textproduct: Juneau

SYNOPSIS

Key Messages:

- Moderate to heavy rain for Ketchikan and Metlakatla possible Sunday evening and overnight. No flooding is expected a this time.

- Confidence is moderate on location of heaviest rain, and strength and direction of winds in the central panhandle and Icy Strait Sunday and Monday.

LONG TERM

Tuesday a longwave trough will continue shifting southeast toward the west coast of Canada, carrying a weakening surface low with it. Widespread moderate to heavy rain will also break apart from north to south, leaving a short and welcome break Tuesday. Upstream, zonal flow becomes briefly established over the Gulf, with a signal for a shortwave trough digging down from the south- central coast. These features will carry west-northwest onshore flow and some moisture into our area; however, deep moisture will likely shear apart before reaching the Panhandle, limiting heavy rainfall potential into mid week. Anticipate low clouds and more typical rainfall, with the farthest reaches of the northern Panhandle likely enjoying drier conditions. Near the end of next week ensembles show agreement on a larger system moving into the Gulf, bringing increased chances for heavier rain and elevated southeasterly winds along our coast into the weekend.

AVIATION.../Through 0z Monday/

Conditions continue to be up and down through Saturday as the remnants of the front over the southern panhandle continues eastward into BC. A majority of the panhandle is now seeing VFR conditions due to the broken nature of the CIGs, though the occasional dips to MVFR are still possible through the evening. Ketchikan and Klawock have held onto MVFR CIGs through much of the day, with periods of heavier rainfall currently bringing VIS down to 3 SM in Ketchikan. Overnight, low VFR conditions are expected to prevail with CIGs sitting around 3000 ft and low scattered layers continuing to filter through.

Through Sunday morning, starting around 12z, conditions are expected to begin to decline again as an unseasonably strong front moves into the panhandle. This front is expected to bring periods of heavy rainfall and gusty winds throughout much of the panhandle, but will particularly be ramping up for the southern panhandle through the end of the current period. Conditions in the northern panhandle are expected to stay mostly VFR with periods of MVFR as the initial front moves through, while the southern half of the panhandle can expect MVFR to IFR conditions with periods of VIS down to 2 to 4 SM and CIGs as low as 700 ft. Southeasterly winds blowing up through Clarence Strait will be the strongest as this front moves through, so Ketchikan will most likely see gusty winds increase through Sunday evening. Other locations up north may see some blue skies peaking out and sea breezes increasing after the front, but showers may still bring periods of MVFR conditions through Sunday night.

MARINE

Outer Waters: A low pressure system moving from the Alaska Peninsula into the Gulf this evening will cause a wind shift from southwesterly to southeasterly. Winds will pick up to 15-20 knots and seas will build to 5-6 feet by Sunday morning, affecting ocean entrances and northern outer gulf zones, particularly from Cape Spencer to Cape Suckling. A weak barrier jet along the NE Gulf coast is also expected to intensify briefly early Sunday morning. As the low tracks further south into the Gulf, winds will shift to northeasterly throughout the day Sunday. By Sunday evening, northeasterly winds out of Cross Sound and Southern Chatham Strait are forecast to build to 10-15 knots. From Sunday evening into Monday morning, winds around the Dixon Entrance area will strengthen to 25-30 knots with gusts up to 35 knots, pushing seas to 8 feet. Conditions will ease through the day Monday as winds subside and turn northerly to northwesterly.

Inner Channels: Driven primarily by the pressure gradient as the low pressure system approaches the panhandle, winds across the northern inner channels will turn northerly by Sunday morning and strengthen to 15 knots by the afternoon. There is high confidence that elevated winds will impact the Clarence Strait to Sumner Strait region between Sunday evening and late Monday morning, with Clarence Strait seeing gusts up to 30-35 knots through Sunday night. Although model guidance varies, with the NAM favoring a slower, stronger system that pushes higher wind speeds northward into Frederick Sound, while other models keep stronger winds to southern areas, current thinking is that the most significant winds will affect mainly the Sumner Strait southward. Seas in Southern Clarence Strait are forecast to build to 8 feet during the passage of this system before subsiding through Monday as winds diminish. Elsewhere across the inner channels, winds are expected to remain around 5 to 10 knots on Monday generally from the north to northeast.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Wind Advisory until 7 PM AKDT this evening for AKZ318. MARINE...Small Craft Advisory for PKZ036.