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Messages - aperson

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My naive impression is that we're seeing the beginning of an equable climate forming in the night time tropospheric polar vortex. In general, the shapes sark is showing look like patterns composed of spherical harmonics that are moving from a lower energy state to a higher state. These higher energy states seem to be stable as they increase meridional heat transport and form stable blocking patterns. In essence, once you break out of the lowest level harmonic (a single large tropospheric vortex), you get self reinforcing patterns that let air in and out of the Arctic (configurations with 4, 6, 8, etc... quasi-symmetric nodes).

Of course, this is all conjecture from me as well since I'm not a researcher in this field. But these patterns have jumped out to me as a casual weather watcher as well.

Edit: Maybe Chladni plates provide another example of what these cross-sections look like as they move from lower to higher energy states (in this case, lower hz to higher hz):

Consequences / Re: Worst consequence of AGW
« on: October 01, 2019, 09:30:57 PM »
I can see quite clearly that it is not a cause of anxiety and unease.  Sorry, but the climate situation is not the cause of every ill on this planet.

I imagine it's pretty easy to see that when your entire posting career is one Type II error after another.

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 16, 2019, 05:39:33 AM »
On the bright side we've now triple-validated our work :)

Arctic sea ice / Re: 2019 sea ice area and extent data
« on: September 16, 2019, 05:35:06 AM »
September 15th, 2019:
     4,006,036 km2, a drop of 19,682 km2.
     2019 is now 2nd lowest on record.

Arctic sea ice / Re: The 2019 melting season
« on: September 16, 2019, 01:15:41 AM »
It's not a denialist mistake to be wrong. Everybody is wrong sometimes with their predictions. It's just a mistake. What do we call people who voted for BOE option THIS YEAR, during this melting season. Or do you think that was more realistic than weatherdude's prediction. They were just wronglike him. That is it. No conspiracies or hidden meanings behind every false prediction. Some are more realistic, some are less.

Hi colchonero, I agree with you. Regardless, I don't think you understand the context for this specific poster. They post denialist rhetoric on other forums like americanwx and then disappear whenever SIE or SIA goes back to low values. They seem to have registered here to do the same.

I agree with making falsifiable predictions and verifying them, in fact I have one coming up in just a few days that may bust that I will be posting about! It is not his prediction I have a problem with, it is his hubris: "Despite all of the hyperbole and wish casting, 2019 will not be in the top 3 lowest sea ice minimums on record in area or extent."

And note that this is not the first time this specific user has done this on this forum or elsewhere. Without this surrounding context I would have not been so judgmental.

Arctic sea ice / Re: The 2019 melting season
« on: September 15, 2019, 11:07:43 PM »
He is a denier troll and it was not a risk, it was a lie designed to further obfuscate and derail the discourse on this forum.

Yep, this isn't the only forum he does this garbage on. Unfortunately he made the denialist mistake of making a falsifiable prediction.

Arctic sea ice / Re: The 2019 melting season
« on: September 15, 2019, 08:12:25 PM »
Hi weatherdude88,

I can't wait to hear your verification summary from this July prediction:

Despite all of the hyperbole and wish casting, 2019 will not be in the top 3 lowest sea ice minimums on record in area or extent. We may not end up in the top 5 in a sea ice area metric (looking at UH AMSR2 and NSIDC daily data and extrapolating).

The regions that will matter at the end of the 2019 melt season are the Central Arctic Basin, East Siberian sea, Beautfort sea, Greenland sea, and Canadian Archipelago.

For the most part, we are lagging the highest melt years in these regions (There are 5 years that lead 2019 in all these areas combined).

There is too much high latitude ice in the critical regions. All the subjective interpretation of data will not translate to reality, no matter how many members reiterate it.

By the end of the first week of August, it will become evident that 2019 will be ordinary, as it relates to sea ice minimums over the last decade.

Consequences / Re: Hurricane Season 2019
« on: September 07, 2019, 10:00:35 PM »
Would it really be so bad if the trust of the "general public" in the NWS was reduced? In those susceptible to "trust reduction" I would argue that most already do not believe in climate change and are generally egregiously stupid. If they get sucked into a tornado or blown away by a hurricane, what's the loss? I would say it is actually a gain in terms of reducing emissions, ironically the roundabout way of doing this is also the most effective.  :)

You're a bit too high on your own supply of irony here friend. Put it down before you start believing other foolish things like an imminent reglaciation.

