FACTOID # 22: South Dakota has the highest employment ratio in America, but the lowest median earnings of full-time male employees.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Ground blizzard
A ground blizzard in Ontario, March 21st, 2004
A ground blizzard in Ontario, March 21st, 2004

The term Ground Blizzard refers to a weather condition where loose snow or ice on the ground is lifted and blown by strong winds. The primary difference between a ground blizzard as opposed to a regular blizzard is that in a ground blizzard no precipitation is produced at the time, but rather all the precipitation is already present in the form of snow or ice at the surface of the earth. Image File history File linksMetadata DSC04049. ... Image File history File linksMetadata DSC04049. ... Weather is a term that encompasses phenomena in the atmosphere of a planet. ...

Contents

Meteorological Criteria

While the term ground blizzard is often associated with intense blowing and drifting snow conditions, there are specific criteria which must be met. Often such criteria will be determined by a country's governing weather agency or other similar body. In the U.S, according to the National Weather Service a blizzard is defined as having sustained winds or frequent gusts of 35 mph or more, visibility frequently below 1/4 mile in considerable snow and/or blowing snow, and the above conditions are expected to prevail for 3 hours or longer. Environment Canada similarly maintains that the temperature must be colder than 0°C, widespread reduction of visibility to less than 1 km due to snow and/or blowing snow and sustained wind speeds or gusts of 40 km/h or more, with all these conditions persisting for at least 4 hours (6 hours for the Northwest Territories and Nunavut).


Types of Ground Blizzards

There are 3 different forms of ground blizzards:

  1. In horizontal advection conditions, the winds blow across the surface of the earth with very little if any large-scale upward motion.
  2. In vertical advection conditions, the winds exhibit large-scale upward motion lifting the snow into the atmosphere creating drifting waves of snow up to 500 meters in height.
  3. In thermal-mechanical mixing conditions, massive convective rolls form in the atmosphere and the blizzard may be observed from space with the blizzards convective rolls creating waves of snow (also known as snow billows) resembling lake or ocean effect snow bands. The extreme conditions can quickly bury a two story home and make breathing very difficult if not impossible if caught outdoors.
    Strong advection rolls during a ground blizzard in North Dakota, January 15th, 1997
    Strong advection rolls during a ground blizzard in North Dakota, January 15th, 1997

Image File history File links Blowing_snow. ... Image File history File links Blowing_snow. ...

Climatology

Ground Blizzards occur throughout the world, however unlike other winter storms, topography either aids in their formation or prevention. The most important topographic element in a blizzard is the requirement for a vast amount of large open and relatively flat land. Any type of flora, especially coniferous forms, will catch any drifting snow significantly reducing the blizzards effects. The environment must also support temperatures cold enough to prevent any snow on the ground from melting and bonding the ice crystals together.


Ground Blizzards are most common in the Arctic and Antarctic during seasonal transition periods, such as the spring and fall. Ground Blizzards are also common in the Canadian Prairies and U.S Midwest as well as Siberia and Northern China.


Famous Ground Blizzards

Great Lakes Blizzard of 1977 To meet Wikipedias quality standards, this article may require cleanup. ...


External links


 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m