bluewave

Yeah, 2007 to 2012 was a truly historic period for the Arctic. Some people may not appreciate the rarity of locking in that dipole patttern for 6 seasons in a row. https://onlinelibrary.wiley.com/doi/pdf/10.1029/2012GL053268 Thus we can say that a six year run of near one standard deviation negative excursions (2007–2012) is unique in the 63 year record. To further test the significance of the 2007–2012 AD patterns we randomly generated 10,000 time series, each with 63 points to match the observed time series and with a normal distribution without autocorrelation. For this simple calculation, the chance for having five consecutive values with a negative AD of magnitude greater than 1.0 standard deviation units in a sample size of 63 is rare, less than 1 in a 1000. Yeah, it seems like the SPG region cooling south of Greenland since 2012 is the result of an atmospheric circulation change to more low pressure. SST’s in that region we’re near record levels of warmth prior to the abrupt circulation shift leading into the 2013 summer. Maybe there is some mechanism by which salinity changes following the 2007-2012 record melt can lead atmospheric circulation shifts by months or years?

The NAO averaged for May and June was the most positive on record. This is in stark contrast to the 2012 season which had the 2nd lowest on record.

A -500 meter anomaly vortex is about as strong as I can ever remember seeing in July. This pattern produced the heaviest July snow in Barrow since 1963. The NWS in Utqiaġvik (Barrow) reported 2.0" of snow on Saturday, making this the greatest July calendar day snowfall there since July 4, 1963, when there was 2.9" of snow. #akwx @Climatologist49 @CinderBDT907pic.twitter.com/lkmlmCAG8N 3:13 PM - 8 Jul 2018

Probably one of the the best June outcomes the Chukchi can expect in a post 2007 sea ice era. Chukchi Sea ice extent (from @NSIDC passive microwave data) decreased by 13% during June. The good news: this is the lowest percent decline in June since 2008. The bad news: trend is for more June melt: this would have typical in the 1980s. #Arctic #akwx @Climatologist49 @ZLabepic.twitter.com/KzgcbGy5Tb 11:39 AM - 4 Jul 2018

Chuck, the lower NAO in some of the forecasts is a result of more east based blocking closer to Europe. Pattern back closer to the CAB and Beaurfort is actually one of the strongest July reverse dipole patterns we have seen. Notice the best ridging is focused over Siberia. The models actually have near record low 500 mb heights near the Beaufort for this time of year.

What a reversal from 2012. All the coldest departures in the NH were focused near Greenland and Labrador in June. Right around the extreme cold pool south of Greenland with the slowing AMOC. after months of a persistent atmospheric circulation pattern, Greenland is having its least surface ice loss in decades while NW Europe has extreme sun and heat... persistent extremes are an expected signature of #climatechange@PolarPortal #ukheatwave twitter.com/severeweatherE…pic.twitter.com/lsXraH5nuK 6:16 AM - 3 Jul 2018 https://mobile.twitter.com/Climatologist49/status/1013986099335753733/photo/1 But Churchill Falls (Labrador) saw its coldest June by a 2C margin; the monthly temperature was 6C below normal. Persistent major circulation anomalies are to blame. pic.twitter.com/Iz5QPeXuBr 8:43 AM - 3 Jul 2018

The 500 mb height reversal near the Beaufort in June has been as extreme as it gets. 2007 to 2012 featured the highest sustained heights on record for a 6 year period. 2013 to 2018 has seen a dramatic decline in heights with 2013 registering a lowest single year record.

While this has resulted in a slowing of the rate of sea ice decline relative to the 2005-2012 period, it's still at a level well below the typical late 1990's and early 2000's ice. The extreme Arctic amplification and circulation changes began when the September average extents began to regularly fall below 6 million sq km. In 50 to 100 years, that may turn out to be the more significant number than when the Arctic first went technically ice free.