Consequences / Re: Hurricane Season 2019
« on: September 07, 2019, 08:31:26 PM »
I do think this is more than a little overblown.
But I won't get drawn into a debate.
It was stupid. It didn't bring the NOAA to a halt.

I think it's a serious problem because it erodes the public's trust in impact forecasting. Can you imagine how much of a nightmare emergency management & response would be if the populace was as distrusting of the NWS as they were of climate scientists?

Arctic sea ice / Re: The 2019 melting season
« on: September 04, 2019, 09:40:55 PM »
I've been watching Lingling and Dorian recently, and I'm interested that they both undergo extratropical transition and integrate their momentum into the jet stream around the same time:

Dorian and Lingling are the symmetrically opposite 968mb lows here. Their angular momentum seems to enhance a dipole pattern, and the timing of their momentum transfer will be critical to how it sets up here. Regardless of the exact configuration, it looks like this will split the initiating tropospheric polar vortex into two lobes and allow a major heat/moisture intrusion from the Pacific

As we enter peak hurricane season, it's important to remember that one of the major heat engines that moves heat from equator to pole are tropical cyclones, so watching their activity will be critical to see how the freezing season initiates (or fails to)

This to me indicates that the melting season is not over yet and way may see losses for the next two weeks. I would be stunned if the AO does not go negative again in the next two weeks, but then again I'm just a naive observer and not a pro meteorologist.

Edit: And after looking at this month's PIOMAS, I really wonder if this will push the Sept 15 update into first place.

Policy and solutions / Re: If not Capitalism... then What? And, How?
« on: June 28, 2019, 11:20:26 PM »
You can't think that you'll be reviled in 50 years if there's no concept of how things might be 50 years in the future.  One has to operate within the reality of the moment.  Do you condemn geologists for talking about the fixed placement of continents prior to Wegener introducing the idea of continental drift in 1912?

There is a difference between scientific fact and moral imperative. I would hope even you are aware that this is an egregious false equivalency.

If you have a basic sense of empathy and compassion you can easily find many things where there is a dissonance between how people act and how people should act. I can spot many things now that are generally acceptable that will likely be seen as taboo in the future: Denying transgender people rights, littering, etc....

I can cultivate compassion and listen to others and spot even more things. I would hope that the leader of our country is a person that does this instead of a means-tested weathervane that naively follows the zeitgeist through bad and good like Joe Biden.

Policy and solutions / Re: If not Capitalism... then What? And, How?
« on: June 28, 2019, 09:35:31 PM »
I suspect many of you, when in your seventies, will be able to look back at things you thought and did when you were much younger and realize that you did not think or do the right thing by current standards.  But at the time that seemed to be the right thing to think or do.

Rather than using this as a rationalization for poor actions, it's a good thought experiment to consider whether what you're doing is truly progressive or not. If you think what you're doing will be reviled in 50 years, maybe try harder?

Arctic sea ice / Re: The 2019 melting season
« on: June 20, 2019, 09:08:22 PM »
Just for the record, I was asking a question, not making a point.  Pedantry would imply I was imparting knowledge.  I was seeking it.

Indeed, I am the one being pedantic  :)

Consequences / Re: Heatwaves
« on: June 17, 2019, 11:40:15 PM »
who cares?

The relatives of the ones who die from this do care quite a lot. Not that i know them, but i feel save to assume so.

Pretty sure what kills people is the wet bulb temperature, not the temperature in the sun. All they have to do in the latter is just to seek shade.

While you are "pretty sure", you are not really correct here. To determine heat stroke threat, the NWS uses the Heat Index, which is a regression that includes both temperature and relative humidity. It is distinct from a dewpoint calculation, see:

Hot and dry environments with a suitably high heat index would have a low dew point yet would still present a high heat stroke threat.

Also note that "All they have to do in the latter is just to seek shade" is not very good advice given how rapidly heat exhaustion can present and how much it affects your physical and cognitive abilities.

Arctic sea ice / Re: The 2019 melting season
« on: June 17, 2019, 09:44:36 PM »
As a layman, I don't really know what I'm talking about, so maybe someone can help me out. Frivolous, who seems to speak with some amount of authority/expertise, is posting 5-10 day forecasts; how much attention should we pay to those? I know that temp forecasts beyond a few days out are often wildly inaccurate, are long-range MSLP forecasts typically better?

It depends. Typically there is high variability around D5 on operational runs, e.g. GFS and ECMWF. If there is consistency between multiple runs, it may be indicating a pattern that models have higher confidence on appearing.

