What we do: We are making sub-seasonal forecasts for time periods of high probability of cold air outbreaks in Eurasia and North America 30-40 days in advance. We issue such forecasts on a weekly basis and this website is updated around Thursday each week.
New Feature: Maps of probability of cold surface temperature anomalies over both North America and Eurasia continents in the vicinity of forecasted stratospheric PULSE events
New Forecast Made on December 30:
No new forecast is made this week.
Follow up on Forecast Made in the Previous Weeks:
STRAT_D1 (12/24 – 12/31), first forecasted on 11/25 and later revised on 12/03, has just happened. The first peak of STRAT_D1 occurred on 12/26 with a net air mass transport into the polar stratosphere about 0.6 trillion tons per day. The second peak occurred on 12/30, transported 0.6 trillion tons air mass per day into the polar stratosphere. The STRAT_D1 event was associated with the winter storm Fortis, which swept through the North American continent, causing below-normal temperature in the Western United States and bringing heavy snow to New England Area.
STRAT_E (01/08 – 01/13), first forecasted on 12/03, is still expected to occur on time. We believe STRAT_E is going to be a mild event with a peak net mass transport into the polar stratosphere over 0.7 trillion tons per day on 01/10. The map of probability of below-normal surface temperature shows high likelihood for cold air outbreaks to take place over the North American continent and northern latitudes of the Eurasian continent (see map forecasts).
STRAT_F (01/23 – 01/28), first forecasted on 12/10 with a 45-day lead. STRAT_F is still expected to occur on time. It looks to be a twin-peaked, strong event with a peak net mass transport into the polar stratosphere about 1.2 trillion tons per day. We expect strong cold air intrusions over the North American continent, especially over Canada and Northern part of the United States during the last week of January. The northern part of Eurasia (north of 45N) is also expected to experience below-normal temperatures (see map forecasts).
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