Winter Storms and the Weather Maps That Depict Them

The winter climate is upon us, and much of the nation has already experienced some degree of winter weather. Winter weather creates an ideal teachable moment…

From Nor’easters impacting the Eastern seaboard from the Carolinas to Maine (and the Canadian Maritime provinces) to blizzards sweeping across the Great Plains and Midwest, our nation experiences more than its share of severe winter weather.

We begin with a case study of the Children’s Blizzard of 1888, an event that was unexpected and poorly forecasted and that, as such, caused incredible hardship. This great tragedy is unlikely to be repeated in modern times, where advances in our ability to monitor and study the atmosphere and to notify others of impending storms enable people to prepare and to prevent the loss of life.

There is a vast amount of online content that facilitates the study of winter storms. Students gain an appreciation and understanding of how to utilize and interpret the wealth of information available online from the National Weather Service and other credible resources. Students will be introduced to conditions required to produce these dangerous yet spectacular storm systems. Interactive exercises introduce students to the vertical structure of the atmosphere and how temperature profiles impact the form of precipitation that occurs. Students examine the various watches and warnings issued by the National Weather Service, as well as the symbolism used by meteorologists to depict various types of weather systems on weather maps.

The Children’s Blizzard

January 12, 1888, dawned across much of the Great Plains with unusually calm and mild conditions as children prepared to go to school. With the unseasonable warmth, many children donned light clothing for the trek to the rural schoolhouses. What the children and their parents did not know was that a powerful, arctic cold front and storm system was about to cause a major change in the weather that would produce a tragedy that is still written about today. The Pawnee County Historical Society details the Big Brash Blizzard of 1888 in photo archives.

The University Corporation for Atmospheric Research has produced Blizzards & Winter Weather, a highly informative Web site that enables the study of blizzards and their impact upon our lives, as well as enabling students to learn a bit about how these storms form. Click each of the links on this page to learn more about these powerful storms. Much of what is presented on this Web site is reinforced through resources appearing later in this same article.

The United States has an interesting history of winter storms from the early 18th century through today. The Winter Storm Timeline, developed by Scholastic.com, enables students to explore significant events by clicking on each event and reading a brief description and viewing a thought-provoking photograph.

Consider prompting a classroom discussion based on a few photos and events by asking students how people of that day in each time period may have been impacted in comparison to storms that affect our nation this winter.

Weather Maps and Weather Imagery

The Internet and modern technology have combined to allow us to study weather using tools not readily available to the public in years past. One of the best purveyors of this knowledge and information, the Weather Channel, has produced an Interactive Weather Map that uses Microsoft’s Virtual Earth to depict the latest national radar image. By clicking the weather layers, tabs, and satellite buttons, students can create a customized weather map. You can generate many questions from such an exercise!

Not to be outdone by the Weather Channel, the National Weather Service (NWS) has created its own interactive map. This map depicts current watches and warnings issued by the NWS. Use this map to explore the various types of severe weather currently occurring nationwide. It is also an opportunity for students to explore the meaning of each watch and warning being issued as well as to stimulate their sense of wonder as to what kind(s) of weather patterns create the current conditions.

Weather satellites contribute greatly to our understanding of our atmosphere and our ability to predict the onset of winter storms across our nation. NASA has contributed Interactive Global Geostationary Weather Satellite Images. Click each image to look at it in greater detail, then locate the link titled more about this image to gain greater insight into what you are viewing.

Consider asking teams of students to become experts on each image. Make sure students understand the difference between visible, infrared, and water vapor images, and the relative merits of each.

Weather maps, especially those detailed on television, often depict a simplified view of weather systems and features traversing across our nation. One such national weather map is produced by Intellicast. The symbols depicted on this map are explored in the next section.

Weather Map Symbols

About.com has produced a highly informative Web site that details An Introduction to Weather Map Symbols and Terminology. Print out the visuals to help students understand the various symbols, as well as the history of how weather maps were first generated. One of the major features on a weather map is a front.

PBS Learning Media has an excellent visualization of fronts that helps students study these features from a variety of perspectives. WW2010, a project developed through the University of Illinois at Urbana-Champaign, has produced an outstanding Web site that provides great information detailing the science of meteorology, as well as access to current or real-time weather data. The section on Fronts provides students with a greater understanding of the changes that occur across frontal boundaries, including changes in temperature, dew points, wind direction, and weather conditions. Study each page. Encourage students to view actual weather maps and to locate the same changes as those that are detailed on this informative Web site.

Learning to Read and Use Weather Maps

Glencoe created the Interactive Weather Map, a highly interactive tool that allows students to create their own weather maps by connecting symbols and features. For example, ask students to place a cyclone in and attach fronts to the Texas Panhandle in a realistic manner. Based upon the material studied earlier in this article, students should know that the symbol L represents a cyclone (a low pressure system); additionally, the warm front often extends from the cyclone to the south and east of the storm’s center, whereas the cold front extends from the cyclone to the south and west of the storm’s center. Using this tool, students create such a depiction.

