textproduct: Juneau

UPDATE

After the 18z TAF issuance. Frontal band/moisture plume over the southern panhandle, which has widespread marginal ceilings of 1200 ft to 2900 ft, and some light rain and occasionally reduced visibilities in the rain. Northern Panhandle ( north of Icy Strait, should stay VFR.

PREV DISCUSSION......ISSUED AT 558 am Friday Jul 3

SYNOPSIS...

Key Messages:

- A front moves into the panhandle today, with rain for the Icy Strait corridor on south.

- Rain diminishes from north to south tonight into early Saturday. Chances for rain showers with some breaks in clouds for the Fourth of July.

- A stronger low pressure may move near the panhandle late this weekend into early next week, with a better chance of rain, gusty winds and increasing seas expected.

SHORT TERM.../through Saturday night/...Low pressure out in the eastern Gulf of Alaska with a front lifting north into the panhandle. Rain is increasing across the southern panhandle and will spread north this morning. Steadier rain from the Icy Strait corridor will continue through the afternoon, then diminish from north to south tonight into early Saturday as the low shifts southeast towards Haida Gwaii, with showers lingering across the southern panhandle into Saturday morning. Have lowered rain totals through tonight across the north (0.10 to 0.30") as the low and steadier rain looks to track a bit further south. Still expecting around 0.50 to 1.00" across the south. Cooler temps continue on Friday due to the abundant clouds and moisture, with highs in the 50s. Winds becoming 10-15 mph (up to 20 mph for Skagway) this afternoon and early evening, diminishing and becoming light overnight. With the clearing and lighter winds night, patchy fog and haze development possible. Surface ridging and weak onshore flow for the 4th of July. Some breaks in clouds expected, but a few light showers will be possible. Warmer with highs in the mid 50s to mid 60s.

LONG TERM.../Sunday through mid week/... Main feature of interest continues to be the possibly stronger system on Sunday night into Monday. An unseasonably strong upper level low looks to move towards the southern panhandle, bringing multiple waves of precipitation from south to north. The amount of moisture available is currently nothing to write home about, near normal amounts of precipitable water, however, given the strength of the winds aloft, IVT values are expected to exceed 250 kg/ms. Furthermore, given lapse rates, particularly with the second wrap during the afternoon timeframe, divergence aloft, and plenty of PVA, could see some thunderstorm development with gusty winds and heavy rain. Ultimately, this storm is still relatively uncertain for exactly how it will develop, how each wave will interact with terrain, how far north will strong energy extend, how much clearing will occur in between waves, and will any clear correspond with peak solar heating for higher CAPE values. We will be monitoring this situation carefully for the next couple days.

AVIATION.../through 12Z Saturday/... A frontal band looks to bring rain to the panhandle through the day. Locations across the southern panhandle have already begun to see light rain, dropping CIGs to borderline VFR/MVFR conditions. This trend is expected to continue through the day with VFR CIGs and VIS prevailing. Light rain brings the possibility for higher end MVFR CIGs, about 2,000 to 3,000ft, through today with the chance for slightly lower CIGs overnight in the northern panhandle, about 1,500ft. Gusty conditions can be anticipated through the day at PAGY and PAHN, but are expected to remain dry.

MARINE... Outside (Gulf and Coastal Waters):A front is moving across the gulf and pushing into the panhandle, primarily impacting the Cape Spencer area and southward. Winds up to 20kts are possible through the morning. Winds are expected to die through the day across the gulf and become light and variable once the front breaks apart and a low pressure center moves though the area. No dominant swell is present, and with the relatively short duration of winds, not expecting any wave heights meeting or exceeding 7 ft for this event.

Inside (Inner Channels): Winds in the inner channels this morning look to remain elevated through the day with higher wind speeds being seen in north/south oriented channels. Specifically Lynn Canal up to 20kts SE, Stevens Passage 16kts SE, and Clarence Strait 20 kts SE. As the front moves through the area, winds might becoming gusty and more unpredictable in direction. Once the front breaks apart through today, winds across the inner channels are expected to become more light and variable on Saturday.

AJK WATCHES/WARNINGS/ADVISORIES

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