ZUMWALT PRAIRIE WEATHER
2014
A summary of the weather year based on data from the Zumwalt Weather Station
Robert V. Taylor1
The Zumwalt Prairie Weather Station (ZumWxStn; Lat 45.577745 N, Long -116.971754) has
operated since fall of 2005 and provides hourly weather data on precipitation, temperature, and
wind speed. Below I briefly summarize recent weather observations – primarily average daily
temperatures and total precipitation, month by month, for 2014, and compare those to station
data from 2006 to 2013.
Summary figures and data tables are included at the end of this report. A detailed description of
the ZumWxStn can be found in (Hansen et al. 2010) and a summary of long-term climate of the
Zumwalt Prairie and nearby areas is provided in (Hansen et al. 2011).
You can learn more about the ZumWxStn, obtain other weather and climate reports, and
download data on the web at:
http://www.conservationgateway.org/ConservationByGeography/NorthAmerica/UnitedStates/oregon/grasslands/zumwalt/weather
January
January is on average the coldest month of the year (average daily mean of -3 C or 27 F) and
is also typically dry (< 2 cm or 0.8 in of precip). The year 2014 started off dry with moderate
temperatures and high pressure. Storms and warmer weather moved in around 9 Jan with high
1
Northeast Oregon Regional Ecologist, The Nature Conservancy, 906 S River St, Enterprise, OR 97828 ([email protected])
Zumwalt Praire Weather
2014
winds. Temperatures for the month were just slightly warmer than average (and a some
rain/snow at the end of the month (1/29) brought precipitation up to about normal (1.7 cm or
about ¾ in). The Chieftain, a local newspaper, reported on 6 Feb that snowpack in the
Wallowas was at around 75%, much better than the rest of the state.
February
February weather is usually very similar to January (just slightly less cold and about as dry). In
2014 the month started off very cold and with several significant snowfalls (Feb 3, 5). Nighttime
temperatures dipped to -21 C (-6 F) on the 5th (the low for the month and the year). Then
things warmed up suddenly on the 10th causing rapid melting of the snow resulting in localized
flooding of small creeks. The Zumwalt Rd was reported to be muddy and slow on the 12th.
Although much of the Pacific Northwest continued in severe drought, February on the prairie
had higher than average precipitation (4.5 cm or 1.8 in).
March
March was very wet (7.7 cm or 3 in) and warm (2 C or 36F) which resulted in continued
melting of earlier snows. On 9 March a “Pineapple Express” charged through the area resulting
in severe flooding of local rivers, including the Grande Ronde at Troy. Lightening Creek near
Midway Barn was in severe flood which resulted in the Little Sheep Creek Highway washing out.
Camp Creek was also in flood but less so, and the water observed near Summer Camp was
clear. On March 7 NOAA reported that
“The snowy blanket that builds in winter and feeds Columbia River rivers and streams
through spring and summer has shown a much desired growth spurt thanks to a wet
February and continued precipitation in early March.”
April
April is the start of the growing season on the prairie and temperatures typically warm
considerably from those of March (average daily temperature of 3 C or 37 F) and spring rains,
hopefully, begin (average total monthly precipitation of 3.4 cm or 1.3 in). This year temperatures
were just slightly warmer than normal and dry; just 2.5 cm (1 in) of precipitation fell, mostly as
rain. A stretch of cool dry weather occurred from the 9th until the 17th which was broken by a
series of storms which brought measurable precipitation each day from the 22nd through the end
of the month.
May
May is typically a wet month with an average of about 5 cm (2.5 in) of rainfall. This year May
was just slightly warmer than average (9 C or 48 F) and had only half the average precipitation
(2.4 cm or 0.9 in). Rainfall was scattered through the month with significant events (≥ 0.25 cm)
on the 4th, 9th, 18th, and 23rd.
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Zumwalt Praire Weather
2014
June
A typical June brings warm weather (average daily means of 12 C or 54 F) and abundant
rainfall (5.6 cm or 2.2 in). This year was about average with respect to temperature (11 C or 52
F but dry (3.5 cm or 1.4 in). Two cold fronts brought two periods of significant rain to the region
(Jun 12-18 and 25-28).
