Weather Canada Marine Forecast
East Coast – north of Cape St. Francis
Issued 10:00 AM EDT 28 May 2017
Today Tonight and Monday
Special ice warning in effect.
1 tenth of first-year ice including a trace of old ice except 9 tenths of first-year ice including a trace of old ice near parts of the mouth of Bonavista Bay and the mouth of Trinity Bay. Unusual presence of sea ice in the western section.
More than 100 icebergs.
The Atlantic ice extents show little retreat during May. Newfoundland coast on the upper left is still locked in ice though less now than 10 days ago. In Barents not much has changed.
The graph below shows May extent through yesterday, May 28.
For the first time the decadal average dropped below 12M km2. 2017 is 300k km2 above average, 400k km2 above 2007 and 1.1M km2 higher than 2016. The graph below shows the Arctic ice extents, excluding the Pacific basins of Bering and Okhotsk.
Note how persistent is 2017 ice extent, currently 500k km2 above both 2007 and the decadal average, and 1M km2 above last year at this date.
The table below shows regional extents for 2017 compared to decadal average and to 2007 on day 148.
Note the strong surpluses of ice in Kara, Barents, Greenland Sea and Baffin Bay. Note also that Bering is nearly ice free, and is having some influence on nearby Chukchi. The two Pacific basins of Bering and Okhotsk now have 136k km2 combined at day 148, which matches where the decadal average will be in 13 days on day 161.
Finally, the image below shows Svalbard comparing 2017 with last year on day 148.
AER provides some insight into these developments along with a forecast in the May 22 posting.
Dr. Judah Cohen:
As I discussed in my previous blog, one constant over the past decade has been the collapse of NH snow cover extent in spring, especially late spring. The rapid disappearance of snow cover across northern Eurasia and northern North America contributes to drying of the soil and warmer temperatures. The resultant warmer temperatures also likely contribute to Arctic sea ice loss.
Snow cover this spring has been more resilient to melt than in previous recent springs. More snow cover results in moister soils. Moister soils result in cooler temperatures. Snow cover and snow mass continue to be relatively high across the NH helped by in part by below normal temperatures in key regions. However the snow cover has been more resilient in Eurasia relative to North America and snow cover across North America experienced a rapid decline over the past week. And with more warm temperatures predicted across Northern Canada, the rapid decline in snow cover will likely continue.
The AO is currently neutral (Figure 1), reflective of mixed geopotential height anomalies across the Arctic and mixed geopotential height anomalies across the mid-latitudes of the NH (Figure 2). Geopotential height anomalies are positive near Greenland and Iceland (Figure 2), and therefore the NAO is negative.
The AO is predicted to remain neutral to positive next week as neutral to negative geopotential height anomalies dominate much of the Arctic (Figure 5a). And with neutral to negative geopotential height anomalies stretching from Greenland to Iceland, the NAO will likely trend positive back into positive territory as well.