


Area Forecast Discussion
Issued by NWS Juneau, AK
Issued by NWS Juneau, AK
284 FXAK67 PAJK 072355 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 355 PM AKDT Mon Jul 7 2025 .SHORT TERM.../Through Tuesday night/...The axis of a broad weak trough & a weak area of low pressure at the SFC is centered across the central Panhandle. This trough & weak low center continues to track northeastward across the Inner Channels through tonight while continuing to weaken. At the mid-levels, there is a low center located over the northeastern Gulf. Positive Vorticity Advection will cause showers across the area to be enhanced from the added lift and will be greatest along the southern & central Outer Coast, tonight. Only slight chances for thunderstorms are in the forecast for that timeframe for those areas. Temps at 850mb of less than 0 deg. C & model fcst CAPE values of up to around 100 to 150 J/kg will be present for that timeframe. Although, LI values are not quite conducive for thunderstorm. Therefore, the chances are only slight. Showers in these areas may have some heavier rates and gustier winds. Rainfall totals through tonight are greatest around Kake & along the western slopes of the Coast Mountains from Juneau southward with values of between around 0.35 to 0.9 inches. In addition to cloud cover, the low pressure system has brought with it some cooler air aloft as has been seen with the cooler SFC high temps over the last day or so, outside of some areas that got sunny breaks, which broke 60 deg F, today. .LONG TERM... Key messages: - A surface ridge allows for a decrease in precipitation Wednesday before the next system. - Another low in the gulf brings moderate to heavy rain toward the entire panhandle Thursday into Friday. - Gale force winds along the NE coast and near Dixon Entrance. Details: The main impact in the long term forecast remains focused on the plume of moisture over the panhandle Thursday into Friday. Ahead of this system, a ridge over the gulf will make for a slight break in rain. Rain will begin to diminish Tuesday night into Wednesday. During this time, onshore flow will continue allowing for short times of light showers. Through Wednesday afternoon into evening, breaks in the clouds will allow for additional heating. These breaks of broken to scattered clouds will mainly occur over the central to southern panhandle. Early Thursday, a low moves into the western gulf that will send a warm front toward the panhandle. This low, with the help of an upper level jet, will also send a plume of increased moisture toward the panhandle. This plume of moisture will bring widespread precipitation with times of heavy rain. Confidence in this system has continued to increase with a rise in IVT values and with more indications from the Extreme Forecast Index (EFI) tables. Multiple ensembles are now showing the likelihood of >500 kg/m/s of integrated water vapor transport moving over the panhandle. Moderate to heavy rain rates will be occur throughout the panhandle, with the heaviest rates focused on the southern panhandle. For most of the southern panhandle, including Ketchikan, the NBM is indicating a 75% chance of >0.5 inches of rain in just 6 hrs. Near Port Alexander, there is currently a 45% chance of >0.75 inches in 6 hours. Overall, in 24 hours, areas across he panhandle will receive 1 to 2 inches of rain, with southern Baranof Island and higher elevations receiving up to 3 inches. Currently, no flooding impacts are expected, but increased snow levels with heavy rain rates can lead to rises in rivers and creeks to bank full. This low will also bring gale force winds of 35 to 40 kts toward the NE gulf with the strongest winds near Kayak Island. Other areas will see increased winds to strong breezes of 25 to 30 kts along the outside marine waters. Inner channels winds increase up to 30 kts with the strongest at ocean entrances and in Clarence Strait near Dixon Entrance. Land areas in the southern panhandle will experience wind gusts around 35 to 40 mph, and areas near Yakutat look to reach gusts up to 30 to 35 mph. That being said, the active weather continues for SE AK into next weekend as onshore flow with a few embedded shortwaves keep the panhandle damp. Stay tuned as we will continue to update the forecast ahead of this system. && AVIATION...Flying conditions across the panhandle still remains widely varied with primarily VFR conditions from Icy Strait northward, down to IFR for the central and southern panhandle. Primary culprit is low visibilities in rain showers and overall saturation near the surface. For the northern panhandle, VFR conditions will give way to high end MVFR conditions later tonight as more showers spread northward from the surface low moving in over the central panhandle through early Tuesday morning. CIGs to gradually drop once more with drops in VIS due to increasing showers once more overnight. No LLWS concerns over the next 24 hours across the panhandle. && .MARINE...Inside Waters: A weak low center currently moving over the central Inner Channels is causing winds to increase up to Small Craft level (25kt) for Clarence Strait, today. As the low weakens further, continues to pass over the central Inner Channels, & departs the Panhandle, expect winds to become light to around 10 kt and become more variable in direction. For the Thursday into Friday timeframe, another much stronger frontal system will approach the Panhandle / Inner Channels with a relatively tight pressure gradient, bringing in up to around 25 to 30 kt Small Craft value winds & seas up to 6 ft(higher near ocean entrances) primarily for the central & southern Inner Channels from Icy Strait, southward. .Outside Waters: As the weather system continues to weaken & depart the Panhandle, winds over the eastern Gulf will continue to trend down to mainly between 10 & 20 kt through the period out of a generally westerly to southwesterly direction. Along with some scattered showers, only a slight chance of thunderstorms remains in the forecast for portions of the central & southern Outer Coast through tonight. Seas at the Gulf buoys are reporting 5 ft with a period of around 16 sec & a southerly swell, which will turn more southwesterly as we progress through tonight & Tuesday. A much stronger frontal system will approach the the region for the late Wednesday night into Friday timeframe, bringing up to 40 kt Gale sustained winds with its much more tightened pressure gradient & up to around 15 to 17 ft seas. && .AJK WATCHES/WARNINGS/ADVISORIES... PUBLIC...None. MARINE...Small Craft Advisory for PKZ036. && $$ SHORT TERM...JLC LONG TERM....EAB AVIATION...STJ MARINE...JLC Visit us at http://www.weather.gov/Juneau