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Alaska Climatology Dashboard

Monthly Climatologies
Aviation Climatologies
Snow Climatologies

About The Data

Monthly climatologies from dynamically downscaled ERA-interim data.

Global climate model (GCM) and reanalysis data are often too coarse (i.e., >100km) to resolve local climate features (i.e. <<100km) that are influenced by steep gradients around topography and coastlines. In data-sparse regions of Alaska there is great reliance on gridded climate products due to lack of weather stations to assess climate variability and change. ERA-Interim reanalysis data were dynamically downscaled to 20km spatial and hourly temporal resolution using the Weather Research and Forecasting (WRF; Skamarock et al., 2008) model to help address this need across all Alaska. The downscaling domain covers the entire Alaska region including adjacent waters (see Figure 1a, Bieniek et al., 2016) through a project funded by the USGS Alaska Climate Adaptation Science Center. The ERA-Interim reanalysis was downscaled for 1979-2015 and was downscaled because it is one of the best performing reanalysis tested over the Alaska region (Lader et al., 2016). The dynamical downscaling simulations provide winds, temperature, and precipitation as well as all elements of the radiation balance and upper-air atmospheric variables on an hourly temporal scale that is suitable for examining climate variability, trends and extremes in complex topography (Bieniek et al. 2016).

References:

Bieniek, P. A., Bhatt, U. S., Walsh, J. E., Rupp, T. S., Zhang, J., Krieger, J. R., and Lader, R. 2016: Dynamical downscaling of ERA-Interim temperature and precipitation for Alaska. Journal of Applied Meteorology and Climatology, 55(3), 635-654.

Lader, R., U. S. Bhatt, J. E. Walsh, T. S. Rupp, and P. A. Bieniek, 2016: 2-m temperature and precipitation from atmospheric reanalysis evaluated for Alaska. J Appl Meteor Climatol, 55, 901-922.

Skamarock, W. C. and Coauthors, 2008: A Description of the Advanced Research WRF Version 3. NCAR Tech Note, NCAR/TN–475+STR, 113 pp.


Click on the thumbnails below to view or download larger images. An option for metric units is provided in the image display window.


Maximum Temperature, 1981-2010 Average

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Minimum Temperature, 1981-2010 Average

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Average Temperature, 1981-2010 Average

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Precipitation, 1981-2010 Average

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

10 m Wind Speed, 1981-2010 Average

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January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Snow Water Equivalent, 1981-2010 Median

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Snow Water Equivalent, 1981-2010 Average

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

Snow Water Equivalent, 10th Percentile, 1981-2010

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January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
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September
Oct
October
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November
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December

Snow Water Equivalent, 90th Percentile, 1981-2010

Jan
January
Feb
February
Mar
March
Apr
April
May
May
Jun
June

Jul
July
Aug
August
Sep
September
Oct
October
Nov
November
Dec
December

About The Data

Aviation flight rules depend on a combination of cloud ceiling height and visibility and dictate the procedures used by pilots when operating aircraft. Establishing a climatological baseline of the frequency of these conditions is necessary in Alaska to bound operational aviation forecasts at airports and are especially critical since a significant portion of transportation in Alaska depends on aviation. Four aviation categories have been established by the Federal Aviation Administration and are Visual Flight Rules (VFR), Marginal VFR (MVFR), Instrument Flight Rules (IFR), and Limited IFR (LIFR). For this analysis hourly ceiling and visibility information were obtained from Alaska automated airport weather observations archived at Iowa State University's Iowa Environmental Mesonet over 1996-2017. The frequency of occurrence of each category was then recorded at key airports throughout Alaska. The aviation frequencies were subdivided by season (JFM, AMJ, JAS, OND) and 3-hr period of the day. Conditional frequencies were also computed by the wind direction at the time of occurrence.


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Bethel Airport (PABE)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Barrow/Post-Rogers (PABR)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Bettles Field (PABT)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Cold Bay Airport (PACD)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Cordova/Mile 13 (PACV)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Kodiak (PADQ)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Dutch Harbor (PADU)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Eagle Airport (PAEG)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Kenai Municipal (PAEN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Fairbanks International (PAFA)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Gulkana Airport (PAGK)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Gustavus (PAGS)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Skagway (PAGY)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Haines (PAHN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Homer (PAHO)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Juneau International (PAJN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

King Salmon (PAKN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Ketchikan International (PAKT)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Kaltag Airport (PAKV)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Merrill Field (PAMR)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Anchorage International (PANC)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Nenana/Muncipical (PANN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Nome (PAOM)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Northway (PAOR)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Kotzebue/Ralph Wien (PAOT)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Petersburg (PAPG)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Nuiqsut (PAQT)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Deadhorse (PASC)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Sitka/Japonski Airport (PASI)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Saint Paul Island (PASN)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Tanana/Calhoun Memorial (PATA)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Talkeetna (PATK)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Portage Glacier Center (PATO)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Wrangell (PAWG)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Wainwright Airport (PAWI)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

Yakutat (PAYA)

Annual
Annual
JFM
JFM
AMJ
AMJ
JAS
JAS
OND
OND

About The Data

Snow cover has important links to hydrology, ecology and transportation in Alaska. The amount water in the snow pack, snow water equivalent (SWE), describes not only the quantity or density of snow on the ground, but the amount of liquid water that will be available for runoff after the spring melt. The end-of-season SWE (EOS-SWE) integrates much of the snowfall through the winter and is a critical indicator of the water available once the melt begins. In this analysis 618 stations with data spanning 1979-2014 were obtained from the IMIQ database for Alaska. The stations included National Weather Service observations at airports, SNOTEL, NRCS snow courses and research sites. The yearly EOS-SWE for each station was determined for three separate dates by selecting the amount SWE on or nearest March 1, April 1 and May 1. The search period for stations without data on the EOS-SWE date was limited to no earlier than the 20th of the previous month or the 20th of the current month. Climatologies were computed for each station with at least 10 years of data, which was used to compute percent of normal EOS-SWE at the corresponding stations for each year.


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End-of-Season SWE Averages in Millimeters

Mar1
Season Ending March 1
   
Apr1
Season Ending April 1
   
May1
Season Ending May 1
   

End-of-Season SWE by Year in Millimeters

Mar1
Season Ending March 1
   
Apr1
Season Ending April 1
   
May1
Season Ending May 1
   

End-of-Season SWE by Year as Percentage

Mar1
Season Ending March 1
   
Apr1
Season Ending April 1
   
May1
Season Ending May 1
   
X