Severe thunderstorm warning

Severe thunderstorm warning

:"See Severe weather terminology for a comprehensive article on this term and related weather terms."

A severe thunderstorm warning is issued when trained Skywarn spotters or a Doppler capable weather radar indicate a strong thunderstorm is producing dangerously large hail or high winds, capable of causing significant damage. It does not account for lightning or flooding. A warning must not be confused with a severe thunderstorm watch.

In the U.S., the National Weather Service defines a severe thunderstorm as having large hail being at least ¾ inch (19 mm) in diameter, high winds as being 58 miles per hour (93 km/h) or greater, producing tornadoes, or any combination of the three.In Canada, a severe thunderstorm has one or more of the following:

*wind gusts of >90 km/h
*hail with a diameter of >20 mm
*rainfall of >50 mm in an hour or >75 mm in three hours
*tornadoes

A severe thunderstorm warning means there is significant danger for the warned area. Occasionally, severe thunderstorms can and do produce a tornado without warning. While not all severe thunderstorms produce tornadoes, they can produce serious wind damage as severe as a tornado. A severe thunderstorm warning can also be upgraded to a tornado warning if a tornado is detected on radar or actually spotted. Generally, but not always, a severe thunderstorm watch or tornado watch will precede a warning.

Some storms, especially in the Great Plains, may produce massive hailstones the size of baseballs or even grapefruits, falling fast enough to kill a person by repeated blunt trauma. Everyone in the path of such a storm should take cover immediately, as it is very dangerous and possibly life-threatening.

In the United States, the National Weather Service issues warnings for tornadoes and severe thunderstorms in polygon shapes. Warnings are usually delineated by county or by a section of a county.

A similar warning is issued by Environment Canada's Meteorological Service of Canada from their offices in Vancouver, Edmonton, Toronto, Montreal and Dartmouth.

Example of a Severe Thunderstorm Warning

An example of a Severe Thunderstorm Warning issued by the National Weather Service in the United States.

SEVERE THUNDERSTORM WARNINGOHC035-153-080300-/O.NEW.KCLE.SV.W.0206.070808T0200Z-070808T0300Z/

BULLETIN - EAS ACTIVATION REQUESTEDSEVERE THUNDERSTORM WARNINGNATIONAL WEATHER SERVICE CLEVELAND OH1000 PM EDT TUE AUG 7 2007

THE NATIONAL WEATHER SERVICE IN CLEVELAND HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR... CUYAHOGA COUNTY IN NORTHEAST OHIO SUMMIT COUNTY IN NORTHEAST OHIO

* UNTIL 1100 PM EDT

* AT 950 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR NORTH ROYALTON...OR ABOUT 11 MILES NORTH OF MEDINA...AND MOVING EAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MACEDONIA...TWINSBURG AND SOLON

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPAREIMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUDTO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

LAT...LON 4146 8139 4127 8139 4126 8138 4126 8140 4126 8151 4125 8167 4128 8168 4128 8179 4137 8182

$$

FITZ

External links

* [http://www.msc-smc.ec.gc.ca/cd/brochures/warning_e.cfm? Meteorological Service of Canada]
* [http://www.nws.noaa.gov United States National Weather Service]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Severe thunderstorm watch — A severe thunderstorm watch (SAME code: SVA; sometimes referred to as yellow box by meteorologists and storm chasers) is issued when weather conditions are favorable for the development of severe thunderstorms. If the thunderstorms are forecast… …   Wikipedia

  • Severe weather — is any destructive weather phenomenon. The term is usually used to refer to severe thunderstorms and related phenomena, such as tornados, hail, and downbursts. [ [http://amsglossary.allenpress.com/glossary/search?p=1 query=severe+weather… …   Wikipedia

  • Severe weather terminology (United States) — This article describes the United States National Weather Service (NWS) severe weather terminology. The NWS defines precise meanings for nearly all its weather terms. This article describes NWS terminology and related NWS weather scales. Some… …   Wikipedia

  • Thunderstorm — Electrical storm redirects here. For other uses, see Electrical storm (disambiguation). A typical thunderstorm A thunderstorm, also known as an electrical storm, a lightning storm, thundershower or simply a storm is a form of weather… …   Wikipedia

  • Severe weather terminology (Canada) — This article describes Severe weather terminology used by the Environment Canada s Meteorological Service of Canada. This article focuses on terminology per se, such as tornado warning. Related weather scales and general weather terms are also… …   Wikipedia

  • Tornado warning — A tornado warning is an alert issued by government weather services to warn an area that a tornado may be imminent. It can be issued after either a tornado or funnel cloud has already been spotted, or if there are radar indications that a tornado …   Wikipedia

  • 2003 Melbourne thunderstorm — The 2003 Melbourne thunderstorm was a severe weather event that occurred over the city of Melbourne, Australia, and surrounding areas of Victoria, from 1 December to 6 December 2003. The Australian Bureau of Meteorology called the storm a once in …   Wikipedia

  • Storm warning — A storm warning generally refers to an advisory issued by an official meteorological department to warn citizens of approaching dangerous weather. A storm watch, on the other hand, typically refers to an advisory issued to indicate that… …   Wikipedia

  • Coastal flood warning — A Coastal Flood Warning is issued by the National Weather Service of the United States when coastal flooding is either imminent or occurring along the coast of the Atlantic Ocean, Pacific Ocean, or the Gulf of Mexico. The flooding must be due to… …   Wikipedia

  • Late-May 1998 tornado outbreak and derecho — The Late May 1998 Tornado Outbreak and Derecho was a historic tornado outbreak and derecho that began on the afternoon of May 30 extending throughout May 31, 1998, across a large portion of the northern half of the United States and southern… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”