textproduct: Juneau

SYNOPSIS

Key Messages:

- Rain showers continue through the remainder of the week.

- Isolated thunderstorm potential Saturday, primarily for the southern and central panhandle.

- Warmer and drier weather is expected for early next week.

LONG TERM

/Sunday through Wednesday/ Overall upper level pattern will be in a state of transition across the state and the Gulf of Alaska for Sunday as we switch out of a broad cool upper trough that dominated the weather over the area this week. The pattern will be switching to a closed upper low over the NW Pacific with weak upper ridging over the southern part of Alaska and the Yukon.

At the surface, this translates to a somewhat strong area of low pressure over the NW Pacific with a ridge of higher pressure building over the panhandle for the first half of next week. With this pattern the trend is toward warmer, drier, and sunnier weather especially for Monday into Wednesday. Sunday will have the beginnings of the warm up, but onshore flow will keep at least a chance of showers around. Tuesday is still looking to be the warmest day of the forecast with widespread highs in the 60s and 70s likely (isolated areas of near 80 in the southern panhandle are possible) as offshore flow becomes the strongest at that point likely canceling out afternoon sea breezes in some areas. Not expecting any areas to exceed record highs on Tuesday, but some areas could get close (Record highs for Tuesday for many areas are in the upper 70s to mid 80s). Marine layer low clouds in the gulf and along the outer coast may not be much of a factor for this period as low level flow is generally out of the NE to E direction which will likely keep those low clouds well offshore.

At the moment, the nicer weather is not expected to last much beyond mid week. An easterly wave from BC is looking likely to move into the panhandle from SE to NW possibly starting as early as Wednesday morning (though it could be as late as Wednesday evening) bringing another round of rain and clouds to the panhandle especially from Cape Fairweather south and eastward. Temperatures by Thursday may be down to more seasonal readings with the clouds and rain moving in (normal highs for this time of year are mid 50s to 60).

AVIATION

Showers will continue across the area bringing variable flight conditions, mainly between MVFR to VFR. Ceilings mainly remain AoA 2500 ft with the lowest ceilings during heavier showers. Along with this, visibilities are anticipated to remain VFR. Starting this afternoon into this evening, showers will lighten as the first initial shortwave passes the area. This will allow for a short slightly drier period, with mainly VFR ceilings AoA 3000 ft. Multiple areas have already seen these lighter showers with clearing skies as this initial wave passes the area. Another wave of energy will then bring showers back late Thursday into early Friday. At this time, the southern panhandle looks to remain more dry with clearing conditions. This may allow for fog development over areas along Frederick Sound, like Kake and Petersburg, and southward. Still variable, but slightly improved VFR conditions are then anticipated for Friday as light showers continue.

MARINE

Inside (Inner Channels): Winds remain on the lighter side as a weakening low pressure remains in the gulf and a ridge builds over SE AK. Southerly and easterly gentle to moderate breezes of 5 to 15 kts will continue through the weekend. The strongest winds will be over Northern Lynn Canal into Taiya Inlet and over southern portions of Clarence Strait on Saturday. Even then the strongest winds gusts are anticipated to be around 20 to 25 kts. For other locations, there will be times of slightly gustier winds due to showers moving over the area. Otherwise, localized sea breezes can quickly create a change in wind direction and slightly increase winds. Starting late this morning we saw a sea breeze develop around the Juneau area allowing winds to become westerly and increase to 10 kts with gusts around 20 kts. These gusts should once again become easterly and decrease this evening.

For the southern panhandle, there is a chance for areas of fog to develop tonight as winds decrease to below 10 kts. Fog potential seems most likely over Frederick Sound and Sumner Strait, especially in protected areas.

Outside (Gulf and Coastal Waters): Waveheights continue to be the main impact across the gulf. Significant waves around 8 ft continue this afternoon and will subside through tonight. Significant waves will then remain around 4 to 7 ft through the weekend. Winds will also remain on the lighter side around SE 10 to 15 kts before a low pressure system moves into the SW gulf late Sunday into Monday. At this time winds over the offshore waters will increase to around 25 to 30 kts. These stronger winds are likely to remain farther offshore with the gulf coast winds remaining around 15 kts. The main change to the nearshore / coastal waters area will be that wind direction will become northeasterly through the day on Monday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ022-641>644-651-661>664-671-672.