A Dry Water Year So Far across Southern Colorado

It has been a dry late Fall and early Winter Season thus far across South Central and Southeast Colorado, with the following graphics indicating 2018 Water Year precipitation totals to date (October 2017 through January 2018) for select weather observing stations across Southern Colorado. A “Water Year” is defined as a 12 month period starting October 1^st, for any given year, through September 30^th of the following year, in which precipitation totals are used by water and land management agencies. In the following graphics, the green line is the current 2018 Water Year tally, with the brown line indicating 30 year normal precipitation to date. The magenta line is Water Year 2002 precipitation to date, with the orange and cyan lines indicating Water Year 2012 and 2013 precipitation to date, respectively. The black dots indicate missing data.

After looking at the data, a fairly typical La Nina pattern can be seen, with near to slightly below normal precipitation for the Water Year thus far across portions of the Central Mountains (Climax), with the Eastern Mountains (Florissant, Lake George, Cheesman, Rye, Westcliffe and Aguilar) and the Southeast Plains indicating below to well below normal precipitation for the Water Year thus far. Also, some eerie similarities can be seen comparing Water Year 2018 to date, with Water Year 2002 to date, the second half of Water Year 2012 to date (the Fall of 2011 was fairly wet across southern Colorado) and Water Year 2013, to date. In the summer of 2002, 2012 and 2013, the Hayman Fire (2002), the Waldo Canyon and Wetmore Fires (2012), and the Black Forest, the Royal George, the East Peak, and the West Fork Complex Fires (2013) all ravaged Southern Colorado. Hopefully the current La Nina will continue to weaken, allowing for more storms to move across South Central and Southeast Colorado through the rest of the Winter and into the Spring.

The data used has been collected from National Weather Service weather observing systems and the NWS Cooperative Observer Program (COOP). Graphics are courtesy of ACIS and the NOAA Regional Climate Centers.