textproduct: Juneau

SYNOPSIS

Key Messages: -Suicide Basin glacier dammed lake continues to fill, 1342 ft as of this morning. At this time, it is expected to be full sometime August 10th or 11th. In the past, it has taken up to 6 days for the main flooding event to start after the basin is full. Visit weather.gov/ajk/suicidebasin for more information.

-No major weather concerns expected into early next week. Periods of light rain and overcast skies continue through Sunday. Highs reach into the mid to upper 60s Sunday and Monday.

-Marine layer low clouds will persist over the eastern Gulf and inner channels through the weekend.

LONG TERM

/Tuesday through Friday/ The current expectation remains for main frontal precipitation to push through on Tuesday with a mean 24 hour rainfall accumulation of 0.20 mainly at higher elevations, with 0.10 more likely over locations at sea level. Intermittent easterly waves may provide additional light rain periodically through the week for the central to northern regions, though probabilities decrease as the surface high pressure over the panhandle strengthens from Wednesday onward. As the midweek system departs, clearing skies across the central and southern panhandle will drive a warming trend, supported by 850mb temperature anomalies reaching approximately 4 to 5 deg C above seasonal norms. The Extreme Forecast Index (EFI) highlights this trend beginning Wednesday and continuing through Friday, particularly at higher elevations and broadly across the panhandle as the upper level ridge settles in. High temperatures are likely to reach the low to mid 70s, with some inland and southern areas potentially nearing heat advisory thresholds (80 deg F) as skies clear toward the weekend. Finally, winds are expected to remain light throughout the period, though diurnal sea breezes will likely increase in response to warmer surface temperatures and a shift to weak WNW onshore flow by Friday.

AVIATION

/through 18z Monday/ Upper level system remains stationary over the Panhandle late this morning keeping a variety of flight conditions across the area with CIGs AoB 3500 ft across the northern panhandle with the lowest conditions around Icy Strait and Cross Sound, and AoB 1000ft along the southern coast line. With the surface high parked over the central Gulf in tandem with the upper level low, overcast skies and unsettled weather will continue through the TAF period though probability of showers reaching the panhandle remains low. Conditions improve during the afternoon to VFR/MVFR with CIGS AoA 4000ft, however diminish routinely overnight AoB 2000ft as marine layer settles in and light rain returns.

Similar to previous days, winds are expected to increase in the coming hours reaching sustained 10 to 15kts this afternoon, can't rule out a gust up to 20kts under any seabreeze influences, particularly near Taiya Inlet. No LLWS concerns through the TAF period.

MARINE

Outside: A 1023mb high pressure remains stationary over the central Gulf through Sunday and into early next week, keeping overcast skies with light and variable winds along in the outer waters. Wave heights remain largely benign through the early week, around 4ft or less along the coast. Accompanying this high pressure is broad westerly to northwesterly winds in the NE gulf coast down to Dixon Entrance around 10 to 15 kts or less. Main marine concern for outer and coastal waters will be nightly return of marine layer, dropping visibilities potentially as low as one quarter mile each morning.

Inside: Conditions across the inner waters remain calm this morning, with cloudy skies across the northern panhandle with some clearing going on across the south, winds largely 10 kts or less, up to 15 kts near Rocky Island. No real driving force for winds through Sunday, outside of the usual daily sea breeze, but will likely see strongest winds in Lynn Canal northward to Taiya Inlet with sustained southerly winds 10 to 15kts. Wave heights remain 4 feet or less through early week.

HYDROLOGY

Suicide basin continues to fill this morning, rising to around 1341 ft as of 4am AKDT. The laser gage in the basin continues to show a steady increasing trend despite a 4 ft drop in the data from the calving event on Saturday due to the shifting ice and waves. Overall message continues to be the same, expecting the basin to be full most likely around August 10th or 11th. In the past, it has taken up to 6 days for the main flooding event to start after the basin is full.

Visit weather.gov/ajk/suicidebasin for more information.

AJK WATCHES/WARNINGS/ADVISORIES

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