textproduct: Juneau

UPDATE

For 06z TAF Issuance and Aviation Discussion

SYNOPSIS

Key Messages:

- Multiple weak fronts look to move over the panhandle through early next week, bringing increases in wind and precipitation chances, with breaks in between.

- A possible atmospheric river could move into the southern half of the panhandle by mid next week. Flooding and an increase in winds are possible, with a hydrologic outlook issued in response. Accumulating snow near Haines and Skagway highways are also a concern.

LONG TERM

For the long range forecast, SE AK continues to remain under the eastern flank of a broad mid/upper level trough for the foreseeable future. While the main areas of low pressure will still be centered well to the west, this will nevertheless set the stage for fronts and shortwaves to continue to progress through the area.

The next wave of note will arrive on Wednesday. Fog which formed late Tuesday night across parts of the area will fade away as a gale force front moves up from the south. While this front will not be as strong as the previous system, still anticipate windy conditions for the southern panhandle, gales for the outer coast, small crafts for the inner channels, and periods of moderate to heavy rain. In the wake of this system showers and diminishing winds are expected on Thursday, although some areas may break out and see the sun on occasion. Shower coverage will likely diminish on Friday before another front arrives from the South on Saturday.

AVIATION

/ Through Tuesday night / The next incoming system is beginning to impact the southern panhandle with a warm front bringing rain and dropping CIGs to AoB 2000ft as of 9pm Monday. These conditions will spread northward overnight Monday into Tuesday as heavier precipitation moves into the area with the follow up cold frontal band. This will also lead to increasing winds aloft and at the surface, with LLWS expected to spread from south to north through the period, with the southern panhandle and outer coast seeing the brunt of it. While the main core of surface winds will remain offshore in the gulf due to the track of the surface low, gusty winds will make their way into the inner channels and last through the afternoon hours and into the evening Tuesday. Brief break Tuesday night before another system slides in from the south bringing deteriorating conditions once more beginning Wednesday morning. This break could lead to some patchy fog development depending upon the extent of cloud cover over the panhandle overnight Tuesday, particularly for the northern inner channels.

MARINE

Inside Waters: Winds will increase in the southern panhandle tonight to gale force by 3 AM tonight, with increasing winds moving south to north. Expecting sustained gales to largely be localized to the southern half of Clarence Strait, but possible to see gale force gusts all the way up to Midway Island and Point Couverden. Tuesday night is looking increasingly like the southerly push will succeed in pushing into Lynn Canal, with fresh to strong southerly breezes continuing through the night. Early Wednesday morning, winds are expected to shift to the north, as another front moves into the area.

Outside waters: Widespread gales to strong gales are expected to ramp up in the following hours as the next frontal band moves over the area. Expecting to see some barrier jet develop with around a 30% chance of sustained storm force winds near areas east of Cape St. Elias. Otherwise, much more likely to see winds increase to strong gales by late Tuesday morning before diminishing late Tuesday afternoon as the energy moves inland. Seas, in turn, look to rapidly increase to 25-30 ft, particularly in the NE gulf coast, from the longer sustained strong winds over a large area of fetch.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Wind Advisory from 3 AM to noon AKST Tuesday for AKZ323-328. Wind Advisory from 6 AM to 6 PM AKST Tuesday for AKZ330-332. MARINE...Gale Warning for PKZ036-053-641>644-651-652-661>664-671-672. Small Craft Advisory for PKZ013-021-022-031>035.