Bellwork 4/20 What kind of weather is associated with a warm front? What about a cold front? What do you think of when you hear the word “cyclone”?

Have you heard of The Wreck of the Edmund Fitzgerald by Gordon Lightfoot?

October 25-27, 2010 Animation

September 26th 2011

Blizzard of 2016

Middle-latitude cyclone Primary weather producer in the middle-latitudes Life cycle Form along a front where air masses are moving parallel to the front in opposite directions Continental polar (cP) air is often north of the front Maritime tropical (mT) air is often south of the front

Life Cycle 1. Stationary Stage Cold air mass and warm air mass run parallel to one another “Birth”

2. Wave Stage Perturbation from aloft causes an indentation in the front “Adolescence”

3. Open Stage -Warm front and Cold front form “Warm Sector” -Warm front and Cold front form -Both move counterclockwise around low pressure -Warm front slowly moves north -Cold front quickly moves south/southeast

Life Cycle 4. Occluded Stage -Cold front catches up to the warm front and occlusion occurs “Maturity” “Warm Sector”

5. Dissipation Stage -Warm sector is forced aloft. -Pressure gradient weakens and fronts stop “Death”

Animation:

“Idealized” weather associated with Mid-Lat. Cyclones Middle-latitude cyclones move eastward across the United States First signs of their approach are in the western sky Require two to four days to pass over a region

“Idealized” weather associated with Mid-Lat. Cyclones On the Warm front Clouds become lower and thicker Light precipitation Bring warmer temperatures to nearby areas

“Idealized” weather associated with Mid-Lat. Cyclones On the Cold front Wall of dark clouds Heavy winds Heavy precipitation – hail and occasional tornadoes After the passage of a cold front, skies clear and temperatures drop

Edmund Fitzgerald Timeline: Nov. 8th, 1975 Stationary front forming Nov. 9th 1975 NWS issues gale-force wind warning (2:30pm) Nov. 10th, 1975 1am: 60mph winds, 10 ft waves Afternoon: freezing rain reported Last weather report from the Fitz

NOVEMBER 9 2:20 PM The Fitzgerald departs Lake Superior en route of Detroit with 26,116 tons of taconite pellets.  2:39 PM The National Weather Service issues gale warnings for the area which the Fitzgerald is sailing in. Captain Cooper on the Anderson radios a freighter (the Edmund Fitzgerald) that he spots. NOVEMBER 10 1:00 AM Weather report from the Fitzgerald. The report from the Fitzgerald shows her to be 20 miles south of Isle Royale. Winds are at 52 knots, with waves ten feet in height. 7:00 AM Weather report from the Fitzgerald. Winds are at 35 knots, waves of ten feet. This is the last weather report that the Edmund Fitzgerald will ever make. 3:20 PM Anderson reports winds coming from the Northwest at 43 knots. 7:15 PM The Fitzgerald enters a squall while still on Lake Superior; the squall obscures the vessel from radar observation by the Anderson; this is normal when in a squall. 7:20 PM Edmund Fitzgerald disappears from the radar. It is estimated that this was the time period when the ship vanished and sank.

Satellite view of a cyclone over the eastern United States

“What’s In A Name?” What do you find when you Google the word “cyclone”?

Cyclones DO NOT necessarily = Tornadoes/Hurricanes/Thunderstorms Mid-latitude cyclones are responsible for changes in our day-to-day weather…not just severe weather Tornadoes and Hurricanes are SMALLER and MORE INTENSE than a mid-latitude cyclone Hurricanes: 600km across Mid-Lat. Cyclone: 1600km across