For anything past D5 we should only be posting ensemble model outputs instead of operational runs, e.g. GEFS and EPS, but we often don't. These ensemble runs are like their operational counterparts, however the initial conditions are modified slightly for each ensemble member to generate a spread of outputs that can better find divergent states or more confidently show that there is convergence on a given single state. The output for things like 500mb heights in ensembles then represents the blended state across all ensemble members rather than the single expected state that one model run sees.

Arctic sea ice / Re: The 2019 melting season
« on: May 26, 2019, 02:59:00 AM »
You care more about looking smart than educating people.

You indicated you were an engineer, I gave you a short response that I figured was geared toward an engineer. I will try to provide a better Simple English answer in the future to spare you from throwing a tempter tantrum.

Arctic sea ice / Re: The 2019 melting season
« on: May 25, 2019, 08:37:34 PM »
edit: I've just seen the ECMWF forecast and it looks pretty terrible indeed. Anything above 1030 hPa around this time of year, is a disaster for the ice. I'll post the latest forecast this evening.
Can you explain why you say it's bad in reference a pressure? I understand Pa refers to a Pascal. I'm an engineer, and the importance of air pressure rather than temperature is not obvious to me.

High pressure indicates subsidence. This inhibits cloud formation which means that the Arctic regions underneath the high will receive more incoming shortwave radiation.

Policy and solutions / Re: Tesla glory/failure
« on: February 26, 2019, 03:12:42 AM »
Oren, if you knew people will read, edit  or censure what you write, would you write the same way? No. Impossible. Censuring your own writing for fear of censorship is probably the quickest way to kill creativity. Elon still enjoys the right to free speech and this tweet did not move the markets in any way.

This tweet was not material information, was after market hours and clarification was offered before  market open. I think he SEC is significantly over reaching. The courts will decide.

Non-public production numbers are material information. The original tweet was made at 7:15PM ET which is 45 minutes before the After-hours market closes.

I understand you like to cheerlead for Tesla. I recommend that you cheerlead by not posting information that is factually incorrect.

The forum / Re: Suggestions
« on: November 18, 2018, 01:24:34 AM »
I wish I could spend likes to force another user to cite their claim or make a falsifiable prediction. If they don't provide, they get banned 1 day for every like I spent.

Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 14, 2018, 12:28:44 AM »
...did you bother reading my post or are you just angry and illiterate?


HB is going to freeze very quickly over the next week, EURO shows most of it falling sub-29/30F through this time. It has taken awhile to get going but my 11/15 prediction for 75%+ coverage (using NATICE) should be off by less than a week which I am not sad about.

Maybe they were referring to your original post:

By 10/25, Foxe Basin should be entirely covered, by 11/15, Hudson should be mostly complete (I will say 75-85% at that point). We can revisit this post 11/16 and see if I am wrong.

You made a falsifiable forecast and it busted. Kudos to you for actually making a falsifiable prediction for once. However, accept your estimation error instead of shifting the goalposts.

Arctic sea ice / Re: The 2018/2019 freezing season
« on: September 27, 2018, 05:41:47 AM »
This seems like the beginning of a repeat of how the DJF trimonth went last year.

1. Low SIE in the Bering/Chukchi seas helps support a Rossby wavetrain that enhances a strong -EPO pattern. The -EPO pattern creates a heat dome over these regions that prevents refreeze and creates a feedback loop.

2. Weak SIE in these regions alongside persistent blocking highs result in more transport of ice into the ESS and a slowing/shutdown of transpolar drift into the Atlantic

3. A lack of ice transported into the Atlantic results in less of a freshwater lens along the Atlantic margin.

4. Atlantification continues deeper into the Atlantic margins of the Arctic as saline water can mix closer to the surface.

Honestly, freezing season is when the Arctic is exciting.

Arctic sea ice / Re: "Stupid" Questions :o
« on: August 23, 2018, 12:44:36 AM »
You could also take the view that heat out varies with 4th power of temperature and this is a strong negative feedback that dominates the system and tends to prevent run away situations.

Please explain.  I'd say justify too, but I think an explanation would cover that.

(This could explain why we are not Pluto or Venus, but I don't understand it.)

The Stefan-Boltzmann law for black body radiation says that the amount of energy radiated from a black body varies with the 4th power of the surface temperature of the body. If you want to go full Venus, you'll need to add energy at a rate strong enough to dominate this effect, see:

Edit: Thank you Ned for correcting my error.

