textproduct: Juneau

UPDATE...Update for the 06Z TAF issuance

Minor edits to the forecast this evening. Biggest concern has been the excessive runoff due to rain and snowmelt across the Juneau area today, along with poor and frozen drainage, has lead to ponding and flooding on area roadways. A Flood Advisory has been issued for Juneau, Douglas and the surrounding area through Wednesday. Otherwise, rain showers across SEAK tonight will transition to a mix with snow and eventual changeover to all snow as cold air advection slowly drops temperatures through Wednesday. Light snow accumulations will be possible, but the bigger concern will be the refreeze of snow and the refreeze of ponding water from recent rain and snowmelt.

HYDROLOGY

Off and on showers will continue through mid week as a low in the NE Gulf sends waves of precipitation across the area. Looking towards the end of the week, the next organized system will push an atmospheric river into the panhandle late Thursday night through Friday. This system will bringing rounds of moderate to heavy rainfall and rapidly rising freezing levels for communities across the panhandle.

For the northern panhandle, current forecast rainfall amounts are around 1 to 2 inches, with locally higher amounts approaching 3 inches at higher terrain. This rainfall in combination with rapidly rising freezing levels around 2000 to 3000ft by Friday afternoon into the weekend. This rainfall in combination with rapidly rising freezing levels around 2000 to 3000ft through Friday afternoon will lead to localized flooding concerns like ponding on road ways and poor drainage due to snow blocking drains along and north of the Icy Strait Corridor, including but not limited to Juneau, Gustavus, Hoonah, Yakutat, Haines, and Skagway.

For the central and southern panhandle, current forecast rainfall amounts are around 2 to 4 inches, with locally higher amounts approaching 5 inches at higher terrain. This rainfall in combination with rapidly rising freezing levels around 3000 to 5000ft will lead to localized flooding concerns like rapid river rises on small streams, ponding on road ways and poor drainage due to snow blocking drains along and south of a line from Sitka to Angoon to Petersburg.

For all of the panhandle, any existing snowpack will become more dense and hard to move by Friday. Additionally, hard pack snow on driveways, parking lots, and sidewalks will become very icy. Preparations should begin for an expected rain on snow event going into the weekend. Stay tuned for further forecast updates on this system moving through the week.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013-022-031-053-641>644-651-652- 661>664-671-672.