Whooping Crane
 

Whipping Winds Again Today (+0 Miles)
October 27, 2010: Migration Day 18

High winds and rain pin the team down again today. The cranes are hunkered down in their pen, doing fine and facing into the wind. One panel of the pen was weakened so the team reinforced the tie-downs and stakes. Everything held fine during yesterday's 60-mph winds, but it is just as windy today. What causes such winds?

The low barometric pressure is to blame. Yesterday set a new record for the lowest atmospheric pressure ever observed over the continental USA. A red "L" on the weather map indicates a low pressure cell. Air normally rushes into low pressure like water into a funnel. In this case, the contrasting temperatures across the region squeeze the low pressure center (picture the funnel), forcing circulating winds into a tighter rotation. The greater the north-south contrast in temperature, the stronger the winds must blow to keep the atmosphere in equilibrium. Big contrasts in temperatures are usual in spring and fall, and this storm system is the result. Is it heading your way?

In the Classroom: Journal or Discussion

  • (a) Why do the cranes face into the wind during stormy weather? (Think about their feathers and the direction in which they lie.)
  • (b-for-bonus) The biggest factor that affects migration is the weather! In which direction does the air move in a low pressure cell: clockwise, or counterclockwise? See this weather primer to answer, and to learn more about the symbols on the weather map above.
  • (c-for-super bonus) Yesterday the USA set an all-time record for the lowest pressure ever observed, even lower than in most hurricanes, which is hard to fathom. The air pressure was 28.22 inches of mercury [953 millibars (mb)] over Orr, MN. Only Hurricane Ike was stronger, at 951 mb. Do some research to find out what "28.22 inches of mercury" means. What changes in air pressure will it take for the kind of weather that will get the cranes moving again?

Journey North is pleased to feature this educational adventure presented in cooperation with the Whooping Crane Eastern Partnership (WCEP).

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