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Old 10-05-2015, 11:04   #16
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Re: Current weather warnings - tropical storms etc

I'm trying to get to 6th grade. Here is a shot from earth.nullschool.net.
O0ops, see next post.

It shows a cyclonic formation over Georgia with windspeed at 50 mph along with cyclonic formations over the North Atlantic. Monte's weather alert indicates the Georgia weather is out at sea, but the photo shows it over land. So my question is at what altitude is earth.nullschool showing the weather patterns?

It seems to me that earth.nullschool should be a usefull tool for voyagers if it weren't so resource demanding.

Joe
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Old 10-05-2015, 11:15   #17
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Re: Current weather warnings - tropical storms etc

Here is the nullschool photo I meant to attach to my earlier post.
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Joe
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Old 10-05-2015, 11:27   #18
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Re: Current weather warnings - tropical storms etc

jdazey, look at the lower left corner of the nullschool screen, where it says "earth". Click on it and choose what you want from the site. Also, check out windyty.com for a different projection, with forecastrs (at the bottom of the screen).
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Old 10-05-2015, 12:09   #19
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Re: Current weather warnings - tropical storms etc

Ah, thanks Roy. Now I've got my units straightened out. Currents are interesting as well.

Cheers,
Joe
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Old 10-05-2015, 12:16   #20
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Re: Current weather warnings - tropical storms etc

Joe the earth pic is current, the chart posed above was a few days ago. The low has moved pretty much as forecast. I think gribs are more useful for us because we can scroll through and watch the forecast data change over time. I think the earth map is just a current time representation of the grib data. This is the current grib and warning for TS Ana.
Unfortunately the gribs are computer models with no human input, this is where we need to consult txt forecasts and synoptic charts to get a bigger picture, unless we are competent enough to make our own analysis from the gribs and other sources.

BULLETIN
TROPICAL STORM ANA INTERMEDIATE ADVISORY NUMBER 10A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL012015
800 AM EDT SUN MAY 10 2015

...ANA INLAND AND WEAKENING...


SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...34.0N 78.9W
ABOUT 15 MI...25 KM NW OF NORTH MYRTLE BEACH SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNW OR 330 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES

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Old 10-05-2015, 12:24   #21
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Re: Current weather warnings - tropical storms etc

Thanks to Barnakiel!

Good explonations! Read them few times, I think I understood maeby little something

So the "tails" of low preassures are a common thing atthis time of year on atlantic? (or even common to all low pressures?) And the speed and the direction that they move is about the same as with the "moteher" low pressure? Maeby big generalizations but still...

And yes Azores low is there, havenīt thought it that way

But have I still understood correctly that the movement of low pressures is going to move northwards (still from west to east) during next few months as it comes southwards during winter months.

Thanks!

JeeJeeRockRock!!
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Old 10-05-2015, 13:31   #22
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Re: Current weather warnings - tropical storms etc

Quote:
Originally Posted by drummer81 View Post

(...)

- So the "tails" of low preassure are a common thing at this time of year on atlantic? (or even common to all low pressures) ?

- And the speed and the direction that they move is about the same as with the "moteher" low pressure?

- have I still understood correctly that the movement of low pressures is going to move northwards (still from west to east) during next few months as it comes southwards during winter months. ?
Great questions.

I will try to answer here much as my knowledge and skills are limited. You will be able to get more accurate answers from Google. You can also contact any Uni with a met faculty, or NOAA forecasters staff. I found people out there are very very helpful when they find they are not all alone ;-)

Here, my take:

- The tail (the S-most part) of a front (in this case we imagine a cold front, but in the lower portion it may in fact be a cold/warm front) (oftenmost trailing behind a Low up N) seems to travel SLOWER than the 'mothership'. Think of it: the distance up North is SHORTER (imagine you are trying to sail rtw twice: one time along 80 degs north, the other time along 10 degs North: is the distance traveled the same at these two latitudes?). The Low up North will try to get on top of the associated High, (if one is present), meanwhile the tail will travel more or less at the speed of the two adjacent Highs below (if both are present). I am not sure on this one, but I think this may be the explanation of why we see the long fronts getting even longer - the Low is traveling fast over shorter route while the trailing front has more distance to cover AND it also travels slower. Long fronts with long tails seem to get shorter and fewer in the summer - but only if and when the High pressure builds high enough to settle down and become what is called the Azores High. The High is then so big, stable and stationary that no front can penetrate the area. Should the high disappear, be it June or July, you will see Lows and fronts flying thru the area as if they had something personal against nice Azorean people.

- The direction is Eastward, following the associated (at times also dissociated) Low. The Low tends to 'escape' the front. The front may actually get stuck out there, alone, almost sad, becoming stationary too (you will see a stationary front has different marking too on a radiofax.

