The only road leading into Valdez, Alaska, has been blocked by avalanches and the resultant flooding.
A large avalanche occurred later on Saturday in Keystone Canyon, blocking the Lowe River. That led to a large backup of water behind the avalanche, the National Weather Service (NWS) in Anchorage reported.
A Flash Flood Watch has been posted by the NWS from Keystone Canyon to mile post 5 along the Richardson Highway in the event the newly formed avalanche dam breaks and rapidly releases the water that has built up.
The Flash Flood Watch is in effect until noon AKST Sunday (4 p.m. EST).
Flash flooding from this situation is not a concern in downtown Valdez since it does not reside along the Lowe River.
Aerial photographs released by the NWS showed that the flood waters and avalanche are covering the Richardson Highway, the only road motorists can use to travel to and from Valdez.
The Richardson Highway connects Valdez to Fairbanks. Near this highway, the Trans-Alaska Pipeline runs.
Saturday's avalanche comes after another--yet smaller--avalanche initially blocked the river and sparked concerns for flash flooding on Friday.
That initial flood threat ended earlier on Saturday as water slowly drained from the avalanche-dammed Lowe River, the NWS stated.
AccuWeather.com Meteorologist Jim Andrews theorizes that the avalanches are being brought on by the abnormal warmth in place across Alaska causing rain, not snow, to fall on the snow-covered Chugach Mountains surrounding Valdez.
Valdez remains in the midst of an unusually warm spell of weather, part of the topsy-turvy weather across the entire United States.
Temperatures have risen into the 30s every day so far this January with only four exceptions. Highs in the upper 20s are more common.
Overall this January, temperatures are running 7.0 degrees above normal.