

GFS forecast of temperature difference from normal between Tuesday and Thursday night next week (WeatherBell.com)

A significant outbreak of cold air will surge into the Rockies and eastern half of the U.S. next week, dropping temperatures 20 degrees or more below normal in many areas. It will be the coldest air of the season. It is too early to say how extreme the cold will be and whether the blast will achieve historic, record-setting status.

The cold air is forecast to dive into the U.S. on Tuesday, arriving first in the Rockies, Plains, and Midwest.

FLASH: Latest modeling shows temps could be 40° below normal by mid-day next TUE in #Denver and possibly only in the teens! #COwx — Josh Larson (@coloradowx) November 6, 2014

By Wednesday, the big chill reaches the Ohio Valley, interior Northeast, Deep South. And finally, on Thursday, it bleeds into the eastern seaboard.

The National Weather Service’s Climate Prediction Center (CPC) appears strongly persuaded on the arrival of the cold, assigning a 70 to 90 percent chance of below normal temperatures from the Plains to the Mid-Atlantic between November 11- 15 (Tuesday to Saturday).



Climate Prediction Center 6-10 day temperature outlook (National Weather Service)

WeatherBell.com meteorologist Ryan Maue points out model forecasts have trended stronger in their forecasts for the outbreak’s Arctic high pressure center and, thus, the intensity of the cold.

Each consecutive GFS upgrade run increasing High Pressure strength -- now 1052 mb into CONUS, next week Arctic blast pic.twitter.com/axJBKAsfF1 — Ryan Maue (@RyanMaue) November 6, 2014

Next Thursday, the GFS model forecasts highs in the 20s and 30s over most of the northern U.S.



GFS forecast of temperature difference from normal between Tuesday and Thursday night next week (WeatherBell.com)

Typhoon Nuri and its transition into a beastly high latitude storm in the North Pacific is in part to blame for the cold surge, as it will pump up a ridge of high pressure over the western U.S. forcing the jet stream to dive into eastern U.S., opening the floodgates for Arctic air. Indeed, a lobe of the polar vortex will break off but is unlikely to infiltrate as far south as last January – according to the latest model guidance.

Cold air reinforcements are expected in the 8-14 day range, when CPC expresses a high probability of wind chills in the single digits (or lower) across a large portion of the northern U.S.

Shaded regions have a better than 50/50 shot at single-digit wind chills mid-late next week according to CPC. #brrrr pic.twitter.com/x39ErTirwT — Steve Seman (@SteveSeman) November 6, 2014

For details on what this means for Washington, D.C. stay tuned for winter weather expert Wes Junker’s forthcoming post.