Anchorage, Alaska

Much quieter (but still somewhat unsettled) conditions are prevailing across Southcentral compared to this time yesterday. The frontal system that brought all sorts of chaos in the form of intense winds, rain and mountain snow has now moved off into the AlCan region and eastern Gulf, allowing southeasterly winds and steadier precipitation to subside. In the wake of the front, a showery regime is taking over as cool air aloft rushes in near a weak low and attendant upper trough shifting east into the region from Southwest. Widespread rain showers are streaming north ahead of the trough axis into the northern Gulf Coast, with some occasional lightning noted with one of the stronger updrafts overnight south of Seward. Marine instability could fuel a few more marine thunderstorms out over the Gulf today, in addition to the ongoing showers. Farther inland, conditions have mostly dried out, but showers are still occasionally working north past the coastline into parts of the Kenai Peninsula and Mat-Su Valleys. Rain could mix with or turn to snow at times along the Seward Highway corridor, especially near Moose Pass and Turnagain Pass, so watch out for sudden reductions in visibility and slick spots along this corridor today.

Looking to the remainder of the weekend into early next week, the overall showery and seasonably warm pattern does not look likely to change much. The trough and weak low currently drifting into the western Gulf will continue to slowly lift northeast, keeping scattered rain showers going over water and periodic rain/snow showers spreading inland over Southcentral on-and-off through Monday. What`s left of the main trough axis will begin to shear apart as it lifts northeast towards the northern Alaska Range by late Monday evening. By around the same time, the next system of interest will also enter the southwestern Gulf. A frontal system associated with a sprawling Bering low will begin to send strong southeasterly winds and rain into the southern Gulf and across Kodiak Island as it approaches from the south towards the end of the day on Monday. This looks like the start of what could be an extended period of more active weather next week, especially in terms of wind and waves in and around the Gulf, so stay tuned for updates.

-AS

Key Messages

• Wind Advisory in effect for Unalaska/Nikolski through 7 AM AKDT this morning (Saturday).
• Cold air from the north moves in behind the strong Bering low as it moves into the Gulf of Alaska for this weekend.
• Pattern remains active across the Bering and Aleutians this weekend and into the new work week. Low tracks look to be a little more southerly than this past week.

The Bering low which brought increased water levels across the Kuskokwim Delta the past few days and brought gusty winds to the Aleutian Chain is currently crossing the the Alaska Peninsula (AKPEN) into the North Pacific this morning. Rain will continue across the Aleutians, AKPEN, and Southwest and become more showery in nature for this weekend with cold air moving in. Some snow flakes may mix in at times across the Kuskokwim Delta and Kuskokwim Delta Coast as precipitation combines with the incoming cold air this weekend. Overall, the forecast remains largely on track. The coastal flood advisory that was out for the Kuskokwim Delta Coast until this morning was cancelled. There will be higher water levels this morning`s high tide, but winds have diminished significantly and the next tide will be lower than Friday morning`s high tide tide.

Flow switches back to the south and southeast for Sunday ahead of the next storm system moving across the Bering. Initially, for today, a North Pacific low tracks south of Kamchatka as its gale-force front moves across Shemya and the western Bering Saturday evening. The gale-force front spreads gusty southeasterly winds to Adak/Atka Saturday night through Sunday morning before making its way to the Pribilof Islands, Unalaska/Nikolski, and the southern AKPEN by Sunday afternoon and evening. Light to moderate rain will also accompany this front on its eastern journey across the Bering this weekend. Behind the front, strong winds are expected to wrap cooler air into the low. This cold air wrapping into the storm will also generate instability over the Bering and North Pacific near the Aleutian Chain where a few lightning strikes will be possible (10 to 30 percent chance) Sunday and Monday. The Pacific side marine zones of the Western and Central Aleutians will have the best chance for marine lightning with the better jet dynamics residing there.

Gale force winds are expected at this time to switch from southeasterly to southwesterly behind the initial front. Stronger gusts above 55 kt will be possible. There is a potential for storm force sustained winds or stronger Sunday into Monday (30 to 40 percent chance) as the low center moves along the Western Aleutian Chain (Shemya) to the Central Aleutians (Adak/Atka) and Eastern Aleutians (Nikolski/Unalaska) by Monday evening and Tuesday morning.

As far as Southwest Alaska and the Kuskokwim Delta Coast are concerned with this system, the front and its gusty easterly to east-southeasterly winds eventually make it to the coastal Southwest by Monday morning, along with rain. Right now, this set up does not look conducive for a coastal flooding threat along the Kuskokwim Delta Coast, due in part to the more offshore/easterly component to the wind. Most of the rain with this system will look to fall along the coast and the AKPEN, especially the Pacific side, Monday into Tuesday, with interior portions of Southwest contending with showers at times. Continue to monitor the forecast for updates as the active weather pattern continues to unfold.

The weather pattern will remain active through the long term as a broad trough with numerous shortwaves remains over the Bering Sea and far northern Pacific. Due to the abundance of shortwaves and interactions along a broad baroclinic zone, models are struggling to reach a consensus on the track of each respective storm/shortwave as they move from the Chain into the Gulf. As such, forecast confidence for the timing of strong winds and/or rain remains low. Given then abundance of warm air from the current system, and another warm and wet system on Tuesday, rain remains the main precipitation type for most populated areas throughout the southern Mainland and Aleutians. Modeled snow levels are forecast to be between 1500 and 2500 ft, but due to the large spread in storm track there is a large variation in which areas may be cold enough to get snow. Overall, the forecast remains noisy, but warmer than normal temperatures and areas of rain will continue. In comparison to the current weather, impacts such as wind and rain are more likely to be over the Aleutians, Kodiak, the Alaska Peninsula and the Kenai Peninsula.

PANC...A strong southeasterly Turnagain Arm wind will persist over the terminal through early Saturday morning. Winds and gusts are likely to be strongest, with gusts 35 to 50 mph, through 4 PM before slowly diminishing, with gusts 25 to 40 mph, through around midnight. While wind are expected to continue to slowly weaken through the overnight hours into Saturday morning, occasional gusts to around 25 kt are likely to remain over the terminal through Saturday morning.

Rain showers are expected to fill back in over the terminal by late this afternoon. MVFR ceilings are likely with MVFR visibilities possible in heavier showers. The precipitation will likely taper off by around midnight. However, another round of scattered showers is likely by early Saturday morning. While VFR conditions are expected to prevail during this time, any heavier showers could result in brief periods of MVFR ceilings and visibilities.