Data Analysis

United States wind speed and direction map created from surface data
downloaded from NOAAs Office of Satellite and Product Operations website.

United States wind speed and direction map created from surface data
that was provided to us by our professor.

Microclimate maps of UWEC campus.

This chart shows the average March temperatures for the United States for each
year between 1901 and 2014. It is useful for comparing current climate and weather
trends to minimum, maximum, and average values from the past.

March temperature trends for Wisconsin. Same as the previous chart, but
specific to the state of Wisconsin. This year, March was well below the average
temperature for March, but not the coldest on record.

Precipitation averages for March in Wisconsin. This year is well
below average, compared to last year which was above average.

This chart shows the average monthly temperatures for
Madison and Milwaukee, WI. These are very similar, since these
cities are so close to each other. It looks like Milwaukee stays
slightly warmer than Madison in the winter. This could be because
it stays cloudier thanks to evaporation from Lake Michigan, and
the clouds trap the heat like a blanket. 

Here is a chart that shows the monthly precipitation averages
for Madison and Milwaukee, WI. The cities are very different
in this chart, compared to the temperature chart. Since these
cities are so close, it has to be the geography that is causing
such large differences in precipitation. Milwaukee gets more
rain in the summer because of evaporation from Lake Michigan.
In April, however, Lake Michigan could still be mostly frozen. Less
evaporation would lead to less rain. The lakes in Madison, which are
smaller, probably thaw sooner allowing for more spring rains.

The following climographs were created in Microsoft Excel using data from www.worldclimate.com. For each location there are several different weather stations collecting data, and the location used for the chart is documented below each one.

Both data sets are from the "Eau Claire County AP, Chippewa County,
Wisconsin USA" station. 

Both data sets from "La Crosse, United States of America"
station.

Both data sets are from "Madison/Dane County Regio,
United States of America," which I assume means the regional
airport.

Precipitation data from "Milwaukee N Side, Milwaukee County,
Wisconsin USA" station, and temperature data from
"Milwaukee USA."

Both precipitation and temperature data from
"Minneapolis/St. Paul Int...United States of America" station,
which is the international airport.

Both temperature and precipitation data from "Superior,
Douglas County, Wisconsin USA" station.

Precipitation data taken from "Wausau Record Herald" station,
temperature data from "Wausau USA" station.

1)      Why is it useful to compare your data to more than one of these locations?

Because these cities show data from all over Wisconsin (and a little bit of Minnesota). If we used only one or two cities, we would not get a good cross section. According to Tobler’s first law of geography, everything is related to everything else, but closer things are more related than things farther away. By looking at several cities of varying distance, we can understand what variables are influenced by what. These cities are all in the same general region, and all have similar climographs, but Wausau and Eau Claire are more similar than Eau Claire and Milwaukee. Once we notice that, we can start to ask ‘why.’

2)      What variables may influence differences between those locations and our location?

Surrounding geography and elevation are big factors, but I think proximity to large bodies of water would be the largest influence here. There are a lot of lakes and rivers in the Midwest (all of the cities examined have a river, lake, or both nearby), and so a lot of water in general. Superior and Milwaukee, however, are on much larger bodies of water than the other cities. Superior is, on average, a bit cooler than the other cities. This is partially because it is the northern most city examined, but also because of the wind coming off of Lake Superior. Milwaukee gets less rain in late summer than the other cities. This is probably because it is on the western side of Lake Michigan. Weather patterns here move east, so I would bet the cities on the opposite coast of Lake Michigan get a lot more rain than Milwaukee.

3)      How might these data vary from your data regarding your data collection techniques?

I don’t really know how reliable any of these sensors are. Some places might have them in a good location on top of a tall structure, others might be blocked by a building or in the shade. These figures and charts are only as reliable as the way the data was collected in the first place. When we did our campus microclimate analysis, we used a Kestral weather meter. These are usually $200 - $300 units. The sensors used to collect the data above are probably far more expensive, and thus (probably) far more accurate. They also have the advantage of collecting data constantly over the course of decades, while we simply collected data within the span of about an hour.


