Area Forecast Discussion

UPDATE

To the aviation section following the 18Z TAF issuance...

SYNOPSIS

Key Messages:

- A front will slowly push through the panhandle over the weekend, with gusty winds and moderate to heavy rain possible.

- Heavy snow possible along upper Klondike Highway over the weekend with a Winter Storm Warning in effect.

- The wet and active pattern will continue into next week as multiple fronts and lows pass through southeast Alaska.

SHORT TERM.../through Sunday night/...A front slowly moving through NE Gulf Coast is pushing into the northern panhandle this morning and will slowly work through the panhandle over the weekend. Moderate to heavy rain and gusty south to southeasterly winds will build into the panhandle along the front. Expanded the Wind Advisories to include Skagway this morning through this evening and Annette Island for Sunday. Wind Advisories may be needed elsewhere, especially Sitka and Ketchikan, but confidence is not high enough to issue. Rain will diminish behind the front by this evening for Yakutat, with occasional onshore showers through the rest of the weekend. For the panhandle, a mesolow developing along the stalled front will push into the southern panhandle by later Sunday, with strong gusty winds and burst of heavier rain possible. Rain will then trend down west to east across the panhandle through Sunday night.

Rain amounts look to be around 0.75-1.75" through the weekend, with some isolated pockets of heavier rain. Temperatures should be warmer as well with the front allowing for places to reach into the mid to upper 40s and lows in the upper 30s to lower 40s. The exception to this will be the Klondike Highway which looks to stay cold enough to see accumulating snow. With the front stalling over the panhandle Saturday into Sunday will allow for moisture to remain in the area and 700mb flow will remain out of the SW. This should allow for snow accumulations to reach up to 9-14" of snow through Sunday morning.

LONG TERM.../Monday through Thursday/...We are back in an active pattern here in Southeast, with a new low and frontal system on the docket every few days. To start the workweek a shortwave will move north through the southern and to a lesser extent, central panhandle. While lighter rain will continue throughout, periods of heavier rain are possible with this wave. Then come Wednesday, another Gulf low will intensify in the western Gulf, meanwhile a front attendant to that low will swipe north and bring the next serious bout of rain to the entirety of the panhandle. Towards the end of the week a quickly deepening low will move quickly from the south into the Gulf. Deterministic guidance is in disagreement of the final track, but most of them have the central pressure reaching between 960-970 mb. The track and intensity should be taken with a grain of salt at this point in the forecast process though.

AVIATION.../Through 18Z Sunday/...As a front overtakes the panhandle this morning, light rain begins ahead of worsening conditions along the NE Gulf coast. PAYA has already begun to experience heavy rain, strong winds, and LLWS, with improvement not expected until early Sunday morning. Widespread OVC CIGs will drop below 2500 ft, and heavier rain may briefly reduce VSBY to 2-4 SM. These MVFR conditions will spread south through the day, with CIGs lowering to 1000-1500 ft. Current VFR conditions across the panhandle will transition to MVFR around 20-22Z in the north and later this evening in the south, replacing a mid-level cloud deck AoA 4000 ft. Widespread clearing is not expected today, though conditions will gradually improve Sunday as the front departs, leaving behind lingering showers.

Winds will be gusty across the region, with northern sites already seeing gusts to 30-40 kt. LLWS is likely at PAYA through the afternoon due to a strong 1500 ft jet. LLWS will build into PASI around 21Z and PAJN around 00Z, with 45-50 kt winds at 2000 ft persisting through late evening. LLWS has also been added to a few southern sites (PAWG, PAKT, PAKW) for early Sunday morning as the front moves further southeast.

MARINE... Outside (Gulf and Coastal Waters): A strong front continues to move eastward over the Gulf of Alaska. South to southeast gale force winds ahead of and along the front. Once the front moves through winds will be subside and become moderate to fresh from the southwest. Combined seas along the front will be 15-20 ft, after the frontal passage seas will ease to 10-15 ft. The front will stall out over the Panhandle tonight into Sunday. A mesolow forming over the NE Pacific will move through the southeastern portion of the Gulf Sunday resulting in another round of increased winds (gale force) and subsequently seas (15-20ft). For next week, the active pattern continues with multiple gale to storm force systems and large seas expected over the outside waters. Winds and seas will subside Sunday night into Monday before the next frontal system begins moving into the area Monday night and into Tuesday.

Inside (Inner Channels): South to southeasterly winds and seas building through inner channels today as front approaches. Fresh to strong winds expected through tonight into Sunday. Gales expected to develop into Clarence Strait late tonight and possibly into Sumner Strait and southern Chatham Strait Sunday as a meso low along the front lifts northeast and tightens the gradient over the southern panhandle. For next week, the active pattern continues with multiple gale to storm force systems and elevated seas expected for the inside waters. Winds and seas will subside Sunday night into Monday before the next frontal system begins moving into the area around Tuesday.

AJK WATCHES / WARNINGS / ADVISORIES

PUBLIC...Wind Advisory until 4 PM AKDT this afternoon for AKZ317. Wind Advisory until 10 PM AKDT this evening for AKZ318. Winter Storm Warning until 9 AM AKDT Sunday for AKZ318. Wind Advisory from 1 AM to noon AKDT Sunday for AKZ328. Wind Advisory from 5 AM to 5 PM AKDT Sunday for AKZ332. MARINE...Gale Warning for PKZ036-641>644-651-661>664-671. Small Craft Advisory for PKZ011>013-021-022-031>035-053-652-672.