High Wind in City and Borough of Sitka, Alaska

A burst of high winds were felt across Sitka during the morning hours of the 29th. A peak gust of 71 mph was recorded by the Sitka ASOS at 910am and a peak gust of 78 mph was measured at the Marine Exchange station at the Sitka Harbor at 1013am. Additionally numerous reports were received of down trees all over town.

A strong storm force low pressure system over the North Pacific lifted north and moved into the Gulf of Alaska by the morning of January 29th. There was an associated atmospheric river along the warm side of the cold front that had a significant amount of sub-tropical moisture within it. Along with the the high anomalous moisture values, there was a very warm airmass with the atmospheric river which increased freezing levels across Southeast Alaska to more than 5000 feet. There was a deep snowpack at upper elevations and near sea level, which melted with the heavy rain to increase the amount of runoff into rivers and streams. Another low pressure system developed along the frontal boundary which stalled the front over the region to produce continued prolog heavy rain but also high winds. The combination of high winds and heavy precipitation on snow at high elevations triggered a number of avalanches near Haines.

The 2 day precipitation total across the northern half of the Southeast Alaska ranged from 2 to over 4 inches along with significant amount of snowmelt and runoff from the high freezing levels and the heavy rain melting the snowpack. The heavy rain triggered a small landslide in Haines near Lutak, another near mile 6 of Zimovia Highway in Wrangell. There was some minor overland flooding from poor drainage near the Haines airport by the afternoon of January 29th. Near the Juneau area there was a lot of minor flooding of small streams going over their banks from the rain and snow runoff through January 30th but there was moderate flooding near Jordan Creek that impacted a few homes, business and roadways.

Tree fall was was widespread across the region from this event due to the saturated ground and high wind gusts of 60 to 90 mph.