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Snowsquall Warning
A snow squall warning ( SAME code: SQW) is a bulletin issued by Environment Canada's Meteorological Service of Canada and the National Weather Service in the United States to warn population of two types of snow events reducing visibility in blowing snow: ''lake effect'' ''snow squalls'' and ''frontal snow squalls''. Phenomenon Lake effect snow squalls are generated by cold arctic air moving over unfrozen water of lake or sea. These will reduce visibility to less than 1 km and produce large accumulations of snow on the ground along narrow corridors in lee of the waters. Duration of these events can extend for days. Frontal snow squalls are associated with a fast moving intense cold front in winter. Visibility must be reduce to less than 500 m, wind over 40 km/h with a wind shift. Quantities of snow is not important with this type but intensity is heavy for a short period, typically 10 to 20 minutes. Criteria Canada In Canada, snow squall warnings are issued for ... [...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] |
Shower (precipitation)
A shower is a mode of precipitation characterized by an abrupt start and end and by rapid variations in intensity. Often strong and short-lived, it comes from convective clouds, like cumulus congestus. A shower will produce rain if the temperature is above the freezing point in the cloud, or snow / ice pellets / snow pellets / hail if the temperature is below it at some point. In a meteorological observation, such as the METAR, they are noted SH giving respectively SHRA, SHSN, SHPL, SHGS and SHGR. Formation Convection occurs when the Earth's surface, especially within a conditionally unstable or moist atmosphere, becomes heated more than its surroundings and in turn leading to significant evaporation. The raised air parcel in a colder environment at altitude will cool but according to the adiabatic thermal gradient forming clouds, and later precipitation above the lifted condensation level (LCL). Depending on the Convective available potential energy (CAPE), the clouds will b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
