textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Unsettled wet pattern continues across Southcentral as two upper level waves anchored to a low in the Bering Sea move through southern Alaska. The first wave moved into Southcentral overnight, bringing widespread rain. The front weakens slowly and spends today exiting to the northeast. Southerly winds through the Copper River will pick up later this morning and persist through Tuesday morning. Peak winds around 20-25 mph are expected through the Copper River this evening, and will aid in keeping the lower elevations of the Copper River Basin drier. Light rain will move in as winds come down.

The second system is stronger in general and has a surface low centered in the Bering Sea. This surface low will also weaken some as it tracks eastwards and moves onshore in the Kuskokwim Delta , but the upper level wave will track over Southcentral Alaska late tonight. The associated upper level trough will continue working its way eastward across Southcentral through Tuesday, keeping precipitation in place over the region. Turnagain Arm winds will bend into Anchorage this evening as the trough approaches, with wind gusts expected to range from 15 to 30 mph.

KM

LONG TERM FORECAST (Days 4 through 7)

The upper level pattern becomes increasingly amplified to begin the long term period as a strong upper level Kamchatka low opens to a trough in the western Bering while a strengthening upper ridge slides east across the Mainland. Ensemble model guidance remains in fairly good agreement for the associated surface low over Kamchatka to track northeast across far eastern Siberia and eventually into the Arctic Ocean by Friday. Its associated small- craft to gale-force front moves east across the Bering through midweek with gusty southwesterly winds and moderate to heavy rainfall across the Aleutians and Pribilof Islands.

The front is set to reach the Southwest Alaska coast Thursday into Friday, spreading the gusty winds and moderate to heavy rainfall across the western Mainland. The long fetch of strong, southwesterly onshore winds could bring the possibility of high surf and minor coastal flooding and erosion along the Kuskokwim Delta coast as the front progresses through the region. Additionally, widespread moderate to potentially heavy rainfall across Southwest Alaska will accompany this system as it taps into a robust stream of subtropical Pacific moisture. Elevated water levels in the Kuskokwim River due to preceding rainfall across the Interior, combined with strong southwesterly winds up Kuskokwim Bay and additional rainfall, could lead to minor river flooding for communities along the river from Bethel southwards. Details will continue to become clearer in the coming days on the exact timing and potential impacts of this upcoming late-week storm.

By the weekend, weaker, more zonal flow takes over the Bering while the weakening frontal system and rainfall continues east into Southcentral and the Gulf. Expect unsettled, showery weather to continue across the Bering, Southwest, and Southcentral through the weekend into early next week as weak upper level perturbations move through the region.

AVIATION

PANC...Light rainfall with mostly VFR conditions will prevail through the TAF period. Ceilings are expected to remain near 5000', with intermittent drops to MVFR (2000' to 3000') during steadier rainfall this morning. Winds will remain light through midday before becoming southeasterly with gusts to 20 to 25 knots during the early afternoon.

-AM