textproduct: Juneau

UPDATE

after 06z TAFs Clear across most the panhandle, with the marine cloud deck over the eastern gulf and the Northeast Gulf Coast. The marine deck will spread into parts of the panhandle. A and of rain moving into the northeast gulf coast overnight as a weakening band overnight and then to the northern coastal areas.

PREV DISCUSSION......ISSUED AT 347 pm Mon 20 Jul

SYNOPSIS...

Key Messages:

- A front will bring showers for Yakutat Monday night, with a few light showers into northern panhandle on Tuesday, along with cooler and cloudier conditions. Warm and dry weather will continue for the southern panhandle. - Elevated winds and seas through Wednesday for the outer coastal waters from Cape Spencer to Dixon Entrance and the southern inner channels.

- Trending cooler and wetter from north to south mid to late week.

SHORT TERM.../Through Wednesday/...With mostly clear skies, temperatures across the panhandle have increased into the mid 60s to 70s. The central to southern panhandle has seen temperatures into the the mid to high 70s, especially in protected areas. Temperatures will remain on the warmer side tomorrow, but be cooler than what we saw today. This is mainly due to a weak system over the far northern gulf that decreases 850 mb temperatures and brings increased cloud cover. This also increases rain chances for the northern gulf and panhandle for Tuesday. Most precipitation will be directed to the west of the area, but light rain is likely to fall from Baranof Island and northward. Highest rain totals will be located near Icy Bay and Yakutat. No significant accumulation or impacts are anticipated with rain totals remaining below half an inch. At this time, the central to southern panhandle remains dry due to the ridge of high pressure remaining over the gulf. Again, cloud cover may slightly increase, but it is less likely for the south.

A full change in pattern arrives late Wednesday into Thursday. At this time an area of low pressure pushes into the northern gulf changing our offshore flow to onshore flow. As this system arrives, rain showers will begin as early as Wednesday evening for northern areas. Widespread rain then begins Thursday as a low moves more into the central gulf.

LONG TERM.../Thursday through Sunday/...Thursday starts with lingering showers in the northern panhandle and increasing cloud cover from north to south, as a front in the northern gulf moves eastward into Yakutat that morning. The front will continue to push inland into the northern panhandle, spreading to the central panhandle through the night and reaching the southern panhandle through Friday morning. Increased PoPs slightly as the front initially moves through, particularly for the outer coast. Rain will start to taper off from north to south through Friday and into Saturday, though potential for showers will keep PoPs elevated through the weekend.

Rainfall rates will remain relatively light through this period, especially behind the initial front, though more developed showers may bring periods of heavier rainfall and gusty winds as they blow over. Winds will increase for parts of the N/S facing inner channels with the front, though expecting speeds to remain around 15 to 20 mph and decrease into the weekend. The strongest speeds are expected through Northern Lynn Canal and into Taiya Inlet, which may be accentuated by any light sea breezing through the afternoon.

As this low dips southward through the weekend, easterly flow indicates potential for Thunderstorms in BC to attempt to make it over the Coastal Range and into the panhandle. While it is still too far out to decide if this will be a strong enough pattern, this will continue to be looked at through the week. High temperatures will be capped around the low to mid 60s with the increased cloud cover and active weather in the forecast.

AVIATION.../through Tuesday afternoon/...High pressure over the region continues to provide fairly benign flying conditions as of Monday afternoon with no significant changes to the TAFs through Tuesday afternoon. A marine layer from Cross Sound into Icy Strait between 1500 and 2000 ft has largely dissipated as of this afternoon, but is expected to reform overnight and progress towards Gustavus once more Tuesday morning. Along the rest of the inner channels, localized sea breezes will be the primary factor through the early evening Monday. For the northeastern coast including Yakutat, intermittent MVFR conditions should continue through the late afternoon until a front moves in bringing rain showers and gradually lowering CIGs. Some brief patchy fog is possible along PoW once more Tuesday morning, along with the marine layer pushing in to the outer coast there before retreating once more later in the morning.

MARINE... Outer Waters: The sharp ridge along the southeast alaska coastline continues through the next few days, with northwesterly flow along the coastline and southerly to southeasterly flow along the northern gulf. An incoming upper level trough will bring just enough lift for low clouds and fog in the gulf waters, with multiple buoys fully saturated. After the trough moves over the panhandle, the surface ridge is expected to strengthen further, letting winds exceed 20 knots almost everywhere along the coastline and bring seas greater than 6 ft later Tuesday.

Inner Waters: The upper level trough has slowed but will gradually move over the panhandle overnight into Tuesday. With upper level dynamics, leeside and thermal troughing, along with a building ridge in the eastern gulf, westerly to northwesterly channels are expected to pick up through the evening. Icy Strait is the big highlight, with winds likely to reach 25 knots from the west. As the ridge in the eastern gulf builds on Tuesday, inner channels winds south of Icy Strait are expected to increase up to 20-25 knots in exposed channels, such as Stephens Passage and Clarence Strait.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ021-022-036-641>644-661>664.