textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

* Showers and thunderstorms return this afternoon, primarily for the Matanuska-Susitna Valley and the Copper River Basin. Coverage of the thunderstorms are expected to be less than yesterday. If you hear thunder or see lightning, seek shelter.

* Convection decreases over the next few days. A low approaching Kodiak will bring rain today through Monday. There is low confidence with how far north the front will affect mainland Southcentral and when it would arrive.

Discussion:

An easterly wave is moving showers through the Copper River Basin this morning. Some of those showers have moved through the lower Matanuska Valley. A weak trough just south of the easterly wave is across Prince William Sound with a few showers and low stratus lifting northwestward. Showers will continue for the Copper River Basin and midday heating will allow for isolated to widely scattered thunderstorms. Confidence with this forecast is medium to high (70-80%). The highest potential for thunderstorms will be through the Copper River, north of Chitina up to the Alaska Range.

Meanwhile, a weak North Pacific low will lift a front northward across the western Gulf, bringing rain to Kodiak Island today and lasting into early next week as the low hovers south of the Island. The front will continue to lift to mainland Southcentral. The ridge over that is currently over the Gulf will get pushed along the Gulf coast Sunday. South to southeast gap winds will increase later on Sunday, including through Turnagain Arm, Knik River, and Copper River.

Model agreement breaks down on Monday, a complex low appears to form as the low dipping south across the eastern Bering Sea interacts with the North Pacific low. This could allow some movement of the low system south of Kodiak to hedge into the Gulf of Alaska where broad troughing sets up. Rain showers is expected to lift north across the Gulf this weekend through Monday, though with poor model consensus, confidence is low with the timing and northward extent of the rain coming from the parent low to Southcentral. At this time, it appears that there is a weak wave that reaches the coast Sunday morning and a more wet wave for Monday morning.

AVIATION

PANC...VFR conditions and light winds will persist.