What About Winter?
Part Two - October Indicators
1) Arctic Sea ice: Slow to rebound from late September melt-off, and seasonal refreeze levels currently lagging behind levels seen before recent winters of 2014 and 2015. Researchers and bloggers alike have noted the unusual nature of this season's sea ice melt and rebound.
2) Snowcover in adjacent areas has rapidly expanded in western and central Siberia to northern & central Canada, relative to seasonal averages. Snowcover is clearly lagging in Alaska as compared to seasonal norms and observations from previous years at mid-October.
3) Polar temperatures: Seasonal readings above 80 North reported by the Danish Meteorological Institute are running several degrees above the seasonal range for this time of year.
OUR EARLY ASSESSMENT OF WHAT IT MEANS:
- Early clues: Arctic/Polar conditions in October provide early indications of how climate factors may interact to influence the start of winter in the Northern Hemisphere, and North America,.
- Strange days ahead: This season follows an above-normal temperature regime from last winter for the Arctic above 80 North. Now with sea ice lagging but snowcover rising in areas farther south than usual, these competing data point suggest a divergent and erratic start to winter.
- Possible results: This inconsistent alignment of ice & snow could lead to wildly fluctuating conditions in early winter. One option would be an early season sharp cold outbreak, then a rapid warm up, followed by equally strong cool downs and erratic snowfall events that briefly disrupt, then quickly disappear.
Part One - Clues from Summer
The preliminary report begins below the bullet summary:
- The above normal temperature pattern in East, connected to growing below normal pattern in West, may be early sign this winter could start like 2015-16: Mild first half, stormy and cold second half.
- Seasonal melt-off of Arctic sea ice appears on level with readings of the past 3 years, not as low as the September 2012 record meltoff.
- Rapid transition of El Nino to La Nina conditions sets stage for surprise ice events throughout the season ahead, especially in the Mid-Atlantic.
Orioles Opening Day in April 2003. Photo credit: The Baltimore Sun
ANALYZING SUMMER CLUES FOR THE PRE-WINTER PATTERN
Late summer in the Foot's Forecast team is the start of our seasonal process to identify how pre-winter indicators stand so as to detect developing trends. Large scale hemispheric trends known to influence how winter develops in the Mid-Atlantic include frequency and location of tropical systems, sea surface temperatures in the eastern Pacific and end-of-summer Arctic sea ice meltoff.
In September 2016, this investigation will be conducted by science students at several high schools in the Baltimore metropolitan area, in collaboration with member of our team across the Mid-Atlantic. Initial findings released arround September 15, draft projections by October 1, full winter assessment by October 30.
Click below if ready for a sneak peek...