textproduct: Juneau

UPDATE

Aviation Discussion refresh for 06z TAF Issuance.

SYNOPSIS

Key Messages:

-No major weather concerns expected through the week, however marine layer low clouds will persist over the eastern Gulf and inner channels.

-Areas of light rain and drizzle return to the northern Gulf Coast and northern panhandle and continue into midweek. No heavy rainfall is expected. -High pressure over the eastern Gulf of Alaska will keep the southern panhandle dry through the end of the week.

LONG TERM

A fairly benign weather pattern is expected to continue throughout the next week, with temperatures remaining relatively steady across the region. High temperatures will generally range from the low to mid-60s, with lower 70s possible for inland areas late this week and early weekend, and no significant warming or cooling trends are anticipated. The ridge in the Gulf will continue to maintain a stout marine layer along the Gulf Coast, causing widespread overcast skies due to a saturated and stable surface layer. However, only occasional drizzle is expected, as there is a lack of upper-level support for more efficient precipitation formation.

The panhandle should remain mostly dry until the weekend and into early next week, as a weakening upper ridge and surface high pressure allow more energy to pass into the region. While there is a shift in coastal flow from northwesterly to southeasterly winds beginning Sunday, we are lacking the strong easterly flow necessary to push thunderstorms into our region. That said, light to moderate rain showers may impact the southern panhandle and inland border regions, from Hyder to Skagway, driven by terrain influences and possible convection from western Canada. Looking ahead to the start of next week, there is currently low confidence in the placement and total amount of seasonably heavier precipitation, as model guidance remains in disagreement over the track of a weak low in the western Gulf. We will continue to watch this development in the coming days.

AVIATION.../Until 6z Friday/

Overall weather pattern remains unchanged this evening, with a persistent cloud deck around 4000 ft over the panhandle with a lower marine layer around 1000 ft making its presence known around Yakutat and elsewhere along the outer coast. Similar to last night, the marine layer in the gulf is expected to reform and push into Icy Strait and Peril Strait, bringing lowered CIGs AoB 2500 ft to Gustavus, Hoonah, Juneau, with lowest conditions expected along the outer coast. Rinse and repeat for Thursday with conditions expected to improve later in the morning with the marine layer receding or thinning, but the mid level deck remaining above, and some light sea breezes developing by the afternoon. Strongest sea breeze likely into Skagway up to 15 kt.

MARINE

Inside Channels: Generally lighter winds across the inner channels with mainly sea breeze winds up to 15 kt showing up in the afternoons for northerly Lynn. Cross Sound and the ocean entrances near Cape Decision are seeing some terrain enhancement of the NW winds from the gulf waters with Cape Decision in particular observing 15 to 20 kt W winds from enhancement off southern Baranof Island this afternoon. This enhancement of winds is expected to continue into Thursday as the NW winds in the gulf stay relatively consistent. Wind directions are mostly westerly and northerly, though the exception is Lynn Canal and Glacier Bay which are showing southerly winds due to pressure gradient forcing. Seas are 3 ft or less for most areas. Generally the inside waters will continue to see mostly 10 kt or less of wind and seas of 3 ft or less through the next few days with no significant weather systems expected to move through the area. Some areas of lower visibility may be found near the outer coast due to some areas of drizzle from the marine layer clouds especially at night and in the early morning.

Gulf Water: Persistent ridge of high pressure over the gulf is driving continued W to NW winds up to 15 kt for most areas of the gulf. This is not expected to change all that much except for a gradual weakening of that ridge and the winds through the late week period. Seas are rather low with most buoys reporting 4 ft combined seas with around 3 ft of that being a 7 sec 3 ft swell from the SW. Little change expected here with 4 ft seas continuing through the late week and little if any swell. Marine layer clouds may produce some areas of drizzle near the coast that could reduce visibilities down to 2 to 4 miles at times mainly at night or in the early morning.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...None.