We are moving right back to a reverse dipole pattern in early July. This has been our typical 2013 to 2018 summer pattern. As long as this continues, we may be able to finish September with an NSIDC average extent not too far from 5 million sq km.

A rare colder than normal month in that region in what has been a sea of record warmth. Technical: ongoing cool wx at Utqiaġvik, Alaska is the largest negative departure of the 30-day running daily standardized temp anomaly since late summer 2014. Illustrates nicely the control by sea ice on Arctic coastal air temps. #akwx #Arctic @Climatologist49 @CinderBDT907pic.twitter.com/PK380UAnXW 9:02 AM - 23 Jun 2018 1pm Friday, Utqiaġvik (Barrow) Alaska hits 40F (4C) for the first time this year. This ties with 1955 as the fifth latest “first 40” in the past 98 years. #akwx@Climatologist49 @CinderBDT907 2:21 PM - 22 Jun 2018

Also a pretty impressive slow down in the melt near Alaska for late June. Sea ice extent around Alaska now running close to the long term average for late June, (passive microwave data from @NSIDC). Early melt in the srn Chukchi Sea has stalled farther north and meltout in the Beaufort Sea is only slowly spreading west. #Arctic @akwx @Climatologist49 pic.twitter.com/d3rbwGXJvV 6:58 AM - 25 Jun 2018

Yeah, CPOM may be close if July and August continue with more low pressure over the Arctic like June. First set of forecasts for the September Arctic sea-ice extent have been collated. Median forecast (4.6M sqkm) is slightly lower than last year’s observed value. The @CPOM_news forecast from @UniRdg_Met is one of the larger forecasts at 5.3M sqkm. arcus.org/sipn/sea-ice-o…pic.twitter.com/kgaROTK7Yr 2:19 PM - 23 Jun 2018

It's as if the historic summer Greenland melt in 2012 really slowed the AMOC. Shortly after that, the cold pool and strong vortex couplet became a persistent feature south of Greenland. The colder waters there seem to go along with more low pressure over the Arctic during the summer. It's pretty much the opposite of the warmer SST's and the summer Arctic mega-dipole from 2007-2012. It will be interesting to see how long this pattern persists. https://www.carbonbrief.org/atlantic-conveyor-belt-has-slowed-15-per-cent-since-mid-twentieth-century https://www.climate.gov/news-features/understanding-climate/summer-2012-brought-record-breaking-melt-greenland

Looks like the HadGEM1 is doing a great job so far. Very impressive considering the paper was first published back in 2012. https://www.the-cryosphere.net/7/555/2013/tc-7-555-2013.pdf Mechanisms causing reduced Arctic sea ice loss in a coupled climate model Abstract. The fully coupled climate model HadGEM1 pro- duces one of the most accurate simulations of the historical record of Arctic sea ice seen in the IPCC AR4 multi-model ensemble. In this study, we examine projections of sea ice de- cline out to 2030, produced by two ensembles of HadGEM1 with natural and anthropogenic forcings included. These en- sembles project a significant slowing of the rate of ice loss to occur after 2010, with some integrations even simulating a small increase in ice area. We use an energy budget of the Arctic to examine the causes of this slowdown. A negative feedback effect by which rapid reductions in ice thickness north of Greenland reduce ice export is found to play a major role. A slight reduction in ocean-to-ice heat flux in the rele- vant period, caused by changes in the meridional overturning circulation (MOC) and subpolar gyre in some integrations, as well as freshening of the mixed layer driven by causes other than ice melt, is also found to play a part. Finally, we assess the likelihood of a slowdown occurring in the real world due to these causes.

It's remarkable how the Oct-May strong blocking ridge pattern over the Arctic finds a way to shift in June. This has been a very reliable reversal over the last 6 years. Notice how the strong Oct-May Arctic blocking pulls back to Siberia/Bering just in time for summer. This seasonal circulation change seems to be the only thing keeping the 2012 record out of reach for the time being.

