textproduct: Anchorage

LONG TERM FORECAST (Days 4 through 7)

A highly amplified pattern is expected through the second half of the week as a deep upper level Kamchatka low opens into a trough in the western Bering while a strong upper ridge slides east across the Mainland Friday through Saturday. Models remain consistent on the overall upper level longwave pattern with the biggest uncertainty continuing to be the exact timing and placement of individual shortwaves embedded within the mid to upper level flow. The strong surface low over eastern Russia continues to trend farther north and west, with ensemble model guidance steady in the general northeastward track across far eastern Siberia and into the Arctic Ocean Friday into Saturday. Confidence remains high on its associated gale- force front tracking east across the Bering through mid to late this week, bringing gusty southwesterly winds and moderate to heavy rainfall across the Aleutians and Pribilof Islands.

The strong front similarly continues to trend farther north in the Bering as its eastward progression stalls against the strong high pressure stretching across the North Pacific into the southern Mainland. The longest duration and strongest core of winds with this system is now expected to affect the Norton Sound and Seward Peninsula region through Friday. Despite this shift in the storm track, a period of gusty small-craft to potentially gale-force winds along the front is still likely to impact the Kuskokwim Delta coast by Thursday night through Friday evening. The long fetch of strong, southwesterly onshore winds could bring the possibility of high surf and minor coastal flooding and erosion along the Kuskokwim Delta coast as the front progresses through the region. Elevated water levels in the Lower Kuskokwim River due to preceding rainfall across the Interior, combined with additional rainfall, could lead to minor river flooding for communities along the river from Bethel to the Kuskokwim Bay. Details will continue to become clearer in the coming days on the exact timing and potential impacts of this upcoming late-week storm.

Behind this system, weaker west-southwesterly flow continues over the Bering and Southwest Alaska through the weekend, while the weakening frontal system and rainfall continues east into Southcentral and the Gulf. Broad troughing remains centered over the Bering, with models hinting at the pattern becoming more amplified once again as a low lifts north out of the North Pacific early next week.

AVIATION

PANC...Waves of rain showers will continue moving across the terminal for the rest of the morning, with a general decrease in coverage by midday. As such, expect MVFR visibilities and MVFR to IFR ceilings for much of the remainder of the morning. There is some uncertainty in how low ceilings fall this morning, especially around the 14-18z timeframe. Also, the Turnagain Arm wind with gusts to around 20 to 30 knots will be the case until midday, with winds thereafter diminishing rapidly as lighter southwesterly winds take over by this afternoon.

-AM