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Everything posted by ORH_wxman
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Sea ice area is the highest value at the end of June since 2013. I'll have my prediction later for final extent and area once I crunch the numbers more...along with the histogram of possible area outcomes based on historical losses for each year since 1979. But as a prelim post, the chances of an area record low are basically zero and top 3 lowest is close to that. We just didn't get enough early melt ponding.
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NSIDC area data looks to be "correcting" back to more normal numbers...we saw an increase of area of 471k after a drop of 750k yesterday...so it's a 2 day net drop of 279k which is 139k per day....much more normal for this time of the year. Still not totally sure if the data is good, but here's where we stand if it is: 2007: -412k 2008: -130k 2009: +388k 2010: -909k 2011: -579k 2012: -1.05 million 2013: +26k 2014: -141k 2015: -226k 2016: -587k 2017: -260k We're basically running neck and neck with 2013 still with two days remaining in the month.
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The current SSMI/S satellite is beyond its lifespan so it needs maintenance more often now. There's no conspiracy to hide data. It wouldn't matter anyway...we have AMSR2 up there which is completely unrelated. So even if SSMI/S never came back or had "conspiracy" data, we would still easily track the ice sheet through AMSR2 to the minimum. AMSR2 is better anyway with the exception of June when the inferior SSMI/S sensor gets fooled more easily by melt ponds so it allows us to predict better...once in July and August, we start looking more at AMSR2 (which is tracked by sites like JAXA and U Bremen)
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Today's data is def contaminated...it's showing a loss of 750k, lol...but yesterday's was not that weird...we've seen 250k drops before many years (not every year though)...esp when you consider that more than half of that was from the Hudson/Baffin alone which were running pretty high. Today's data is no good though, so the outage is definitely here. We'll just have to see how long it lasts. Hopefully we're back up in 2-3 days. The concentration map got all mucked up in the CAB and CAA, so it's clear they are doing something with it.
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Yeah weird, I thought we'd stop getting data, but it's still flowing in. Melt picked up big time though....1 day loss was 256k (!!). Largest by far yet this season for area loss. 2007: -782k 2008: -308k 2009: +323k 2010: -1.08 million 2011: -449k 2012: -1.06 million 2013: +64k 2014: -216k 2015: -253k 2016: -714k 2017: -470k Obviously still a ton of work to do to be in contention for a top 5 year despite the big one day area loss.
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I'm not sure exactly what they are doing but previously when SSMI/S has been out, the data didn't look suspicious when it came back online so I wouldn't be too worried. I'd expect a definite uptick in losses though if it's out for 3-4 days and then comes back because the weather is turning more hostile up there in the next day or two. The Chukchi/Beaufort region was by far the most vulnerable coming into the season with the later refreeze there this past winter...the ice was pretty thin. Esp the Chukchi. The huge stall there in June is going to protect the adjacent CAB that could have been taking on a very early assault had the Chukchi melted out very early.
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I'm not that impressed either with the dipole that is forecasted for the rest of the week and maybe into early next week. It's going to help pick up the melt again but it's kind of an ugly dipole...low pressure still over Greenland and the high is centered more over the Beaufort/Chukchi rather than over the CAB and Greenland and it's not that strong. Usually like to see 1030+ or if not, a very strong gradient between Greenland and Siberian coast to sweep lots of warm air over the pack...but we don't really get either.
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Yeah looks like we snuck in one more day of data....here's updated area numbers. The gap continues to widen as 2018 has basically stopped losing area for the past several days. 2007: -1.03 million sq km 2008: -228k 2009: +352k 2010: -915k 2011: -429k 2012: -1.05 million 2013: -77k 2014: -245k 2015: -295k 2016: -817k 2017: -483k Given how little melt 2018 has had recently and the fact it has a lot of area still in Hudson bay, I decided to filter out the peripheral seas. Even when I do that, 2018, is basically neck and neck with 2013 and 2014. It is 10k ahead of 2013 and a lowly 300 sq km ahead of 2014 when i eliminate Hudson, Baffin, Greenland, Othotsk, St. Lawrence, etc....and it is much further ahead of 2015 than above when I use that filter. 2015 still had a lot of ice in those peripheral seas too which was masking the central area deficiency a bit. It is hard to imagine a top 5 being really possible given that data...but I suppose we cannot completely rule it out if some crazy weather pattern locked in.
