NOAA outlook still leaning toward warmer temperatures and reduced precipitation in the West

NOAA, the National Oceanic and Atmospheric Administration, released its latest predictions for November and the coming months on October 31. Not much has changed since their report earlier this month.

Warmer-than-average temperatures are forecast for much of the U.S. this winter according to NOAA’s Climate Prediction Center. Although below-average temperatures are not favored, cold weather is anticipated and some areas could still experience a colder-than-average winter. Wetter-than-average weather is most likely across the Northern Tier of the U.S. during winter, which extends from December through February.

Their updated temperature outlooks indicate a monstrous transition in the pattern from the first half of the month to the second half, increasing uncertainty in the outlook. The bone-chilling cold likely early in the month across the Great Plains, Great Lakes and Northeast is weighted more heavily than the warming forewarned by many of the models for the eastern CONUS, so moderate probabilities of below normal temperatures are favored for much of the east, except over Florida. Across the western CONUS, all signals point toward above-normal temperatures, potentially enhanced where below-normal precipitation is also favored. Across Alaska, the ice edge is still far from the coast, which strongly favors above normal temperatures for the immediate coastal areas, whereas trends and recent model output favor above normal temperatures. That signal over Alaska weakens from west to east.

While the El Nino Southern Oscillation (ENSO) climate pattern often influences the winter, neutral conditions are in place this year and expected to persist into the spring. In the absence of El Nino or La Nina, long-term trends become a key predictor for the outlook.

Compared to the mid-month outlook, the precipitation outlook expands the area where below-normal precipitation is favored over the west, while also moving the area of highest odds to the Great Basin. The latest official outlooks and model guidance through the first two weeks show the possibility of some precipitation in the Pacific Northwest, with some of that extending to Montana.

The storm track into the Pacific Northwest is not likely to spread precipitation southward into the Sierra Nevada and Great Basin, where the outlooks through the first 14 days favor below-normal precipitation. North of the predicted mean baroclinic zone and in the core of the colder air forecast for the first half the month, drier than normal conditions should prevail in the Middle Mississippi Valley. Along the mean baroclinic zone, above-normal precipitation is forecast for the Southeast, and over west Texas and eastern New Mexico where the western ends of fronts can sometimes trigger precipitation events over climatologically dry regions.

NOAA will be releasing its next 30-90 day forecasts on November 21.