Near St. Lawrence Island
Satellite imagery shows a large polynya along the southern and western coastline of St. Lawrence Island, stretching 30 to 150 miles beyond the shoreline. Grease ice and strips of young ice cover parts of the polynya. Open pack ice composed of small to vast floes lies off the northern coastline beyond the shorefast ice extent with new and young sea ice in between the floes. The shorefast ice along the northern coastline of the island extends roughly 1 to 12 miles, while the shorefast ice along the southern coastline is mainly limited to the lagoons.
Wales to Shishmaref
The outer extent of the shorefast ice from Ikpek up to Shishmaref destabilized and broke off again this past week. The shorefast ice extent along the coast now varies from 2 miles off Shishmaref to 10 miles off Ikpek to 8 miles off Mugisitokiwik. The outer extent of the shorefast ice along this coastline formed later in the year and the outer extent of the shorefast ice from Wales up to Ikpek may destabilize this week. Very close pack ice lies near the Bering Strait and mainly consists of medium to vast floes with areas of leads freezing over with new and young ice.
5 to 10 Day Forecast
Weather System/Wind Synopsis
A low-pressure system centered in the Eastern Aleutians on Friday, 25 April will move into the Gulf of Alaska Saturday the 26th and remain through Sunday the 27th. Meanwhile, high pressure will be centered over Eastern Russia and slide into the Chukchi Sea. The resultant winds for Friday through Sunday morning will be north to northeast 15 to 25 mph (10 to 20 kt). The winds will begin to shift to the south and weaken (<15 mph or <10 kt) as a low-pressure system enters the Kamchatka area. The low will move to just west of St. Lawrence Island Monday, 28 April with winds increasing to 15 to 25 mph (10 to 20 kt) from the east. The low will move through Eastern Russia Monday and Tuesday with winds switching to the south 15 to 25 mph (10 to 20 kt). The first low will move into the Arctic Wednesday with another low entering the Southern Bering Sea continuing the southeasterly winds at 20 to 30 mph (15 to 25 kt). The winds will decrease to 15 to 25 mph (10 to 20 kt) on Thursday, 1 May as the low remains in the southern Bering Sea. The low will weaken in the southern Bering Sea Friday the 2nd and Saturday the 3rd with winds becoming light (<15 mph or <10 kt). The weaker low will transition into the Gulf of Alaska Sunday the 4th and Monday the 5th with winds becoming northerly at 10 to 15 mph (5 to 10 kt).
Temperature Trend & Ice Forecast
Temperatures from Friday the 25th through Monday the 5th of May will remain near normal near St. Lawrence Island to above normal (10 to 15 degrees above) along the west coast of Alaska. This means temperatures along Mainland Alaska will be above freezing during the daylight hours and near freezing temperatures overnight. Consequently, with warmer temperatures and mostly northerly winds through the weekend – high concentrations of thick ice will flow south through the Bering Strait and toward St. Lawrence Island. The outer extent of the shorefast ice from Wales to Ikpek may continue to destabilize and break off due to good ice flow from the north and then some offshore southeasterly winds midweek then northerly late next week.
We can expect the polynya south of St. Lawrence Island to expand during the weekend. During the midweek, southerly flow will close the polynya a bit. By next weekend, the light northerly flow will increase the polynya a bit before Monday the 5th.
Observations and Comments
Images from Savoonga
28 April 2014 - Olivia Lee, UAF
Comments from Shishmaref
25 April 2014 - Curtis Nayokpuk
We've had snow (wet) and fog daily, and can't see a 1/4 mile. This morning, we are again in heavy spring fog.
Comments from Nome
25 April 2014 - Fred Tocktoo
A lot of melt ponds are present in the shorefast ice. The shore ice was formed in late January and the warmer temperatures and rain during the winter contributed to the formation of thin shorefast ice. There is a lot of ice movement 1/2 mile to 1 mile out from the shorefast ice, and the ice around town broke out this morning (April 25) causing some excitement as some mining equipment was still out on the ice. There is a lot of ice seen out south of Nome's shore ice. We've had an early break-up compared to years' past, at least a month early. Rivers are beginning to run off, too.
We're seeing ice separation about three miles from shore. The gap is increasing its distance from the shore. Once the broken shore ice starts to move it's going to be gone, but will linger on going back and forth for several weeks more, to the shores while moving continuously northward through the Bering Straits.