IntermtnClimateSummaryJan2008

• Title: Intermountain West Climate Summary
• Date: 1/22/2008
• Description: Water Availability Task Force Meeting Report
• Basin: Statewide
• Drought Mitigation - Doc Type: Reports

INTERMOUNTAIN WEST CLIMATE SUMMARY, JANUARY 2008

Precipitation 12/1/07 -12/31/07

Total precipitation for December 2007 in the Intermountain
West region ranged from 0.25 to 3+ inches (Figure 3a). West-
ern Colorado and central Utah received the highest totals (3+
inches). Southeast Colorado, northeast Wyoming, and north-
central Wyoming received the lowest amount (0.25 - 0.50
inch). December 2007 was the wettest on record for western
Colorado, according to the NWS Grand Junction. Total
precipitation at the Grand Junction Airport was 2.05 inches for
the month of December, which broke the previous record of
1.89 inches set in 1951.
While there were some areas of below average precipita-
tion in December, most of the region had near or above aver-
age precipitation (Figure 3b). Western Colorado and most of
Utah reported above average precipitation (200% +). Areas
in northern Wyoming reported the lowest percent of average
(<40 - 80%). Salt Lake City received 3.35 inches of precipi-
tation for December, which is 272% of normal, according to
the NWS Salt Lake.
Precipitation since the start of the water year is near
average or above average for most of the region (Figure
3c). Below average areas include southeast Colorado and
northeast Wyoming (<50 - 70%). The \vettest areas \vere in
western Colorado, eastern Utah, and southeast Wyoming
(110-150%+).

Notes
The data in Figs. 3 a-c come from the High Plains Regional
Climate Center. These data are considered experimental
because they utilize the most recent data available, which have
been subject to minimal quality control. These maps are derived
by taking measurements at individual meteorological stations
and interpolating (estimating) values between known points to
produce continuous categories. Interpolation procedures can
cause incorrect values in data- sparse regions. For maps with
individual station data, please see web sites listed below. The
water year runs from October 1 to September 30 of the following
year. The 2007 water year began October 1, 2006 (Figure 3c).
The water year better reflects the natural cycle of accumulation
of snow in the winter and run-off and use of water in the spring
and summer. It is a better period of analysis for presenting cli-
mate and hydrologic conditions. Average refers to the arithmetic
mean of annual data from 1971- 2000. Departure from average
temperature is calculated by subtracting current data from the
average. The result can be positive or negative. Percent of
average precipitation is calculated by taking the ratio of current
to average precipitation and multiplying by 100.

Figure 3a. Total precipitation in inches for the
month of December 2007.

Figure 3b. Percent of average precipitation for the
month of December 2007.

On the Web
· For the most recent versions of these and maps of other climate variables including individual station data, visit: http://
www.hprcc.unl.edu/products/current.html.
· For precipitation maps like these and those in the previous summaries, which are updated daily visit: http://www.cdc.
noaa.gov/Drought/.
· For National Climatic Data Center monthly and weekly precipitation and drought reports for Colorado, Utah, Wyoming,
and the whole U. S., visit: http://lwf.ncdc.noaa.gov/oa/climate/research/monitoring.html.
· For a list of weather stations in Colorado, Utah, and Wyoming, visit: http://www.wrcc.dri.edu/index.html.

RECENT CONDITIONS I 6

3
2
1.5

0.5
0.25
o

Inches

Wet

200

150

120

80

50

40

Dry

Wet

150

130

110

90

70

50

Dry