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We will be without NSIDC data for a few days. Planned maintenance from 6/25-6/29.
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The data is from NSIDC...it is sea ice area (not extent). Area from NSIDC (or anyone who uses SSMI/S) is a better predictor of final minimum extent at this point than extent itself is...and that is because the SSMI/S sensors are sensitive to melt ponding....and melt ponding in June is very crucial to the final minimum. So using the area data from that source is sort of like de facto real-time melt pond data. The ice sheet has gotten off to a very slow start with melt ponds which will make it difficult to reach extremely low extent and area in September....even if the weather turns more hostile. It is still probably theoretically possible to get a bottom 3 year, but we will have to see a very special pattern sustain itself for weeks to make up for the slow start.
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We've made the comment before...but that North Atlantic cold pool really started becoming noticeable in spring 2013 and that was also the last time we saw sustained NAO blocking in the cold season. We've since seen shorter intervals occasionally (like Jan 2016 before the mid-Atlantic blizzard and this past March perhaps may have been the most impressive since 2013) but it's been hard to come by what we saw multiple times during winters between 2009-2013. Ive wondered if these were all related. I tend to lean in the direction of yes.
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Paltry area melt continues for the time being in 2018....updated numbers: 2007: -988k 2008: -162k 2009: +439k 2010: -776k 2011: -401k 2012: -995k 2013: -29k 2014: -207k 2015: -268k 2016: -749k 2017: -363k
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The model would suggest pretty flat trends in extent minimums out to the late 2020s before resuming a faster downward trend. It is definitely fairly impressive it predicted the current stall....we will just have to see if it is accurate in how long it lasts. It would suggest another decade of mostly the same.
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Here's other years compared to 2018 now: 2007: -886k 2008: -77k 2009: +554k 2010: -599k 2011: -358k 2012: -908k 2013: +3k 2014: -125k 2015: -213k 2016: -666k 2017: -242k Only 2013 and 2009 have higher area than 2018 now in the post-2007 world, and 2013 is basically a dead heat...only 3k difference. I'm surprised 2014 has fallen lower than this year...though 2014 does finish the month slow. The forecast definitely calls for worsening weather for the ice in a few days, so we may pick up a little steam before June ends....finishing the month with less area than 2014 wouldn't be surprising given those two pieces of information. That said, we will need to see something pretty special to achieve a top 3 or even top 5 melt season.
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I think that is Nikolai on that forum...who used to post on here. There's no empirical evidence whatsoever that the ice is in worse shape than 2012 was at this point.
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Yeah I'd agree with that. It's not a real death ridge like we had at times during 2007, 2010, 2011, and 2012....or even July 2015. But it should accelerate the melt ponding more. The area loss has been really weak the last few days. We're falling way behind the big dog years now. I'm on my phone now, but probably tomorrow when back on my PC I will do another rundown on the numbers. I think we're around a million sq km behind a year like 2012 now.
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The pattern next week definitely looks more favorable to melt, but hard to say how long it lasts. Euro ensembles put the vortex back over the CAB in the 11-15 range...but it could be wrong. Sometimes the patterns lock in longer than models initially show.
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Their forecast was for 5.3-5.4 million sq km September average extent. So the melt ponding must have been weak relatively speaking. The pattern does change though. Models have a pretty good dipole developing middle of next week. We will see how strong it gets and how long it lasts.
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Looks good for melt from about 144-240 or so....but the 11-15 day on that doesn't look impressive as it just builds the vortex back into the middle of the CAB extending over to Greenland. That's usually the opposite of what we want for big melt. Ideally we'd see a massive ridge bridge from Greenland to AK for big melt.
