Ice Storms Problem Set: I. Consider a flat roof of a residence

QUESTION

Ice Storms Problem Set: I.Consider a flat roof of a residence. The roof’s dimensions are 40 meters on each side(a square).40 metersa.) If an ice storm occurred with a total accumulation of 2.5 cm(about one inch), approximately how much mass of ice has fallenon your roof?Hint: Assume the density of ice is 0.92 g/cm3 at 0 °C.Provide your answer in kg.b) If a snow storm, instead, occurs with a total accumulation of 2.5 cm (about oneinch), approximately how much mass has fallen on the roof?Hint: Assume that the density of snow is 0.1 g/cm3 at 0 °C.Provide your answer in kg.c) What other factors would favor the lessening of the impacts of snow on the roof, asopposed to freezing rain?d) If an ice pellet storm occurred with a total accumulation of 2.5 cm (about oneinch), that same amount of mass of ice would have accumulated on the roof, as foryour answer in part a. Compare the impacts of one inch of ice pellets with one inchof freezing rain.4II.Consider the following map of elevation throughout North America. The elevations (meters) are shown according to the color shading shown on the right. . The NCEP Regional Reanalysis domain and its 32 km/45 layer topography.a) Using this elevation map, outline the regions where you would expect freezing rain events are most likely to occur. Explain your reasoning, using the information provided in the on-­‐line lectures. ussion of our data used and dataavailable computer and manpower resources were fullyb) Once you have completed a), compare your answer with that of the actual map of North in Shafran et al. (2004, this CDengaged in the production effort, limiting our ability toAmerican freezing rain occurrences discussed in the on-­‐line lectures. What are the inspect the and those differences between your answers in a) results. of the actual climatology? Provide one or more plausible explanations for these differences. In presenting the precipitation results of our pilot andTH OBSERVATIONS AND WITHpreliminary runs, we compared monthly totals for JanuaryYSIS2 and July of the NARR precipitation with those of thel Reanalysis data have been“observed” (i.e., analyzed) precipitation assimilated intoIII.Consider the following surface weather map that shows sea-­‐level pressures (contoured every 4 hPa, with cold fronts indicated in blue, and warm fronts in red). Remember that the winds blow counterclockwise around low pressure systems in the Northern Hemisphere, and clockwise around high pressure systems, with small directional changes towards lower pressures. Identify regions with where you would expect to see the highest chance of rain, snow, ice pellets, and freezing rain. Provide your reasoning. IV.Given your answer to the previous question III, sketch the preferred wind vectors (arrows indicating the wind directions) at each of the surface and the “free” atmosphere (about 1.5 km above the surface) that is favorable for the production of freezing rain. Using your on-­‐line lecture materials, discuss the specific roles that winds play in producing these freezing rain conditions. 3 V.Consider the following two cases of freezing rain, in which the area covered is that of a rectangle, oriented east-­‐west, that is 1000 km long and 100 wide: 1000 km 100 km a) Case 1: If the area of freezing rain is moving at a speed of 15 km per hour, and Montreal is located 100 km to its north at 8:00 PM local time, estimate the start and end times of the freezing rain event at Montreal. Assume the area of freezing rain does not change its shape during its movement. b) Case 2: If Montreal is located 50 km to the east of the region of freezing rain, and the area of freezing rain is traveling to the east at 15 km per hour, estimate the start and end times of the freezing rain event at Montreal. Assume the area of freezing rain does not change its shape during its movement. c) Given your answer in part a) of the question, estimate the total freezing rain accumulation at Montreal. Assume the freezing rain rate is 2 mm per hour throughout the rectangle. d) Given your answer in part b) of the question, estimate the total freezing rain accumulation at Montreal. Assume the freezing rain rate is 2 mm per hour throughout the rectangle. e) Relate each of the scenarios in a) and b) to those of actual freezing rainstorms in the vicinity of either warm, cold, or stationary fronts, as appropriate. 4 VI.a) Review the following real-­‐life weather soundings and identify the type of winter precipitation that is most likely occurring. Explain your reasoning for each of the cases a) and b). The numbers for each of the soundings below include temperatures (degrees C) along the horizontal axis, and pressures (hPa)/elevations (m) along the vertical axis. Temperature soundings, such as the ones shown below are available at http://weather.uwyo.edu/upperair/sounding.html 5 b) 6

ANSWER:

REQUEST HELP FROM A TUTOR