Warm, tropical air is being drawn into the state along a strong upper level jet. This is a classic "Pineapple Express", with a strong ridge over the eastern Pacific and western Lower 48 forcing this rich moisture to the north into Alaska. Snow and rain have been heavy at times along the southern coastline and will continue today.
A Chinook wind in Anchorage didn't materialize, although temperatures in the higher elevations of the city have climbed above freezing. This storm has made a mess of many locales, however. Sloppy wet snow and periods of rain with temperatures in the 30s and 40s have been reported around Bristol Bay, the Alaska Peninsula, the Kenai Peninsula, PWS, and the northern SE Panhandle.
Moisture has been much more limited in the Interior, but this warm southerly flow has brought an end to the biting cold for many areas. Temperatures are some 25 to 40 degrees warmer this morning than yesterday morning.
The jet aloft moved east rather quickly last night, so the primary threat for heavy precipitation will be coastal areas from the eastern PWS region into the Panhandle. However, snow will contiinue in the Cooper River Basin with up to a foot along the hills through tonight.
Snow showers are still possible today along Cook Inlet, but, without the effects of warming downsloping winds, temperatures should remain below freezing.
While the threat for above-freezing temperatures existed with this weather system in Anchorage and the Valley, it was not a high probability. By the weekend, another storm brings with it a greater likelihood of seeing a Chinook wind event. Light rain and snow and gusty winds will be threats in town both Saturday and Sunday.
