textproduct: Juneau

SYNOPSIS

Key Messages:

- More benign weather with a slight chance for rain showers and breaks in the clouds are in store for the Fourth of July.

- A stronger low pressure system and front will impact the panhandle later Sunday into early next week. This system is expected to bring widespread rain, potentially heavy across southern panhandle, and gusty winds.

- Outer coastal and inner channel winds and seas will also increase and become elevated with the strong low pushing through the Gulf.

SHORT TERM.../through Sunday night/

Low pressure near Haida Gwaii will continue to push away from SEAK today, with showers over the southern panhandle diminishing through the day. Partial clearing and light winds further north have allowed fog patchy fog to develop, with dense fog near Angoon. Behind the departing system, surface ridging and weak onshore flow will set up for the 4th of July. Some breaks in clouds are expected, but a few light showers and sprinkles will be possible. Winds will be light tonight and any clearing could lead to more fog development. Pre-frontal showers look to increase on Sunday ahead of stronger low approaching SEAK. A front extending from the low will lift northeast towards the panhandle late Sunday night, with rain becoming widespread over the panhandle by daybreak Monday. Moderate to heavy rain, along with breezy winds, will be possible, mainly across the southern panhandle. Slightly warmer temps this weekend with highs in the mid 50s to lower 60s.

LONG TERM.../Monday through Wednesday/...The stronger system impacting the panhandle Sunday night through Monday continues to be the main focus for the long term, as it brings moderate to heavy rain and gusty winds for the southern panhandle Monday. The unseasonably strong upper level low will move into the Gulf by Sunday night and gradually move southeastward into the beginning of the week, as two fronts move across the panhandle from a main low developing in the western Gulf before moving into the central / eastern Gulf Sunday / Monday. The first will push through Sunday night into Monday morning, followed closely by the second front midday Monday into Monday night after the low moves into the eastern Gulf.

The second of these fronts appears to be stronger, as the upper level low pushes a vorticity max over the area during the day Monday, and as a jet max sets up over the southern panhandle with some divergence aloft coinciding more with this second wrap. This second front will move S to N over the panhandle, with largely a S to SE-ly component, looking to bring heavier rainfall to the far southern panhandle alongside some elevated winds (15-20 mph with gusts to 30 mph) to the southern coast. So far the 24 hr rainfall accumulation for this system Monday will be highest for Annette Island, Ketchikan, and PoW. At this time, the rainfall amounts look most uncertain for the first front as well as during the onset of the second wrap, but at this time are expected to be between 1.75 and 2.75 inches in 24 hours for Annette Island and Ketchikan, and between 1 and 2 inches for PoW for the same period of time.

Rainfall amounts will depend heavily on the orientation of both fronts, the influence of terrain, and the moisture availability and IVT orientation as it pushes into the panhandle. And the system itself remains largely uncertain on the timing of the fronts and thunderstorm potential. The increased certainty on the location of the heaviest rainfall being centered around the SE coastline around Ketchikan, as well as today's EFI table and the NBM EPFT chance of exceeding the 2 and 5 yr RI this far out, has increased our confidence on an unseasonably wet system that will continue to be watched.

AVIATION...12Z TAFs

Overnight, conditions have been inconsistent, ranging from IFR to VFR. Light winds and low level moisture across the panhandle this morning are keeping CIGs lower or low level clouds scattered near TAF sites. Periods of rain showers across the southern panhandle are also impacting visibilities, causing them to lower to 2 or 3 SM as rain moves through. Conditions are expected to improve across the panhandle this morning as a drier air moves in before the next system. Any lingering precipitation is expected to clear through the morning. Winds are expected to stay light across the panhandle and be variable in directions. However, PAGY is expected to have gusty conditions that will settle towards the end of the period.

MARINE

Outside (Gulf and Coastal Waters): Winds are expected to be light and variable in direction today and tonight across the gulf. Maximum winds are likely to be 10-15kts with strong southerly or westerly components. Winds are then expected to become more organized in direction as the next low pressure system moves into the area. A front ahead of this low looks to move into the area early Sunday morning, causing winds to increase and become southeast in direction with speeds of 20-25kts and last through Monday. Today, waves are not expected to exceed 5ft but are likely to build to 8-9ft on Monday.

Inside (Inner Channels): Winds are expected to remain relatively benign across the inner channels today except for Northern Lynn Canal. A southerly sea breeze can be expected today with speeds up to 18kts. By Sunday night, winds are expected to increase as a frontal system moves across the panhandle. Overall, winds will be shifty as the front passes through with wind speed up to around 15kts. Clarence Strait is expected to have elevated wind speed Monday as winds are channeled up Dixon Entrance. Near the Dixon Entrance, winds are likely to reach 20-25kts SE.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ652-672.