More favorable for melt, but nothing too extreme looking.The dipole ridge won't be anywhere near as strong as the ridge that was located over Siberia this month. Check out the record heat under that ridge. 31°C (89°F) is mighty impressive at 73N latitude along the Arctic Ocean.twitter.com/EKMeteo/status… 5:21 PM - 23 Jun 2018

September averages have remained in a very narrow range since 2013. It appears to be near the lowest amount of variability since 1980 for a 5 year period. 2017....4.87 2016...4.72 2015...4.63 2014...5.28 2013...5.35

Looks like the greatest SIA loss slowdown in late June of the 2010's so far. Now close to 2014 on this date for area on the chart below. Very impressive turnaround from May when we were the lowest on record for a few days. I am guessing the melt pond situation was toward more favorable side of recent years by the CPOM forecast. https://www.arcus.org/sipn/sea-ice-outlook/2018/june

The continuing colder than average temperatures in Barrow during June are indicative of the less hostile reverse dipole pattern. It's remarkable how the extended record warmth over the last year suddenly reversed around the start of June. This is exactly what was needed to avoid challenging a record year like 2012. In September 2012, nobody would have bet that the 2012 record would still be standing near the end of the decade. Rick Thoman The high temperature so far this year (thru June 20 mid-afternoon) at Utqiaġvik (Barrow) is 37F (+3C). Since 1921, only 3 years have gone this late into June with a lower max temp, most recently 1955 (high temp thru June 20th 36F, +2C. 6:05 PM - 20 Jun 2018

The planet's five warmest Mays have all occurred in the past five years—including 2018, the warmest May on record for Germany, Sweden, the U.S., and more bit.ly/2M2seGO pic.twitter.com/9FbEtzyitK 9:14 AM - 18 Jun 2018

It's been tough to bet against the reverse dipole pattern since June 2013.

I compiled a list of the 3"+ heavy rain events in the OKX forecast zones since 2010. Feel free to include any of your local events that I may have missed. The dates below are when the rainfall event ended at each location. 2022 7-18….Tarrytown, NY….4.31…..Fair Lawn, NJ…..4.25 4/7-4/8…..Ridgewood, NJ ….3.79 2021 10/26-10/27….Ridge, NY…..6.82 9-24….Darien, CT….4.52….North Massapequa, NY….3.05 9-1…Staten Island……9.64…….Manhattan…..9.55……Cranford….9.05….Ida 8-28 Bayport,NY 3.39 8/21-8/22 Brooklyn 9.43 with Henri 6-17……Hillside, NJ…..4.30 6-12…..Ringwood, NJ…….3.46 6/8-6/9…….Locust Valley, NY…..6.38…Tropical Storm Elsa and moisture streaming north in advance interacting with stalled front 5-28-5/30…Upton, NY…..4.38 2020 11-30…Otisville, NY…..3.14 9-30....Sloatsburg, NY....3.88 9-10....Pt Lookout....6.47.....Massapequa....5.41...Wantagh Mesonet...4.64....Amityville....4.04....Copaigue....4.05 8-4.....Ringwood, NJ....4.04...Tropical Storm Isaias 7-10....Montclair, NJ...3.17....Tropical Storm Fay 7-3.....BDR....3.99 2019 12-13/14...Woodbury, NY....3.44 10-27...Westport, CT....3.04 10-17....Norwich, CT...6.15...numerous 3.00+ amounts across the area 8-8....Livingston TWP, NJ...3.21 7-22/23...Syosset, NY....3.94 7-17...Canoe Brook, NJ....3.80 7-11...Oakland, NJ....3.10 2018 12-21...Woodbridge, CT...3.28....Seymour...3.24 11-2/3...Monroe, NY....4.96 10-11/12...Sayville, NY....3.94 10-2...Fairfield, CT....3.95 9-25...Hamden, CT....8.51...Trumbull, CT....7.32...White Plains, NY....4.41...Totowa, NJ....7.44....Bayonne, NJ...4.77 8-11 to 8-13 NWS Upton........6.60 8-7.......North Merrick..............4.73 7-27.....Travis, Staten Island....4.45 4-16.....EWR...3.43....NYC....3.29 3-2.......ISP....3.35 2017 10-30....EWR...4.08...NYC...3.28...JFK...3.20...BDR...3.02...ISP....4.02 10-25....BDR....3.78 8-18......East Shoreham....3.80 5-6.......EWR....3.15....NYC...3.20 2016 11-30...EWR...3.09...LGA....3.19 8-20.....Calverton.....3.85 8-1......West Milford.....4.51....New Windsor....5.34 2015 9-10....Wantagh...6.05 6-1.....EWR..........5.39 2014 12-10....JFK...3.15 8-13.....JFK...3.26....ISP....13.51...Massapequa....8.20.....Wantagh...7.84 5-1......EWR...5.31....NYC...5.09....LGA...5.41....JFK....4.92...BDR...3.99 3-30....JFK...3.13.....BDR....3.20....ISP....3.86 2013 6-8....EWR...3.89...NYC...4.64.....LGA...4.12....JFK...4.39....BDR...4.54...ISP....4.58....Old Bethpage...6.13 5-9....NYC....3.52 2012 6-25...ISP...4.16 4-23...Lynbrook....3.49 2011 9-7.....EWR...4.27...NYC...4.43...LGA....3.32 8-28...EWR...8.92...NYC...6.87...LGA....5.78....JFK....5.03....BDR...3.35....ISP...3.03 8-15...EWR...6.56...NYC...6.37...LGA...6.64...JFK....7.80...BDR....3.17....ISP...6.49....Lido Beach....10.20 5-18...BDR....3.61 2010 10-01...EWR...3.57...NYC...3.56...LGA...3.06...JFK...3.08... 3-30....EWR...3.15....NYC...4.03...LGA...3.87....JFK...4.37...BDR...3.54...ISP...4.82 3-14....EWR...4.57....NYC...4.10...LGA...3.33....BDR...3.70

