textproduct: Juneau

UPDATE

Looking at the latest observations, along with the latest radiosondes available in Annette, WAA has taken over the southern half of the panhandle. Most areas have either transitioned fully to rain or heavy mixed precipitation in sheltered areas. Stronger winds have also moved in, with SE winds in Metlakatla up to Kake increasing with gusts up to 45 mph. With strong WAA, cut down on snow accumulations in Juneau. Given the latest snow accumulations for Juneau and surrounding areas, and the incoming warm air advection cutting snow ratios down, the Juneau area is looking at much lower snow totals. That being said, looking on satellite, a frontogenesis band looks to have set up north past Auke Bay in Juneau over to Gustavus, which is expecting to stay somewhat stationary for the next few hours. Therefore, these areas are expected to be most inline for heaviest snowfall, with rates well over one inch per hour. For down south, heavier rain rates are on our doorstep, with PW over 200% set to stream in in the following hours.

AVIATION

For the 06Z TAF update we have increased visibility and ceilings in the southern and coastal areas (Sitka, Ketchikan, Klawock, Wrangell) to MVFR prevailing through the rest of tonight into tomorrow given the warm advection off the surface has overtaken the snow production process, and mostly rain expected there through tomorrow. Rain could be heavy at times during the day tomorrow with short periods at IFR in the south. Further north, the transition zone to a snow/rain mix has shifted north to just south of Juneau. Higher resolution models are pointing to increased southeasterly to eventually southwesterly flow (and warmer air in the snow growth zones through 700 mb), and that will start to shut off the heavy snow process for Juneau through morning as we start to see a transition to a snow rain mix and eventually to all rain by late afternoon. For the Icy Strait corridor to Haines, a zone of heavier snowfall is being observed in the satellite data, and this is occurring closer to the Arctic front where the heavier forcing for snow, lower visibilities and lower ceilings are being seen from Elfin Cove, to Gustavus, northern Admiralty Island and north to Haines. Haines is where the lowest ceilings and visibilities will prevail through morning and where the heavier snow rates will continue to be seen at IFR/LIFR through at least 20Z. Skagway will eventually trend down prevailing more towards IFR as well through late morning.

PREV DISCUSSION

ISSUED AT 415 PM AKST Sat Dec 27 2025

SHORT TERM...Moderate to heavy snow continues to fall across most of the panhandle. Temperatures have been slowly warming with the precipitation coming down. Most places remain below freezing but some of the outer coastal locations like Sitka have started to warm above freezing and seen a transition from snow to rain. This warm up is expected to work into the Inner Channels still and bring a transition from snow to rain. The central and southern panhandles are still expected to switch to rain tonight through tomorrow. The main question still remains the Icy Strait corridor. Depending on how far north the warm air gets, Juneau could still make the transition to full rain or potentially see freezing rain mix in. With the uncertainty, elected to keep the current forecast going with only some updates to precipitation amounts, especially for the southern panhandle. Precipitation is expected to continue through Monday as onshore flow continues with a low remaining in the Gulf of Alaska.

LONG TERM.../Tuesday through Wednesday Night/...The overall message is that this timeframe will be the downhill slope in terms of receiving heavy precipitation, with precip becoming lighter as we progress through the period. Generally, in the mid levels of the atmosphere the long wave trough will be closing off to a more simplified closed low pattern over the central gulf by midweek. Meanwhile, the surface feature goes from an extend low/trough pattern to a single low, as well, & becomes more vertically stacked & weaken.

The biggest challenge we are still working on honing in on is that the warming may not end up reaching a stopping point as far northward. The gradient indicating the location of the arctic frontal boundary looks to stay in the southern Lynn Canal / Icy Strait Corridor area appear & would keep the cooler air filtered south into the Juneau area & would also keep Juneau in a rain / snow mix or snow setup.

