csnavywx

3 minutes ago, WxUSAF said:

Euro was really close D8-9. Has this weird frontal timing so it's rain for everyone, but just need to time the cold air a little more like the GFS or GGEM.  Lots of chances post-Xmas.

EPS looked better timing-wise, so that's encouraging at least.

11 hours ago, Prestige Worldwide said:

Accumulating snow possible for us on Christmas?  Oh yes- let’s bring this one home crew!

It's possible. Wouldn't count on the post-frontal stuff on X-mas eve. Those typically underperform unless the setup is just right. However, there does seem to be a window on Xmas day proper with the big mid-level vort and very steep low-to-mid level lapse rates. Would be a snow shower type setup with 850mb temps around -15C.

Regardless of the post-frontal stuff (which I find it hard to get excited about -- post-frontal setups rarely produce much), those soundings and the position of the cold pool aloft look somewhat favorable for snow showers on Christmas Day proper. Very cold temps aloft. Might be enough weak surface-based instability to kick off some popcorn snow showers ahead of the mid-level vort.

Warm nose aloft making steady progress. Should be a pretty wide area of sleet for a while -- freezing rain where the nose gets thick enough. Haven't seen any thunder reports yet, though.

4 minutes ago, PivotPoint said:

Can @psuhoffman explain this sounding. This is the back edge. Do we lose lift here? Looks like there’s no snow growth...

That's still snow, but not particularly efficient. Saturation cutoff is around -10C.

There's going to be a LOT of sleet with a warm nose/WCB of that strength. May also be some embedded thunder with those soundings showing a narrow ribbon of conditional upright instability getting entrained aloft.

1 hour ago, jbenedet said:

Kinda surprised no one has dropped the “Harvey” analog yet.. 

I haven’t looked into it but I believe Harvey also occurred during a significant -NAO, which seems we will likely have this time as well. 

 

 

The amount of spread in the ensembles even 24-48hr out is pretty amazing. That said, if this thing manages to stay offshore after the westward turn, it'll have a favorable period for intensification. Oh, where have we heard that one before?

The Beaufort is once again demonstrating why it is no longer a safe area to store ice, even in somewhat favorable years.

On 9/9/2020 at 12:20 PM, donsutherland1 said:

I might be a bit pessimistic, but I suspect that it will take either the Millennial Generation or Generation Z to bring about the big changes needed. By that time, the societal commitment to even greater warming will already have been made by current policy choices. Tragically, the status quo has too much momentum at present. Generations preceding the Millenial Generation are, by and large, overly committed to the status quo. We are exceptions to that condition. These earlier generations see fossil fuels as an immutable part of the energy landscape. In contrast, at least the early opinion polling shows that the Millennials reject notions of a fossil fuel constraint. They don't see the industry as "untouchable." But for now, their political influence is limited.

Historic experience reveals that societies can make great technological leaps over very short periods of time. Development of the atomic bomb, the technologies needed to reach and return from the moon safely, and the rapid emergence and development of the Internet and related technologies provide some examples.

The energy sector, with some modest exceptions, has been relatively stagnant when compared against the above examples. Advances have been incremental e.g., how to extract hard-to-reach fossil fuels via fracking, etc., as opposed to the development of carbon free sources despite the companies' possessing enormous financial resources and engineering talent.

Absent sustained and growing pressure for big and rapid change e.g., the kind of pressure present during the Manhattan Project, large parts of the energy sector could well remain a relative backwater. The Millennials and Generation Z will likely place increasing pressure for big breakthroughs through their societal choices. Both see addressing climate change as the biggest and most urgent issue confronting their generation.  As their political clout grows, they will likely favor policy changes that require fossil fuel companies to pay for externalities associated with carbon pollution--and yes, pollution is the correct term, as excessive dumping of even naturally-occurring compounds can be hazardous to the environment.  Once that happens, the balance of incentives will shift toward carbon-free energy.  Ensuring that fossil fuel producers pay the full costs of their carbon pollution would probably accomplish far more than simply eliminating tax expenditures that help incentivize such production.

One complicating factor is that certain countries such as Russia and Saudi Arabia, even if the U.S. changes its policy course, may stubbornly persist in producing and marketing fossil fuels. They may even subsidize them to a greater extent than exists today to keep such energy sources viable.

We (M and Gen Z) have precious little wealth (~4% of the total according to analysis by American Compass and others) and influence. Getting us to vote is harder partially due to the fact that many feel that they don't have a stake in the economic system and little hope for change. While I do think we'll eventually overcome that, it may take a considerable amount of time. Time we don't really have. We're just trying to hang on to survive economically and in a lot of cases -- emotionally. Case in point: 
 

Source:

https://www.cdc.gov/mmwr/volumes/69/wr/mm6932a1.htm#suggestedcitation

34 minutes ago, bdgwx said:

So what kind of evidence would you accept that would falsify the natural hypothesis and convince you that the anthroprogenic hypothesis can survive falsification?

Bingo. This is the heart of it right here. I am keenly interested in the reply. Oh, and no goalpost moving. You're free to change your mind based on evidence, as any good scientist should, but not the goalposts.

How many more nails do we need to drive into this UHI coffin before the zombie finally stops moving?

Yeah, the Chukchi just dropped off a cliff. Now sitting about 350 above 2012 for extent, tied on area and probably lower volume than 2012, given how hard the CAB was whacked.

