Earth Science Weather Review Key

Weather Review Air Masses Describe the major air masses that affect North America: Air Mass Weather Location(s) cP Cold, dry Northern US & Canada cT Warm, dry Southwest US mP Cool, moist NW Pacific (Alaska), NE Atlantic mT Warm, moist SW Pacific, Gulf of Mexico, SE Atlantic Indicate what type of air mass each city is dominated by. (Use your U.S. Map) Salem, Oregon: mP Santa Fe, New Mexico: cT Fargo, North Dakota: cP Tampa, Florida: mT Fronts Explain how fronts are related to air masses. Boundary between 2 air masses (the front of an air mass) Describe warm and cold fronts: Front Symbol Weather Cloud Type Warm (Image of a warm front symbol) Precip over a large area High cirrus, stratus at the base Cold (Image of a cold front symbol) Strong storms w/ heavy precip & wind Large cumulus & cumulonimbus A warm front passes Michigan during the next 24 hours. Predict the temperature change (increase, decrease, stay the same). increase EXPLAIN your prediction. Behind the warm front is a warm air mass that will cause the temp in MI to ↑ As the warm front gets closer to Michigan, you would expect to see high, thin cirrus clouds overhead. These would then thicken and lower to form layered stratus clouds. If enough of the cloud droplets coalesce into rain drops, these clouds would be called nimbostratus1 clouds.   Pressure Systems & Wind Describe high and low pressure systems: Pressure System Air Movement Weather Direction of Air Flow High Descending ↓ Dry and clear skies Clockwise and outward Low Ascending ↑ Cloudy Counterclockwise and inward Use the weather map to answer the following questions: Which city has higher temperatures: Ottawa, Ontario or New York City, NY? Ottawa Explain. Warm air mass and a warm front near NY Which city has lower temperatures: Tulsa, OK or Charlotte, NC? Tulsa Explain. A cold front has just passed Tulsa. Describe the different sky conditions in Tulsa, OK and Lansing, MI. Tulsa: Clear Lansing, MI: Cloudy Draw wind arrows on the map isobar map on the right. What is the wind direction in the following cities: Sacramento, CA: North St. Louis, MO: West/Southwest Salt Lake City, UT: East List a city where winds are calm. List a city where winds are strong. Explain how to determine wind speed. Close isobars = high wind speeds Wide isobars = low wind speeds Severe Weather 11. DESCRIBE how lightning and thunder form. Lightning heats the air causing it to expand. When it cools quickly and collapses, it produces sound waves. 12. EXPLAIN why more tornadoes form in "Tornado Alley". Geographic location where CP air mass meets MT air mass 13. DEFINE the stages of hurricane formation. Tropical Depression: Several thunderstorms (<38 mph) Tropical Storm: 39-73 mph Hurricane: >74 mph 14. DESCRIBE the structure of a hurricane. Rotation N. Hemi CCW, S. Hemi CW Eye: center, calm, clear Eyewall: wall of clouds surrounding eye Rain Bands: long bands of rain spiraling in 15. IDENTIFY hurricane steering forces. Trade winds - toward US Westerlies - away from US (back to Atlantic) DESCRIBE the path of an Atlantic hurricane. 16. DESCRIBE hurricane dissipation. No more warm, moist air Friction with the land 17. COMPARE the characteristics of severe weather. Characteristic Thunderstorm Tornado Hurricane Ingredients Warm, moist air mass (mT) Low pressure, mT, cP, cT Warm water, low pressure, strong winds Season (Month → Month) April → July April → July June → Nov Most frequently hit US states Texas, Kansas, Nebraska Texas, Kansas, Nebraska East coast Hazard causing most damage Debris carried by strong wind Debris carried by strong wind or under structure collapse Storm Surge Safety Avoid high places, water, metal Go to basement or sturdy shelter, stay away from windows, protect head Be prepared, obey warnings