July
July is typically a hot (average daily temperature of 18 C or 64 F) and dry (average
precipitation of 0.9 cm or 0.3 in) month. This year was exceptionally dry with no precipitation
recorded despite a weak cold front that moved through the area around the 17th. Temperatures
were warmer than normal (daily average of 20 C or 68 F) and a heat spell in the latter part of
the month brought three consecutive days (27th through the 29th) of maximum temperatures of
32 C (90 F) which was also the record high for the year.
August
In August temperatures usually cool just slightly (average daily temperature of 17 C or 63 F)
with continued dry conditions caused by persistent high pressure systems over the region. This
year August brought pretty much average temperatures and was relatively wet. Temperatures
were warmer in the beginning of the month and cooled gradually; the exception was a period of
very warm weather from 10-12 Aug which matched the record daily high temperature of 32 C
(90 F) that was set in July. Three storms (on the 2nd, 14th, and the 22nd) brought significant
rainfall more than 0.5 cm or ¼ inch). The event on the 22nd brought 2.5 cm (1 in) of rain, the
greatest single daily amount for the year (through October at least).
September
By early September weather usually begins to change bringing cooler temperatures (average
daily temperature of 13 C or 55 F) and more precipitation as high pressure systems across the
region weaken and allow storms to push into the region. Average rainfall is 2.4 cm or 1 in. This
September was about average in temperature but very dry, especially for the first 3 weeks in
which no measurable precipitation fell. Dry weather broke on the 22nd with 0.4 cm of rain; wet
weather persisted until the end of the month with rainfall recorded on all days except the 24th,
27th, and 28th. Total rainfall for September was 1.2 cm (0.5 in) or just one half the 2006-13
average. September is also the last month of the six month growing season (which begins in
April) and a good time to take stock of the total precipitation falling during that period. For 2014
growing season precipitation totaled 14.1 cm (5.6 inches), substantially lower than the 20062013 average of 19.3 cm (7.6 inches).
October
Much cooler temperatures generally arrive this month (daily average temperatures of 6 C or 43
F) and trends towards wetter weather also continue (average monthly precipitation of 2.9 ± 5.8
cm or 1.1 inches). This year early October was very warm and very dry with no measurable
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Zumwalt Praire Weather
2014
precipitation until the 11th of the month after which several storms brought enough rain to bring
the total for the month almost to average (2.6 cm or 1.1 in). Temperatures remained very warm
though resulting in an average daily temperature of 9 C (48 F) for the month. Throughout the
Pacific Northwest, October was extremely warm; in nearby Lewiston, Idaho the average daily
temperature of 15 C (59 F) was the third warmest on record (source:
http://inlandnorthwestweather.blogspot.com/).
November
Heavy rains and mild temperatures signaled the start of the month with 1.6 cm (0.6 in) of
precipitation falling the very first day. Daily high temperatures exceeded 10 C (50 F) in 4 of the
first 9 days of the month and a total of 1.7 cm (0.7 inches) of rain fell. Temperatures cooled
significantly in the middle of the month reaching a low of -21 C (-6 F) but continued stormy.
Around the 18th warmer, dryer air entered the region which was followed by more unsettled
weather and precipitation. Of the 30 days in November 19 had measurable precipitation which
totaled 5.0 cm (1.1 inch), nearly double the 2006-14 station average. Temperatures dropped
sharply at the very end of the month but overall average November temperatures still ended up
slighter lower than the long-term station average at -1 C (30 F).
December
December started cold and wet but a period of warm and dry weather began after just a few
days. The average temperature from the 4th to the 11th was 6 C (43 F) and no measurable
precipitation fell. The weather changed on the 12th with moderate temperatures and a mix of
rain or snow (mostly rain) falling several days in the two weeks or so before Christmas. A
severe storm with heavy winds came through the area on the 14th knocking down many trees in
the Wallowa valley. Heavy rains on the 20th and the 21st brought over 2 cm of rain (0.9 inches)
to the prairie. Temperatures began dropping on Christmas Eve and storms brought abundant
snow making for a very white holiday but with bitterly cold temperatures on the 30th and the 31st
(lows of approximately – 25 C or -13 F on both nights ). Measurable precipitation fell nearly
half of the days in December including snow on 7 of the last 8 days of the month. bringing total
precipitation for December to 4.7 inches. Despite December’s very cold finish the average
temperature was -1 C (30 F) which was much higher than the long-term station average of -4
C (25 F).
Acknowledgments
Thanks to Janyne Little for her assistance with downloading and organizing data and for her
review of this report!
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Zumwalt Praire Weather
2014
References
Hansen, J. D., V. S. Jansen, and R. V. Taylor. 2010. Zumwalt Weather and Climate Annual
Report (2006-2009). The Nature Conservancy, Enterprise, OR.
