Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
430 FXAK67 PAJK 051739 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 939 AM AKDT Sun May 5 2024 .UPDATE...Update to aviation discussion to include the 18z TAF issuance. && .SHORT TERM...Satellite imagery and surface analysis depict low pressure system over the SW gulf with an occluded boundary across the NE gulf coast stretching SE just off the outer coast early this morning. Sat derived rain rates indicate precip over much of the panhandle early this morning, but with the relatively dry BL, reports have been mainly limited to the NE gulf coast overnight. Precip has spread into the Icy Strait corridor attm and expect BL to continue saturate with precip becoming more widespread through the early morning. Precip will persist through the day with rainfall totals ranging from 0.25-0.75" through Mon morning. .LONG TERM...An active weather pattern continues as system after system moves into the panhandle, with each one bringing concurrent chances of rain and wind across the area. Aloft, the upper level pattern has sharply departed from its previous state of the past few weeks. The primary steering flow which was directing systems to the south and away from the panhandle will instead be directly overhead as a strong jet streak developing along the E flank of a deepening trough over the Bering Sea moves the primary area of upper level support over the panhandle. Closer to the surface, this will enable multiple waves to develop and enter the panhandle. Lingering chances of precipitation associated with onshore flow in the wake of a system from Sunday will remain through Tuesday before another, stronger system arrives later on Tuesday or Wednesday. This second system will move up from the SW, moving around the broader area of upper level troughing. Expect a surge of more widespread precipitation to be possible with this system alongside the potential for small craft winds for many locations and gale force winds potentially in the gulf. Beyond this point operational guidance begins to falter as model spread grows, but ensembles are indicative of another system arriving immediately in the wake of the previous one, delivering another round of rain and wind to SE AK, with the active weather pattern likely to continue thereafter. The primary changes to the forecast for next week were centered around adding additional detail to the wind forecast, as timing is slowly beginning to come into better agreement. Some changes to the QPF forecast were made as well, based on better consensus regarding the arrival of the main bands of precipitation across the panhandle. && .AVIATION...This morning, periods of MVFR conditions are being reported as the band of rain tracks northward. Behind the front, isolated periods and areas of MVFR are possible where the rain showers are, but overall, VFR conditions should return to SE AK this afternoon with VFR lasting into tonight. && .MARINE...Generally light to gentle southerly breezes over the inner channels this will become moderate to fresh southerlies Sun morning and persist into the evening before diminishing. Over the gulf, fresh E to SE winds will prevail with a SW swell building combined seas to 8-10ft tonight. Conditions will ease Mon into Tue before deteriorating Tue into Wed as another low moves into the gulf bringing near gales to gales over the gulf along with building seas. Inner channels will see fresh to strong winds in response to the tightening pressure gradient. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ641>644-651-652-661>664-671-672. && $$ SHORT TERM...BC LONG TERM....GFS AVIATION...GJS MARINE...BC Visit us at http://www.weather.gov/Juneau