Homework answers / question archive / Here you will work with a meteogram (courtesy of the University of Wyoming) from Harrisburg, PA, on February 17, 2003, during the height of the storm that became known as "President's Day Snowstorm II" because it occurred around President's Day that year (and there had been a previous blockbuster snowstorm along the East Coast on President's Day 1979)

Here you will work with a meteogram (courtesy of the University of Wyoming) from Harrisburg, PA, on February 17, 2003, during the height of the storm that became known as "President's Day Snowstorm II" because it occurred around President's Day that year (and there had been a previous blockbuster snowstorm along the East Coast on President's Day 1979)

Earth Science

Share With

1. Here you will work with a meteogram (courtesy of the University of Wyoming) from Harrisburg, PA, on February 17, 2003, during the height of the storm that became known as "President's Day Snowstorm II" because it occurred around President's Day that year (and there had been a previous blockbuster snowstorm along the East Coast on President's Day 1979).  The hour (in UTC) is shown across the bottom.
   1. What is the general tendency of the air pressure during this storm (that is, is the pressure increasing or decreasing)? From what direction(s) is the wind blowing most of the time?
   2. In the row that contains the cloud cover circle and the wind speed and direction indicators, there is an "X" in the center of some of the station model circles. What does this "X" mean? Briefly explain.
   3. There is an "X" in the center of the station model at 14 UTC. But unlike the other observation times when "X" appeared in the center of the station models, the 14 UTC observation is different. What kind of weather (obstruction to visibility) sets the 14 UTC observation apart from the others?
   4. Freezing rain occurs when snowflakes melt into raindrops as they descend through a layer of air of temperature 32°F or higher (such a layer of air is formally called a melting layer). Raindrops then freeze when they fall onto a subfreezing surface at the ground (such as trees, power lines, roads, etc). At what time did freezing rain occur at Harrisburg? What was the air temperature at that time?
   5. Based on this case, if precipitation is occurring and the air temperature near the ground is lower than 32°F, is snow always observed? Lesson learned: During winter, you cannot always use the temperature near the ground as the sole indicator of the precipitation type.
   6. Using all the information in the meteogram, describe in words the weather conditions at Harrisburg during the period 04-05 UTC on this day.