Projected Decadal Averages of Monthly Snow-Day Fraction 771m CMIP3/AR4

These files include downscaled projections of decadal average monthly snow-day fraction (in percent) for each month of the decades from 2010-2019 to 2090-2099 at 771 x 771 m spatial resolution. Each file represents a decadal average monthly mean. Projections were produced for 5 models contributing to the IPCC's Fourth Assessment Report (CCCMA-CGCM3.1 t47, GFDL-CM2.1, MPI-ECHAM5, MIROC3.2 medres, and UKMO-HadCM3), a composite 5 model average, and two emissions scenarios (A1B and A2).

These snow-day fraction estimates were produced by applying equations relating decadal average monthly temperature to snow-day fraction to downscaled decadal average monthly temperature. Separate equations were used to model the relationship between decadal monthly average temperature and the fraction of wet days with snow for seven geographic regions in the state: Arctic, western Alaska, Interior, Cook Inlet, SW Islands, SW Interior, and the Gulf of Alaska coast.

Although the equations developed here provide a reasonable fit to the data, model evaluation demonstrated that some stations are consistently less well described by regional models than others. It is unclear why this occurs, but it is like related to localized climate conditions. Very few weather stations with long records are located above 500m elevation in Alaska, so the equations used here were developed primarily from low-elevation weather stations. It is not clear whether the equations will be completely appropriate in the mountains. Finally, these equations summarize a long-term monthly relationship between temperature and precipitation type that is the result of short-term weather variability. In using these equations to make projections of future snow, as assume that these relationships remain stable over time, and we do not know how accurate that assumption is.

These snow-day fraction estimates were produced by applying equations relating decadal average monthly temperature to snow-day fraction to downscaled projected decadal average monthly temperature. The equations were developed from daily observed climate data in the Global Historical Climatology Network. These data were acquired from the National Climatic Data Center in early 2012. Equations were developed for the seven climate regions described in Perica et al. (2012). Geospatial data describing those regions was provided by Sveta Stuefer.

Perica, S., D. Kane, S. Dietz, K. Maitaria, D. Martin, S. Pavlovic, I. Roy, S. Stuefer, A. Tidwell, C. Trypaluk, D. Unruh, M. Yekta, E. Betts, G. Bonnin, S. Heim, L. Hiner, E. Lilly, J. Narayanan, F.Yan, T. Zhao. 2012. NOAA Atlas 14. Precipitation-Frequency Atlas of the United States.

Data and Resources

Additional Info

Spatial resolution

771 meters

Temporal extent

Start date: January 2001

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
Field Value
Maintainer Tom Kurkowski
Version 1.0.0
access_constraints [""]
bbox-east-long 180179.83740000002
bbox-north-lat 71.41994
bbox-south-lat 49.10694
bbox-west-long -179.32041
coupled-resource []
credits ["Matthew Leonawicz", "Michael Lindgren", "Tom Kurkowski", "John Walsh", "Scott Rupp", "Stephanie McAfee"]
dataset-reference-date [{"type": "creation", "value": "2012-05-08T00:00:00"}]
frequency-of-update asNeeded
graphic-preview-description thumbnail
graphic-preview-file pr_decadal_mean_monthly_total_mm_cru_TS31_historical_06_1950_1959_thumb_s.png
graphic-preview-type png
guid 3d9a696c-eec7-4c1a-be1e-d5b288afc6cd
licence []
license Creative Commons Attribution 4.0
metadata-date 2018-05-22T14:46:09
progress onGoing
responsible-party [{"name": "Scenarios Network for Alaska and Arctic Planning (SNAP)", "roles": ["pointOfContact"]}]
spatial {"type": "Polygon", "coordinates": [[[-179.32041, 49.10694], [180179.8374, 49.10694], [180179.8374, 71.41994], [-179.32041, 71.41994], [-179.32041, 49.10694]]]}
spatial-reference-system 3338
spatial-resolution 771
spatial-resolution-units meters
spatial_harvester true
temporal-extent-begin 2001-01-15T00:00:00
temporal-extent-end 2100-12-15T11:00:00