Unusually cold weather near the Beaufort region for a change with the strong TPV. This is actually the coldest departures around that region over the last year. My guess is that this impressive June TPV behavior will keep the 2012 record out of reach again for this season. From the Alaska Weather Blog: http://ak-wx.blogspot.com/2018/06/chilling-in-summer.html Northern and interior Alaska has seen some very chilly weather for the time of year in the past few days, as a strong upper-level trough and an unseasonably cold air mass plunged south out of the Arctic at the beginning of the week. Despite the fact that the summer solstice is now less than 10 days away, and daylight is continuous, sub-freezing temperatures have occurred in many of the usual cold spots in the interior. The airport has seen 37°F, 36°F, and 37°F in the early mornings of the past three days, which is a remarkably cold series of daily minimum temperatures for this time of year. In fact, this is the closest to the solstice that Fairbanks has ever observed 3 straight days with low temperatures of 37°F or lower at the official climate site (1930-present). It's also interesting to note that with a high temperature of only 53°F, Monday's daily mean temperature was a mere 45°F. It's been almost 70 years (1949) since Fairbanks saw such a chilly day this late in June (or in July).

Coldest start to June over the CAB since 2014. More active June TPV pattern beginning in 2013 continues. This is in stark contrast to the extreme June dipole pattern of 2007-2012. Intense sub 970 mb Kara low this week was near record levels for early June. The TPV that produced this storm just split with a piece spinning toward the Beaufort. http://ocean.dmi.dk/arctic/meant80n.uk.php https://weathermodels.com/index.php?r=site%2Fpreview&mode=animator&set=14-km EPS Global&area=Northern Hemisphere&param=500 hPa Height Anom&offset=4

Updated for May 2018. 5...2018...EWR...6....NYC...6...LGA....2....JFK...5....BDR...4.....ISP....4