Marine Weather and Tide Forecast for Kokhanok, AK

FXAK68 PAFC 200025 AFDAFC

Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 425 PM AKDT Tue May 19 2026

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3/Tonight through Friday)...

There is no end in sight for this very active pattern, so expect continued cloud cover, cooler than normal temperatures, and generally wet conditions - especially considering this is typically one of the driest times of year. Starting with the current analysis, a long-wave trough encompasses all of the Bering Sea/Aleutians and extends eastward to mainland AK/extends across the Bering Sea. A deep low which had served as the anchor of the trough in the Bering has dissipated, but a new deepening low along the western Aleutians is moving right in and will ultimately take the place of the original low. A short-wave ridge over the northeast Pacific is amplifying ahead of a digging short-wave.
This is steering the short-wave crossing the north Pacific northward toward mainland AK. A surface low has formed ahead of this short-wave and is tracking northward toward the Gulf.
Meanwhile, a short-wave is tracking northward across Southcentral and beginning to exit to the Interior. This is producing some showers inland and steady rain along the coast (mainly from Valdez to Cordova). Southeasterly gap winds have weakened from their peak, but persist for Turnagain Arm into Anchorage, the Knik River Valley into Palmer, and along the Copper River. While the day started out cloudy, breaks of sun are developing behind the short- wave this afternoon.

The aforementioned north Pacific short-wave and surface low will lift northward into the Gulf tonight. The short-wave will amplify and become negatively tilted, with the strongest portion of the trough crossing Prince William Sound and the Copper River Basin on Wednesday. Have increased rainfall totals, with an inch or more likely for Prince William Sound communities and around a quarter of an inch for much of the Copper Valley. Models are in much better agreement on spreading light rain north and west to the western Kenai, Anchorage, and Mat-Su by early Wednesday morning.
Thus, have adjusted the latest forecast to indicate the likelihood of light rain Wednesday morning. The main wind impact will be the development of a barrier jet along the north Gulf coast ahead of the surface low on Wednesday. Gale force winds are likely from south of Cordova eastward to Cape Suckling. The upper short-wave will exit quickly northward late Wednesday. Cooler air aloft behind the trough combined with some breaks of sun will trigger a few afternoon/evening showers.

There will be very little break before the new Bering storm begins to affect Kodiak, the Gulf waters, and Southcentral. A leading frontal system will cross the western Gulf Thursday while a series of generally weak upper level short-waves stream northward across Southcentral. There will be a big difference in the mean flow of this storm system, with much deeper south to south-west flow as you head up in the atmosphere. There will still be southeasterly gap winds at the surface, but these winds will be much shallower and downslope flow will be much weaker. As a result, expect much more widespread rain and rain showers with this storm Thursday through Friday - including the western Kenai, Anchorage, and the Matanuska Valley. With weaker short-waves, rainfall along coastal areas will be somewhat lighter than it has been in recent storms.
The Copper Valley will be notably drier than the rest of Southcentral under this flow. Temperatures will remain below normal under mostly cloudy skies.

-SEB
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