Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
351 FXAK67 PAJK 181312 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 512 AM AKDT Tue Aug 18 2026 .SYNOPSIS... Key Messages: - More seasonable conditions will prevail through the end of the week with mostly cloudy skies and periods of rain, especially across the north, as multiple systems traverse the region. - The marine layer and weak onshore flow will keep high temps in the upper 50s to lower 60s across the north. Breaks in clouds across the south could bring high temps into the mid to upper 60s and possibly low 70s. - Marine conditions will improve through the day. The next system looks to bring increasing Gulf winds and seas by Wednesday night. && .SHORT TERM.../through Wednesday night/... The front has weakened and cleared the panhandle overnight. Pockets of low stratus and fog are present across portions of the central and southern panhandle this morning. A Dense Fog Advisory is in effect for Kake. High pressure is building back over the eastern Gulf into the southern panhandle today. Expect lighter onshore flow bringing marine layer into the panhandle today, with mostly cloudy skies and periods of light rain across the northern and central panhandle. Late tonight into Wednesday, a weak disturbance will ride over the ridge and into the panhandle, bringing an increased chance of light rain. A frontal boundary will then straddle the central and northern panhandle Wednesday as the next low lifts towards the Kenai Peninsula. The low and front will bring increasing rain potential across the northeast Gulf coast and into the northern panhandle through Wednesday night, with moderate to heavy rain at times possible. The cooler, but seasonable, temperatures will continue across the north, with highs in the upper 50s to lower 60s. Across the south, some breaks in cloudiness and slightly warmer temperatures with highs in the mid to upper 60s, possibly reaching the low 70s. .LONG TERM.../Thursday through Sunday/... Active weather continues into the long term period, especially over the northern panhandle. To end the work week, an area of low pressure moves into the northern gulf continuing to bring onshore flow, rain, and slightly increased winds to the northern and central panhandle. An area of high pressure southwest of the panhandle with a positively tilted ridge axis will remain near Prince of Wales Island. This ridge will likely keep the far south drier, but a few periods of light showers may occur. That ridge, southwest of the area, breaks down Friday into Saturday as a stronger low pushes into the northern gulf. There is still some uncertainty on how strong this low will be. The strength of the low will really help to indicate what weather hazards to expect, like how much rain we may receive and how strong winds may get. Confidence on the location and timing of this low has slightly increased, but it is still a ways out. Temperatures through the long term period remain near average with high temperatures in the mid to high 60s. There are indications that areas near Hyder will see temperatures into the mid to high 70s on Thursday and Friday. The main indicators of this is continued dry weather along with 850 temperatures between 12 to 15 C. The limiting factor will be the amount of cloud cover that they receive as the low pressure system moves into the gulf bringing more moisture into the area. && .AVIATION.../Until 12z Wednesday/...A mixed bag of cotton balls and thumb tacks are in store for those flying around the panhandle this Tuesday morning with conditions ranging from fairly poor south of Frederick Sound, to generally benign up north. Exception up north would be Cross Sound and Icy Strait which has had a cloud deck around 1500 feet pop up within the past few hours. Otherwise CIGs have largely lifted to AoA 4000 ft, with isolated showers still pushing in along the northern gulf coast bringing light rain or drizzle and brief drops in VIS. For the panhandle from Frederick Sound southward, conditions have been as low as LIFR due to VIS down to 1/4 sm in dense fog and CIGs briefly as low as 100 feet, particularly in the vicinity of Sumner Strait and Frederick Sound. Areas of fog and low stratus are the primary hazards this morning, though some improvements have been seen after 4am. By 18z this morning, conditions are expected to be on an upward trend with those sites flirting with LIFR conditions consistently hitting MVFR conditions or better by 0z this afternoon at the latest. Strongest winds will once again be up towards Haines or Skagway out of the south with gusts reaching upwards of 30 kt by the afternoon. No significant LLWS concerns through the TAF period however. && .MARINE... Outer waters: Building high pressure in the gulf contributed to decreasing winds overnight, and this trend will continue through Tuesday. Waters near Cross Sound are the exception here, with isallobaric winds (rising pressures) increasing near this area, channeling into Cross Sound up to 15 knots. Similar story for wave heights, but with a predominantly southwest swell up to 6 ft, wave are expected to be slow to diminish. Buoy 083 off Cape Edgecumbe is reporting 8 ft seas dominated by a westerly swell with a wave period around 10 seconds. Waveheights up to 10 feet were observed up to 3am. Looking ahead in the week, a system moving up along the western gulf late Wednesday into Thursday morning will develop a barrier jet bringing increased seas and winds to the coast near Cape St Elias. Inside waters: While some increased southwesterlies near the mouth of Glacier Bay and Cross Sound from the aforementioned isallobaric winds are present, they are expected to gradually weaken through the day today. With the gradually increasing high pressure over the panhandle and lower pressure over the interior, Lynn Canal is expected to hover between 15 and 20 kt through the day with gusts up to 30 kt, particularly near Taiya Inlet. Other than the winds up north, the primary hazard for marine travel will be persistent low clouds, mist, and fog potential, primarily for the central and southern panhandle through the morning hours. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ022-641>644-651-652-661>664-671-672. && $$ SHORT TERM...DS LONG TERM...EAB AVIATION...STJ MARINE...STJ Visit us at http://www.weather.gov/Juneau