textproduct: Juneau

LONG TERM

/Tuesday through Sunday/ Upper level pattern is rather dynamic through the long range. It starts out with a broad ridge of high pressure situated over the Gulf of Alaska while a sharp trough is at around 180 longitude. That trough will be advancing east through the start of the long range period and will proceed to push the ridge east into Canada by Thursday. Behind it more zonal flow takes over, but not for long. An upper level low will be digging SE from Russia by the weekend and will eventually anchor a broad trough stretching from the Bering Sea to the Panhandle by Sunday.

This means that the forecast for the panhandle is rather dynamic as well. It will start out rather quiet with the ridge over the gulf initially keeping most precipitation at bay. However, that ridge will be starting to flatten enough that flow turns more onshore over the northern panhandle and precipitation starts to return to the forecast. The rain is not expected to start in ernest until Wednesday as a front works its way eastward across the gulf. This front does have some tropical connections, but it is moving eastward at a decent clip and looks like it will be weakening as it goes. So while there may be periods of moderate or heavy rain rates (especially for the NE Gulf coast), the rapid eastward movement and weakening nature means that those rain rates will not be over any particular area for long. Expected rain totals for Wed look to be around 1 to 3 inches mainly from the central panhandle Northwestward with the highest totals expected along the NE gulf coast. This system will also bring some wind with 25 to 30 kt SW winds possible in the gulf while the northern inner channels will see a burst of southerly winds up to 30 kt during the day Wednesday.

The general trend for late week and beyond is first a drying trend for late week as surface ridging builds over the panhandle through lingering onshore flow could mean that showers and clouds will be still around. The latter half of next weekend is looking to be rather active as a more substantial front is possible as the strong upper low that is moving into Bering sea sends a front across the gulf. We will be watching this feature as some guidance is suggesting this front could be min gale force as it crosses the central gulf and somewhat wet as well.

AVIATION

/through 12z Monday/

Predominate VFR flight conditions across majority of the panhandle this morning. Main headache overnight remains MVFR to LIFR along the SEAK coastal terminals of Yakutat, Sitka, and Klawock due to encroaching marine layer around 3000ft and developing fog leading to reduced visibilities a quarter mile or less at times. Anticipating a similar trend to yesterday, a gradual but slow improvement into the late morning, becoming widespread VFR across the area under clear skies once more through 22z. Winds remain light, increasing to around 8 to 12 knots through 00z as the usual seabreeze wind gets underway. VFR flight condition will continue into Sunday night as winds return to light and variable once more with a persistence based forecast expected. Marine layer redevelops along the coast with patchy fog development possible by 06z to 12z Tuesday. No LLWS concerns through the TAF period.

MARINE

Inside Waters: High forecast confidence of no major inner channel weather hazards through Sunday. As expected, a marine layer had redeveloped out in the Gulf and along the coast overnight, encroaching into Icy Strait/S Glacier Bay and over Baranof Island towards Angoon. In addition, areas of dense fog ongoing across the inner fjords within W Prince of Wales near Naukati Bay and southern Wrangell Island. Similar to yesterday, expecting fog and marine later to retreat through the late morning. Winds will remain light through much of Sunday, outside the typical afternoon seabreeze influences, around 10 kt or less, with a sporadic gusts to 20 kts for a couple hours in the afternoon before quickly diminishing into the evening. Winds overnight are expected to become light and variable, with some northerly component near Taiya Inlet from interior drainage winds. Wave heights remain ranging 0 to 3 ft through Sunday night.

Outer waters: No major changes from the previous forecast, with the persistent message of high pressure dominating the Gulf through the rest of the weekend bringing winds generally out of the W-NW. Places north of Cape Fairweather should see more of a westerly component to the wind. Wave heights remain 4 to 6 feet along the coast and outer water from the westerly swell moving through the area. As the high pressure moves to the east, winds for the central and southern portion of the gulf will increase to 15-20 kt while points north of Cape Edgecumbe should see NW winds remaining around 10-15 kt.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Dense Fog Advisory until 10 AM AKDT this morning for AKZ317-328. MARINE...None.