Post by iconPost by n chaka | 2018-12-28 | 08:00:29

Actuellement il y a 2 tableaux dans Times to Equator.
Pourquoi et lequel choisir ?

commenticon 13 Comments
Post by iconPost by alguair | 2018-12-28 | 14:31:34
Ce sont les tableaux avec et sans options!!
Post by iconPost by toxcct | 2018-12-28 | 19:56:01
First Line of the arrays says : "Full Options" and "No Options".
Post by iconPost by Ben | 2019-01-04 | 21:54:48
What means it. GFS model ?

4.1 12z
4.1 06z
4.1 00z
3.1 18z
2.1 12z
2.1 06z
2.1 00z
1.1 18z
Post by iconPost by zezo | 2019-01-04 | 22:40:30
It's the NOAA GFS run.

"4.1 12z" means "According to the weather forecast from 4th of January, 12 h (noon) UTC"

12z actually means "forecast, based on data at 12 UTC". The forecast itself becomes available 4-5 hours later.

Post by iconPost by Ben | 2019-01-05 | 10:26:22
Ok, thank's
(ah ah, 12z ==> is not z as zezo !)

Post by iconPost by zezo | 2019-01-05 | 10:28:05
Post by iconPost by Benoit | 2019-01-09 | 12:54:25
Hi, Why "The forecast itself becomes available 4-5 hours later." ?
Time to include to zezo ?
Post by iconPost by zezo | 2019-01-09 | 13:54:32
That's the time the NOAA supercomputer cluster takes to compute the entire weather model.

It starts about two hours about 12:00 (it takes some time to collect observation data from various sources all around the world) , then it takes a bit more time to compute a complete model of the current conditions based on observation data (called analysis), and then it starts issuing forecasts.

The actual schedule can be found here

Post by iconPost by Ross2105 | 2019-01-14 | 18:41:20
thanks for the Noaa scheduling, but now I have just a question:
from the end of a previous transmission up to the start of the next one, is there any changing in weather forecast? If not, as I guess, why I have often seen changing in optimal route on zezo routing simulator during the no transmission periods?
Thanks a lot in advance.

Post by iconPost by zezo | 2019-01-15 | 10:54:18
If you ask about the predicted tracks for the Jules Verne - they should not really change between updates (unless you are at "Start now")

The 16-day forecast is finished downloading at 5:00/11:00/17:00/23:00 UTC, and the predictions table is generated about 5 minutes later, so there should not be a any between e.g. 11:00 and 15:35, then between 15:35 and 17:00 new data is fed into the router incrementally.

While underway small changes are inevitable at every step. Like exact tack/gybe times, exact directions and so on. There exists a huge amount of routes with very little difference in the outcome, and the router picks one at random. It has no memory of the routing it did for you 5 minutes ago. Also, exact following of the optimum angles is not guaranteed (and sometimes there is a optimum range like TWA 141-143 with same VMG), so you can do a bit better by checking the polars for the exact current wind speed.
Post by iconPost by Ross2105 | 2019-01-15 | 17:19:34
Thank you so much, Cvetan. Your answer have been really exhaustive.
Post by iconPost by Fouras_17 | 2019-01-16 | 14:30:42
For a while on J.V bugg road the weather is not good.
Post by iconPost by zezo | 2019-01-16 | 16:21:45
My mistake. Fixed.
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