BornFromTheVoid

15.6C and 50mm, thanks. Of note, if May finishes on 10C after corrections, a June CET of 15.9C would make the May to June increase the 10th largest on record. A June of 17.6C would be needed for a new overall record (10.5C to 18.0C in 1676 is the current largest, next largest is 8.7C to 15.1C in 1817).

New laptop and stuff sorted now, so the weekly sea ice animations are back.

Here's the new sea ice poll for May. In March, from 11 votes the average was 4.1 million km2 with a standard deviation of 0.5 million km2. In April, from 49 votes the average was also 4.1 million km2 with a standard deviation of 1.0 million km2. Extent has varied between 12th and 5th lowest over the last 4 weeks. Volume is at 7th lowest on the latest update from PIOMAS (mid May), while the combined SMOS and CryoSat dataset was lowest on record at the end of it's reliable seasonal measurements at the end of April. As a reminder, the extent minima since 2010 in millions of km2 from the daily NSIDC data are: 2020: 3.7 2019: 4.1 2018: 4.6 2017: 4.6 2016: 4.1 2015: 4.4 2014: 5.0 2013: 5.0 2012: 3.3 2011: 4.3 2010: 4.6 The thread will lock at midnight at the end of the month.

Latest estimate from the GFS is a finish of 10.5C before corrections. The final 5 days average could be in the top 15% warmest on record, and the final 3 days just outside the top 5% and warmest since 2003.

Assuming a post corrections May CET of ~9.8C, the next big target becomes an April to June average of under 10C. This was last achieved in 1923, and would require a June CET under 13.7C this year (June <13.7C was reached quite recently too, in both 2012 and 2013)

Latest projections The chances of finishing: Close to average (11.4C to 12.4C) is to 0.0% (4 days ago was 8.4%) Above average (>12.4C) is remains at 0.0% (4 days ago was 0.0%) Below average (<11.4C) is to 100% (4 days ago was 91.6%) The period of the 21st to the 26th looks like averaging about 9.6C, 3.3C below the 91-20 average. I'd say odds are now in favour of a sub 10C finish after corrections, and not far off 50/50 before.

Latest PIOMAS data. 2021 is 7th lowest on record, well above 2017 & nestled close to several other years. It's also: 8,600 km³ below 1980s, 7,000 km³ below 1990s, 3,600 km³ below 2000s and 100 km³ above the 2010s average Regionally, volume is dropping relative to other years along the Russian Arctic coast, from 13th to 10th lowest since the end of April. For the central Arctic, 2021 has gone from 4th to 5th lowest, and still appears to be increasing

Latest projections The chances of finishing: Close to average (11.4C to 12.4C) is to 8.4% (4 days ago was 10.8%) Above average (>12.4C) is remains at 0.0% (4 days ago was 0.0%) Below average (<11.4C) is to 91.6% (4 days ago was 89.2%) The period of the 17th to the 22nd is forecast to average 11.1C, 1.1C below the 91-20 average.

Yep, large floes, but given that they're separated it suggests that the leads are not refreezing and with near 24 hour daylight, the risk of warming up the sea increases. Plus, the current forecast has some big temperature anomalies in the region, and maxima nearing 0C in the next 5 days, and climbing above by next weekend. With the lower concentration and high mobility, I think a big storm in the region could do some long lasting damage. So, the floes may be somewhat thick, but the pack is in a more weakened and vulnerable state than usual for the time of year.

Latest slow sea ice animation for the week. Slow losses in the peripheral seas, but a surprising acceleration of ice loss in the Arctic ocean itself. Open water has appeared in many regions and the ice between Franz Joseph Land and the N. Pole looks particularly weak.

Latest projections The chances of finishing: Close to average (11.4C to 12.4C) is to 10.8% (3 days ago was 18.5%) Above average (>12.4C) is to 0.0% (3 days ago was 0.4%) Below average (<11.4C) is to 89.2% (3 days ago was 81.1%) The period of the 13th to the 18th is forecast to average 10.4C, 1.0C below the 91-20 average. Assuming we're on 9.3C to the 18th, the remainder of the month would have to average 10.9C or higher to reach 10C. Assuming even a small 0.2C correction, the 19th to 31st average would have to be at least 11.4C to reach 10C overall. A sub 10C May still seems very much possible

Latest projections The chances of finishing: Close to average (11.4C to 12.4C) is to 18.5% (3 days ago was 21.7%) Above average (>12.4C) is to 0.4% (3 days ago was 1.6%) Below average (<11.4C) is to 81.1% (3 days ago was 76.7%) The period of the 10th to the 15th is forecast to average 10.7C, 0.6C below the 91-20 average.

