Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
535 FXAK67 PAJK 162251 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 251 PM AKDT Mon Sep 16 2024 .SHORT TERM.../through Tuesday night/... Quick notes: -Quick moving low south of the gulf will keep rain chances in the forecast for the southern panhandle tonight. -Dry weather and light winds expected for SE AK tomorrow. -Next front moves in from the west late Tuesday night. The details: A quick moving low tracking eastward south of the panhandle will keep rain in the forecast for areas mainly south of Sumner Strait tonight. For those to the north of Sumner Strait, a building ridge will help fade out those rain showers dotting the landscape late this Monday afternoon. The fading clouds may lead to some fog developing tonight in the northern half of the panhandle as well. Brief 500mb ridging will give the area a short break in the rainy weather, and even some breaks in the clouds, on Tuesday. Light winds expected as well, so an overall pleasant day. Tuesday night, the next round of rain and wind approaches from the west. So expect wind speeds to slowly increase Tuesday night in the marine areas. .LONG TERM.../Wednesday through Sunday/...This extended range forecast period sees Southeast Alaska situated on the north side of the upper level jet stream with periods of upper level zonal flow punctuated by pronounced upper level troughs. The single exception to this will be on Friday when an upper ridge transits the area from west to east. What this means: No less than three lows pressure centers will transit across the Gulf of Alaska and Southeast Alaska over the next five days with the only meaningful chance of dry weather occurring on Friday when the upper level ridge passes overhead. Model divergence gets rather large on Friday going into Saturday with regard to a low over the far southeast Gulf. Details on how strong and precisely where it will make its closest approach to the southern outer coast are lacking big time. Fortunately we have several days to pin down this potentially storm force low. As is often the case, GFS is offering the strongest solution. If the worst case GFS solution pans out, potential exists for the first high wind warning of this Autumn season for the southern outer coast. Stay tuned. && .AVIATION...Across the panhandle, flying conditions are VFR except for the far southern panhandle, specifically Ketchikan. A low is developing south of the panhandle that will move over the southern area tonight into tomorrow. This will create low enough ceilings and visibilities for IFR conditions in the far southern panhandle. These conditions are expected to get better starting tomorrow morning. For the rest of the panhandle, VFR flying conditions will prevail for the rest of the day, with times of MVFR possible. There is potential for fog development early in the morning, possibly lowering ceilings and visibilities to IFR conditions. This fog will dissipate Tuesday morning creating good flying weather once again. && .MARINE...Winds over marine areas should see a decreasing trend going into tonight. Northern Lynn Canal is flirting with a marginal Small Craft Advisory wind conditions (winds around 25 kt) so went ahead and put in Small Craft Advisory for the early evening. But wind speeds should calm quickly this evening so that advisory will expire this evening. Late Tuesday night, the next front will move in from the west, causing wind speeds to increase. 20 to 25 knots in the gulf with 10 to 20 knots in the inner channels. The exception for the inner channels is Lynn Canal where wind speeds will increase to 20 to 30 kts by late Tuesday night with elevated winds lasting into Wednesday. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-661-662. && $$ SHORT TERM...GJS LONG TERM....Fritsch AVIATION...EAB MARINE...GJS Visit us at http://www.weather.gov/Juneau