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Winter Storm Warning
A winter storm warning ( SAME code: WSW) is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public that a winter storm is occurring or is about to occur in the area, usually within 36 hours of the storm's onset. A similar warning is issued by Environment and Climate Change Canada (ECCC) through local forecast offices of the Meteorological Service of Canada. Definition Generally, a Winter Storm Warning is issued if the following criteria, at minimum, are forecast: snow accumulations usually between or greater than , or snow accumulations of usually or more with significant accumulation of ice ( sleet or freezing rain). In the Southern United States, where severe winter weather is much less common and any snow is a more significant event, warning criteria are lower, as low as in the southernmost areas: as one goes from north to south, the accumulation estimates needed to meet warning crit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Area Message Encoding
Specific Area Message Encoding (SAME) is a protocol used for framing and classification of broadcast emergency warning messages. It was developed by the United States National Weather Service for use on its NOAA Weather Radio (NWR) network, and was later adopted by the Federal Communications Commission for the Emergency Alert System, then subsequently by Environment Canada for use on its Weatheradio Canada service. It is also used to set off receivers in Mexico City and surrounding areas as part of the Mexican Seismic Alert System (SASMEX). History From the 1960s to the 1980s, a special feature of the NOAA Weather Radio (NWR) system was the transmission of a single attention tone prior to the broadcast of any message alerting the general public of significant weather events. This became known as the Warning Alarm Tone (WAT). Although it served NWR well, there were many drawbacks. Without staff at media facilities to manually evaluate the need to rebroadcast an NWR message using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winter Weather Advisory
A winter weather advisory (originally identified as a Traveler's Advisory until the 2002-03 climatological winter when officially renamed, and informally as such by some local television stations thereafter) is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service in the United States when one or more types of winter precipitation—snow, rain and snow mixed, freezing rain, sleet, graupel, etc.—presenting a hazard, but not expected to produce accumulations meeting storm warning criteria (usually below 10 cm / 4 inches), are forecast within 36 hours of the expected onset of precipitation or are occurring in the advisory's coverage area. A Winter Weather Advisory is similar to a significant weather advisory, but a winter weather advisory is an official product and is specific to cold weather. A similar warning is issued by Environment and Climate Change Canada's Meteorological Service of Canada offices. The advisory criteria vary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Advisory
A wind advisory is generally issued by the National Weather Service of the United States when there are sustained thunderstorm winds of and/or gusts of over land. Winds over the said cap will trigger high wind alerts rather than a wind advisory. The advisory is site specific, but winds of this magnitude occurring over an area that frequently experiences such wind speeds on a basis will not trigger a wind advisory. A slightly lower wind speed in areas around lakes may trigger a Lake wind advisory instead. Example The following is an example of a Wind Advisory issued by the National Weather Service Office in Norman, Oklahoma on Sunday November 25, 2018. URGENT - WEATHER MESSAGE...UPDATED National Weather Service Norman OK 1147 AM CST Sun Nov 25 2018 OKZ004>024-033>038-TXZ083>085-087-088-252100- /O.CON.KOUN.WI.Y.0019.000000T0000Z-181125T2100Z/ Harper-Woods-Alfalfa-Grant-Kay-Ellis-Woodward-Major-Garfield- Noble-Roger Mills-Dewey-Custer-Blaine-Kingfisher-Logan-Payne- Beckham-Washit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Effect Snow Warning
A lake effect snow warning is a bulletin issued by the National Weather Service in the United States to warn of heavy snowfall accumulations that are imminent from convective snow generated by very cold airmass passing over unfrozen lakes (lake effect snow). The criteria for amounts may vary significantly over different county warning areas. On October 2, 2017, some National Weather Service Forecast Offices discontinued issuing the Lake Effect Snow Warning, and consolidated it with the Winter Storm Warning. On October 15, 2018, the National Weather Service discontinued issuing Lake Effect Snow Warnings nationwide all together, and all offices consolidated it with the Winter Storm Warning. Lake effect snow warnings were reinstated for the 2019–20 winter season. Environment Canada's Meteorological Service of Canada issues similar warnings but they are called '' snowsquall warnings''. Examples 879 WWUS41 KBUF 171935 WSWBUF URGENT - WINTER WEATHER MESSAGE National Weathe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake-effect Snow
Lake-effect snow is produced during cooler atmospheric conditions when a cold air mass moves across long expanses of warmer lake water. The lower layer of air, heated up by the lake water, picks up water vapor from the lake and rises up through the colder air above. The vapor then freezes and is deposited on the leeward (downwind) shores. The same effect also occurs over bodies of saline water, when it is termed ocean-effect or bay-effect snow. The effect is enhanced when the moving air mass is uplifted by the orographic influence of higher elevations on the downwind shores. This uplifting can produce narrow but very intense bands of precipitation, which deposit at a rate of many inches of snow each hour, often resulting in a large amount of total snowfall. The areas affected by lake-effect snow are called snowbelts. These include areas east of the Great Lakes in North America, the west coasts of northern Japan, the Kamchatka Peninsula in Russia, and areas near the Great S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy Snow Warning
