carolina Municipality in Puerto Rico... Canovanas Municipality in Puerto Rico... Guaynabo Municipality in Puerto Rico... Bayamon Municipality in Puerto Rico... Cidra Municipality in Puerto Rico...* Until 700 AM AST* At 533 AM AST, National Weather Service Doppler radar indicated extreme winds, associated with the eyewall of Major Hurricane Maria already moving onshore and will quickly impact Rio Grande, Canovanas, Aguas Buenas, Cidra and the San Juan Metro Area within the next hour. This is an extremely dangerous and life-threatening situation!PRECAUTIONARY/PREPAREDNESS ACTIONS...TAKE COVER NOW! Move immediately to the safe room in your shelter.Take action now to protect your life!The safest place to be during a major landfalling hurricane is in areinforced interior room away from windows. Get under a table orother piece of sturdy furniture. Use mattresses, blankets or pillowsto cover your head and body. Remain in place through the passage ofthese life-threatening conditions.

This Extreme Wind Warning was issued by the National Weather Service in Tallahassee in association with Hurricane Michael prior to landfall.

BULLETIN - EAS ACTIVATION REQUESTEDExtreme Wind WarningNational Weather Service Tallahassee FL1111 AM EDT WED OCT 10 2018The National Weather Service in Tallahassee has issued a* Extreme Wind Warning for... Gulf County in the Panhandle of Florida... Southern Bay County in the Panhandle of Florida... Southwestern Franklin County in Big Bend of Florida...* Until 215 PM EDT/115 PM CDT/.* At 1109 AM EDT/1009 AM CDT/, National Weather Service Doppler radar indicated extreme winds in excess of 130 mph, associated with the eyewall of Hurricane Michael, were moving onshore. THIS IS AN EXTREMELY DANGEROUS AND LIFE-THREATENING SITUATION!PRECAUTIONARY/PREPAREDNESS ACTIONS...TAKE COVER NOW! Treat these imminent extreme winds as if a tornadowas approaching and move immediately to the safe room in yourshelter. Take action now to protect your life!

Examples

See also

References