(11/26/2014 − 12/04/2014)
· The first peak of the STRA_D event passed through on Nov. 29 which resulted cold air outbreaks in East Asia. The STRAT_D event has not finished yet. It is expected to have several peaks till December 8, as we first forecasted on October 28 to occur in the first week of December. The remnant of STRAT_D is NOT expected to bring major storm events.
· STRAT_D1, first forecasted last week, is still expected to peak between December 18 -24 with peak intensity of more than 700 billion tons per day transported into the polar stratosphere. Therefore, this is going to be a strong circulation event. Associated with STRAT_D1 are wintery precipitation and major cold air outbreaks over a large portion areas over the east coast of North America and East Asia, and Europe in the week before Christmas, which has a high potential in impacting pre-holiday travel.
· Between the STRAT_D and STRAT_D1 events, the circulation is expected to be very weak. Therefore, most of areas in the two continents will experience mild winter condition till around December 15 when STRAT_D1 is expected to emerge. Perhaps the only exception is for the West Europe where cold air outbreaks could occur.
· STRAT_E, which we first forecasted on November 20, will bring in another round cold air outbreaks within the week around New Year. Although STRAT_E is expected to be a weaker event, it still poses a thread to affect post-holiday travel.
· We officially forecast STRAT_F event to peak between January 15-20. STRAT_F event is expected to be a STRONG event with peak intensity exceeding 900 billion tons per day. Because of its high intensity, we expect STRAT_F event to produce cold air outbreaks both continents, but with strongest impact over the east coast of North America.
Forecasts Made on December 4, 2014
Follow up on Forecast Made in Previous Weeks:
· As forecasted last week, STRAT_D1, is still expected to peak in the week centered on December 20 with peak intensity exceeding 700 billion tons per day into the polar stratosphere. We continue to expect cold air to cover a majority of the mid-latitudes leading to another round of cold-air waves. The series of wintery precipitation events associated with this event will have a high possibility of impacting early holiday travel. This cold air outbreak could quite possibly bring the coldest temperatures so far all winter across much of the mid-latitudes.
· As first forecasted on November 20, STRAT_E still indicates a drop in temperatures scheduled for the first week of January following New Years Eve, approximately taking place between 12/31/2014 and 01/03/2015. The cold air outbreaks associated with STRAT_E, although not as strong as those before Christmas, can still hinder post-holiday travel.
New Forecasts Made on December 4, 2014
· Another round of cold waves is expected to show up towards the third week in January. We officially name this stratospheric event that lead to this round of cold air outbreaks as STRAT_F. The STRAT_F is expect to peak within the dates of 1/15/15- 1/21/15. STRAT_E looks to be a strong event with peak intensity exceeding 900 billion tons per day into the polar stratosphere. Because of its high intensity, we expect STRAT_F event to produce cold air outbreaks both continents, but with strongest impact over the east coast of North America.