Hansen, J. D., R. V. Taylor, and H. J. Schmalz. 2011. Climate of the Zumwalt Prairie Of
Northeastern Oregon from 1930 to Present. The Nature Conservancy, Enterprise, OR.
Figures and Tables
Figure 1. Monthly temperatures(C) at the Zumwalt Weather Station. Green
boxplots show averages from 2006-2013. Red boxplots show 2014 data.
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Zumwalt Praire Weather
2014
Table 1. Average Daily Mean Temperature s, 2006-2014 in (a) Celsius, and
(b) Farhenheit.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
All
2006-13
Mean
Std Dev
-3.27
5.15
-1.82
4.08
0.67
3.90
3.38
4.15
7.90
4.46
11.98
3.82
17.65
3.31
16.70
3.49
12.62
4.25
5.24
4.40
0.67
5.04
-4.00
5.32
5.68
8.52
2014
Mean
Std Dev
-1.97
N/A
-2.33
N/A
1.81
N/A
3.99
N/A
8.65
N/A
11.41
N/A
20.03
N/A
17.02
N/A
12.84
N/A
8.93
N/A
-1.22
N/A
-1.12
N/A
6.57
8.52
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
All
2006-13
Mean
Std Dev
26.12
9.27
28.73
7.35
33.20
7.03
38.08
7.48
46.21
8.03
53.56
6.88
63.77
5.95
62.07
6.29
54.72
7.65
41.43
7.93
33.21
9.07
24.79
9.58
42.23
15.33
2014
Mean
Std Dev
28.45
N/A
27.80
N/A
35.26
N/A
39.19
N/A
47.56
N/A
52.55
N/A
68.06
N/A
62.64
N/A
55.10
N/A
48.08
N/A
29.80
N/A
29.98
N/A
43.83
15.34
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Mean
-3.12
-1.87
0.79
3.45
7.98
11.91
17.92
16.74
12.64
5.65
0.46
-3.68
5.78
All
Std Dev
4.94
4.18
3.82
4.01
4.35
3.73
3.31
3.52
4.20
4.47
5.37
5.54
8.52
Mean
26.38
28.63
33.43
38.20
46.36
53.44
64.25
62.13
54.76
42.17
32.83
25.37
42.41
All
Std Dev
8.89
7.52
6.87
7.22
7.83
6.72
5.96
6.34
7.56
8.04
9.66
9.97
15.34
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Zumwalt Praire Weather
2014
Figure 2. Monthly Precipitation (cm) at the Zumwalt Weather Station, 20062014. Green bars show 2006-2013 station averages. Red bars are results
from 2014. Each error bar is constructed using 1 standard deviation from the
mean.
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Zumwalt Praire Weather
2014
Table 2. Average monthly precipitation, 2006-2014, in (a) centimeters and (b)
inches.
(a)
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
All
2006-13
Mean
Std Dev
0.76
0.31
0.58
0.28
1.26
0.50
1.37
0.37
2.16
0.81
2.32
1.55
0.39
0.30
0.61
0.47
0.98
1.27
1.16
0.78
0.99
0.34
1.02
0.20
1.13
0.89
2014
Mean
Std Dev
0.70
N/A
1.79
N/A
3.05
N/A
1.00
N/A
0.94
N/A
1.39
N/A
0.03
N/A
1.73
N/A
0.49
N/A
1.03
N/A
1.96
N/A
1.84
N/A
1.33
0.81
All
Mean
Std Dev
0.75
0.29
0.71
0.48
1.46
0.76
1.33
0.36
2.03
0.86
2.22
1.49
0.35
0.31
0.74
0.57
0.93
1.20
1.14
0.73
1.10
0.45
1.11
0.33
1.16
0.88
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
All
2006-13
Mean
Std Dev
0.76
0.31
0.58
0.28
1.26
0.50
1.37
0.37
2.16
0.81
2.32
1.55
0.39
0.30
0.61
0.47
0.98
1.27
1.16
0.78
0.99
0.34
1.02
0.20
1.13
0.89
2014
Mean
Std Dev
0.70
N/A
1.79
N/A
3.05
N/A
1.00
N/A
0.94
N/A
1.39
N/A
0.03
N/A
1.73
N/A
0.49
N/A
1.03
N/A
1.96
N/A
1.84
N/A
1.33
0.81
All
Mean
Std Dev
0.75
0.29
0.71
0.48
1.46
0.76
1.33
0.36
2.03
0.86
2.22
1.49
0.35
0.31
0.74
0.57
0.93
1.20
1.14
0.73
1.10
0.45
1.11
0.33
1.16
0.88
(b)
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