textproduct: Juneau

SYNOPSIS

Key Messages:

- Isolated showers and mostly cloudy skies continue across SE AK through Thursday evening as an upper level system moves across the panhandle. The far northern panhandle will see more consistent light rain begin to dissipate later in the evening.

- Warmer temperatures, sunny skies, and drier conditions are anticipated for this weekend as an area of high pressure remains over the gulf, with high temperatures reaching into the 70s.

- A region of good heating Friday may lead to stronger convection along the Chilkat range and north to British Columbia border. and the remains of an upper level features on Saturday cloud develop the stronger convection for the Misty Fjords north to about Ernest Sound.

LONG TERM.../Sunday through Wednesday/

The region will remain under the influence of an upper-level ridge through this weekend and into next week. By Wednesday, an upper- level low is forecast to track eastward over the region, introducing energy into the lower levels and increasing PoPs slightly over the central and northern panhandle. Moderately warm 850mb temperatures will support weekend highs, and low relative humidity aloft will work to suppress cloud coverage across the region.

Maximum temperatures will remain elevated into Monday, particularly across the inland areas, the southern panhandle, as well as near Hyder, and the Chilkat Valley. Sunday looks to be about as warm as Saturday, with high confidence that temperatures will remain the mid 70s in the warmest locations, while general highs range from the mid to high 60s across the region. A gradual cooling trend begins Monday, with high temperatures steadily declining throughout the week.

Remnants of surface high pressure will persist through Monday and Tuesday, however, winds in the Gulf are expected to shift to onshore flow, introducing marine layer influence to coastal communities. Given the preceding warm and dry conditions, current thinking is that the marine layer will not push far inland. Rain chances will begin to increase late Wednesday, though precipitation is expected to remain light and impact the north gulf coast initially.

There remains significant disagreement between ensemble members on the timing, strength, and formation of a mid-week surface low. Guidance is trending toward the ridge holding firm, causing any returning precipitation to be delayed towards the end of next week.

AVIATION

Conditions have been generally improving through the early afternoon hours on Thursday, and look set to continue improving into the evening. CIGS have climbed to 3000 - 5000 ft for most of the panhandle, with the lower CIGS generally found along or near the coast; or in Gustavus. Overnight, anticipate the potential for some reduction in CIGS to 1500 - 2500 ft for for the outer coast and parts of the Icy Strait Corridor, depending on how far a residual cloud deck can rebuild. A pew areas of patchy fog can't be ruled out either, although at this time, do not think that is the most likely scenario. Through the daytime on Friday, conditions will improve to VFR across the area as a strengthening ridge builds, although a marine layer building offshore could move in Friday night. No LLWS concerns during the time frame, though the potential for an isolated thunderstorm or two around Skagway cannot be ruled out on Friday.

MARINE

Outer Coastal Waters: A strengthening ridge of high pressure will lead to increasing NW flow along the Gulf Coast. These northwesterly winds are expected to be accelerated by the coastal terrain, specifically around prominent capes, causing winds to reach up to 20-25kts by this evening. In the northern outer waters, 15-20kts are more likely to be expected around Cape Fairweather and Cape Spencer, while winds in the southern outer waters will have more time to accelerate up to 20-25kts. This phenomena is expected to continue through the day Friday before diminishing through the day Saturday. Through the period , waves are expected to sit around 4-5ft and build up to 8 ft in the southern outer waters with the acceleration of wind along the coast.

Inside Waters: A weak low traversing along a building ridge is bringing with it chances of scattered rain showers through the day on Thursday, before shower chances slowly diminish on Friday. Prevailing northerly flow for N/S channels will remain at or under 10 kt for most of the channels through the remainder of the week and into the weekend. The exceptions will be Clarence Strait, which will see 10-20 kt NW winds, and northern lynn Canal, Taiya Inlet, which at times will see S 10-20 kt winds.

E/W channels will see prevailing westerly winds. Sea breeze influences will strengthen winds during the late afternoon and evening hours around Icy Strait and Point Couverden to 15-20 kt through the weekend.

The chance of a few isolated thunderstorms for far northern lynn Canal and Skagway harbor can't be ruled out tomorrow (Friday), and on Saturday for locations east of Ketchikan including Behm Canal and Portland Canal.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ641-661.