Arctic sea ice / Re: Arctic Image of the Day
« on: July 05, 2018, 05:45:18 AM »
Those are clouds formed from Lee Waves

Arctic sea ice / Re: The 2018 melting season
« on: July 01, 2018, 11:00:06 PM »
Yearly comparison of HYCOM CICE thickness for July 1st (June 30th on 2017 for the nearest date with data). Click to animate.

The main remarkable feature continues to be the thickness of ice along the Barents sea into the basin proper. The lack of transpolar drift associated with this also appears to be showing up as thicker ice along the Siberian side of the CAB as well. It appears that 2016 shows similar behavior but is less extreme both in terms of where thickness is lost and gained.

Arctic sea ice / Re: The 2018 melting season
« on: July 01, 2018, 10:10:36 PM »
Looks like I was right. Thanks for the confirmation!

I hate going OT but this is too clear of an example of confirmation bias to avoid, and it's something we all need to work on here.

You did not make a falsifiable prediction. You implied that the Nares would open at some point soon. Approximately two months later, it did. Was that soon? According to you, it was.

The real issue is that you didn't even bother making a falsifiable prediction in the first place. Whenever you make a prediction, state clearly what success and failure outcomes look like. What is the time frame to "...imminently entail the re-opening of Nares for export"? Is it a day? A month? Some time during the melting season? We'll never know because you never stated the failure criteria for your prediction.

Because you only state the success criteria for your predictions and you hide this success in imprecision, you give yourself a recipe to repeatedly "confirm" your suspicions and lead yourself into chasing down noise.

I'm definitely not an expert in any of the stuff we're discussing here, but I know damn well what a good experiment looks like, and I'm sick of seeing the same cycle of bad hypothesis -> confirmation bias -> worse hypothesis bat deduction going down in this thread.

Arctic sea ice / Re: The 2018 melting season
« on: June 23, 2018, 11:52:03 AM »
One part I'd like to know re SMOS data: Is the meltponding appearance in the CAA from actual top melt or from recent rain over the region? It has been raining there, but there was a strong temperature inversion layer with a cool surface. How do we know how much actual melt has occurred there?

Also, midrange forecasting has been pretty useful here. It showed us the Warm Air Advection event from the first cyclone well in advance to form a -DA pattern, and now it's showing us moving into opposite phase with a +DA pattern. That's essentially a forecast for a 1-2 punch to set up proper melt-ponding around the entire Arctic during peak insolation.

From looking at worldview I haven't seen much evidence of bottom melt so far. Most ice that's melted has broken up into smaller floes or has drifted into open water that has had time to warm.

The only notable Sea Surface Salinity event I've seen is that we have Atlantic water intruding farther poleward along Svalbard compared to previous years. Attached is HYCOM Sea Surface Salinity for June 22nd.

Consequences / Re: Global Surface Air Temperatures
« on: June 21, 2018, 03:25:35 AM »
The image just provided uses Fahrenheit while the one above it uses Celsius.

Arctic sea ice / Re: The 2018 melting season
« on: June 14, 2018, 05:28:19 AM »
Much smaller ice-pack bunching up? Yes.
Zero ice-pack anywhere, and just some icebergs distantly floating around? No chance.

Ice-Free in this forum is typically understood to mean < 1 million km^2 of sea ice extent to avoid this sort of semantic debate.

Arctic sea ice / Re: The 2018 melting season
« on: June 13, 2018, 05:09:38 AM »
Terra / MODIS Bands 7-2-1 imagery from June 10th to 13th of the East Siberian Sea (ESS) coastline (click to animate. It may load slowly but I think it's instructive to see what sustained insolation and above freezing temperatures due to ice).

I recommend using this band over visible imagery since it makes melt pond intensity much clearer, and it separates clouds from snow better in the melt season since fewer clouds are composed of ice droplets. From the description:

Liquid water on the ground appears very dark since it absorbs in the red and the SWIR. Sediments in water appear dark blue. Ice and snow appear as bright turquoise. Clouds comprised of small water droplets scatter light equally in both the visible and the SWIR and will appear white. These clouds are usually lower to the ground and warmer. High and cold clouds are comprised of ice crystals and will appear turquoise.

In this series of images we can sea rapid snowpack retreat and melt pond formation. I am surprised at the change in albedo over 4 days.

Thankfully differing opinions result in a good ensemble spread of estimates!

Arctic sea ice / Re: "Stupid" Questions :o
« on: June 10, 2018, 09:20:19 AM »
A non-ensemble 10 day max provides so little information I'm not sure why the site would offer charts of it. Model biases after 5 days quickly become extreme.

