Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
830 FXAK67 PAJK 061806 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 1006 AM AKDT Sat Jul 6 2024 .UPDATE...Updated Aviation discussion to include the 18z TAF issuance. && .SHORT TERM...High pressure remains over the Gulf this morning, with marine stratus impacting parts of the outer coast and a low level cloud deck across much of the northern panhandle as moisture continues to move over the ridge axis. By the afternoon, the ridge axis will finally be moving further to the W, encouraging more NW flow into the N half of the panhandle, and resulting in increasing breaks in the clouds and decreasing chances of precip, though a few light showers may linger. Anticipate that clearing skies will have largely taken over by Sunday, with dry weather across most areas with the exception of Yakutat. .LONG TERM...Overview: High pressure ridge over the AK Gulf remains in place into the weekend keeping overall quiet weather. Increasing probability of rain & wind mid week next week. On Sunday and Monday, the previously entrenched ridge will strengthen with anticyclonic flow aloft strengthening as well. The result is a clearing of skies throughout the panhandle with temperatures in most areas hitting above 70 degrees. Naturally, typical sea breezes will develop, and areas around Point Couverden, Cross Sound, and Northern Lynn Canal will increase wind speeds in the afternoon. Otherwise, enjoy the calmer weather before clouds and potentially rainy and windy pattern sets in mid week. As for model preference for this forecast, while the NBM was used as a base for the forecast, blended preference towards the 0z and 12z Euro. These models matched relatively closely to ensemble 500 mb heights. One particular note for beyond the drier period is the potential for a windier system to move into the panhandle. EFI tables are beginning to show a shift of tales of 0 with 80% of members agreeing. What all this means is there is potential for higher than normal wind gusts for this time of year. Furthermore, moist, southwesterly flow hitting up against the northeast shore will cause moderate rain for around two days mid week. Thinking the 60th to 75th percentile of the NBM for rainfall due to closer match with the Euro solution. While the Euro solution is a fair bit wetter (75th to ~85th percentile of the NBM), tempering down the forecast seemed appropriate. All in all what this translates into is up to about 1 inch per day for Yakutat mid week. && .AVIATION...This morning, the area is split in two by two very different weather patterns. Areas along and south of Frederick Sound have VFR conditions with clear to mostly clear skies with winds on the lighter side. Going forward, these conditions should continue through today, tonight, and into tomorrow. Areas north of Frederick Sound have a wide range of conditions ranging from IFR to VFR. High-end MVFR to VFR conditions in the north are mainly contained to Lynn Canal. IFR to MVFR conditions are found along Icy Strait and south to near Frederick Sound, and along the coast. Lowered conditions are mainly due to lowered CIGs but there are some reports of rain that are causing brief lowered VIS to around 2 to 5 SM. There are a couple of outliers to all this, the Yakutat and Elfin Cover areas are seeing times of LIFR conditions due to CIGs near 500 feet. Going forward, as a ridge builds over the gulf, and leftover rain should fade out and CIGs should improve. So overall improving conditions are expected to high-end MVFR to VFR. There is some evidence of brief lowered conditions overnight, but those conditions would improve quickly around 15z to 18z tomorrow. && .MARINE...No significant systems in the area. Clouds will help diminish sea breeze impacts. Anticipate wind speeds of up to 20 to 25 kt for parts of the outer coastal waters, northern Lynn Canal, and ocean entrances. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ022-644. && $$ SHORT TERM...GFS LONG TERM....NC AVIATION...GJS MARINE...GFS Visit us at http://www.weather.gov/Juneau