Historical and Projected Decadal Average Monthly Snowfall Equivalent and the Ratio of Snowfall Equivalent to Precipitation 771m CMIP5/AR5/CRU TS3.1

These files include climatological summaries of downscaled historical and projected decadal average monthly snowfall equivalent ("SWE", in millimeters), the ratio of snowfall equivalent to precipitation, and future change in snowfall for October-March at 771-meter spatial resolution across the state of Alaska.

Derived snow variables and summaries. Data are for summary October to March Alaska climatologies for:

1) historical and future snowfall equivalent ("SWE"), produced by multiplying snow-day fraction by decadal average monthly precipitation and summing over 6 months from October to March to estimate the total SWE on April 1.

2) historical and future ratio of SWE to precipitation ("SFEtoP"), SFEtoP is the ratio of October to March total SWE to October to March total Pr is calculated as total SWE/total Pr. (expressed as percent, 0-100)

3) future change in snowfall equivalent relative to historical ("dSWE"), calculated as(SWE future – SWE historical)/SWE historical

The historical reference period is 1970-1999, (file name “H70.99”), calculated from downscaled CRU TS 3.1 data

Future climatologies (both RCP 4.5 and 8.5 emissions) are for:
-2020s (2010-2039)
-2050s (2040-2069) and
-2080s (2070-2099)
for all 5 GCMs: NCAR-CCSM4, GFDL-CM3, GISS-E2-R, IPSL-CM5, and MRI-CGCM3 as well as a 5-model mean (“5MM”)

Following Elsner et al. (2010), <0.1 is rain dominated, 0.1 < SFE:P 0.4 is snow dominated. Only calculated for historical reference climatology 1970-1999 and three future climatologies: 2010-2039, 2040-2069, and 2070-2090, with each climatology representing the mean of three decadal averages from the available decadal grids.

Snow fraction data used can be found here:


Precipitation data used can be found here:



  • Note: In Littell et al. 2018, "SWE" is referred to as "SFE", and "SFEtoP" as "SFE:P"

Data and Resources

Additional Info

Spatial resolution

771 meters

Temporal extent

Start date: January 1970

End date: December 2100


The following people worked on producing this data set:

  • Matthew Leonawicz
  • Michael Lindgren
  • Tom Kurkowski
  • John Walsh
  • Scott Rupp
  • Stephanie McAfee
  • Jeremy Littell
Field Value
Source http://data.snap.uaf.edu/data/Base/AK_771m/SWE_dSWE_SFEtoPR/
Maintainer Tom Kurkowski
Version 1.0.0
access_constraints ["Please cite: Littell, J.S.; McAfee, S.A.; Hayward, G.D.\tAlaska Snowpack Response to Climate Change: Statewide Snowfall Equivalent and Snowpack Water Scenarios. Water 2018, 10, 668.", "https://creativecommons.org/licenses/by/4.0/"]
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contact-email takurkowski@alaska.edu
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credits ["Matthew Leonawicz", "Michael Lindgren", "Tom Kurkowski", "John Walsh", "Scott Rupp", "Stephanie McAfee", "Jeremy Littell"]
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metadata-date 2018-05-31T16:33:15
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temporal-extent-begin 1970-01-15T00:00:00
temporal-extent-end 2100-12-15T11:00:00