DataStreme Activity 10A:

THE MIDLATITUDE CYCLONE

Do Now:

  1. Print this file.
  2. Print the Monday Image 1 and Image 2 Files.
  3. Print (when available) the Tuesday, 14 November 2000, Daily Summary File.

To Do Activity:

  1. Read Chapter 10 in STUDY GUIDE, Part A: Narrative.
    Note: Figure 10.8a is missing the cold front symbol. See Fig. 10.8b.
  2. Go to STUDY GUIDE, Part B: Applications. Start Activity 10A.
  3. Return here (Monday Activity A File) when told to do so.

Go To STUDY GUIDE - Activity 10A Now


WELCOME BACK: Procedure continued from STUDY GUIDE.

  1. The past weekend saw a storm system cross the central US. A low pressure system travelled from New Mexico into Minnesota. To the northwest side of the storm track (path of the lowest pressure center), the storm system laid a trail of up to 15 inches of snow across the northern plains while to the southeast side thunderstorms with wind damage, hail, and tornado reports occurred. For details consult the Monday, 13 November, Daily Weather Summary.

    Image 1 is the surface weather map for 12Z 13 NOV 2000, Monday morning. The main low pressure center associated with the storm system was located over southern Minnesota (1008 mb) with a secondary 1007-mb at Green Bay, WI. An occluded front arcs eastward from the Low center to central Indiana and continues as a cold front to off the Texas Gulf coast.

    The pattern of winds in the region around the low-pressure center is [(clockwise) (counterclockwise)] and [(outward) (inward)].

  2. Temperatures to the east ("ahead") of the occluded and cold fronts from Tennessee to Michigan are in the 40's while those to the west of ("behind") the fronts from Oklahoma to the Dakotas are from [(40's to 30's) (20's to negative single digits)].

  3. Precipitation, as shown by radar echoes, is located mainly [(along and just ahead of) (in bands perpendicular to)] the fronts. From Iowa around to the Dakotas and southern Canada, the arrow symbols for weather conditions denote [(thunderstorms) (fog) (snow)]. (Weather symbols are given in the User's Guide, linked from the homepage.)

  4. Lexington, Kentucky, reported a pressure of 1012.9 mb, temperature 48 °F, dewpoint 40 °F, and winds of about 5 knots from the south. St. Louis, Missouri, behind the cold front, was under the influence of air that was [(warmer) (cooler)] and [(more) (less)] humid. The wind was from the [(west) (north)] at about ________ knots and the pressure was [(higher) (lower)] than Lexington at _________ mb.

  5. While this was a significant autumn storm system (especially to those shoveling the snow), other more dramatic storms have occurred at this time of year. The cooling of air masses to the north under shorter days of weaker solar heating and longer nights of radiational cooling brings great temperature contrasts as they travel south. Many memorable storm systems have crossed the US in early November. Image 2 is the the surface weather map for 12Z 10 NOV 1998. An historic storm was raging in the upper Midwest at that time. The following are excerpts from the 11 November 1998 Daily Weather Summary describing that storm.

    "A STORM OF HISTORIC PROPORTIONS -- This most recent storm appears to be one of the most intense November storm systems that moved across the Upper Midwest and western Great Lakes. ... While this system was accompanied by snow, rain and thunderstorms, this rapidly intensifying storm will long be remembered for its extremely low barometric pressure and exceptionally strong winds ... Duluth recorded a sea level corrected pressure reading of 964.3 mb (28.475 inches of mercury) ... Winds gusted to 95 mph at Mackinac Island, MI, to 93 mph at La Crosse, WI ... These strong non-thunderstorm winds were responsible for a fatality in Wisconsin, one death and 2 injuries in Kentucky and 2 injuries in Illinois as buildings were damaged, trees uprooted and high profile vehicles tipped across the Midwest. Semi-trailers were tipped over in Wisconsin and in Illinois, a school bus in Minnesota and a railway car derailed in central Illinois ... The strong winds also were responsible for reduced visibilities in blowing snow resulting in blizzard conditions across western Minnesota, the eastern Dakotas and Nebraska. Numerous roads were closed because of the blowing and drifting snow. The largest snowfall totals associated with the storm were approximately 12 inches near Sioux Falls, SD ... Warm air advection on the southerly winds ahead of the cold front was also responsible for record high temperatures across Ohio ... Large hail and high winds accompanied thunderstorms that moved across southern Missouri early Tuesday morning. Thunderstorm wind damage was reported across the lower Mississippi Valley into the Ohio Valley. Tornadoes were reported in southern Illinois and Louisiana."

