textproduct: Juneau

UPDATE.../to add the 06z aviation discussion/

SYNOPSIS

Key Messages:

- Periods of rain return to the northern and central panhandle as a low lingers in the Gulf of Alaska, sending a series of weak fronts inland through mid-week.

- Drier conditions are expected to continue for the S Panhandle communities through at least Tuesday. Rain chances increase through Thursday as a stronger system moves out of the N Pacific towards Haida Gwaii.

LONG TERM.../Thursday through Monday/

A stronger low will develop in the north Pacific during the week, moving into the eastern Gulf towards Haida Gwaii by Wednesday night. This system will bring more widespread rainfall across the panhandle starting with the southern panhandle and south/central outer coastline late Wednesday night, before moving eastward through the day Thursday. There is higher confidence on this system bringing rainfall the southern panhandle up to Icy Strait Corridor, with less confidence on extending into the far northern panhandle from Yakutat over to Skagway and Haines. It will move onshore just around Haida Gwaii into BC by Friday, but there is potential for a meso low connected to this main system that may move in closer to the panhandle rather than stay just southward. The strength and location of this feature may result in rainfall pushing further northward into Skagway and Haines. Overall the precipitation will be heaviest across the southern coastline, with between 0.5 and 1.0 inches expected from Sitka along the coast down to PoW and 1 to 1.5 inches expected for Ketchikan / Annette Island.

Behind the low pressure system Friday, on shore flow is expected to develop with a ridge of high pressure. While on shore will keep showers in the forecast, the overall rain chances will be lower for the Alaska Panhandle.

As the ridge builds Saturday, some stronger winds are possible from the eastern Gulf Coast toward Haida Gwaii and Dixon Entrance. In the inner channels, winds look fairly benign, other than some sea breeze formations Saturday, but that will depend on skies clearing which seems unlikely at this time with showers around.

By early next week, another low pressure system looks to form in the Gulf of Alaska and potentially increase shower chances. However, there is model disagreement on this exact timing and placement of the low pressure system early next week, so confidence is low in this system.

AVIATION.../Until 06Z Wednesday/

A weak front will continue to push its way northeastward into the northern Panhandle through tonight & into Tuesday morning while continuing to weaken. Light rain showers over that area will weaken & taper off into the morning hours. CIG & VIS conditions will improve from the current MVFR/IFR range to the VFR category by late Tuesday morning. The remainder of the Panhandle should stay in the VFR flight category through the entire TAF-period. The only exception may turn out to be PAKW late overnight as the marine layer may advance back into that area before retreating during the mid-to-late morning hours. SFC winds will remain rather benign for most places. Afternoon sea breezes will likely occur on Tuesday. PAGY looks to become breezy/gusty out of the south, once again, from late Tuesday morning into the evening hours. LLWS values remain benign through the forecast period.

MARINE

Outside (Gulf and Coastal Waters): A swath of moderate to fresh southeasterly breezes is moving northeastward into the northeastern gulf coast this afternoon, bringing periods of showers for the northern panhandle and gusty winds along the coast overnight. Winds along the coast will diminish through Tuesday, with the exception of Dixon Entrance seeing westerly fresh breezes continue through the period. 5 to 6 ft wave heights will persist along the coast as the swath of winds moves inland, diminishing overnight to a more consistent 4 ft across the gulf. Southerly 3 ft swell at a period of around 14 seconds will decrease to 2 ft through Tuesday. On Wednesday, gulf winds will begin to turn from predominately southerly to northerly by Thursday as a more organized low tracks across the N Pacific towards Haida Gwaii.

Inside (Inner Channels): Much of the inner channel winds are still relatively benign today as a swath of moderate to fresh breezes moves onshore in the northern panhandle. Many interior communities have developed 8 to 12 knot sea breezes this morning, though with a band of showers currently moving into the panhandle, sea breezes in the northern panhandle have been slightly dampened. The exception to this is Taiya inlet, where increased southerly winds to near 20 kts will continue through Monday evening. Overall, a decreasing trend is expected through Tuesday as a low tracks towards the panhandle through the southern gulf and continued shower potential limits sea breeze potential. 1 to 2 ft wave heights are prevailing through the channels, with channel entrances seeing 3 to 4 ft.

HYDROLOGY

Snow melt and a string of above normal temperature days across the Chilkat Valley have resulted in elevated stream flow in rivers and streams across the area. While temperatures will cool somewhat through the week, snow levels in excess of 5000 feet will continue to support these elevated stream flows through the time frame.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...None.