West Turns Cooler and Wetter While Milder Air Strengthens East of the Rockies

From November 17th to 21st, most areas east of the Rockies have a good chance of warmer than normal temperatures for the time of year, and that milder pattern extends into the Northwest near the Canadian border. Coastal parts of the southern Mid-Atlantic and Southeast lean closer to typical temperatures at first before turning relatively warmer later in the period. Farther west, portions of California, the Great Basin, and the Southwest tilt toward near- to below-normal temperatures, helped by more clouds and precipitation. Much of Alaska has elevated chances of above-normal warmth, while the Aleutians stay near to slightly below normal; Hawaii is expected to run near to above normal. Confidence in this temperature outlook is well above average thanks to strong agreement among the forecasts.

During November 17th to 21st, the western and central United States have increased chances of wetter than normal conditions, with the highest odds—better than 60 percent—focused on the Four Corners and Southwest. Surface high pressure favors drier than normal weather across parts of the East, yet return flow and possible storm development raise the odds of above-normal precipitation from the Southeast into the Great Plains and Mississippi Valley. Alaska is expected to see near- to above-normal precipitation overall, though southern parts of Southeast Alaska lean drier; Hawaii stays near normal. This precipitation outlook also carries well above average confidence.

Looking ahead to November 19th to 25th, chances of warmer than normal temperatures rise across much of the country from the Rockies eastward, reaching into the northwestern states near the Canadian border and southward along the West Coast. The strongest odds, above 60 percent, center on the Great Lakes and Northeast. The Southwest tilts cooler than normal as shortwave systems move through. Most of Alaska has increased chances of above-normal warmth. Over Hawaii, Kauai leans slightly below normal, the central islands stay near normal, and the Big Island has higher odds of above-normal temperatures. Confidence remains above average for this period.

From November 19th to 25th, above-normal precipitation chances extend from much of the West into the Great Plains, Mississippi Valley, and parts of the East, with odds rising above 50 percent through the Central Plains and Middle Mississippi Valley. Elevated chances also cover the Southwest and California. Parts of the Northeast lean near normal early on under high pressure, though wetter influence is possible later. Alaska is expected to see near- to above-normal precipitation, while Hawaii slightly favors below-normal amounts. Overall confidence for the precipitation outlook is above average.