2017-18 Winter Outlook
Based on differently weighted factors and trends, including: ENSO, QBO, PDO, AO, NAO, EPO, NPI/Jim's index, solar, and overall pattern progression.
Top tier analogs: 1954, 1970, 1984, 1989, 1996, 2000
Second tier analogs: 1956, 1962, 1974, 1981, 1985, 2007
Third tier analogs: 1949, 1961, 1967, 1971, 1995, 2013
More difficult winter outlook than normal, due to a lack of analogs without major holes, and fairly different timing of patterns depending on if November ends up warm or cold in the West.
IF November ends up cold in the West, I'd strongly favor 1956, 1961, 1971, 1985, and 2000.
IF November ends up warm, I'd favor 1954, 1962, 1989, 1995, 2007 and 2013.
Strong signal for cold across the northern tier of the U.S., with the cold anomalies centered in the northern plains/upper Midwest. Warm across much of the southern tier. Anomalously high heights over the Aleutians, with the polar vortex likely spending some time in northern Canada. -1 to -3 anomalies predicted in the PNW, with northern areas likely to see the greatest cold. Decent chance this is the coldest month of the winter for New England.
Good signal for cold throughout the West, centered in the interior West/Great Basin. Expect NE Pacific ridging near the sweet spot for Arctic blasts offshore of North America, with the intensity of said blasts depending on amplification of the ridge. -2 to -5 anomalies predicted for the PNW. Under the influence of -EPO and perhaps weak -NAO, the rest of the country looks cool to near normal. Some moderation likely in the northern Plains.
Two main signals emerge this month: strong SE ridging, and a weakening of the -EPO, with strong ridging alternating between offshore and over the West coast. Expect most of the West to be below normal once again, but with the coldest anomalies shifting back to the northern plains. Warmth likely extends all the way up the east coast. Much of Canada is VERY cold. -1 to -3 for the PNW.
Hardest month to read by far, with not much in the way of meaningful signals. Moderation looks likely for the middle of the country, though the Northwest could easily remain cool. There is still some ridging in the NE Pacific, but also increasing likelihood of +EPO. The entire southern tier should be warm, especially the SE. 0 to -2 for the PNW.
There is an above average chance that this winter ends up drier than normal for much of the West Coast and northern plains. Near normal precip for the Great Basin/Rockies, and wetter than normal storm track along southern plains and lower Midwest, which should be the battle ground between warmth/cold.