I would stick to ensembles like GEFS or EPS and stick to mean temperatures instead of min or max.

Arctic sea ice / Re: The 2018 melting season
« on: June 10, 2018, 03:47:21 AM »
I tried to get information from Worldview but am left guessing here (my fault, not yours).  Can I assume this image shows black-body IR from the Earth?  (I can see from the Worldview scale and the data itself that red values are close to 273K and more orange values represent higher temperatures.  And I can guess strange diagonal lines of discontinuity are results of different passes of the satellite.)  In cloud-free conditions, is this the best method of analysis of temperature?  Is it tricky to interpret?  Are the other surface temperature maps mostly interpolated from this data?  It seems to me that, among many things, this is a great tool to detect ice that is either melting or about to melt. 

Yes, this is using the brightness temperature band from Suomi / VIIRS which uses longwave IR. This will show the cloud top temperature (and by proxy the cloud top height) in cloudy environments, and the surface temperature in cloud free environments.

It is good to see which ice is thinning as well as the surface temperatures of water. For example, the Lena River delta in the above image is extremely warm. In tandem with subgeometer's animation above we can get a qualitative understanding of discharge rate and total thermal energy of the delta.

Suomi / VIIRS and MODIS both perform multiple passes and stitch images together. Discontinuities occur along these lines. However, the IR and True Color imagery should be from essentially the same time on each section, so the overlay should match up with the underlying truecolor rendering.

Arctic sea ice / Re: The 2018 melting season
« on: June 10, 2018, 01:58:39 AM »
June 9th with IR overlay from the 272.8-273.4K bucket (-0.35C - 0.25C) to the 292.9-293.5K bucket:

Image link:
Worldview link:

Arctic sea ice / Re: The 2018 melting season
« on: June 09, 2018, 06:59:05 AM »
Lena River delta melt 2018-06-05 to 2018-06-09 (click to animate)

Arctic sea ice / Re: The 2018 melting season
« on: June 08, 2018, 10:20:49 PM »
More concern to me is moderate high pressure ridge setting up in the Pacific sector, and the strong import of warm air between the ridge and this low.  I see strong sunshine and surface melting kicking off from Laptev to Chukchi/Beaufort.

Absolutely agreed. There's an extreme amount of warm air advection in this region followed by a stagnant block that will cook the area for week(s).

Here's the entire t=-72,384 run of GFS to hammer the point home. This is going to be disastrous for Siberian permafrost and ice.

Arctic sea ice / Re: The 2018 melting season
« on: June 08, 2018, 07:04:36 AM »
Rapid melt at the Gusinaya River delta in the East Siberian Sea.

Arctic sea ice / Re: The 2018 melting season
« on: June 08, 2018, 12:36:06 AM »
I think this storm will end up being more than a flash in the pan, some of the main features I'm noticing from it:

- Increased Fram export
- Rapid blueing of ice around the cyclone
- Floes near the cyclone decreasing in surface area
- Substantial rain in different regions of the Arctic for the next week
- Transport of ice into areas along the Alaskan coast with high SSTs

This is compounded by recent runs essentially showing the cyclone zip back across the Arctic in reverse once it runs into a large 5H block near Alaska.

Consequences / Re: Floods
« on: June 07, 2018, 04:22:43 AM »
The Harris County Flood Control District report on Harvey was published today. It is available at I highly recommend reading it, it is a wild ride.

Selected Quotes:
60,049 residents were rescued by government resources across all portions of Harris County, most of them from their homes with 32,000-34,000 staying in 65 temporary shelters. Tens of thousands of additional residents were rescued by local civilian resources and help that arrived from around Texas and surrounding states.


It is estimated that over 300,000 vehicles were flooded across Harris County many of which were at homes, parking garages, and dealership lots.

Dr. John Nielson-Gammon examined the largest rainfall events ever recorded in
United States history and compared against Hurricane Harvey for durations of 48, 72, and 120
hours and in spatial coverage of 1,000, 2,000, 5,000, 10,000, 20,000, and 50,000 square miles.
Harvey exceeded the previous records in all of the 18 different combinations except one. The
most astounding statistic is that for the 120 hour duration over 10,000 square miles, Harvey
exceeded the previous record from June 1899 by 13.33 inches or 62%.

Of the 154,170 homes flooded, 48,850 were within the 1% (100-yr) floodplain, 34,970 within the .2% (500-yr) floodplain, and 70,370 were outside of the 1% (100-yr) and .2% (500-yr) floodplains. Of the 154,170 homes flooded, 105,340 or 68% were outside the 1% (100-yr) floodplain.


