Alaska Statewide Summary
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Alaska Statewide Summary
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| April 2009 | Dramatic warm-up and record highs at month's end | |||||||||||||||||||
| As the month began, there were weak westerly winds aloft over Alaska. This continued until the final week of the month, when southerly flow developed ahead of a low in the Bering Sea, and then gained considerable strength. The change in circulation brought a very large rise in temperatures over the mainland during April's closing days with several new record high temperatures. Precipitation was above normal in the west, reflecting the influx of maritime air during the first 3 weeks of the month. Below normal precipitation was the rule in the east, especially interior valleys situated in the lee of the Alaska Range. Compared to the month before, the weather in April was quiet. There were only a few highland blizzards, and these were limited in their extent and duration. The snow pack over most of the mainland was substantial. At McGrath, in the southern Interior, the snowfall for the season was 138.8” - the 6th greatest winter snowfall in 70 years of records. The winter snowfall at the top of the Mount Alyeska Ski resort southeast of Anchorage totaled 615”. The rapid influx of southerly flow in the closing days of the month brought record high temperatures for much of Interior and Arctic Alaska, including sites such as Barrow, Fairbanks and Kaltag. Taken together, the sudden warming and the large snow pack produced a great surge of snow melt. The first showing of this was in the Salcha area, southeast of Fairbanks, which was flooded by high water and ice jams on the Tanana River. |
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| Along with this, the sudden warming and drying of the air during the last several days of the month rapidly increased fire danger. The State Division of Forestry suspended all outside burnings on the 30th. Ironically, the rising fire danger came at the same time as rising water levels and ice jams were developing on area rivers. The first migrating waterfowl appeared at Delta Junction on the 6th and at Fairbanks on the 9th - about 4 days earlier than average. The first few bugs showed up in the southern Interior on the 12th, but cooler weather limited their numbers. Mosquitoes made a tentative entrance in Fairbanks on the 27th. Out as sea, gales blew somewhere over Alaskan waters on 26 days of the month. None of these winds were particularly strong. On the 17th, a sudden squall capsized the 55 foot fishing vessel Seafarer in Thorne Bay, in Southeast Alaska. All five hands aboard were quickly and safely pulled out. The strongest storm of the month was a 982 millibar (29.00 inches) low in the southeast Bering Sea on the 26th. Southerly gales and rough seas developed ahead of this low. A large rise in temperatures to levels near to all time April records occurred over much of the mainland. The first rain event of the year fell at Barrow on the 26th. The extent of the pack ice in the Bering Sea was greater than normal. Little change in the location of the edge of the pack ice occurred until the third week of April. The pack ice edge ran from the western Alaska Peninsula to just south of Saint George Island during the first half of the month. By the end of April, the ice edge had retreated to northern Bristol Bay to about 100 miles south of Saint Matthew Island. While the aerial extent of the ice was well above normal, the ice within the pack was rather thin, as has been the case in the past several years. This situation often sets up a rapid retreat of the ice pack as summer begins. On the first of April, the ice in Cook Inlet extended down to Salamatof on the east side and along a strip of shore fast ice about 10 miles wide extending down almost to Cape Douglas. A rapid retreat was in progress by mid month, and the Inlet was ice free on the 24th. Sea surface temperatures in the Gulf of Alaska were 2 to 3°F cooler than normal during April. In the west, surface water temperatures were near normal in the Aleutians and 2 to 3°F warmer than normal near the edge of the pack ice in the central Bering Sea. The major event of the month continued to be a series of explosive eruptions at Mount Redoubt, on the west side of Cook Inlet. The largest eruption in the series occurred on the morning of the 4th. Massive snow on ice melt on the mountain brought an enormous surge of mud, water and debris down through the Drift River. The Drift River oil terminal was engulfed, but retaining walls around the terminal stood and withheld the onslaught. There was a significant ash fall over much of the Kenai Peninsula. The sky in Homer turned nearly as dark as night, and visibility dropped to one tenth of a mile. As the month went on, eruptions at Redoubt decreased considerably, but steam clouds and ash emissions went on continuously. |
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Click on the graphic for an expanded view. For a high resolution image, please email us.
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| Posted: May 15, 2009 Summary information is compiled and produced monthly by the Fairbanks Forecast Office of the National Weather Service and the Alaska Climate Research Center, with contributions by Ted Fathauer, Anton Prechtel, and Martha Shulski. Portions of this summary appear in Weatherwise magazine. Preliminary climatological data are used for the graphical products. For official data, please contact us or the National Climatic Data Center. |
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