That's the North Pole now. As the article states, mush up through 88N and that's what's at the pole. Safe to say that the MYI and thicker ice didn't make it through the melt season unscathed. CAB and the thickest ice took the biggest hit this year. It will be interesting to see what CryoSat shows this fall.

On 8/14/2020 at 7:16 AM, bluewave said:

While the models have captured the general decline in Arctic sea ice as the planet has warmed, specific regional forecasts have really struggled. Remember how the extreme dipole patterns during the summers just popped up around 2007. They continued through the record minimum in 2012 and then reversed for a while beginning in 2013. We need to be able to forecast those circulation changes far enough in advance to know whether the first ice free summer will be closer to 2035 or 2055. Perhaps the insights from this new study will help clarify the issue leading to  improved regional climate forecasts.

 

 

https://www.awi.de/en/about-us/service/press/press-release/mosaic-expedition-reaches-the-north-pole.html

Not much attention is paid to long-term morbidities that will spring from the virus (and in some cases, already are) that could run into the millions or tens of millions. Only focusing on the death count is a myopic view of the situation, imo.

Amazing how it's only mid-July and there's virtually nothing left in the Laptev and only scraps in the ESS. The open water front is now in the CAB in record time and with some quality insolation time left on the clock. EPS/GEFS suggest this nuclear blocking pattern is finally backing off, but there are hints that it may be a temporary reprieve if the idea of a more NA centered blocking event past D5/D6 is correct. If that sets up into another event, this year will likely kill off 2012's record. Threre isn't enough peripheral ice left to keep the CAB from taking the brunt, except on the Beaufort side (which is actually doing better than any time since 2013). Having said that, we should see some slowdown in extent losses after D2/D3 for a while. The pack is already pretty compressed, so some dispersion is probably inevitable with the incoming lows.

I'm thinking there's a legit chance of clear open water at the pole this year. We've had a couple of years where it came close, but nothing with the start on the Eurasian side like this year has had.

Big dipole to start the month, relaxed a few days later and then a monster Greenland ridge centered around the 12th. That pattern relaxed into a strong +PV for a while with a weaker dipole event to end the month. GAC strikes at the end of the first week of August and by that point is able to sweep away most of the low-extent ice. Overall the first half is dominated by storminess, with a return to Greenland ridging and a dipole-like pattern to finish the month.

Most of the damage is done with the early June and early July dipole events (with the mid-July Greenland ridge pattern no doubt helping export).

21 hours ago, bdgwx said:

I'm still trying to learn the ins and outs of Arctic sea ice. I've gotten a pretty good understanding of some of the things that negatively affect the ice. 

What was the pattern like in July and August of 2012?

2020 now lowest for both extent and area. The pack has been getting absolutely hammered for the past week -- pretty much everywhere. There's still some area/extent left in the Hudson (moreso than most recent years), so 2020 could build up a pretty sizeable lead over the next week or two, which would put it in position to be competitive with 2012's turbo August melt. The hole that is being blown open on the Laptev/ESS side is getting big and getting big early. The difference has been that the Beaufort and Chukchi look to be in halfway decent shape right now. We'll have to see if any of that can survive, but the experience of the post-2007 years has been for most of that to melt out.

I suspected that whopping May dipole did more damage than was originally appreciated. The timing was just close enough to the solstice for sun angle to really matter and there was clearly some deterioration in the snow pack when it did cross. Perhaps more importantly, it destroyed the tropospheric low-level cold pool that is typically still present at that time of year. With the sun angle already high, it could not regenerate through clear-sky longwave radiation, only mainly through recirculation and diabatic processes. Surface temps never did fall/recover after that, despite some decent +PV action afterwards.  We're now seeing ponding cover virtually the entire basin, with no "safe spots" like we've seen the past few years, where melt would start later. Also unlike past years, the strongest area drops recently have been driven by melting and losses the basin proper and not on the periphery, which is actually higher this time around. In fact, the only thing keeping this above 2012 right now are the peripheral areas, which have been running above the 2010s average lately. 

Much like that year, the rot is widespread and no real snowcover remains. There's more ice in the Beaufort/Chukchi, but even favorable recent years have seen that melt out rapidly in late July and early August, so I don't expect that to survive. Combined with the very poor state of the pack on the Eurasian side of the Arctic (which has been absolutely hammered this year), we do have a real shot at the record. Of course, a strong sustained +PV pattern can always swoop in and save it.

EOSDIS Worldview looking 2012-ish with the very widespread melt ponding on virtually the entire basin. CAB/CAA are being especially hard hit. Cross-posting this video from Neven's forum of a video uploaded by GAWLab at Alert:

Incidentally, this isn't the first setup like that this year. The one in January that produced a forced line of low-topped showers had a somewhat similar evolution (CAA and dry slotting aloft with some surface heating). It lacked the more beefy mid-level CAPE or it would have produced a similar result wrt wind damage.

Normally with that much shear and low cape, updrafts are simply tilted and sheared out of existence before they can do much. Yesterday was different. The total amount of cape was low (~500J/kg), but it was very low topped (around 450-500mb top, around -20 to -25C, just cold enough for charge separation and lightning) and concentrated. A more "normal" sounding with a higher top would've resulted in values 2-3x that large. That didn't matter in this case. The amount of instability was concentrated vertically and parcel acceleration was large enough to balance the shear somewhat and thus these shallower, but stronger updrafts could tap into the extremely high ambient helicity.

Should have a few more days of big gains from the remnant open water area in the Laptev, then a marked slowing as the Pacific side OHC remains high and the weather pattern turns hostile for growth.