Forecasts made on October 28, 2014

• The STRAT_B event peaked on Oct. 27, a few days earlier than our original forecasted dates (during Halloween weekend) that had been issued consistently since 9/22/2014. Accompanied with this event, there was a strong cold air outbreak event in North America and a weaker one over Eurasian continent (see “link” for details). 

• As we first forecasted on October 9, we still forecast the STRAT_C event to take place in the first week of November. However, this event seems relatively very weak and therefore, we don’t anticipate strong cold air outbreak events associated with it (just modest below normal temperature weather).

• Now we officially call for the STRAT_D event that was mentioned in our previous forecast.  The STRAT_D event looks to be a monster event which is a prolonged event consisting several peaks of strong mass transport into the polar stratosphere with peak intensity as large as 800 billion tons per day, which reaches the same intensity level as those occurred in January of 2014. The STRAT_D event is expected to take place between the last week of November and the first two weeks of December, which combines the STRAT_D event and the one around Dec. 12-15 mentioned in our previous forecast.

• Between STRAT_C and STRAT_D, the mass circulation is expected to be very close to normal. Therefore, we expect that the temperature over the two continents is above normal.

• After the 3 weeks of warm weather, we expect a series of major Arctic clod air assaults in the period of the last week of November and the first two weeks of December for two reasons: (1) the STRA_D is going to be an anomalously stronger mass circulation event which would bring more Arctic cold air into mid-latitudes and (2) the Arctic cold air has three weeks of charging time over Arctic due to the weaker mass circulation prior to the STRAT_D event. 

• The December of 2014 is expected to be a very cold December. Beside anomalously below normal temperature in the first two weeks, it appears that another anomalously stronger STRAT event could take place in the week before Christmas.  These two back-to-back strong STRAT events would bring several rounds of major Arctic air assaults into mid-latitudes, making the December of 2014 a very cold winter month.