09/27/2020, 11:17 am EDT

Western U.S. Drought To Expand Into Great Plains. Western Russia Drought Continues.

Recent helpful research published in the AMS Journal of Climate identifies deep layer soil moisture deficits as a potential catalyst to future drought (and flash drought during the warm season). Northern hemisphere summer has ended BUT there area significant deep layer soil moisture shortages likely to cause Southwest U.S. drought to expand to the central and southern Great Plains. Similarly, emerging deep layer soil moisture anomalies in Southwest/West-central Russia foreshadow intensifying drought ahead.
09/23/2020, 10:24 am EDT

“Warm blob” in northeast Pacific Ocean could lead to polar vortex mid-winter.

3rd strongest “warm blob” on record emerges Northeast Pacific Ocean. If persistent, could lead to a “polar vortex” mid-winter pattern. Climate Impact Company winter 2020-21 outlook issued Friday. Fig. 1:  A marine heat wave (MHW) associated with a large region of oceanic warming has emerged in the northeast Pacific Ocean. Known as the “warm blob” first recognized in 2014, the current episode is 3rd strongest on record. Fig. 2-3: The strongest and second strongest MHW (or “warm blob” episodes) on record occurred in 2014 and 2019. Discussion: What is a marine heatwave? MHW’s occur when ocean temperatures are much warmer than normal for an extended period of time. MHW’s became a new ocean/climate field of study following the sudden and unexplained warming of the northeast Pacific in 2014. An area of warming which became known as the “warm blob”. The strongest “warm blob” (or MHW) occurred in 2014, the second strongest in 2019 and 3rd strongest on record emerged this month (Fig. 1-3). There is a general ocean-to-climate relationship of the “warm blob” that favors high pressure ridging on the West Coast of North America and a downstream upper trough across central or eastern North America. This relationship is a contributor to unusually dry climate in western North America and during winter promotes cold outbreaks into the U.S. We need to watch the September 2020 “warm blob” closely as to potential effects on the winter ahead North America climate pattern (and downstream influences on Europe). If the “warm blob” persists and ALL global SSTA forecast models indicate that possibility is likely, there should be a tendency for increased incidence of upper ridge patterns on the U.S. West Coast and downstream troughing into the central and/or eastern U.S. La Nina has formed in the eastern equatorial Pacific. During a La Nina winter there is a tendency for a cold climate featuring increased risk of arctic air in Western Canada. If the “warm blob” induced upper ridge pattern over western North America is semi-permanent this winter season, delivery of that cold air in the Western Canada source region to the U.S. will occur with important frequency. Fig. 4: The January 2021 global SSTA forecast by ECMWF maintains the northeast Pacific “warm blob” which could induce a polar vortex upper air pattern for mid-winter.   Fig. 5-6: The January 2021 upper air forecasts indicate a moderate-to-strong presence of the polar vortex affecting the northern U.S. and representing a cold and snowy influence for mid-winter.
09/21/2020, 11:47 am EDT

La Nina Is Intact Now

La Nina is intact and plenty of subsurface eastern equatorial Pacific Ocean cool water is present to sustain La Nina. Forecast models indicate La Nina peaks later this year. Interestingly, a reversal toward a weak El Nino next summer is also indicated.
09/20/2020, 1:55 pm EDT

Northern Hemisphere Sea Ice Extent 2nd Lowest on Record

The northern hemisphere sea ice extent ranks 2nd lowest on record for the September 2020. The only year in which northern hemisphere sea ice was less abundant was 2012. The lack of sea ice does not mean that winter ahead will be warm.