|
|
07-12-2009, 18:34
|
#46
|
Registered User
Join Date: Feb 2009
Posts: 1,315
|
Quote:
Originally Posted by LeaseOnLife
Viewfax portion of the latest beta airmail
|
Thank you for the information. Do you have any idea what the little "red stick" next to the "pan" box is or do? and also the "diamond" next to the red stick.
|
|
|
07-12-2009, 19:34
|
#47
|
Registered User
Join Date: Jul 2008
Location: Plimmerton, New Zealand
Boat: Samsara, a Ross 930
Posts: 380
|
Do you find GRIB forecasts ?
Thanks for starting this thread.
I found GRIB and other 'global' forecasting models (e.g. WindGuru.com) badly under-estimate wind strength in my area. Cook Strait has strong terrain effects, so no great surprise? But how well do they work in [1] your coastal area, and [2] open ocean conditions?
What % of time do you find them within 10 kts of actual wind strength?
Agree with Hud3, JohnA, etc re: using local forecasts. GRIBs help me pick risks some days out, but 15 knot GRIB forecasts for the Cook Strait often compete with 35 kt MetService forecasts and 30 kt actual winds.
At very least, local effects seem to matter ...
We don't whistle for wind round here!
|
|
|
11-12-2009, 08:14
|
#48
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Hi Roger...
You should try ExpeditionLT in combination with PredictWind. They have created a special modelling method for GRIBS which are more accurate,but,there is a price...
Quote:
PredictWind combines sophisticated wind weather prediction technology with local topography maps to create the highest resolution marine forecast available for over 20,000 locations around the world.
In addition you can access a lower resolution marine forecast for any area around the world. The marine weather modelling technology is only available through the PredictWind website.
Developed by research scientists over 30 years, it has been adapted to provide hourly predictions to localised areas as small as one square kilometre.
PredictWind, used by the winner of the last two America’s Cups, is now accessible at no charge with a 1 Month Free Trial
|
Have a look:
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
26-12-2009, 07:07
|
#49
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
The latest release of OpenCPN does not show the wind barbs or speed in this grib report from the Skagerrak,only bar. pressure and wave height.
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
26-12-2009, 11:31
|
#50
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Based on the grib listing in #49,here are the various outputs using ExpeditionLT. A click on a map position shows the info box.
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
26-12-2009, 18:50
|
#51
|
Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
|
Overlays (layers):
- wind, waves, rain, pressure, water temp, air temp
A spot meteogram nice. A 'following the course/time, multi spot' one I would simply LOVE!
b.
|
|
|
27-12-2009, 04:15
|
#52
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Dave...
I don't know if it only occurs in Vista,but I feel the barographs are a bit too heavy, also the wind barbs. Could the lines be made somewhat thinner?
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
27-12-2009, 06:50
|
#53
|
Registered User
Join Date: Dec 2005
Location: Helsingborg
Boat: Dufour 35
Posts: 3,891
|
Sinbad7
Do you have access to a grib viewer that is able to display 500mb data? In Saildoc lingo this is a request similar to:
Quote:
send gfs:10N,45N,70W,40W|1,1|24,48,72,96,120,144|PRESS, WIND,WAVE,HGT
|
The 500mb data is the "HGT" at the end. I was just wondering if it is worthwhile to "pester" Dave with this one. I assume that it's only wind speed and direction, but hope for streamlines as well, and dream of "short waves" on top of that!!
Any screen dumps would be appreciated.
Thomas
|
|
|
27-12-2009, 07:16
|
#54
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
High resolution grib predictions are available by subscription from Wind Forecast, Marine Weather, GRIB, Marine Forecast, Wind Prediction
The attached is based on the Central European grib for 1800 UTC today.
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
27-12-2009, 08:41
|
#55
|
Registered User
Join Date: Dec 2005
Location: Helsingborg
Boat: Dufour 35
Posts: 3,891
|
Sinbad
This is what I'm talking about :
"Mariner’s Guide to the 500 – Millibar Chart" is found here:
Mariners Weather Log Vol. 52, No. 3, December 2008
Thomas
|
|
|
27-12-2009, 08:54
|
#56
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Thomas..
Very interesting article indeed although somewhat complex...
Requires the preparation of the grib file using data from a more stable altitude.
I don't know whether PredictWind uses such a data source for their grib files.
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
27-12-2009, 10:01
|
#57
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Latest OpenCPN v 1226 working perfectly now in Vista.
Also proper display of windbarbs in the European gribs.
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
23-02-2010, 06:44
|
#58
|
Registered User
Join Date: Sep 2003
Location: Ubatuba,SP,Brazil (Ex Norway)
Boat: (Ex) Alu. 60' yacht-"Eight Bells"
Posts: 2,731
|
Hi all.
OPCN has come a long way since it's first GRIB presentation but it is still not possible to read 'Current' messages as in "ggeo-Oslofjord00.grb" from retro.met.no
(File is too large to upload here.)
__________________
"And all I ask is a tall ship and a star to steer her by."
|
|
|
23-02-2010, 07:17
|
#59
|
Registered User
Join Date: Aug 2009
Location: Central New Jersey USA
Boat: Cape Dory 28 (Sold Nov 2019)
Posts: 236
|
GRIB Animations
Perhaps this is a "feature request" post, but in any case ...
I note that in zyGrib (for both Linux and Windows) and Ugrib (for Windows), it's possible to construct an animation based on successive 6 hour predictions. It's really quite an entertaining little weather movie, as well as very informative when doing research on weather windows. In my view this would be both "cute" and helpful in OpenCPN. Not urgent, but perhaps worth considering.
__________________
Good luck and good sailing.
s/v Kerry Deare of Barnegat
|
|
|
23-02-2010, 08:27
|
#60
|
Registered User
Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 20,420
|
Hi,
1) If wave data is available in a grib file, will OpenCPN display it?
2) Will weather routing function be part of OpenCPN (alike it is done in MaxSea), and, if so, will it use the wave data (to avoid or take advantage of specific wave conditions)?
b.
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|