    At map time, the low pressure center of 971 mb was located in northwestern Iowa. A short occluded front went to eastern Iowa where a [(warm) (cold) (stationary)] front extended to eastern Tennessee. From eastern Iowa to southern Texas, the analyzed front was a [(warm) (cold) (stationary)] front. Where the fronts all meet in eastern Iowa is termed the "triple point".

  6. Temperatures to the north (ahead) of the warm front were in the 40's while those in the "warm sector" between the warm and cold fronts were generally in the [(60's) (40's) (30's)]. Temperatures to the west of (behind) the cold front were generally in the [(60's) (40's) (30's)].

    Dewpoints in the warm sector were [(higher) (lower)] than those either ahead of the warm front or behind the cold front.

  7. The precipitation was generally located:


  8. The strong winds that accompanied this 1998 storm were the result of the [(strong pressure gradient) (intense solar heating)] that is evidenced by the [(many isobars) (clear skies)] around the low center.

The NOAA weather radio as well as the DataStreme "State Surface Data - Text" are excellent ways you and your students can keep track of hourly weather conditions that show changes as storms with their fronts approach and cross your location. Note how these conditions change and fit the general pattern expected with passing wave cyclones. NOAA radio is particularly valuable when severe weather threatens your area as most weather radios are equipped with warning alarms that can be triggered by the National Weather Service when conditions warrant. (You can track hourly weather conditions using a blank meteogram from the DataStreme homepage, under Extras, "Blank Metgram".)


Hold this activity until you have completed all applications for this week. Instructions for faxing your LIT mentor will appear at the end of this week's Activity B.


Notice: Participants are reminded that Plans of Action are to be formulated and taken to the final course meeting.

YOUR PLAN OF ACTION:

Each DataStreme course participant is asked to develop a plan of action describing how she/he intends to promote weather education and the classroom use of electronically-delivered environmental data following completion of the course.

We ask you to prepare such a Plan of Action and submit the Plan to your LIT leader at the final course meeting. Be prepared to informally discuss your plans at the meeting. The plan should be no more than a page or two in length.

Keep in mind when preparing the plan that the DataStreme Project is an NSF-funded Teacher Enhancement project. Its purpose is to assist you, as teachers, to help other teachers. The major goal of the Project is to work collegially with teachers who become weather education resource persons for other teachers in their home schools. Your participation in the DataStreme distance-learning course is intended to be the first step in this process.

The plan can simply be a list of ways in which you intend to peer train and assist other teachers to employ weather topics or electronically-delivered weather information and data in student learning experiences. Think of current weather and the meteorological data stream as vehicles for learning across the curriculum (not just for science).

As you develop your plan of action, we want you to know that you will be given multiple copies of a teacher’s guide entitled Today’s Weather at the final course group meeting. It is intended for peer training purposes and contains adaptations of Chapter 1 of the DataStreme Study Guide, Part A: Narrative and 4 activities from the Study Guide, Part B: Applications dealing with drawing isotherms, drawing isobars, using the “hand-twist” model, and interpreting a surface weather map. The 28-page teacher’s guide is intended to be given to the teachers you peer train.

Start your plan of action by listing those actions you have already undertaken or have underway as the result of DataStreme participation. We also ask that you consider including in your plan those actions that would employ products from the DataStreme Homepage to demonstrate to fellow teachers, school administrators, school boards, and community leaders the value of providing Information Age learning experiences to children.


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