textproduct: Juneau

SYNOPSIS

Key Messages:

- A series of fronts will push into the panhandle through the end of the work week with rounds of light precipitation expected.

- Increasing forecast confidence of drier and warmer conditions heading into the weekend.

LONG TERM

The spring weather pattern continues unabated through the week, as high temperatures in the upper 30s and 40s remain, and a front moves across the panhandle from NW to SE Thursday through Friday. The weekend offers a respite from the rain, with the sun breaking out across much of the area.

The upper level ridge over the area will have flattened out by Thursday, allowing a system to break through and move across the panhandle. Am expecting rain to be predominant, as snow levels remain between 1000-2500 feet (with the higher snow levels for the southern panhandle). 1000-850mb thicknesses will also remain at or above 1290 decameters across SE AK. This will significantly limit chances of snow near sea level with this system, and while some snow flakes will mix in during the overnight hours for the Icy Strait Corridor northward, expect rain to remain the primary precip type. The QPF totals look to be rather limited, with NBM 75th percentiles at or below 1 inch for most locations, and so don't expect any flooding concerns with this system either.

As the system departs to the south Friday into Saturday, anticipate weak northerly outflow winds developing. Particularly during the overnight and early morning hours, winds of 20 to 25 kt will spread across Lynn Canal with gusty conditions expected for areas like Chatham Strait, and Stephen's Passage. During daytime hours, these winds will be far weaker, as the Northerly pressure gradient force clashes with diurnal heating (ocean effect sea breezes). Clearing skies are expected in the wake of the system as a ridge rebuilds, and then lasts through much of the weekend. Ensemble guidance struggles once we enter next week, with the usual difficulties in trying to time the breakdown of the ridge in the extended range. However, the general ensemble and NBM trends are favoring a low and front to push into the gulf later Sunday and towards SE AK Monday as the ridge weakens and shifts east. Rain potential looks to increase Sunday night into Monday. Temperatures also likely to remain seasonable, with highs in the 40s and nighttime temps in the mid to upper 30s.

AVIATION...VFR conditions continue for most of the panhandle with this evening although a few locations have started to report MVFR conditions. Places from Sitka northward are possible to see MVFR conditions as precipitation moving into the area attempts to reach the surface. Although most of the precip hitting the surface is fairly light, there is still the potential to see some of the rain switch to snow. Some visibility drops to 4-5 SM are possible while ceilings could be down to flight level 015. Farther south, VFR conditions continue this evening and are expected to continue. The only place that could come into question for potentially seeing deteriorating conditions would be Klawock as the marine layer tries to move along the coast.

AVIATION

/ through Wednesday night / Most of the panhandle has VFR Conditions this morning especially the southern half of the panhandle. Ceilings of 1500 to 3000 are starting to spread into the northern panhandle ( Gustavus, Haines and Sitka for example ) Preciptiation spotty early this morning, but should be spreading in around midday. The next rain band is moving across the central gulf coast and into the are a this morning expect that the lower conditions for the northern panhandle and the Northeast Gulf Coast area, for the afternoon an evening. Should see the the lower conditions there continue into the night. While the southern portion of the panhandle, should have the better flight conditions and may start to lower overnight.

MARINE

Outside (Gulf and coastal waters):As of 0300 Wednesday morning, ASCAT/AMSR2 satellite wind passes, ship observations, and coastal buoys all highlight south to easterly winds along our coast, with speeds of gentle to fresh breezes. The wind passes highlight the approaching front for the northern coast, with an increase of easterly winds to strong breezes along Cape St. Elias forecasted for Wednesday morning. On the backside of the front, anticipate southwesterly winds of fresh breezes to continue to shift slowly east.

Moving on to sea state, satellite altimeter wave heights, buoys and a lone SOFAR buoy highlight significant wave heights of 3 to 5 ft. The dominant wave system along Cape St. Elias is fresh seas out of the south and south east, with the rest of the coast feeling westerly decaying fresh seas of 3 to 4 ft near 7 to 8 seconds. Anticipate southwesterly fresh breezes to begin to increase westerly seas this afternoon, with significant wave heights increasing back to 7 to 9 ft and a period less than 10 seconds along the coast. Winds and seas begin to relax by Thursday, with southwesterly moderate breezes and significant wave heights dropping below 6 ft.

Inside (Inner Channels): Winds of gentle to moderate breezes continue to impact much of the inside this morning, with Lynn Canal holding onto fresh breezes out of the south. Anticipate winds to continue to diminish this morning as a shortwave trough ejects east into Canada, breaking down the surface pressure gradient. The feel for much of the inside Wednesday will be winds of moderate breezes or less; the primary threat being smaller recreational vessels navigating coastal ocean entrances, where west to southwesterly seas might catch folks off guard. Southern Clarence Strait near Nichols Passage will likely see more extensive and organized moderate breezes out of the northwest.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ642>644-651-652-661>664-671-672.