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 and inner channels.

-A stronger trough advances into the southern panhandle Friday, and to the northern half of the panhandle Friday night bring some light rain.

-Suicide basin glacier dammed lake continues to fill at this time.

LONG TERM

Not expecting to see any major weather events this coming week. However, as high pressure in the Gulf breaks down, several minor disturbances will move through the area, leading to the development of showery precipitation. By Sunday, the lingering remnants of a front will support rain showers primarily in the northern panhandle. 24 hour rainfall amounts on Sunday are expected to be around 0.1, with the highest rates occurring overnight into Sunday morning. Most precipitation will be isolated to higher elevations.

Something of note, some models are indicating favorable lower level lapse rates along the international border, which may help thunderstorm development at higher elevations from Sunday through Tuesday. However, limited shear and a lack of instability in the mid to upper levels should inhibit deep convection. Most if not all storms are expected to remain in Canada rather than crossing the Coast Range into our AOR.

Through the weekend, a weak upper level trough is expected to move over the eastern Gulf, followed by the formation of a jet streak south of the region by Tuesday. This, combined with a low-pressure center tracking east from the Bering Sea across the Gulf, may provide sufficient energy for widespread rain showers and higher QPF amounts as a front pushes northward on Tuesday. While guidance is beginning to agree on the track of the Gulf low, there is still large spread in rainfall totals, which will likely be more influenced by local effects than anything else.

AVIATION

Still seeing mostly VFR conditions with CIGs around 3500 to 4500 ft in the inner waters for most of the panhandle. Areas along Icy Strait and the NE gulf coast have successfully risen to AoA 1500 ft, with conditions expected to continue into the evening. Still anticipating conditions for the NE gulf coast and Icy Strait over to Gustavus to return to at least IFR conditions, with CIGs AoB 900 ft after midnight tonight. Could see some nearby fog as well, but confidence is low that this will advect over TAF sites at this time. For the incoming weak system on Friday, confidence is increasing to at least see widespread MVFR CIGs spreading south to around the central panhandle during the morning hours. Not expecting any significant impacts to VIS from any isolated rain showers.

Skagway continues to follow the diurnal gustiness trend for another day, with wind gusts not expected to exceed 30 knots from the south. Still no LLWS concerns for the incoming system tomorrow

MARINE

Outside waters: Weakening but constant high pressure in the eastern gulf is the primary driver of wind speeds through the weekend, with moderate northwesterly breezes along the coast diminishing to 10 knots or less going into the weekend. A weak shortwave moving up from the south may shift winds northwesterly to westerly in the waters to the west of Prince of Wales Island on Friday. Otherwise, conditions are relatively stagnant with wave heights 4 ft or less. May see some visibility issues from low clouds, mist, and fog off the coast of Prince of Wales Island and near Cross Sound.

Inside waters: Similar ideas for the inside waters, with forcing generally being driven by large scale thermal gradients between SE AK and British Columbia/Yukon. Winds are beginning to pick up in Taiya Inlet, with higher speeds expected to spread southward near Eldred Rock, along with areas near Icy Strait for westerlies. Not expecting speeds to exceed 15 knots at this time, as higher wind speeds would require clouds to clear significantly more than they are currently.

AJK WATCHES/WARNINGS/ADVISORIES

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