


Weekly Highlights
(12/18/2014 − 12/24/2014)
· STRAT_D1 event, first forecasted on 11/25 to peak on 12/16 and 12/20-22, had peaked on 12/17 and 12/21, a very accurate forecast with lead time of 3+ weeks. As we forecasted, STRAT_D1 had brought weather activities and cold air to East Asia (peaked at 12/20) and is bringing stormy conditions across North America (12/20-present) with heavy precipitation and severe weather over the Southeastern United States, snow in the Midwest, and 3-day rain in a row over the east coast. Therefore our forecasts for STRAT_D1 were successful.
· STRAT_E event, first forecasted on 11/20 to peak on around the New Year Day (lead time of 40 days), will peak faithfully around the first day of 2015. The intensity of the STRAT_E is anomalously strong, delivering 1.2 – 1.5 trillion tons of air per day at its peak time into the polar stratosphere. Synchronized with the STRAT_E, the cold air branch will intensify greatly, delivering a net of 12 trillion ton of the polar cold air per day at its peak time to mid-latitudes. Therefore, STRAT_E, as we forecasted since 11/20, is going to cause major cold air outbreaks over both continents, particularly over North America. Week long continental scale below-normal temperatures are expected to occur starting few days before the New Year Day. The heavy wintery precipitation will impact post-holiday travelers greatly across the two continents, especially for travelers across North America.
· Due to the anomalously strong intensity of STRAT_E event, which could lead to a major sudden stratospheric warming event, we now forecast the STRAT_F event to peak around 01/22, a few days later than the period of 01/15 – 01/20/2015 that we first forecasted on 12/4. Although STRAT_F event is not as strong as STRAT_E, it is expected to cause another round of cold air surges over both continents.
· Due to the relatively weak circulation between STRAT_E and F, we expect mild winter conditions over both continents in the second week of January of 2015.
· Last week we officially forecasted our STRAT_G event to take place in the last week of January and the first week of February (lead time of 50+ days). This event appears to have two peaks: one around 01/27-30 and another one around 02/04-06. Since these two peaks are about a week apart, we now split them into two named STRAT events: STRAT_G1 and STRAT_G2. Therefore, we expect that STRAT_G will lead two back-to-back cold air outbreaks over the two continents.
· The back-to-back STRAT_F, STRAT_G1, and G2 events will make the last 10 days of January and the first 10 days of February be the cold period over both continents.
Forecasts Made on December 24, 2014
Follow up on Forecast Made in Previous Weeks:
· We believe that we have correctly forecasted the timing of STRAT_E event at a lead time of 40 days. Our STRAT_E event is expect to deliver 1.2 – 1.5 trillion tons of air per day at its peak time into the polar stratosphere and a total of about 12 trillion tons of the polar cold air per day at its peak time to mid-latitudes. Therefore, STRAT_E, as we forecasted since 11//20, is going to cause major cold air outbreaks over both continents, particularly over North America. Therefore much of North America can expect colder conditions and heavier precipitation with the passing of this system in the week centered at New Years.
· Due to the anomalously strong intensity of STRAT_E event, the STRAT_F event will peak around 01/22, a few days later than the period of 01/15 – 01/20/2015 that we first forecasted on 12/4. Although STRAT_F event is not as strong as STRAT_E, it is expected to cause another round of cold air surges over both continents in the week around 01/22.
· STRAT_G event, first forecasted on Dec. 17 to take place in the last week of January and the first week of February (lead time of 50+ days), appears to have two peaks: one around 01/27-30 and another one around 02/04-06, which have been re-named as STRAT_G1 and STRAT_G2, respectively. Therefore, we expect that STRAT_G1 and G2 will lead to two back-to-back cold air outbreaks over the two continents in the last week of January and the first week of February.
New Forecasts Made on December 24, 2014