textproduct: Juneau

SYNOPSIS

Key Messages:

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

-Mainly dry and mild weather expected through tonight, before precipitation chances return to the northern Gulf Coast by Monday. No heavy rainfall is expected.

-High pressure over the eastern Gulf of Alaska will keep the southern panhandle dry through at least mid week.

LONG TERM

The surface ridge of high pressure over the eastern Gulf of Alaska looks to persist through the extended forecast period. This will keep the heavy rain threat on the west side of the ridge axis and outside of our forecast area. However, marine layer clouds will likely be held under that ridge over the gulf and along the outer coast. As a mid-level trough passes over the marine layer Tuesday night thru Wednesday the PVA will be just enough lift to have a chance/slight chance of rain (more likely drizzle) along the northern and central outer coast and into the Icy Strait corridor. The ridge will periodically flatten some (dirty ridge) and allow moisture/clouds to stream in, namely for the Yakutat area. Meanwhile, areas on the lee side of the ridge axis (Chatham Strait to Clarence Strait) will have NWLY (downslope) flow and mostly clear skies for majority of the next week.

Most models were in lock-step today on keeping the ridge offshore for the work week and sharper as well. The GFS represented these wind directions well with NWLY flow along the southern outer coast and southern inner channels to Dixon Entrance as well as stronger wind speeds. These speeds were raised in the forecast to about 15- 20kt, but some areas of 25kt are possible in vicinity of Cape Decision to Dixon Entrance and will be monitored over the coming days.

AVIATION.../Through 12Z Monday/

A marine layer continues to move back into the region as high pressure builds into the eastern Gulf. MVFR ceilings are most prevalent at this time, and reductions to IFR are possible through about 16Z-18Z, before ceilings begin to very slowly lift once again. PAKW and PAKT are likely to remain MVFR longest and may only briefly improve to VFR late this afternoon before again lowering. Overall, ceilings will once again gradually lower across the area tonight, especially after about 06Z as the marine layer pushes back inland. Surface winds will generally remain 10kt or less, although sea breeze development will cause sustained speeds to reach close to 15kt with gusts to 25kt at PAGY late this afternoon and evening.

MARINE

Outside (Gulf and Coastal Waters): The marine layer continues to bring low clouds to much of the region early this morning. While winds have subsided in many areas overnight, we expect NW winds of moderate to fresh breezes by late morning and afternoon. Significant wave heights of 4 to 5 ft will continue through at least Monday afternoon.

Inside (Inner Channels): Gusty winds in the northern Lynn Canal and portions of the Icy Strait were slow to decrease overnight, but have recently trended weaker. Low clouds associated with the marine layer has helped to keep fog formation to a minimum, although some patchy fog is certainly expected through the morning hours, especially in the southern panhandle.

Like yesterday, a sea breeze of 15 to 20 knots will likely impact Icy Strait and Lynn Canal with locally higher gusts by later today. We are not currently anticipating advisory level conditions, but a short-fused small craft advisory may be needed for these areas late this afternoon and early evening, particularly if there are prolonged and significant breaks in cloudiness, which could effectively increase thermal gradients and result in higher winds for a period. A similar pattern is likely again Monday afternoon and evening.

AJK WATCHES/WARNINGS/ADVISORIES

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