As Portland braces for a Christmas weekend of winter storms, one weather forecasting model shows the temperature next week could drop to 3 degrees Fahrenheit.
Seven days out, that forecast is far from certain. But two of the models used by the National Weather Service show temperatures dropping into the single digits on the night of Wednesday, Dec. 29.
One of those predictions, which predicts a low of 9 degrees Fahrenheit, comes from the same modeling system that correctly predicted a “heat dome” would raise Portland temperatures above 110 degrees last June. (The coldest temperature ever recorded in Portland is minus 3 degrees. None of the NWS models currently show that record being eclipsed next week, although at least one model has coughed up such a forecast.)
Lisa Kriederman, an NWS meteorologist, says the Portland office is taking those models into account, but currently projects the overnight low Wednesday at a brisk 16 degrees Fahrenheit. “A lot of model guidance is showing really, really low numbers,” she says. “We have been nudging our numbers down.”
Wednesday’s lows will follow a winter storm expected to dump around 4 inches of snow on the city starting Christmas night.
The possibility of bitter cold adds a new threat to a region that has proven unprepared for increasingly common weather extremes. At least 59 people in Multnomah County died from hyperthermia, or overheating, during the June heat dome.
Last February’s power outage amid an ice storm also proved fatal. It killed at least four people, who died in Clackamas County from carbon monoxide poisoning as they tried to heat their homes.
Shaken by the past year’s weather deaths, Multnomah County Chair Deborah Kafoury and Portland Mayor Ted Wheeler on Thursday declared a state of emergency through at least Dec. 31.
“With this cold snap, what is a matter of holiday inconvenience for some is a matter of life and death for others,” Kafoury said during a press conference. “Please, please check on your neighbors during this cold snap. We need your help to help one another.”
Kafoury said TriMet has guaranteed free bus and MAX rides to warming shelters, and local utilities have agreed not to shut off electricity or gas service for nonpayment until Jan. 3.
Dr. Jennifer Vines, the tri-county health officer, asked people to keep an eye on signs of hypothermia and not assume that houseless people are intoxicated. She also said the weather event had slowed the pace of COVID-19 vaccinations as the Omicron variant arrives.
And she noted a bleak symmetry. “We’re six months to the day from our extreme heat event,” Vines said.
Kriederman, the meteorologist, said the cold snap has one silver lining: It is unlikely to produce the freezing rain and ice that snapped a record number of power lines in Oregon last February. “The entire air column is cold,” she said, “so it’ll just be snow.”
Find a list of severe weather warming shelters here.
Update, 8 pm: Oregon Gov. Kate Brown has also declared a state of emergency, warning of stranded traffic and power outages.
“Our state has experienced a number of climate-related emergencies this year, and with another coming, I urge all Oregonians to make a plan with your family now and be prepared,” Brown said in a statement.
Earlier in the day, Kafoury explained the uses of an emergency declaration, which range from securing contracts to simply getting people’s attention.
“It’s like typing in all caps: This is serious, please pay attention,” she said.