textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Continued wet and windy pattern over Southcentral is expected through the early portion of this week as a series of upper-level lows traverse Southern Alaska from Southwest to Southcentral. Synoptically, the pattern will be wet and windy through early Wednesday as the pattern evolves, with many localized effects expected. Through this afternoon, expect chance rainfall over inland, downsloped favored areas to fill in with rain into the evening. Rainfall from the Susitna Valley to the northern Gulf of Alaska coastline will increase from a light rainfall this evening to a moderate-to-heavy rainfall rate early Tuesday morning, becoming relatively lighter again later Tuesday morning. Expect rainfall to persist over Southcentral through Tuesday, diminishing by Wednesday morning.

With regards to winds, expect gusty winds along the south-and- western portion of Anchorage tonight, as winds through the Turnagain Arm increase, and decrease through Tuesday morning. Similarly, this evening through Tuesday morning, gusty southerly winds through the Copper River will pick up, with peak winds reaching 20-25 mph, helping keep the Basin relatively drier than the rest of Southcentral. By Tuesday afternoon, westerly winds will increase into Kachemak Bay, rising the sea- state in the Outer Bay. This does not coincide with a high tide cycle so significant coastal erosion impacts are not expected.

As the upper-low transits overhead Tuesday, there is the chance for isolated elevated thunderstorms in the Copper River Basin area and surrounding mountains, stay tuned. Outflow gap winds out of Seward and Whittier are expected to pick up Wednesday morning, with gusts to 35 mph possible, peaking Wednesday afternoon.

-CL

LONG TERM FORECAST (Days 4 through 7)

A highly amplified pattern is expected through the second half of the week as a deep upper level Kamchatka low opens into a trough in the western Bering while a strong upper ridge slides east across the Mainland Friday through Saturday. Models remain consistent on the overall upper level longwave pattern with the biggest uncertainty continuing to be the exact timing and placement of individual shortwaves embedded within the mid to upper level flow. The strong surface low over eastern Russia continues to trend farther north and west, with ensemble model guidance steady in the general northeastward track across far eastern Siberia and into the Arctic Ocean Friday into Saturday. Confidence remains high on its associated gale- force front tracking east across the Bering through mid to late this week, bringing gusty southwesterly winds and moderate to heavy rainfall across the Aleutians and Pribilof Islands.

The strong front similarly continues to trend farther north in the Bering as its eastward progression stalls against the strong high pressure stretching across the North Pacific into the southern Mainland. The longest duration and strongest core of winds with this system is now expected to affect the Norton Sound and Seward Peninsula region through Friday. Despite this shift in the storm track, a period of gusty small-craft to potentially gale-force winds along the front is still likely to impact the Kuskokwim Delta coast by Thursday night through Friday evening. 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. Elevated water levels in the Lower Kuskokwim River due to preceding rainfall across the Interior, combined with additional rainfall, could lead to minor river flooding for communities along the river from Bethel to the Kuskokwim Bay. Details will continue to become clearer in the coming days on the exact timing and potential impacts of this upcoming late-week storm.

Behind this system, weaker west-southwesterly flow continues over the Bering and Southwest Alaska through the weekend, while the weakening frontal system and rainfall continues east into Southcentral and the Gulf. Broad troughing remains centered over the Bering, with models hinting at the pattern becoming more amplified once again as a low lifts north out of the North Pacific early next week.

AVIATION

PANC...Ceilings will waiver between VFR and MVFR with periods of light rain through the rest of today. Steadier rainfall arrives tonight through Tuesday, bringing ceilings down to MVFR with periods of IFR. Winds become southeasterly with gusts of 20 to 30 knots tonight through Tuesday afternoon.