- The whole wx thing will be moving upwards now BUT it will also evolve towards summer (summer here but winter in NZ!) patterns. But yes - it all is moving up and down following the Sun. If you look at where the wx equator is (not the Equator) you will see that not only the whole thing shifts N and S following the Sun but also (interestingly) that the wx equator is N of the Equator most of the year!!! (at places: throughout the year (sic!).

I am attaching some more images that I think explain things much better than I can.

Have fun,
b.

images attribution:
- okfirst.mesonet.org/train/meteorology/Fronts.html
- courseware.e-education.psu.edu/courses/earth105new/content/lesson07/03.html
- okfirst.mesonet.org/train/meteorology/Fronts.html
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Old 10-05-2015, 15:10   #23
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Re: Current weather warnings - tropical storms etc

Regarding the earth wind map. I have tried to match current winds at my location with the EWM and the EWM always seemed to show the winds displaced some distance to the west. Remember the arctic vortex that was stationary for quite some time last (2013-2014) winter? I did send an email and got a reply explaining how the winds were calculated but there was no change as far as I could see. Still a very useful tool IMO.
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Old 12-05-2015, 13:36   #24
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Re: Current weather warnings - tropical storms etc

Quote:
Originally Posted by atoll View Post
it is cloudy and overcast here
and I really want to take out my windows to reseal them........
advice please


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Sent from my iPad.......i apologise for the auto corrects !!!
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Old 12-05-2015, 14:18   #25
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Re: Current weather warnings - tropical storms etc

Quote:
Originally Posted by Hoofsmit View Post
Attachment 101958


Sent from my iPad.......i apologise for the auto corrects !!!
infallible technology!

@pete7...... the new view!
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Old 12-05-2015, 14:28   #26
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Current weather warnings - tropical storms etc

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It was a bit small in the picture above, I didn't know if you had your glasses with you!

Your pic : The tide is out, how I remember those days, we only get a foot here, can't even put her up for a scrub, but at least the water is always warm enough to do her wet !

Apologise for the thread drift......... Back to the weather...... It's windy with sunny spells in Jolly with the trades still


Sent from my iPad.......i apologise for the auto corrects !!!
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Old 18-05-2015, 19:07   #27
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Re: Current weather warnings - tropical storms etc

It looks like the Azores high is starting to get comfortable, for the next week or so at least..Click image for larger version

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Old 26-05-2015, 07:24   #28
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Re: Current weather warnings - tropical storms etc

it seems we are having our first tropical wave since arriving in the Caribbean. Anyone have experience as to what to expect with these? Some electrical activity and rain for a couple of days I guess. I think most tropical depressions begin from a tropical wave so we will be keeping an eye on it at least...
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Old 26-05-2015, 16:08   #29
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Re: Current weather warnings - tropical storms etc

How vigorous the wave is may be hard to say before it lands but you can get an early indication for Grenada and upwards if you watch sensors on Barbados (if any, to be found at Windfinder e.g., look under reports NOT forecasts).

Once you have seen one, you will learn to guess the following ones. You will possibly notice the wx can get unusually clear before the wave - probably the best days to watch out for the green flash. And then the clouds get better formed, the wind backs, you get some rainy squalls and then the wind veers and the weather is not at its best for maybe a day or two.

So that's I think roughly that. Some waves are nasty, others are benign. The bent in the isobars gives you some idea of what to expect. I have seen some thunderstorms too but only under very heavy clouds and these seem to hit the mountains and interior rather than the coasts.

Bueno. It is a great wx learning experience if you care to download the NOAA wx daily and watch the corresponding gribs and compare it all mentally with what is going on around you. You will be a tropical wave expert in no time.

PS It makes heaps of sense to stock up on coke and sprite before the wave lands: you do not want to be confined to your boat for hours with raw Caribbean rhum being the only option left. ;-)

Have fun,
hugs,
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Old 06-06-2015, 20:43   #30
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Re: Current weather warnings - tropical storms etc

The stone in ooLasPalmas, by the way, says that it is time to sail back north via azores. Or just north, without azores. The coast of iberia looks not good for going north... The weather map has been confused lately or is it allways so? I am waiting for the stable times in the world And next thursdat or saturday looks like it. Eaven the tail of the low that is coming from caribia looks good, maeby in ten days on azores or south of it... and yes ten days is a lot!

So is it a good time to sail or maeby not. Everything can hapen like a lightning from the sky or there might be something to do with the time and place where one is. But Iīm shure to leave some tip for the servant .





I think the posts that one makes after drinking lots and lots of rum are the best

But how to predict the low from caribia not to be like "another bad year for azores" kind of stuff. Not planning to leave the boat

Hasta luego!!!

By the way Barcelona won!!!

With all my love!
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