The Southeast Regional Climate Center created an excellent Weather Map Activity that enables students to explore weather systems (cyclones and anti-cyclones) in an interactive manner and to learn where various conditions are experienced. Students are asked to identify where the warm sector, coldest conditions, and areas of highest and lowest pressures are located. Individual work or a group discussion will likely engage students, especially if you follow the theory with a real-time application by studying an actual national weather map. WW2010 provides an excellent series of real-time surface maps.

Winter Precipitation

Winter storms often generate a variety of types or forms of precipitation. Atmospheric conditions determine whether snow, rain, sleet (ice pellets), or freezing rain will occur. The Weather Dude presents an excellent site that details a vertical profile of the atmosphere required to produce each of the major forms of precipitation. Make sure students understand that snow only occurs when the majority of the atmospheric profile (from the clouds to the ground) is below freezing.

On occasion, snow will reach the ground even if there is a thin layer of above-freezing air near or just above the ground. Rain, of course, occurs when the lower atmosphere is too warm to permit frozen or freezing precipitation to occur. Many people confuse sleet (frozen precipitation, or ice pellets) and freezing rain (freezing precipitation as rain freezes when it hits a surface). Both require conditions near the ground to be below freezing, along with warmer air aloft. Sleet, however, requires a thick enough layer of cold air to cause rain to freeze before reaching the ground.

USA Today contributes its own highly interactive and visual tool, How winter storms bring rain, ice, and snow. Encourage students to scroll over each of the four major forms of winter precipitation to study the vertical profile that can produce each form of precipitation. A final note: although hail may resemble sleet, it is not considered a form of winter precipitation, as it can only form in cumulonimbus clouds, also known as thunderheads. These small scale storm systems are more of a spring and summertime phenomenon.

How Winter Storms Form

North Carolina is frequently a .breeding ground for winter storms that later impact the upper Mid-Atlantic and Northeastern seaboards. Therefore, it is appropriate that WRAL of Raleigh-Durham has produced a fine Web site on this very topic. How Winter Storms Form enables students to explore and study these storms. Use the navigation tab to explore various aspects of the site. Click winter precipitation for yet another depiction of the major forms of winter precipitation and the conditions required for each to form. Of great importance is the link titled, forming a winter storm. Study the clash between arctic and maritime tropical air, along which cyclogenesis (the formation of a cyclone) can occur. Students observe where the snow is likely to fly, as well as the typical path of some winter storms. By clicking the .weather map link, students study the normal winter snowfall totals. Use this map to discuss the relative impact of proximity to a coastline, the effect of altitude, and proximity to the Great Lakes. For example, notice the increased average snowfall totals in the Rocky Mountains, the Appalachians, and just east of the Great Lakes. Also compare the snowfall totals along coastal (low elevation) Washington to the state of Maine.

Ask students to identify which region is more impacted by its adjacent ocean. The Pacific Ocean insures minimal snowfall at low altitude due to persistent onshore winds; thus, rain is much more prevalent than snow in these low-lying regions. Similar low lying regions in coastal Maine receive much more snow because of a persistent flow of cold air from Canada and persistent Westerlies carrying air from the mainland to the coastline.

Blizzards are a relatively common winter occurrence across much of the northern United States in the winter months. Modern technology and communication virtually insure that a repeat of the tragedy of the Blizzard of 1888 will not recur. However, even with modern technology, people need to take appropriate measures to insure their safety when these storms occur. The Internet has enabled our study of these storms. Helping students to understand the various tools available and how to read and interpret these tools will enable them to appreciate what Mother Nature brings their way during this and future winters. Winter storms provide an outstanding teachable moment to capture students’ attention and imagination along with the inevitable hope of a snow day should a winter storm head your way!

NS.K-4.1 Science as Inquiry
including the abilities necessary to do scientific inquiry and understanding about scientific inquiry.
NS.K-4.4 Earth and Space Science
including changes in the Earth and Sky.
NS.5-8.4 Earth and Space Science the Earth System
The specific item that points to the study of hurricanes states:
Global patterns of atmospheric movement influence local weather

TEKS
§112.4. Science, Grade 4,
Science Concepts: The student knows that change can create recognizable patterns. The student can identify patterns of change such as in weather.
This would include identifying the circulation around a cyclone’s center and changes that occur as it strengthens over time

Reference:

The Big Brash Blizzard of 1888

http://www.pawneecountyhistory.com/yesteryear/blizzard.html

Pawnee County Historical Society

http://www.pawneecountyhistory.com/

The School Children’s Blizzard: Photo Archives

http://wintercenter.homestead.com/photoscblizzard.html

The Winter Center

http://www.geocities.com/donsutherland1/snow1.html

Blizzards & Winter Weather

http://eo.ucar.edu/webweather/blizzardhome.html

University Corporation for Atmospheric Research