textproduct: Juneau

UPDATE

See Aviation Section

AVIATION...06z TAFs

Main message changes going forward for aviation is the inclusion of possible fog for the Icy Strait corridor. As seen on satellite, the main band of precipitation and lift is somewhat stalling to the south of Juneau, with a dry pocket setting up over the aforementioned area. With recent rainfall, dewpoints are relatively high, in the upper 40s. With temperatures expected to drop into the mid 40s for a low, and some clearing allowing some additional radiative cooling, could see some fog development.

Confidence is low to moderate for fog development. Therefore, did not go further than IFR starting around 3 AM tonight.

PREV DISCUSSION

SYNOPSIS...

Key Messages:

- Active weather continues as another front moves into the central and southern panhandle through this evening

- Heavier showers are expected for the far southern panhandle with a slight chance (15%) of thunderstorm development

- Elevated winds across the panhandle due to tightening pressure gradient, becoming gusty as showers pass through

SHORT TERM.../Through 12Z Saturday/...Our next frontal wave is affecting the southern half of the region with plenty of cloudiness and numerous showers. This activity will persist tonight with some scattered showers also pushing north and impacting the inner channels, perhaps even a bit north of Juneau and Gustavus. Satellite imagery also continues to suggest some convective elements, and with some CAPE and sufficient cold air aloft combined with pockets of enhanced lift, there will be at least some gusty, heavy showers with reduced visibilities. A few thunderstorms cannot be ruled out, with strong winds as the primary hazard, especially to mariners.

Farther north, including Yakutat, conditions should remain mostly dry into early Thursday. However, areas that see breaks in cloud cover overnight may again see some patchy fog development toward daybreak. With the exception of the far southern sections, precipitation chances will stay rather low Thursday. But, moisture associated with low pressure in British Columbia and a couple weak shortwaves will begin to impact the far northeast portion of the region by late in the day, which will then expand farther south on Friday. There could still be a few thunderstorms on Friday and potentially Friday night, mainly across the northern panhandle, but much of the organized activity may remain to our northeast. Recent model solutions have also leaned a little weaker with the mid level forcing and lift, so convective potential may be somewhat muted. We should have more clarity on this by late tonight or early Thursday. By Saturday, weak ridging will begin to approach the area, which should help gradually lower precipitation chances once again.

Temperatures are expected to remain seasonably mild across the region through the short term. High temps on Thursday may need to be bumped a bit warmer if model trends persist for a decrease in sky cover around midday Thursday.

LONG TERM... /Saturday through Wednesday/... As the low pressure system from Friday moves southeastward, the chance for a disturbance from British Colombia to bring showers and perhaps some rumbles of thunder will continue for Saturday. A ridge should build in behind the high pressure system, and that should decrease chances for precipitation.

By Sunday night into Monday, a low pressure system looks to form in the Gulf of Alaska. Right now, models are still disagreeing on the exact timing and strength of the low, stronger winds (up to 20 kts or 23 mph) in the Gulf and some higher rain chances are expected for Southeast Alaska with the low. As of now, the low pressure system looks to not be very organized, but it is something to monitor. Heading into next week, there will be greater confidence of the timing and impacts of the low, but we look to overall enter a wet pattern.

AVIATION...A front associated with a low in the Gulf, is currently driving moderate to heavy localized rain showers to the southern panhandle this afternoon, lowering CIGs and VSBYs into MVFR conditions with brief drops during passing showers. Showers will linger over the southern panhandle through the night, though precipitation amounts will start to lighten and move more central by tomorrow afternoon. Sites from Sumner Strait southward are trending toward high-end IFR early tomorrow morning, while the rest of the southern panhandle will remain in prevailing MVFR conditions with increasing pockets of clearing as the front moves out. Conversely, the northern panhandle will clear out tomorrow, remaining VFR from Frederick Sound northward, though there is potential for morning low clouds to linger within the Icy Strait corridor. Winds will generally blow from the SE ahead of the front, keeping many sites across the panhandle breezy through this afternoon before steadily decreasing in the evening. However, localized winds near southern Clarence Strait will keep PAKT elevated at around 15 kts through the night.

MARINE... Inside Waters (Inner Channels): A front ahead of a Gulf low will continue to push its way northeastward into the Southern Inner Channels this afternoon into Thursday morning, bringing winds up to around 25 kt for the tonight period for the Dixon Entrance & southern Clarence Strait before the low weakens & dives southeastward, exiting the area by Friday morning. The rest of the Inner Channels should remain around 20 kt or less during the same timeframe. Then, a weaker pressure gradient causes winds and seas to calm as high pressure moves in for Friday & Saturday.

Outside Waters (Gulf and Coastal Waters): The Gulf low with its associated front will continue to push its way northeastward into the eastern Gulf of Alaska through Thursday morning, bringing winds up to around 20-25 kt along the front just to the northeast of the low center tonight over the east-central & southeastern Gulf before the low weakens & dives southeastward, exiting the area by Friday morning. Expecting 6 to 8 ft seas over the aforementioned region through Thursday evening. Then, as the pressure gradient relaxes, winds and seas calm resultantly as high pressure moves in for Friday & Saturday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ036-661>663.