A heavy snow warning was a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service (NWS) in the United States which indicates a high rate of snowfall was occurring or was forecast to occur. Generally, the warning was issued for snowfall rates of or more in 12 hours, or or more in 24 hours. This warning was discontinued beginning with the 2008–09 winter storm season, replaced by the winter storm warning for heavy snow. In Canada, comparable warnings were issued by Environment Canada through the Meteorological Service of Canada (MSC). Example of a heavy snow warning URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE FAIRBANKS AK 221 PM AST SUN DEC 9 2007 .A STORM SYSTEM MOVING NORTH OVER THE CENTRAL BERING SEA WILL MOVE TO SOUTHWEST OF SAINT LAWRENCE ISLAND MONDAY AFTERNOON. THE STORM WILL BRING SNOW AND EAST WINDS OF 30 TO 45 MPH TONIGHT OVER MUCH OF WESTERN ALASKA FROM THE YUKON DELTA TO THE SEWARD PENINSULA TON ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Chill
Wind chill or windchill (popularly wind chill factor) is the lowering of body temperature due to the passing-flow of lower-temperature air. Wind chill numbers are always lower than the air temperature for values where the formula is valid. When the apparent temperature is higher than the air temperature, the heat index is used instead. Explanation A surface loses heat through conduction, evaporation, convection, and radiation. The rate of convection depends on both the difference in temperature between the surface and the fluid surrounding it and the velocity of that fluid with respect to the surface. As convection from a warm surface heats the air around it, an insulating boundary layer of warm air forms against the surface. Moving air disrupts this boundary layer, or epiclimate, allowing for cooler air to replace the warm air against the surface. The faster the wind speed, the more readily the surface cools. Alternative approaches Many formulas exist for wind chill beca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Chill Warning
A wind chill warning is a hazardous weather statement issued by local forecast offices of the National Weather Service (NWS) in the United States and previously by the Meteorological Service of Environment and Climate Change Canada (ECCC) when wind chills are forecast to reach values low enough for residents and travelers to be susceptible to life-threatening medical conditions (such as severe frostbite and hypothermia) or death associated with accelerated body heat loss. Extreme wind chills meeting Wind Chill Warning criteria can generate a significant decrease in body temperature, and induce frostbite damage to exposed skin and other tissue over an accelerated period of time (onsetting within as little as 10 to 15 minutes in severe cases). People within the warned area are advised to avoid venturing outdoors unless conducting necessary travel; if going outside, extra precaution should be taken against the likelihood of developing hypothermia and frostbite by wearing multiple la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Chill Advisory
A wind chill advisory is a hazardous weather statement issued by Weather Forecast Offices (WFO) of the National Weather Service (NWS) in the United States to alert the public that wind chills are forecast to reach values low enough that it poses a threat to human health and life if adequate protection is not taken against hypothermia and frostbite. The exact criteria meriting the issuance of an advisory varies from state to state, and areas prone to colder temperatures will often require the wind chill to be lower before issuing an advisory. Example The following is an example of a wind chill advisory issued by the National Weather Service office in Detroit, Michigan. 920 WWUS43 KDTX 212131 WSWDTX URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI 431 PM EST FRI JAN 21 2011 ...EXTREME COLD WIND CHILLS TONIGHT... .COLD TEMPERATURES IN ADDITION TO WINDS INCREASING TONIGHT AHEAD OF A LOW PRESSURE SYSTEM WILL ALLOW WIND CHILLS TO DROP BETWEEN -15 AND -20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freezing Rain Advisory
A freezing rain advisory was an advisory issued by the National Weather Service in the United States when freezing rain or freezing drizzle was expected to cause significant inconveniences, but did not meet warning criteria (typically greater than of ice accumulation). On October 2, 2017, issuance of the freezing rain advisory was discontinued. A winter weather advisory is now issued when the above criteria are forecast to be met. However, ice storm warnings continue to be issued. Example Freezing Rain Advisory URGENT - WINTER WEATHER MESSAGE NATIONAL WEATHER SERVICE GOODLAND KS 248 AM MST THU DEC 18 2008 ...FREEZING DRIZZLE AND FREEZING FOG EXPECTED TO DEVELOP TODAY... .AN UPPER LEVEL STORM SYSTEM WILL MOVE INTO THE CENTRAL HIGH PLAINS TODAY. AS WARM AIR ALOFT OVERRIDES COLD AIR AT THE SURFACE...FREEZING DRIZZLE AND FREEZING FOG WILL DEVELOP. WHILE WIDESPREAD ACCUMULATIONS OF ICE ARE NOT ANTICIPATED...TRAVEL COULD BECOME HAZARDOUS AS ICY SPOTS DEVELOP ON THE ROADS A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ice Storm Warning
An ice storm warning is a hazardous weather statement issued by the Weather Forecast Offices of the National Weather Service in the United States which indicates that freezing rain produces a significant and possibly damaging accumulation of ice on surfaces. The criteria for this warning vary from state to state, but typically an ice storm warning will be issued any time more than of ice at peak is expected to accumulate in an area, else a freezing rain or drizzle advisory is issued; in some areas, the criterion is instead. Prior to October 2017, a freezing rain advisory or freezing drizzle advisory was issued when a small amount of icing was possible. In Canada, a freezing rain warning has the same meaning. Example of an ice storm warning 632 WWUS44 KLZK 200235 WSWLZK URGENT - WINTER WEATHER MESSAGE National Weather Service Little Rock AR 835 PM CST Tue Feb 19 2019 ARZ003-012-013-200600- /O.UPG.KLZK.WW.Y.0004.000000T0000Z-190220T0600Z/ /O.NEW.KLZK.IS.W.0001.190220T0235Z-1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Weather Service
The National Weather Service (NWS) is an Government agency, agency of the Federal government of the United States, United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce, Department of Commerce, and is headquartered in Silver Spring, Maryland, Silver Spring, Maryland, within the Washington metropolitan area. The agency was known as the United States Weather Bureau from 1890 until it adopted its current name in 1970. The NWS performs its primary task through a collection of national and regional centers, and 122 local List of National Weather Service Weather Forecast Offices, Weather Forecast Offices (WFOs). As the NWS is an agency of the U.S. federal government, most o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