Slow sea ice animation for the last week. Steady losses across most peripheral seas, but mixed in the Barents Sea where northerly winds persist. Ice-free stretches appearing and disappearing around the Arctic Ocean edges, indicating quite a mobile central pack.

@Geordiesnow I had a look at November to April period, and it's a more clear 12th warmest, and just a little warmer than last year. 0.5C warmer than the 91-20 average, 1.9C warmer than 1971-00 and 2.2C warmer than 51-70 @Midlands Ice Age how are these?

It's tricky getting the right combination to suit all types of colour blindness, so I'm glad to take any feedback to improve the graphs/images. I'll try post up an altered version of them later today if I get the time. If not then during the weekend.

Forgot to add the PIOMAS data. 2021 is 6th lowest on record, well above 2017 & slightly above 2011,16, 18 & 19.It's also: 8,400 km³ below 1980s 6,900 km³ below 1990s 3,500 km³ below 2000s 200 km³ below the 2010s average Regionally, volume is holding steady along the Russian Arctic coastline, from 9th most volume since 2000 in mid April to 10th most now. For the central Arctic, 2021 has gone from 3rd to 4th lowest (but a near tie for 3rd lowest with 2010 and 2018) Here's a comparison between this year, last year and the 3 other lowest volume years across all Arctic regions in Mid April. Of final note, this is in slight contrast to the CryoSat2/SMOS dataset, which still has 2021 as the lowest volume on record

Latest projections The chances of finishing: Close to average (11.4C to 12.4C) is to 21.7% (2 days ago was 22.9%) Above average (>12.4C) is to 1.6% (2 days ago was 3.6%) Below average (<11.4C) is to 76.7% (2 days ago was 73.5%) The period of the 5th to the 10th is forecast to average 10.4C, 1.0C below the 91-20 average.

Latest projection for May The chances of finishing: Close to average (11.4C to 12.4C) is to 22.9% (2 days ago was 19.3%) Above average (>12.4C) is to 3.6% (2 days ago was 3.2%) Below average (<11.4C) is to 73.5% (2 days ago was 77.5%) The period of the 5th to the 10th is forecast to average 8.9C, 2.5C below the 91-20 average.

I'll do the usual update tomorrow, but... The latest GFS has the CET at about 8.5C to the 15th (29th coldest on record). Assuming that's accurate, we'd need to average 11.3C or less for the 16th to 31st to finish below 10C. For the whole record, 32% of years have achieved this. In the last 50 years, 13 years have achieved this - the most recent year was 2015, which averaged just 10.9C for the 16th to 31st. Downward corrections will help a lot too. So, a sub 10C CET is well within the realms of possibility, close to a 1/3 chance at the moment.

The Hudon and Baffin Bay area has taken a hit over the last week. Persistent easterlies/south easterlies from the -ve NAO eating into the ice quite quickly.

First projection for May The chances of finishing: Close to average (11.4C to 12.4C) is at 19.3% Above average (>12.4C) is at 3.2% Below average (<11.4C) is at 77.5% The period of the 3rd to the 8th is forecast to average 7.6C, 4.0C below the 91-20 average.

Latest weekly animation

At 6.4C, April 2021 was the 36th coldest in a record dating back to 1659. It was also: 2.6C below the 91-20 average 1.5C below the 61-90 average 1.7C below the 20th century average 1.5C below the 18th century average Compared with 1991-2020 average, 3 days were above average and 27 days were below. Three days were in the top 10 coldest, but no daily records were set. At 1.0C, the mean minimum for April was the coldest on record, beating the previous record of 1.4C in 1917. Three daily low minima records were set, -3.3C, -2.0C and -2.3C on the 7th, 12th and 13th (previous records were -3.0C, -1.7C and -1.4C). At ten, April 2021 had the 2nd most sub 0C minima on record, beaten only by 1917 with 12. No daily maxima records were set

The export through Fram is also quite high at the moment. I'm not sure I'm following your argument. The wind driven ice loss from the central pack towards the Atlantic sector is still driving thick ice into a region where it will inevitably melt. This has to have a strong effect on volume loss, especially as it's still not warm enough for substantial melt across most of the Arctic ocean at the moment. Heat from the continents will matter more as we move into the 2nd half of May. Basically, exporting thick ice into warmer areas is the best way to lose volume at this time of year, imo. Also, there is a conflict between the observational data, CS2/SMOS, vs the modelled, PIOMAS. The observational data suggests an opposite pattern over much of the Siberian coastline to PIOMAS, and has 2021 as easily the lowest volume on record for the time of year.

Yep, short term extent gain, long term volume pain!