Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
274 FXAK67 PAJK 170050 CCA AFDAJK Southeast Alaska Forecast Discussion...UPDATED National Weather Service Juneau AK 404 PM AKDT Sun Jun 16 2024 .SHORT TERM...Similar to yesterday, the story of today is a slight chance of thunderstorms near Haines Customs and White Pass, and a marine layer moving ever further into the inner channels overnight into Monday. Current thoughts is the marine layer near the surface (foggier conditions over water) will reach towards the entrance of Glacier Bay before encountering continental air and moving aloft. For Sumner Strait, An increasing robust dry airmass looks to inhibit marine layer movement inland and will likely remain as a broken layer of low clouds stopping around Port Protection. By morning, the marine layer will retreat yet again back to the gulf, meanwhile causing a thermal gradient between the rapidly increasing temperature of the inland areas and the gulf waters. The result is an increase in westerly winds in areas such as Icy Strait and possibly Peril Strait. For thunderstorms: yet again, initiation in Canada has sparked several thunderstorms with a northerly to northeasterly direction. At this time, the storms looked to be cut off by the Coast Mountains. A few may make their way on the extreme northern portion of the panhandle and possibly into Misty Fjords and Hyder. Judging from model soundings, a majority of the energy and shear appears to be cut off even if storms make it over the terrain into the AOR. .LONG TERM...Summer continues across SE Alaska through the first half of the week, though more active weather is on the horizon. Get out and enjoy it while you can. A ridge will continue to hover over SE AK through Wednesday, with the axis slowly moving E over the Gulf and across the area. Dry, with afternoon sea breezes in the inner channels is the main theme over the next few days. By Thursday, a weak wave will attempt to advance through the ridge, bringing with it chances of rain, though operational guidance is likely overemphasizing PoP chances with this system. Anticipate fairly minimal QPF totals and wind impacts, if the system isn`t largely eroded away by the ridge itself. By the end of the week, an extension of a closed low over the Aleutians attempts to form into a longwave trough and move into the Gulf, bringing some onshore flow, cooler temperatures, and increasing PoPs through the weekend. Think that there is a good chance that much of the energy will move S of the panhandle, but still anticipate at least some chances of rain for the area. Afterwards, some clearing is increasingly likely for the latter half of Sunday or Monday, though this is not set in stone, with the GEPS being more pessimistic. Threats to coastal and gulf waters remain low through Thursday, with our swells significant deep ocean wave heights remaining largely under 8ft. With that said, stout 15 to 20 knot northwest winds along the coast will bring short period wind driven waves to the west coast of Prince of Wales and into Dixon Entrance. && .AVIATION...VFR conditions continue for most of the inner channels. The exception to this is areas near the outer coast where a marine layer has lingered around today. Conditions near this layer vary from VFR down to pockets of IFR. These conditions will last through the evening with redevelopment of this layer expected tonight. Otherwise, winds should be calm once any sea breezes settle. && .HYDROLOGY...A flood advisory remains in effect for the Chilkat River through 4 AM Wednesday morning. Continued warm temperatures will enable snow melt to result in the river remaining near or above minor flood stage. The river height will diminish during the evening time frame before increasing again during the overnight and morning time period, becoming higher each day. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...None. && $$ SHORT TERM...NC LONG TERM....GFS AVIATION...GJS HYDROLOGY...GFS Visit us at http://www.weather.gov/Juneau