(SitNews) Ketchikan, Alaska - The unseasonably cold temperatures statewide in Alaska from April extended (with a short reprieve on the 9th and 10th) well into May. Above normal mean statewide temperatures returned on the 23rd, and stayed until the end of the month.

The mean temperature of all first order stations statewide for May was 39.9°F, 3.1°F below the long-term mean of 43.0°F. Eighteen of the 20 First Order Stations reported negative deviations, with Interior and Western stations reporting the most extreme deviations from their expected temperatures.

Bettles topped the list with a significant negative deviation of -8.2°F. Following Bettles were: Bethel (-6.6°F), Nome (-5.7°F), Kotzebue (-5.5°F), and Fairbanks (-5.1°F). Barrow reported the largest positive deviation of 1.6°F, followed by Annette Island (Ketchikan) with 1.2°F. Fairbanks had its first 50°F day on May 8th, for a total of 215 days since that temperature had last been reached. This is the fifth longest stretch of under 50°F days for Fairbanks in more than one hundred years. For Nome, the first 40°F days was reached on the 25th, for a total of 224 days below 40°F. Details for each station can be reviewed in the table below.

May precipitation was heavier than normal statewide with twelve of the 20 stations reporting above average totals. The mean value of all 20 stations was calculated to 35% above normal. Topping the stations with heavier than normal precipitation was Valdez with 271% above normal. Next came: Gulkana (228%), Barrow (122%) and Anchorage (113%). Bettles reported the greatest negative deviation with just 3% of the expected value. Rounding out the stations with less than a quarter of normal totals were: McGrath (6°%), Delta Junction (10%), and Bethel (18%).

Unsurprisingly, considering the low temperatures during much of the month, snowfall for May was above normal with eight of the sixteen stations reporting heavier than normal snowfall, resulting in an overall mean of 214% above normal. However, much of this positive deviation was from Valdez where more than ten times the normal snow fell during the month; with most of this snowfall arriving during the first five days of the month. Bettles (669% above normal), Kotzebue (425%), Nome (370%), Kodiak (350%) and Anchorage (333%) topped the stations with highly elevated snowfalls. Trace or more of snow was recorded for 24 days of the month in Barrow.

A large number of precipitation and snowfall records were set in May; many of them centered on the storm events of in the Southeast on the 1st, and in the Southcentral / Interior areas on the 3rd and 4th. A number of the snowfall events occurred on days for which snowfall had never been recorded before. The cold temperatures, the prior months' snowfalls as well as heavy May snowfalls in Valdez resulted in a mean snow depth for the month of more than twenty times normal. May was the snowiest on record in Nome with a total of 10.8", topping the 1977 record of 10.0".

On May 1st, Ketchikan precipitation measured 3.68 inches breaking the old 1980 record of 2.01 inches -- a whole 1.67" higher than the previous record. In Southeast Alaska, Juneau, Petersburg, Haines and Sitka also set new precipitation records on May 1st.

Along with Barrow, Ketchikan was one of two stations that had a monthly mean May temperature (50.7°F) that was warmer than normal (48.6°F). The highest temperature of the month was observed on the 22nd, a pleasant 67°F, while the lowest temperature for the month was recorded on the May 1st, at 38°F.

Alaska's tempest of the 3rd of the month brought winter storm warning across much of the state. More heavy snows on the 6th of May dropped up to two feet in Nabesna and Mentasta Pass. Storm warnings were again issued on the 13th for much of the state, and hazardous driving conditions were reported on the Dalton and Parks Highways. The Dalton also saw an unprecedented number of avalanches during the month, and they continued up to the end. Despite ongoing work by the road crews, the Denali Highway was not opened to summer traffic by the 31st.

May's cold weather also resulted in later than normal break up across many of the rivers. Flooding from an ice jam on the Yukon hit Eagle on the 17th. Flooding moved down river to Circle on the 19th, with the locals calling it the worst flood to ever hit the community. Fort Yukon residents prepared to be next, but the town was mostly spared. Heavy flooding next hit Galena on the 26th, resulting in most of the town being evaluated. Water did not recede until the 28th. Minor flooding was reported along the Salcha River around the 25th. The Steese Highway was closed due to flooding on the 28th.

By mid May the unusual weather was having its effects felt in the annual migration of many bird species that travel through the Interior. The Nenana Ice Classic recorded its latest break up on record on the 20th. The annual guessing game has a 97-year record. Finally, Green-Up-Day for Fairbanks was recorded on the 26th, which was also the latest on record.

Edited by Mary Kauffman, SitNews

This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. This summary is based on the 20 first order stations in Alaska operated by the National Weather Service. Extreme events of other stations are also mentioned. It should be noted that the new climate normals for the time period of 1981-2010 are applied for the calculations of the deviations, and they can be slightly different from the old normals (1971-2000), which were in use up until end of July 2011.

Source of News: 

The Alaska Climate Research Center
http://climate.gi.alaska.edu

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