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Showing results for tags 'waac'.
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With the Arctic sea ice extent by some measures reaching close to or event setting record lows today and area doing the same, it feels like it's about time the melt season thread got underway for 2019. There's been a phenomenal crash in the past week with the extent moving from 9th to 1st lowest position. In the GEFS mean 850 hPa and 500 hPA GPH anomaly plots for the next 5 days averaged, we can still see a large and strong footprint from the events that brought this crash about: There's essentially a 'warm Arctic, cold continents' (WACC) event going on. The impact on ice from this has been mostly via the unusual wind patterns moving unusually thin, fragile ice around, as opposed to melting it directly. It's still too cold near and at the surface for the most part even with such large anomalies aloft. The pattern shows strong persistence during the next 10 days or so. Ice declines may continue at above normal rates during this time, which could take 2019 well below any previously observed years, depending on the surface wind patterns and how much more ice is still in a position from which it may be driven into a melting environment. The pattern also served to decelerate the mid-latitude westerlies faster than usual. Once the displaced from Arctic cold air disperses or warms out, it's possible that this will facilitate an unusually rapid warm-up in regions without snow cover. Meanwhile, late snow gains across the likes of Scandinavia and E. Canada may manage to restrain the rate of advance of heat onto the Arctic, depending on how much the weather patterns de-amplify as the WAAC event subsides. I'm concerned that they may not do so very much given the El Nino event currently underway. That aside, this big loss of sea ice cover opens the door to the open water feedbacks that, before this event came into view, I had been wondering if would be negated for this melting season. Will anomalous atmospheric moisture content yet again (as was particularly evident each season 2016-2018) bring about more cloud and LP formation than usual to diminish the solar-driven melt April through July? Science really is built on questions! p.s. If for whatever reason this new topic is to be deleted, may I please request that this leading post is placed into the topic being used instead, TIA.