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Update on SIA (sea ice area).....here is how other years compare to 2018 (i.e. a -542k on 2007 means that 2007 had 542,000 sq km less area than 2018 on this date) 2007: -542k 2008: +163k 2009: +721k 2010: -217k 2011: -263k 2012: -664k 2013: +124k 2014: +152k 2015: -57k 2016: -424k 2017: -13k As you can see, 2017 is the closest match right now...though 2015, 2014, 2013, and 2008 weren't far off. That group of 4 right there shows how things can still change a decent amount....years like 2008 and 2015 still finished pretty low while 2014 and 2013 were the top 2 highest area minimums in the post-2007 era (2009 was the highest minimum extent though....and you can see how much area 2009 had at this point compared to those other years). We'll see how the next 10 days goes, but even by now, the contenders were already separating themselves from the pretenders.
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Models are showing a reverse dipole for the remainder of June....if that sticks, then we're prob out of any top 3 running this year. Unless we get an obscene pattern in July....2015 was able to make somewhat of a comeback in this manner.
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Laptev is taking a beating for sure right now...in fact it is the lowest area on record at the moment for this date in the Laptev. However, this is being offset by the East Siberian Sea and Beaufort...and to a lesser extent the CAA. The ESS has the highest area for this date since 1988...that's pretty impressive actually, and it's going to be a problem for getting massive melt. The lowest 3 on record for this date in the ESS? That would be 2007, 2012, and 2016 in that order. The ESS often has an "arm" of ice extending outward near the end of the season that can protect the central arctic basin from assault....and eroding that arm is a key to getting really low extents. The latest forecast doesn't look impressive for that area either after about Friday or Saturday...it looks like most of the warmth stays near the shoreline in the Laptev region and Kara sea. I'm not saying this is going to go 2013 or 2014 on us at this point, just that we need to see something better than a reverse dipole to get it up into the top tier of melt years...even if that reverse dipole is warm in the Laptev and Kara. It's also acting to protect all that vulnerable ice in the Chukchi that we started the season with. There's been very little progress in eroding the Chukchi ice the past week-plus and it probably won't change much with the reverse dipole.
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First check on area this season....looks like we're in the middle of the pack though skewed a little more toward the lower melt years in the post-2007 environment. We're about 30k above 2017 and about 150k below 2014. 2012's freefall was already well under way...2018 is currently 500k above 2012 at this point. There's still time though....for example, 2007 was still only 25k lower than 2018 at this point, but it went nuclear over the next 10 days losing nearly 1.5 million sq km of area...an average of about 150k per day. Not sure 2018 has the weather forecast in its favor to do anything like that. For anyone new in here, we usually track SSMI/S area in June because it has a much higher correlation to the minimum extent in september than June extent does. The reason is meltponding...the SSMI/S sensors get fooled by meltponding so the area concentration falls. Because of this, it is giving us a measurement of meltponding which is an excellent predictor of minimum ice extent. I'll usually make a prediction of final minimum extent and area based on the area numbers at the end of June. They have worked quite well over the years with a notable exception in 2016.
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This period was originally forecasted over a week ago to be pretty warm, but it never seems to pan out that way the last few years around this time. There does look to be some decent warmth that hits the Beaufort and Chukchi this weekend....but on the other hand, the dipole pattern forecasted by the euro ensembles has mostly disintegrated and now they have a low over the CAB. Cold up there now as we end May.
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The ensembles are tryng to split the PV and have one half over the Kara region and the other half over Baffin Island...with the latter weakening and becoming less of an influence. We see some weak signs of blocking trying to get into Greenland from the east as you said. I'd def be in the "wait and see" camp though. We've seen this a lot in recent summers, where the ensembles try and do something, but every time, the PV just sort of reconsolidates over the CAA/Greenland corridor. I'd want to see a good dipole get within 7 or 8 days on the ensembles to start really thinking about a different pattern this summer. I'd also add that the GEFS are more enthusiastic about a dipole pattern than the EPS.