GG101  Introduction to Physical Geography Lab 5: Interpretation of Surface Weather Data Tasks and Questions Review the weather data from Toronto International Airport over the interval October 28th to November 3rd, 2020

Subject:GeographyPrice:10.01 Bought5

Share With

GG101  Introduction to Physical Geography

Lab 5: Interpretation of Surface Weather Data

Tasks and Questions

Review the weather data from Toronto International Airport over the interval October 28th to November 3^rd, 2020. The data are shown in a series of graphs in the file Weather Graphs.pdf and in the Excel Spreadsheet Daily_Weather_Data_Toronto_Intl_A_Oct_28_Nov_3_2020.xlsx.

In this lab exercise there are a series of questions that will ask you to: (i) describe the weather conditions during certain intervals, (ii) relate those conditions to the broader synoptic pattern, and (iii) to explain changes in weather conditions over given periods.

Task 1

Examine the data from October 28^th from 12 am to 11 pm. What you should note are the following:

At 12 am the temperature was 3.5^oC, the peak temperature was at 3 pm at 11.3^oC, and by 11 pm the temperature had fallen to 6.0^oC. In the early morning hours the weather was cloudy but then it was clear to mostly clear during much of the day, mostly cloudy conditions were reported at 11 pm. The winds were from the west and southwest almost the entire day and were very light in the early morning and evening, and moderate in the late morning and early afternoon. Through the course of the day, the dew point temperature changed very little, it was lowest at 4 pm at -1.8^oC and highest at 9 am at 2.9^oC. Recall the dew point temperature gives us information on the water vapour content of the air, when the dew point is very low the air is dry, when it is very high the air has a much higher water vapour content. Examine the air pressure data, we see that over the course of the day the air pressure started relatively high (1020 mb adjusted to sea level pressure values) and dropped very slowly to 1014 mb by 11 pm.

Question 1            (1  mark )

Describe the changes in relative humidity over the course of the day and the relation between relative humidity and the air temperature. 

Open the powerpoint presentation that shows the simplified synoptic charts from NOAA. Make certain you are aware of the general location of Toronto International Airport. Start at slide number 3 and view to slide 6. These slides show synoptic charts from 2 am on October 28 to 8 pm on October 28th.

Question 2            (1  mark )

What type of air pressure system influenced Toronto on October 28^th?

The data show that overall on October 28^th there was relatively consistent wind direction, a very gradual and slow change in air pressure, a consistent dew point temperature, a moderate temperature range, and no periods of precipitation.

Question 3            (2  marks )

Why were the weather conditions experienced on October 28^th so consistent without any dramatic shifts or changes through the day?

Task 2

Examine the data from October 29^th from 12 am to 11 pm, just as has been done above for the 28^th. The air temperature fluctuations are similar as is the pattern in relative humidity (the values differ but the patterns are similar for the two days). The data do show a major shift in wind direction. Early on the 29^th the winds are very light but by midday they are consistently coming from the northeast and north, and moderate in strength. Note that when winds are very light the direction can appear to fluctuate from hour to hour. We also see a change in air pressure with values falling until midday then gradually rising. The dew point temperatures on the 29^th are slightly higher on average than on the 28^th, which indicates the air mass on the 29^th has more moisture. We also see a major change in the state of the weather over the course of the day.

Question 4            (1  mark )

Describe the state of the weather on October 29^th.

Open the powerpoint presentation that shows the simplified synoptic charts from NOAA. Make certain you are aware of the general location of Toronto International Airport. Start at slide number 7 and view to slide 10. These slides show synoptic charts from 2 am on October 29^th to 8 pm on October 29^th. Examine the movement of high and low pressure systems in eastern North America on that day that could potentially influence the weather conditions at Toronto.

Question 5            (2  marks )

Explain why the wind direction changed from the west and southwest on October 28^th to the north and northeast on October 29^th.

Task 3

Examine the data on October 30^th to midday on the October 31^st.  The data show much cooler conditions over this interval with the lowest being -4.8^oC at 6 am on October 31st . We see lower dew point temperatures during this interval as well. The winds speeds were light over this period. On the 30^th the wind direction was from the north and it gradually shifted to the northwest and west on the 31^st. The air pressure increased over this interval and reached a maximum of 1033.2 mb in the morning on the 31^st. There was a mix of clear and cloudy skies over this interval.

Open the powerpoint presentation that shows the simplified synoptic charts from NOAA. Make certain you are aware of the general location of Toronto International Airport. Start at slide number 11 and view to slide 17. These slides show synoptic charts from 2 am on October 30^th to 2 pm on October 31^st. Examine the movement of high and low pressure systems in eastern North America on that day that could potentially influence the weather conditions at Toronto.

Question 6      (3  marks )

Consider the follow air masses: mP (maritime polar), cP (continental polar), cA (continental Arctic), and mT (maritime Tropical). Based on the synoptic pattern and on the weather conditions experienced at Toronto on October 30^th to midday on October 31^st identify the air mass that influenced Toronto over that interval. Support your choice with evidence.

Task 4

The afternoon of October 31^st brought a change in weather to southern Ontario, the winds shifted to the south and the temperature did not fall in the evening. On November 1^st the temperature was highest in the morning and dropped in the afternoon with precipitation in the afternoon and evening. On the following pages there are six charts (preliminary charts from Environment Canada) that are from the times: (i) Oct 31 8 pm (Nov 1 00Z), (ii) Nov 1 1 am (Nov 1 06Z), (iii) Nov 1 7 am (Nov1

12Z), (iv) Nov 1 1 pm (Nov 1 18Z), (v) Nov 1 7 pm (Nov 2 00Z), and (vi) Nov 2 1 am (Nov 2 06Z)

The chart below shows the conditions at 8 pm on October 31^st for Ontario and the surrounding areas.

 

The chart below shows the conditions at 1 am on November 1 The chart below shows the conditions at 7 am on November 1 The chart below shows the conditions at 1 pm on November 1 The chart below shows the conditions at 7 pm on November 1

 

The chart below shows the conditions at 1 am on November 2^nd

 

Question 7            (6  marks )

Using the synoptic charts above, complete the table below.  For this table select the station from the charts that is closest to Lake Ontario (e.g. Toronto or Hamilton area). In some charts you will have to pick the station on the north shore of Lake Ontario that is east of Toronto.

Date	Local Time	Sky Cover (8ths)	Cloud Types (list all)	Air Pressure Tendency	Wind Direction and Speed	Present Weather
Oct 31	8  pm
Nov 1	1  am
Nov 1	7  am
Nov 1	1  pm
Nov 1	7  pm
Nov 2	1  am

Open the powerpoint presentation that shows the simplified synoptic charts from NOAA. Make certain you are aware of the general location of Toronto International Airport. Start at slide number 18 and view to slide 23. These slides show synoptic charts from 8 pm on October 31^st to 1 am on November 2^nd. Examine the movement of high and low pressure systems in eastern North America on that day that could potentially influence the weather conditions at Toronto.

Question 8            (2  marks )

Explain why the air temperature increased overnight on the morning of November 1^st.

Question 9            (2  marks )

Explain why the air temperature decreased in the afternoon of November 1^st