textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Temperatures remain warmer aloft as upper level ridging continues to anchor itself over Southcentral Alaska. There are a couple of subtle shortwaves upstream of the ridge, with one of them arriving to Kodiak Island this evening with lower ceilings and foggy conditions. This is coincident with the ridge beginning to somewhat flatten and lose amplitude over the region as a North Pacific upper level low nudges in from the southwest and cuts into the ridge. Until then, the inversion in place as noted by the afternoon Anchorage sounding will keep the chance of fog in the forecast for valley locations as atmospheric mixing will be limited. This threat will be increased anywhere where there is clearing and if any of the high clouds streaming over the region can scatter out, allowing for more efficient radiational cooling. For the Anchorage Hillside and mountain locations, generally expect "warmer" overnight low temperatures than the valleys and increased cloud cover. As the ridge loses its grip of the area by the latter half of Wednesday, the expectation is for higher cloud cover to decrease, except for locations with elevation as there is really no big synoptic feature to mix out the inversion. Models show a North Pacific low moving into the Gulf with its front late week, but solutions vary on placement and timing. Current deterministic runs of the GFS/NAM generally want to take the low northwestward towards the Alaska Peninsula and its attendant front northward across the Gulf.

-AM

AVIATION

PANC...Light and variable winds will prevail through the TAF period. With narrow dewpoint depressions near the surface as well as the light winds, the setup remains conducive for low stratus and fog formation. With ridging and a strong inversion overhead, this will be the case over the next few days.