Marine Weather and Tide Forecast for Kachemak, AK

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

The persistent northerly flow continues over Southwest Alaska and the Bering Sea. Generally, Southwest Alaska and the western Bering Sea will stay dry, while the Alaska Peninsula and eastern Aleutians contends with the remnants of showers associated with a shortwave dropping through the area. Winds along the Alaska Peninsula and eastern Aleutians remain breezy, allowing for the continued possibility for mild blowing snow and reduced visibilities through this afternoon and evening before snow showers diminish.

For the remainder of the weekend, conditions dry out while the same pattern of ridging across the western Bering and northerly flow across the eastern Bering and Southwest Alaska continues.
This will mark a prominent shift to a relatively inactive pattern across Southwest Alaska, the Bering Sea, and the Aleutians. With ridging dominating the pattern, expect dry conditions across the region through the weekend, with cold northerly flow persisting.
By the end of the weekend, models have come into better agreement on an Arctic trough digging south across the Interior and into the western Gulf of Alaska. This will again allow for northerly winds to strengthen across Southwest Alaska, the Alaska Peninsula, and the eastern Bering Sea for Sunday into Monday. These stronger winds combined with low level cold air advection will lead to areas of heavy freezing spray in coastal waters along the ice edge and the Pacific-side of the Alaska Peninsula.

-JH/CL

.LONG TERM FORECAST (Days 4 through 7: Monday night through Friday)...

The long-term begins late Monday with a deep upper-level low centered just east of Kodiak Island moving to an area south of Middleton Island by early Tuesday morning. The eastward progression of the upper-level low is in response to a secondary shortwave diving south across the western half of the state, moving south of the Alaska Peninsula late Tuesday before developing into another upper-level low by early Wednesday as the one over the Gulf begins to weaken.

The upper-level low in the Gulf is acting to support a surface low that will continue to deepen through Tuesday before filling in, occluding, and eventually weakening as it loses upper-level support. Nonetheless, precipitation, falling as snow, will continue to fall over the Gulf, and, perhaps across areas of the immediate Gulf coast, through midweek.

The bigger story with these features will be the push of yet another arctic airmass southward, with the coldest air spilling into interior Southcentral and all of Southwest Alaska as 850 mb temperatures fall back to as low as -28C late Monday into Tuesday.
The combination of cold air, strong low-level jet, and tight pressure gradient between a building ridge over the Interior and low in the Gulf, will also result in the redevelopment of very strong gap winds through favored terrain, with the strongest winds and gusts likely across the Alaska Peninsula and the coastal waters from the Barren Islands to Unimak Island.

The cold air advection diminishes for a time Wednesday as a transient upper-level ridge slides south over the west coast of Alaska. However, another potent upper-level wave then follows and digs south across Southwest Alaska, lifting the weakening Gulf low north with light snow for portions of Southcentral and more arctic air and gusty winds for Southwest Alaska and the Alaska Peninsula for the latter half of the week.

AVIATION

PANC...VFR conditions and light winds will persist through at least Saturday morning. An upper level short-wave digging southeastward across Southwest AK tonight will move into Cook Inlet saturday morning and stall through Saturday night.
Meanwhile, a weak surface low will form ahead of the trough over the northern Gulf, with low level moisture advecting across the coastal mountains toward Anchorage. The airmass in place is quite dry, so it will take some time to saturate. However, it is looking increasingly likely that the terminal will see a period of light snow Saturday afternoon-evening. This will reduce ceiling/vis to MVFR sometime tomorrow afternoon. The duration of snow and lower conditions is very much in question, but it appears unlikely conditions would get any lower than MVFR.

-SEB