textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- Hot and dry conditions today through Sunday morning then a shift back to cooler and wetter for a good portion of Southcentral for early next week.

- Heat Advisory remains in effect for Anchorage, Mat-Su, and parts of Kenai Peninsula and Copper River Valley into the weekend.

- Flood Watch remains in effect for Susitna and lower Matanuska Valleys from Tuesday morning through Friday morning, due to heavy rain.

Discussion:

An amplified ridge of high pressure positioned from the Gulf northwards across much of Interior Alaska will result in another day of hot and dry conditions over Southcentral. Fog and low stratus has once again pushed up along the northern Gulf coast and Prince William Sound this morning, but will once again scour out by mid- morning. May also see a few pockets of patchy fog develop for inland Southcentral, but this too will quickly mix out this morning. While still hot for most areas today...it does look like a bit more cloud cover will be able to spill over the ridge as a trough advances eastwards across the Bering. As a result, some areas will see temperatures a few degrees cooler than yesterday. Coastal areas will also see warm temperatures today, but will have some relief as the sea breeze develops. The thermal ridge axis will set-up over the Copper Basin today where some of the lower valleys will see temperatures near 80, and in the mid to upper 70s Sunday as the axis shifts over the southern ALCAN border. Despite the hot and dry conditions, light winds will keep fire weather concerns low today and Sunday. Fire weather concern will increase across the Copper Basin Monday as gusty southerly winds develop and rainfall chances remain low.

From Sunday into Monday, a low in the Bering Strait will begin to influence weather in Southcentral. Winds will pick up by Sunday evening--especially through southeasterly gaps and into Anchorage, Palmer, and central Copper River Valley--as the surface pressure gradient tightens and reorients ahead of this incoming low. The main concern, however, will be rain amounts. As such, a Flood Watch remains in effect for the Susitna Valley from Tuesday morning through Friday morning. While confidence is high that this late weekend/early workweek storm will advect a lot of moisture and lead to areas of heavy rain, exact amounts and timing are difficult to pinpoint at this time. This will ultimately depend on how quickly the incoming low and its front can displace the ridge over Southcentral. That said, have continued to lean towards the higher- end model solutions and, thus, towards a higher rain forecast. Models are in good agreement with more widespread, moderate rainfall moving into the Susitna Valley by mid to late morning Monday, then continuing to spread south and east through late Monday into Tuesday morning. Stay tuned to the forecast, and safely enjoy this weekend's warmer weather before our deluge arrives early next week.

-KC/PP

AVIATION

PANC...VFR conditions and light winds will persist. Expect a westerly afternoon and evening sea breeze Saturday.