textproduct: Juneau

UPDATE

after 06z TAF update. VFR condition for the southern panhandle to start. Should see that the ceilings lower close to 3000 feet or down to 2000 feet by morning as rain spreads into towards morning and into Thursday. The northern panhandle has snow leading to lower visibilities and ceilings of 1500 to 2500 feet. Expect those conditions continue to the morning. The rain snow line that is across the central panhandle, will be starting to see the rain line northward to be along Icy Strait.

PREV DISCUSSION...ISSUED AT 322 pm Wed Mar 4

SHORT TERM...The low that has been bringing snow to the area has moved inland and we are now seeing the onshore flow behind this system take hold. Winds have slowly been shifting to the west for most stations that are not sheltered from a west wind. With this surge of wind from the west, temperatures have also been rising above freezing with this surge. Most locations in this warmer air have managed to jump into the mid to upper thirties allowing for a switch from snow to rain. Satellite imagery shows another wave of precip moving towards the area and some light returns have started to show up off the coast on radar. These showers should bring some more rain and snow to the area but current thinking is that most locations will be limited to just a few inches of snow for areas that remain snow or switch this evening.

The next front is then expected to move into the area tomorrow bringing more rain and increased winds to the panhandle but is expected to be weaker than the previous systems we have. After this front moves through, a stronger system looks to enter the area for the start of the long term period.

LONG TERM...A warm and moist airmass looks to move across Southeast Alaska through Friday as a strong low pressure system tracks north of the panhandle. Associated with this strong low is a particularly strong jet aloft, exceeding 130 knots, spreading over the northern panhandle. The resulting pattern will see height falls and pressure drops in the yukon, and pressure rises near the southern panhandle. Therefore, a predominantly southerly wind regime is in order for late this week into the weekend. Widespread moderate to heavy rain is expected across the region on Friday along with elevated snow levels. Rising snow levels combined with strong southerly flow looks to mix out any remaining cold air, transitioning areas in the northern panhandle to all rain.

Going into Friday night and Saturday, a surge of colder and moist air will slowly begin to drop snow levels and convert precipitation type back over to snow. The northern panhandle looks to see all snow by Saturday morning, with areas to the south following over the course of the day. Late in the weekend will see the aforementioned jet drop south, driven by the northerly, cold winds aloft. This will allow more cold air to move from north to south. Additionally, with continued onshore flow, snow remains in the forecast late in the weekend and into next week.

Forecast confidence in the overall synoptic pattern evolution is moderate to high, particularly regarding the transition to colder temperatures and a snowier regime by late Saturday and Sunday. Confidence in precipitation type transition from rain to snow is high. Main sources of uncertainty is in exact precipitation amounts, especially for Friday and Saturday. As rain transitions to snow, will need to pay attention to QPF trends particularly for the Central Inner Channels and Prince of Wales Island Saturday into Sunday.

AVIATION..../Through 00z Friday/... Snow showers have held on longer than anticipated across SE AK, with areas across the northern half of the panhandle still lurching into IFR territory on occasion, though areas without shower activity have seen CIGS and VIS improve into VFR. While shower activity will diminish through the evening hours, by Thursday night, chances of snow begin ramping up as another system approaches. As this system moves through on Thursday, expect an initial burst of snow for areas from Wrangell northward, with a changeover to rain through the late night and morning hours on Thursday as warm air advances back northward. MVFR to IFR conditions are expected with this system, with MVFR for most locations and intermittent IFR conditions as heavier pockets of precip move through. By Thursday afternoon, expect the Icy Strait Corridor to be changing over to rain, and for more widespread MVFR conditions as a result, as CIGS and VIS somewhat improve.

MARINE...Outside (Gulf and Coastal Waters): Winds continue to trend down across the Gulf waters this afternoon ahead of the next front that is expected to move across the area late tonight into tomorrow. This front will approach from the south bringing fresh to strong breezes for the Gulf and coastal waters. Some pockets of near gales are possible especially as the front moves closer to the Icy Bay and Cape Suckling areas. Seas are expected to trend down through this evening into tomorrow but could see a slight tick upward as the weak front moves into the Gulf. Winds are expected to trend up though with the system that is expected to move into the are for Friday.

Inside (Inner Channels): Outflow winds have diminished and are shifting to the south and west this afternoon. Gales continue for Cross Sound this afternoon as the westerly surge continues to push inland. This surge is expected to diminish through the evening. Winds are expected to drop to fresh to strong breezes for most places but some pockets of near gales could be possible as a weak front moves across the panhandle. Seas are expected to be around 3-6 ft for the Inner Channels with the exception of near ocean entrances. Gales are expected to return to parts of the Inner Channels by Friday as we see a gale force system affect the area.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013-022-036-053-641>644-651-652- 661>664-671-672.