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.