The following charts were created using data collected by the weather station on top of Phillips Hall here on campus for January - April 2014. There are chunks of data missing, though I am not sure why. Most data is still intact, however.

This line graph shows the high, low, and average temperatures
for Eau Claire for each day in January of this year. These low temperatures
were probably caused by the polar vortex. Variation from day to day was probably
caused by fluctuations in pressure and cloud cover, as well as changes to the
jet stream. For example, on the 6th (when the low was below -20), we were probably
experiencing high pressure, little cloud cover, and cold winds from the west
or northwest.

The data for February of this year was incomplete, but we can
still see trends even with the partial data. The temperatures
seem to start to climb, but drop dramatically towards the end
of the month. I would again think that high pressure and cold
winds led to this drop in temperature. Going back to the 27th
in my weather blog confirms this. The pressure was at 1023.8 mb
that day, with light winds from the west. On the 20th and 21st,
there was a very large low pressure system and a winter storm.
This kept temperatures warmer. Prior to the storm, the jet stream
was fairly straight bringing warmer air from the Pacific.

March looks like it started generally getting warmer, with
some significant dips. March 25th brought a return of the
subpolar jet stream, engulfing Wisconsin in a trough that ensured
winter temperatures again for a couple of days.

Data for April was also partially missing. We can still see that
temperatures continued to climb during spring, but with some
set backs. Again, towards the end of the month, we found
ourselves in a sub polar jet trough. Through these several months,
we can see how huge of an impact the shape of the jet stream has
on the day-to-day weather.

This chart shows January 2014 temperatures again, but with
rainfall as well. January had 0 inches of rain, however, so only
temperatures are shown. Unfortunately, the station must only track
rainfall, instead of all kinds of precipitation. As you can see from
the chart, temperatures were never warm enough to produce rain
during this month, so any precipitation was snow or ice. If we had
snowfall data, I think we would see that the days where temperature
was highest would have been the days with the most snowfall.
Cloudy days in the winter trap heat from escaping the surface, so
it is usually warmer on cloudy, low pressure days.

Similar to January, very little precipitation in the form of rain
fell during February. One day we did get a little bit of rain, though.
This makes sense, since it was one of only two days when the
average temperature was above freezing.

March would typically see more rain than this, but temperatures
this year were quite lower than normal. Again, temps rarely made
it above freezing. We received well below half of the rain that we
got last year during March.

From the data we do have for April, we can see that we finally
got some spring rains. Again, we can easily compare this to
temperatures and see that April is the first month this year to
have temperatures regularly above freezing.

During January, winds were usually coming from the west
and west/northwest. This is probably because we had far more
days with high pressure during January. This led to colder days
with little precipitation.

Again, the dominant direction that winds came from during
February was the westerly directions (in this case WSW and W).
Temperatures were also very low during this month as we again
spent most of our time in high pressure domes.

In March, winds were still predominantly from westerly directions,
however we are now seeing a much more diversity. More rain
during spring months usually means more low pressure systems
south or southwest of our location. This brings winds from a more
easterly direction during rain or storms. This year, March was much
cooler than average which meant less spring rains than normal. I
would guess that this pie chart would look more like April's (below)
during an average March.

April did have a large chunk of data missing, but we can still see
that winds this month were coming more from the east than
any other month. This month also saw more rain than any other
month. This is not a coincidence, as I mentioned above. The
spring rains we are receiving usually mean low pressure systems
south of us, which would be responsible for winds out of the east,
southeast, and east/southeast.

In general, there is a correlation between precipitation, temperature, and wind direction. During January and February, when we had many days of bitter cold, we had more high pressure domes in the area which lead to less precipitation and brought winds from westerly directions. During March and April, temperatures started to warm and frozen lakes started to thaw. This led to more evaporation, more water vapor in the atmosphere, and more rain when low pressure systems moved in. These low pressures systems brought easterly winds, which is why we had many more days with winds from that direction during the spring months. Both temperature and precipitation are below average for these months, however, which seems to basically mean that winter conditions (cold temps, westerly winds, less precipitation) are lasting longer into the spring than they normally would.