.SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA/ALEUTIANS (Days 1 through 3)...

A front over Southwest Alaska this afternoon continues inland, bringing light to moderate rain across the region before deteriorating over the Interior Sunday afternoon. Close behind the front will be the remnants of tropical depression Leepi, helped along by a 120+ knot jet streak. Pockets of gale force wind will surround this somewhat compact low. Rain begins on the heavier side, up to 1.0 inch near Shemya and Adak tonight, due to its tropical origins. But, expect intensity to lessen as it continues eastward and cooler air is entrained into the system. Less than 0.40 inch is expected for all other locations along this system's path. The center of the low is expected to reach the Alaska Peninsula late Sunday night, but the north/south track varies between the models by as much as 100 miles as it progresses eastward between the Pribilof and Aleutian Islands. The consensus this afternoon, is that by Monday this system will track across Bristol Bay into the Western Gulf, and into the Eastern Gulf by Tuesday morning.

.LONG TERM FORECAST (Days 4 through 7: Wednesday through Saturday)...

The long-term pattern across southern Alaska looks to remain active, albeit progressive. A low in the eastern Bering Sea Wednesday looks to head for the Gulf Wednesday afternoon into the first part of Thursday and strengthen to gale-force as it does so.
Light to moderate rain across Bristol Bay and the Alaska Peninsula will work towards Kodiak Island and the eastern Kenai Peninsula. There is relatively good agreement amongst guidance with easterly flow associated with the front, and a track near Kodiak Island before turning east into the central Gulf Thursday morning. With these ingredients, the most rain looks to fall along Kodiak Island and the coastal mountains of the north Gulf Coast and Prince William Sound Wednesday through Thursday. The storm then moves to Southeast Alaska Thursday evening and Friday.

Meanwhile, behind the Gulf storm, ridging builds across the central Bering Sea for Thursday as mainland Southwest Alaska looks to remain showery with weak shortwaves rotating through on the backside of the Gulf system. This ridge will move eastward to the eastern Bering Sea and mainland Southwest for Friday and Saturday.
The best days for quieter conditions across the southwestern mainland look to be Friday and Saturday when the ridge is more in control of the pattern.

Further out west, and more notably, a storm system forming in the Sea Okhotsk Wednesday will start to become the main weather player across the Bering with time. The front initially moves across the western Aleutians and western Bering Wednesday into Thursday. As the main upper-level trough amplifies and digs further south into the North Pacific, additional moisture looks to be pulled northward into the central Aleutians, Pribilof Islands, and central Bering for Friday. With this moisture surge, moderate to heavy rain will be possible for the central Aleutians Friday.
This threat looks to move east to the eastern Aleutians and eastern Bering Friday night into Saturday and eventually to mainland Southwest Alaska also on Saturday. Guidance, both operational and ensemble varieties, depicts a track for this gale- force system from Kamchatka Thursday, eastward to the west-central Bering Friday evening, before turning north towards the northern Bering and Bering Strait Saturday and Saturday evening. Given this track, this could be a good setup where the southwestern coast could see high surf or potential surge Saturday into Sunday given the good fetch of southerly and southwesterly winds into the coast as the system pulls northward.

AVIATION

PANC...VFR conditions are expected for most of the TAF period.
Turnagain Arm winds are expected bend into Anchorage and impact the terminal this evening. A front that moves in early Sunday will take advantage of moisture already in place and will develop rain showers early Sunday morning. However, coverage of these showers will be localized, so expect periods of VFR mixed with periods of MVFR. A Turnagain Arm jet will impact the terminal again on Sunday, but there is uncertainty regarding the duration of the event.

-JR