64% of the homes flooded did not have a flood insurance policy in effect.

Arctic sea ice / Re: The 2018 melting season
« on: June 07, 2018, 01:06:19 AM »
GFS joins the Euro on a major rain event (on the order of 1"+ of rain in large swaths) across the CAA in the 5d range. This will be due to moisture / warm air advection from an omega block centered over North America.

We're currently looking at over a week more of conditions that will severely negatively impact the ice, all the way from the kara sea to the ESAS and along the CAA.

Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 09:04:33 PM »
12Z ECMWF bottoms out fairly early as well with a minimum SLP of around 970hPa. Given the different location and timing of this cyclone compared to the GAC, I think the effects will be qualitatively different and we will need to hold on any comparisons until reanalysis. However, this setup appears to be catastrophic.

Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 07:46:22 PM »
While surface ice has been advected west up the Alaskan coast for months by winds, the silt is just spreading out, indicating no current even at continental shelf depths.

The silt is also accumulating heat rapidly. Above freezing values are shaded in 0.6C increments starting at -0.3C - 0.3C bucket. The hottest regions are currently around 4C. Models are showing ice getting transported into this region in the D4-D8 range due to actions of the upcoming Arctic cyclone.

(June 4th worldview).

Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 08:53:17 AM »
I've been looking for a quick way to validate temperatures from models across the Arctic. VIIRS Brightness Temperature (Band I5, Day) and Night overlays seem to work pretty well. In tandem with using Terra / MODIS Bands 7-2-1 to locate clouds, one can look at the surface temperatures where there are no clouds.

Here is June 4th with the day band overlayed. The lowest shaded bucket is 270.9-271.6K (-2.25C - -1.55C). Above freezing temps occur at the transition to purple and max out at 4.05C.


Here is a link to Worldview which has this overlay specified for VIIRS day and night bands:,VIIRS_SNPP_CorrectedReflectance_TrueColor,MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden),Coastlines,VIIRS_SNPP_Brightness_Temp_BandI5_Day(opacity=0.67,palette=rainbow_1,min=270.9,271.6,max=276.6,277.2,squash),VIIRS_SNPP_Brightness_Temp_BandI5_Night(hidden,opacity=0.67,palette=rainbow_1,min=270.9,271.6,max=276.6,277.2,squash)&t=2018-06-04-T00%3A00%3A00Z&z=3&v=-2860023.1037379596,-1120673.8055663547,3038216.8962620404,2700894.1944336453

My biggest takeaway is that the open water on the Pacific side is a kill zone for ice that gets transported into it.

Arctic sea ice / Re: The 2018 melting season
« on: June 05, 2018, 06:33:51 AM »
00z GFS Animation 0h - 168h of the possible trajectory of the possible GAC:

Arctic sea ice / Re: The 2018 melting season
« on: June 04, 2018, 09:21:12 AM »

~60mb pressure gradient and a closed circulation all the way up to the 200mb level. Yikes, I'm definitely staying up for the 00z ECMWF tonight to see its take.

Aperson or bbr2314, if you would have time. Is it possible to describe the things you are talking about in other words. And what the impact is.

In the Sea Level Pressure charts posted above, the pressure difference from high pressure (~1025) to low pressure (~965) is around 60 millibars.

In these graphs you will see isobars of equal pressure drawn around the high pressure and low pressure centers. The tighter these isobars are, the faster wind flows along them. In the northern hemisphere, low pressure rotates counter-clockwise, and high pressure rotates clockwise, so this should let you figure out the direction of the wind.

The wind that flows along the isobar contours of constant pressure is known as geostrophic wind. See this for reference:

From this exercise, you can work out how strong wind is blowing and where it is bringing air from just by looking at the Sea Level Pressure charts. This lets us figure out that lots of heat is being brought in from the midlatitudes with strong winds in the charts posted above.

Arctic sea ice / Re: The 2018 melting season
« on: June 04, 2018, 06:33:28 AM »
First GAC of the season? The ATL front is about to get... quite a wallop. GFS upped ante and heat at 00z.

~60mb pressure gradient and a closed circulation all the way up to the 200mb level. Yikes, I'm definitely staying up for the 00z ECMWF tonight to see its take.

Edit: You may also want to download and reupload those analysis images since they will break once it cycles out of TropicalTidbits range (I think they store the last month's of runs).

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