INTRODUCTION TO EARTH SCIENCE (ESCI 121)
Weather Watch Assignment
Dr. Sanders
EXAMPLE of How to Analyze Weather Observations
Insert your weather data here, either as a small table (as below) or as a full page table. Keep a
copy of the bigger table for your presentation!
STUDY SITE: “Location A”
WEATHER
OBSERVAUNITS
1:05
TIONS
pm
TemperaDeg F
41
ture
3:05
pm
42
41
38
34
34
34
Sunny
Sunny
Fair
Partly
cloudy
Partly
cloudy
Cloudy
4
12
10
9
8
NW
NW
NNW
N
%
Inches
68
29.70
65
29.71
67
29.73
↑↓→
→
↑
Deg F
31
31
Sky Cover
Wind
Speed
Wind
Direction
Humidity
Pressure
Pressure
Tendency
Dew Point
mph
4:05
pm
TIME AT STUDY SITE WHEN PAGE UPDATES
5:05
6:05
7:05
8:05
pm
pm
pm
pm
2:05
pm
9:05
pm
10:05
pm
11:05
pm
12:05
am
34
34
34
32
32
Cloudy
Cloudy
Fog
Light
rain
Fog
Cloudy
14
6
6
3
3
5
6
NNW
N
NNE
N
N
NNE
WNW
NW
73
29.76
79
29.78
82
29.79
82
29.83
82
29.85
87
29.86
87
29.86
87
29.88
92
29.89
↑
↑
↑
↓
→
↑
→
↓
↑
↑
31
30
28
29
29
29
30
30
28
30
TEMPERATURE: Temperature at “Location A” [your analysis should actually name the city!]
peaked at 2 pm and dropped throughout the day. By midnight it was about 10 degrees colder
than it was at 2 pm. This is what would be normally expected, as daytime temperatures are
typically warmer than nighttime temperatures. But in addition, the weather map shows a cold
front passed through the area just after I began recording my observations. That would have
caused the temperature to drop, as well.
DEW POINT and HUMIDITY [depending on your own specific location and observations, you
may want to comment on these separately instead of together]: Dew point followed a trend
similar to that of temperature: highest in early afternoon, and lowest by midnight. However,
the difference between temperature and dew point did something interesting: it became
smaller and smaller as the day went on. At 1 pm, the two measurements were 10 degrees
apart, but by midnight, dew point and temperature were nearly equal. This coincided with a
rise in relative humidity. These three trends are shown in the attached graphs.
WIND SPEED/DIRECTION: Wind speed was higher (8-12 mph) during the early part of the
afternoon, as the cold front was passing through. This makes sense, because cold fronts are
generally associated with wind. Later, after the front passed, the wind speed fell to 3-6 mph.
Direction of the wind was from the north throughout the entire 12 hours. That corresponds
with the trend toward lower temperatures throughout the day, since continental polar (cP) air
masses from Canada are usually cold.
SKY COVER/PRECIPITATION: Sky cover went from sunny (in the early afternoon) to fair, then to
partly cloudy, then to fog, and finally, by 10 pm, to rain. This trend coincided with the rise in
relative humidity from 68% to 87%. It makes sense, because the weather map showed a cold
front coming into the area, which probably involved a sudden change in the weather. As the
warmer air was displaced by cold air, precipitation resulted. However, near the end of the 12hour period, the cold front changed to a stationary front. That means the mass of colder air
stopped advancing, and the weather “Location A” was experiencing will continue until the
stationary front either dissipates or starts to advance once again as a cold front.
PRESSURE and WIND SPEED/DIRECTION [depending on your own specific location and
observations, you may want to comment on these separately instead of together]: Barometric
pressure rose steadily throughout the afternoon and early evening. This is what would
generally be expected as a high pressure system moves into an area. But it surprised me,
because the weather went from sunny to rainy during that same time period, and generally I
would expect the opposite trend when higher pressure moves in. I can’t think of how to
explain this other than to hypothesize that the cP air mass was accompanied by higher pressure
as air sinks down from higher in the troposphere. But no specific high pressure system was
shown on the map, so I’m not completely satisfied with this explanation.
You may want to paste in smaller versions of your graphs here, or just attach the larger
versions. Keep copies of the bigger graphs for yourself! You will need them for the presentation!
Attach your 12 weather maps at the end of your analysis.
INSERT 12 WEATHER MAPS HERE.