Pictured: The Climate Impact Company temperature and precipitation anomaly forecast for December.
December 2017: There is no major change to the December Outlook. Snow cover will be a leading indicator of both the thermal pattern and prevailing storm track(s) for early winter. Canada is snow covered and much of it is deeper than normal except south-central sections where snow cover is relatively thin. To the south, the prevailing warm influence of the warm oceans either side of the U.S. cause a warmer-than-normal month. The colder northern climate clashing with the anomalous warmth to the south causes the prevailing storm track to form over the Northwest and Great Lakes/Midwest to Quebec. Northwest flow on the back side of stronger storms can cause a strong polar or potential arctic outbreak into the U.S. but such events are short-lived as mild Pacific influence quickly follows.
Pictured: The Climate Impact Company temperature and precipitation anomaly forecast for January.
January 2018: An arctic outbreak is likely during mid-winter. The fore-runner is a heavy snow storm centered on the Ohio Valley to Quebec. Timing of this event is uncertain. The cause of the event is a greater than 50% chance that a potent MJO episode will lead to a brief SSW regime causing arctic air generation and release into the U.S. The cold target is the Midwest and into the East. Duration of this event is brief and returning mild Pacific influence will be impressive. Areas maintaining snow cover will stay colder than normal for the month. Once again the bulk of precipitation affects the northern half of the U.S. and almost the entire southern U.S. is drier than normal. The forecast change is a little colder East-Central U.S. and a little warmer for California into the Northwest U.S. Â The precipitation forecast is less snowy in the Northwest.
Pictured: The Climate Impact Company temperature and precipitation forecast for February.
February 2018: The forecast trend for the final month of meteorological winter is warmer. The warmer change is stretched across the U.S. just south of the prevailing snow cover. The northern U.S. stays cold and snowy. The southern starts ae warmer and drier than normal. The risk of an arctic outbreak is there due to the plentiful colder than normal air across Canada. However, the MJO-induced arctic outbreak for winter 2017-18 is determined to occur in in January with a repeat performance less likely. The southern U.S. is developing drought conditions and the dryness is starting to creep north through the southern portion of the Great Plains.