The atmospheric river continues to slide southward away from the southern panhandle through Tuesday. We may have a few remaining minor flooding issues, still, as the precip continues to taper down. As the main flow pattern shifts southward, temperatures will slowly cool down a bit, again, & push chances for a wintry mix of precipitation back down toward the central & southern panhandle again by Wednesday. With the surface low still sitting in the central gulf into midweek with atmospheric waves rotating around it, onshore flow will continue, & chance-level PoPs into the Wednesday night remain likely.

AVIATION.../Until 00Z Monday/...A potent frontal system continues its push into Southeast Alaska through the period, bringing a mixed-bag of weather to the region. For the northern panhandle TAFs, conditions primarily in the IFR/LIFR range continue through the end of the TAF period as these areas continue to receive significant snowfall. Southern panhandle TAFs will continue the process of changing over to rain through the evening & into the overnight hours as a warm front gradually pushes northward. Central & southern Outer Coast areas like PAKW & PASI are seeing this changeover first as those locations are currently either already mixing or have fully changed over to rain. PAKT in the southern panhandle will be next, then the central panhandle. When the full changeover to liquid occurs, these central & southern panhandle & Outer Coast areas will experience improving conditions approaching & moving into the MVFR category. Winds will generally be gusty out of a generally easterly or southeasterly direction for most places. The exception will be the Lynn Canal area TAFS(PAGY & PAHN), which will maintain a northerly direction through the period. LLWS magnitudes peaking out at up to around 45 kt, between 150 & 200 degrees in direction, & centered aloft between 1 & 2 kft are in store through the 24-hour TAF period as the frontal system continues moving through.

MARINE... Outside (Gulf/Coastal Waters): As of 3pm Saturday a southeasterly storm force front is moving ashore into the inner channels, weakening to gale force. Upstream, SW winds are becoming dominant, with strong breeze to near-gale force strength. Southeast seas reached peak intensity along the northern coast of 20 to 25 ft this afternoon, and are expected to slowly subside to 12 to 18 ft Sunday, with the dominant energy out of the southwest; highest seas aimed at Prince of Wales coast. Several gale force systems will rotate around the parent storm over the next few days, freshening up winds along the northern coast to gale force at times.

Inside (Inner Channels): For Saturday evening a frontal passage will be the primary threat, with winds reaching peak intensity of gale force into Saturday evening with gusts to strong-gales, potentially storm force in Clarence. While Stephens Passage and Clarence Strait hold on to gale force conditions Sunday morning, most areas will start to reach fresh to strong breezes. Lynn Canal continues to see northerly winds of fresh to strong breezes, building to gales by Monday.

HYDROLOGY...A rain on snow event is ongoing for the area starting lasting into Sunday starting for the southern panhandle. Temperatures will continue to warm into the mid 40s to low 50s through the southern panhandle as well as snow levels increasing to around 5,000 to 7,000 ft. Farther north, the temperatures for the central panhandle and Icy Strait corridor warm up to the mid 30s to upper 30s while snow levels warm up to 2,000 to 4,000 ft during this time as well. Most of this warming is expected to occur during the day Sunday, continuing into early Monday for the southern panhandle. 24 hour rainfall amounts on Monday are expected to reach up to 3-5" during the day for the southern panhandle, while in the central panhandle, 24 hour totals are closer to 2-3.5" of rain. Most of the heaviest rain rates are expected this evening through early Monday morning. We have issued a flood watch for Sunday and Monday from Sitka eastward to Petersburg and south to Dixon Entrance due to the significant snow amounts on the ground, what is expected to fall on Saturday, and the heavy rain and snow melt.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Winter Storm Warning until 6 AM AKST Monday for AKZ317>320-325. Strong Wind until 9 AM AKST Sunday for AKZ317. Winter Storm Warning until 3 AM AKST Sunday for AKZ321-322. Flood Watch from 3 AM AKST Sunday through Monday afternoon for AKZ326>330-332. Strong Wind until 6 AM AKST Sunday for AKZ329. Winter Storm Warning until midnight AKST Sunday night for AKZ331. MARINE...Gale Warning for PKZ031-034>036-053-644-651-652-664-671-672. Small Craft Advisory for PKZ012-013-021-022-032-033-641>643- 661>663.