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Old 12-12-2019, 21:16   #1
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Weather gurus

Studying Dashewís fine book titled Marinerís Weather Handbook. What a gem.
In studying it I have had to reread several things many times to Ďget ití. I think one of the things that blew some essential circuitry between the ears was the 500 mb height chart. It comes slowly to me these days. It is fascinating.

So on my lunch time today I was looking at windyty.com. There are two lows north and east of Japan and south and east of Kamchatka. What are the chances of these two combining? The other thing is that I associate lows as warm air and highs with colder air. At this latitude it really isnít a low pressure area with warm air is it? It is just that the air in that is warmer then the air diverging from the high pressure areas in mainland China?

Still trying to get a better grip on high altitude 500 mb charts to predict how it influences surface conditions. Iím really enjoying this book. I have cookie crumbs in it to mark my trail of discovery.
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Old 13-12-2019, 06:31   #2
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Re: Weather gurus

Wait until you get into Barometric pressures - then you'll really begin to see dimenions in your head. I often visualize a weather system as big bowls with the spinning Highs (1020 Mbs, for instance) spilling "downhill" into the associated Low (900 Mbs)(there are always associated Lows and Highs)- it's that spilling that creates the wind and its speed.

Remember also that in the Northern hemisphere, Lows circulate counter-clockwise and Highs circulate clockwise.

In the States, this is a good link to help you with a visual picture: https://www.weather.gov/oun/sfcmaps

Don't know about Japan, but if you search "Current Surface Weather Maps Japan" , you might find something.

Good luck with your weather-prognosticating!
Warmly,
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Old 13-12-2019, 08:10   #3
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Re: Weather gurus

I've been collecting tutorial material to help me and my crew quickly come up to speed on weather forecasting and I am indebted to this blog (https://www.vos.noaa.gov/MWL/dec_08/milibar_chart.shtml), which if you've ever heard Lee Chesneau speak, has his enthusiasm for 500 mb charts all over it. Check out the text that references figure 3 that shows the west/east cross section. I think that might help with your Japan scenario because he talks (all too briefly).about the relationship between temperature and increasing pressure.

The Dashew's book is on my list too!

I so get what you mean about how this stuff comes slowly and then blows the circuitry when the light finally comes on. I hope this thread continues with cool weather examples to follow along with to help the newbies
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Old 13-12-2019, 09:25   #4
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Re: Weather gurus

How 'bout mixing in a bit of the ephemeral? Such as old sailors' sayings like: "Mackerel skies and mares' tails make tall ships carry short sails."

This visual is the impending edge of a front. (First comes the 'mackerel skies' which are high, small clouds looking like fish scales, which are followed by 'mares' tails' - the long, whispy clouds blown into long tails by upper winds - which will soon be sinking to the surface and blow like stink.) In the UK, it translates as 6-12 hours' warning before the big winds hit. Here in Toronto where the weather comes sweeping across the large land mass of North America, I'm finding the timeline harder to predict.

Anyway, cool oldtime maxim that is really useful.

Fair winds All,
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Old 13-12-2019, 09:45   #5
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Re: Weather gurus

If you want the fine weather picture and have internet access, I recommend Weathertap.com. It gives you the individual straight line microbursts inside a front. Those are the ones that used to slam airliners into the ground before the FAA banned landing in thunderstorms. They also flatten boats on this forum from time to time. Not tornadoes, 90+ mph straightline downbursts.

Windy is great for visualization, MyRadar Pro gives you the radar with windy behind it in the tablet and laptop versions.
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Old 13-12-2019, 12:02   #6
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Re: Weather gurus

Quote:
Originally Posted by LittleWing77 View Post
How 'bout mixing in a bit of the ephemeral? Such as old sailors' sayings like: "Mackerel skies and mares' tails make tall ships carry short sails."

This visual is the impending edge of a front. (First comes the 'mackerel skies' which are high, small clouds looking like fish scales, which are followed by 'mares' tails' - the long, whispy clouds blown into long tails by upper winds - which will soon be sinking to the surface and blow like stink.) In the UK, it translates as 6-12 hours' warning before the big winds hit. Here in Toronto where the weather comes sweeping across the large land mass of North America, I'm finding the timeline harder to predict.

Anyway, cool oldtime maxim that is really useful.

Fair winds All,
LittleWing
I call those mackeral skies "scallop clouds" (I know there's a proper name for them), which seem to often precede a coming front in the San Francisco Bay area by about 2 days. Why would that be? The weather here seems so much more dynamic than along the Northern Florida Gulf or even what I experienced near the Mid-Atlantic states.
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Old 13-12-2019, 13:38   #7
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Re: Weather gurus

Mammatus clouds?
https://en.m.wikipedia.org/wiki/Mamm...d_panorama.jpg
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Old 13-12-2019, 15:27   #8
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Re: Weather gurus

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Was actually thinking cirrocumulus clouds. Does anyone know which is a "mackerel cloud"?

Ah....Nevermind, I see I should be calling them "popcorn clouds."
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Old 13-12-2019, 16:56   #9
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Re: Weather gurus

500 mb and 850 mb charts are excellent. (18,000 and 5,000 altitude, respectively.)
https://www.aviationweather.gov/progchart


Mackerel skies are Altocumulus undulatus. Reading that you'll go, Of course! Knowing the names of clouds is fun but knowing what caused the cloud to form is more important.
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Old 13-12-2019, 16:59   #10
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Re: Weather gurus

Mammatus is sign of strong downdrafts and snotty weather. Downdrafts concern aviators more than mariners but wind is wind.
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Old 13-12-2019, 17:20   #11
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Re: Weather gurus

Huh, I always heard it as mackerel scales and mareís tails... and I think they are cirrocumulus too... they never worked out to be a reliable predictor for me though in these here parts. I believe the air temperature mentioned is relative to adjacent air masses or previous day(s.)Typically higher pressure will result in higher air temps ( more air piled up, more pressure, more temperature,) and vice versa. I canít imagine a scenario where pressure goes up and temp goes down and vice versa. At least thatís my take on it....
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Old 13-12-2019, 18:10   #12
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Weather gurus

I know mares tales, thatís cirrus I believe without looking anything up. But I donít know what clouds look like fish scales.
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Old 13-12-2019, 20:03   #13
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Re: Weather gurus

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Originally Posted by a64pilot View Post
I know mares tales, thatís cirrus I believe without looking anything up. But I donít know what clouds look like fish scales.

Cirrocumulus or altocumulus


https://en.wikipedia.org/wiki/Mackerel_sky
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Old 13-12-2019, 22:50   #14
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Re: Weather gurus

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Cirrocumulus or altocumulus


https://en.wikipedia.org/wiki/Mackerel_sky
Yes, that's them right thar!
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Old 14-12-2019, 17:07   #15
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Re: Weather gurus

A feature of Windy which may help get your head around upper level winds is that you can set the altitude for wind forecasts. This very cool feature makes it easy to visualize upper level winds...which is ultimately the purpose of upper level charts.
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