Climate of Alaska
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The climate of Alaska is determined by average temperatures and precipitation received statewide over many years. The extratropical storm track runs along the Aleutian Island chain, across the Alaska Peninsula, and along the coastal area of the Gulf of Alaska which exposes these parts of the state to a large majority of the storms crossing the North Pacific. Onshore flow into the various mountain chains across the state leads to significant spacial variability in precipitation, with snowfall constituting a bulk of the annual precipitation each year. The climate in Juneau and the southeast panhandle is a mid-latitude oceanic climate (Köppen climate classification Cfb) in the southern sections and a sub Arctic oceanic climate (Köppen Cfc) in the northern parts. The climate in south central Alaska is a subarctic climate (Köppen Dfc) due to its short, cool summers. The climate of the interior of Alaska is best described as extreme and is the best example of a true subarctic climate, as the highest and lowest recorded temperatures in Alaska have both occurred in the interior. The climate in the extreme north of Alaska is a Arctic climate (Köppen ET) with long, very cold winters and short, cool summers.
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[edit] Precipitation
The extratropical storm track runs along the Aleutian Island chain, across the Alaska Peninsula, and along the coastal area of the Gulf of Alaska which exposes these parts of the state to a large majority of the storms crossing the North Pacific. Onshore flow into the various mountain chains across the state leads to significant spacial variability in precipitation, with snowfall constituting a bulk of the annual precipitation each year.[1] This makes the actual liquid equivalent precipitation across the state more uncertain than elsewhere, due to the variety of methods of measuring precipitation originating as snowfall and difficulty of catching snowfall in precipitation gages across the Arctic.[2] January through April are the drier months statewide. The interior receives more rainfall during the summer.[3] Southern and western Alaska have a maximum during the late summer and fall months.[4]
Juneau averages over 50 inches (1,270 mm) of precipitation a year, while other areas in southeast Alaska receive over 275 inches (6,990 mm). South central Alaska does not get nearly as much rain as the southeast of Alaska, though it does get more snow. On average, Anchorage receives 16 inches (406 mm) of precipitation a year, with around 75 inches (1,905 mm) of snow. The northern coast of the Gulf of Alaska receives up to 150 inches (3,800 mm) of precipitation annually.[1] Across western sections of the state, the northern side of the Seward Peninsula is a desert with less than 10 inches (250 mm) of precipitation annually, while some locations between Dillingham and Bethel average around 100 inches (2,540 mm) of precipitation. Inland, often less than 10 inches (250 mm) falls a year, but what precipitation falls during the winter tends to stay throughout the season.[5] La Niña events lead to drier than normal conditions, while El Niño events do not have a correlation towards dry or wet conditions. Precipitation increases by 10 to 40 percent when the Pacific decadal oscillation is positive.[6]
[edit] Temperature
[edit] Southeast
The climate in Juneau and the southeast panhandle is best described as a "cooler version of Seattle." It is a mid-latitude oceanic climate (Köppen climate classification Cfb) in the southern sections and a sub Arctic oceanic climate (Köppen Cfc) in the northern parts. On an annual basis, this is both the wettest and warmest part of Alaska with milder temperatures in the winter and high precipitation throughout the year. This is also the only region in Alaska in which the average daytime high temperature is above freezing during the winter months.
[edit] South
The climate in south central Alaska, with Anchorage as a typical city, is mild by Alaskan standards. This is due in large part to its proximity to the coast. While it does not get nearly as much rain as the southeast of Alaska, it does get more snow, although days tend to be clearer here. It is a subarctic climate (Köppen Dfc) due to its short, cool summers.
The climate of Western Alaska is determined in large part by the Bering Sea and the Gulf of Alaska. It is a subarctic oceanic climate in the southwest and a continental subarctic climate farther north. The temperature is somewhat moderate considering how far north the area is. This area has a tremendous amount of variety, especially when considering precipitation. The northern side of the Seward Peninsula is technically a desert with less than 10 inches (250 mm) of precipitation annually, while some locations between Dillingham and Bethel average around 100 inches (2,540 mm) of precipitation.[5]
[edit] Interior
The climate of the interior of Alaska is best described as extreme and is the best example of a true subarctic climate. Some of the hottest and coldest temperatures in Alaska occur around the area near Fairbanks. The summers can have temperatures reaching into the 80s°F (near 30 °C), while in the winter, the temperature can fall below −60 °F (-52 °C).
[edit] North
The climate in the extreme north of Alaska is what would be expected for an area north of the Arctic Circle. It is an Arctic climate (Köppen ET) with long, very cold winters and short, cool summers. Even in July, the average low temperature is barely above freezing in Barrow, at 34 °F (1 °C).[7]
[edit] Extremes
The highest and lowest recorded temperatures in Alaska are both in the Interior. The highest is 100 °F (38 °C) in Fort Yukon on June 27, 1915,[8][9] tied with Pahala, Hawaii as the lowest high temperature in the United States.[10][11] The lowest Alaska temperature is −80 °F (-64 °C) in Prospect Creek on January 23, 1971,[8][9] one degree above the lowest temperature recorded in North America (in Snag, Yukon, Canada).[12]
[edit] References
- ^ a b Western Regional Climate Center. Climate of Alaska. Retrieved on 2008-03-19.
- ^ Dennis Lettenmaier. 4. Hydrological Cycle in the Arctic Region. Retrieved on 2008-03-21.
- ^ Alaska Geospatial Climate Animations. Patterns for Precipitation. Retrieved on 2008-03-19.
- ^ Alaska Geospatial Climate Animations. Alaska Geospatial Climate Animation: Precipitation. Retrieved on 2008-03-19.
- ^ a b Mean Annual Precipitation in Alaska-Yukon. Oregon Climate Service at Oregon State University. Retrieved on 2006-10-23.
- ^ John Papineau, Ph.D. Understanding Alaska's Climate Variation. Retrieved on 2008-03-19.
- ^ History for Barrow, Alaska. Monthly Summary for July 2006. Weather Underground. Last accessed 23 October 2006.
- ^ a b NOAA Weather Radio All Hazards Information - Alaska Weather Interesting Facts and Records (PDF). National Oceanic and Atmospheric Administration. Retrieved on 2007-01-03.
- ^ a b State Extremes. Western Regional Climate Center, Desert Research Institute. Retrieved on 2007-01-03.
- ^ SD Weather History and Trivia for May: May 1. National Oceanic and Atmospheric Administration. Retrieved on 2007-01-03.
- ^ FAQ ALASKA - Frequently Asked Questions About Alaska: Weather. Statewide Library Electronic Doorway, University of Alaska Fairbanks (2005-01-17). Retrieved on 2007-01-03.
- ^ Ned Rozell (2003-01-23). The Coldest Place in North America. Geophysical Institute of the University of Alaska Fairbanks. Retrieved on 2007-01-03.
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