So since 9am PST (oldest observation at the bottom, most current at the top) PDX has been hovering right around 0C/32F and alternating between "Light Rain" and "Light Freezing Rain" observed. The NWS Portland Forecast has them under a Freezing Rain Advisory today, with temps forecast to slowly rise this evening/overnight to the upper 30s.

Data at: 2214 UTC 09 Dec 2016
KPDX 092210Z 13011G16KT 4SM -RA BR SCT007 BKN014 OVC020 01/M01 A3000 RMK AO2
KPDX 092153Z 12015KT 2SM -RA BR SCT007 OVC014 00/M01 A3001 RMK AO2 SFC VIS 3
KPDX 092053Z 13011KT 2SM -RA BR SCT007 OVC014 01/M01 A3002 RMK AO2 SFC VIS 3
KPDX 091958Z 12013KT 1 1/4SM R10R/4500VP6000FT -FZRA BR SCT007 OVC014 00/M01 A3004 RMK AO2 TWR VIS 1 1/2
KPDX 091953Z 12013KT 2 1/2SM R10R/4500VP6000FT -FZRA BR SCT007 BKN014 OVC020 00/M01 A3004 RMK AO2 UPB02E04FZRAB04
KPDX 091910Z 11011KT 3SM -FZRA BR SCT007 BKN014 OVC020 00/M02 A3005 RMK AO2 SFC VIS 4 UPB02E04FZRAB04
KPDX 091853Z 12012KT 4SM BR SCT007 BKN014 OVC025 01/M02 A3006 RMK AO2 FZRAE51
KPDX 091809Z 14008KT 2SM -FZRA BR SCT007 OVC014 00/M02 A3008 RMK AO2 SFC VIS 3
KPDX 091753Z 13009KT 3SM -FZRA BR SCT008 OVC014 00/M02 A3007 RMK AO2 SFC VIS 4

Even for those parts of the country where winter weather is routine, the potential for icing + aviation = A BIG DEAL.

The FAA hasn't been carrying any "official" delays into or out of PDX all day, which makes the untrained among us assume that the ATC volume has been voluntarily diminished by the airlines to a level that the system(s) can handle whatever is left. http://www.fly.faa.gov/ois/

As for what deicing equipment various airlines have access to (or don't) and/or how that is handled at a specific airport, one of our resident experts will eventually happen along here to share their wealth of knowledge.