This just-released NOAA outlook for the months of January-February-March calls for a cold and occasionally snowy winter for sizeable parts of the Northern Plains, Midwest, and Great Lakes regions. Above-normal temperatures are anchored across the Southwest and southern tier of the nation.
Blue = Colder Than Normal Brown = Warmer Than Normal
Green = Wetter Than Normal Brown = Drier Than Normal
Let’s discuss a number of weather features that could influence the 1- and 3-month outlooks. These include:
Climatology: Winter Jet Stream
In the map below, areas shaded in blue and green receive a relatively-higher amount of precipitation in January while areas shaded in red receive less.
From a climatological perspective, precipitation is enhanced across the Pacific Northwest (PNW) as well as parts of the Southeast and Mid-Atlantic regions. Much lesser amounts of precipitation tend to fall over the Plains.
ENSO Neutral conditions are expected to persist well into 2020. The past weak El Niño (Region Niño 3.4) has ended and should not have any significant impact on winter weather.
However, a persistent area of unusually-warm water over the North Pacific is likely to influence the position of the jet stream, and thereby temperature and precipitation anomalies.
It’s possible that this “wavy” jet stream pattern could emerge from time to time resulting in unusually-mild coastal temperatures and an unusually-cold middle U.S.
Atmospheric Rivers have been active so far this season resulting in heavy west coast precipitation in spots. These streams of highly-focused moisture could continue into January.
Despite the recent extremely-cold late Fall, a study of past winter temperature data shows that winter is warming over the entire U.S.
Note the close alignment with NOAA’s 3-month precipitation outlook at the NMME climate model (below).