12:14 p.m.
At a recent boat show, someone ask if they could access grib data. I told him I thought
it was possible, so where would I direct such a person?
Herb Thoms
Warning Preparedness Meteorologist | Météorologue en sensibilisation aux alertes
Environment Canada | Environnement Canada
PO Box 370
Gander, NL A1V 1W7
herb.thoms(a)ec.gc.ca
Telephone | Téléphone 709-256-6631
Facsimile | Télécopieur 709-256-6627
Government of Canada | Gouvernement du Canada
Website | Site web www.ec.gc.ca
-----Original Message-----
From: dd_info-bounces(a)lists.ec.gc.ca [mailto:dd_info-bounces@lists.ec.gc.ca] On Behalf Of
dd_info-request(a)lists.ec.gc.ca
Sent: Tuesday, December 07, 2010 8:30 AM
To: dd_info [mailman]
Subject: dd_info Digest, Vol 15, Issue 1
Send dd_info mailing list submissions to
dd_info(a)lists.ec.gc.ca
To subscribe or unsubscribe via the World Wide Web, visit
http://lists.ec.gc.ca/mailman/listinfo/dd_info
or, via email, send a message with subject or body 'help' to
dd_info-request(a)lists.ec.gc.ca
You can reach the person managing the list at
dd_info-owner(a)lists.ec.gc.ca
When replying, please edit your Subject line so it is more specific
than "Re: Contents of dd_info digest..."
Today's Topics:
1. Regional GRIB domain update :: Mise ? jour du domaine GRIB
r?gional (Miguel Tremblay)
----------------------------------------------------------------------
Message: 1
Date: Mon, 06 Dec 2010 16:10:10 +0000
From: Miguel Tremblay <miguel.tremblay(a)ec.gc.ca>
Subject: [dd_info] Regional GRIB domain update :: Mise ? jour du
domaine GRIB r?gional
To: "dd_info [mailman]" <dd_info(a)ec.gc.ca>
Message-ID: <4CFD0AE2.9040608(a)ec.gc.ca>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
(Le fran?ais suit)
Dear GRIB users,
The new GEM LAM regional forecasting system was deployed operationally
at CMC on October 20th. The new model grid is implemented differently
than in the previous operational model, having an effect on many
downstream products. Unfortunately, one issue slipped past the
operational implementation date.
Due to the mismatch between the 2 grids, spurious values are present for
about 50 low resolution and 100 high resolution grid points. All the
defective points are located in the extreme northeastern corner on the
Regional products.
This means we need to shrink, ever so slightly, the Datamart GRIB
geographical domains:
1. The Low Resolution Regional domain will change from 135x95 to 132x95
grid points eliminating the easternmost 3 columns.
2. The High Resolution Regional domain will change from 501X399 to
493x399 grid points eliminating the easternmost 8 columns.
3. The High Resolution Global Polar Stereographic domain will also
shrink in order that users may still overlay it with the High Resolution
Regional domain. It will now change from 251x200 to 247x200 grid points
eliminating the easternmost 4 columns.
GRIB1 change will be done on February 15th 2011.
GRIB2 data has already been fixed.
Documentation will be updated on January 13th 2011. New grid points
latitude/longitude files will also be made available at that time. In
the meantime users can easily make their own by eliminating the
appropriate columns from existing files on the Datamart.
Sample files with the new domains are available at:
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/reghires
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/reglores
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/psglb
We apologize for any inconveniences but we feel this must be done to
prevent users of the entire domain from inadvertently using erroneous
data in their calculations.
Moreover, we want to remind you that GRIB1 files will be removed on
April 26th 2011, as already announced on this mailing list. More
information can be found here:
http://dd.weatheroffice.ec.gc.ca/model_gem_global/WARNING_retrait_GRIB1_w...
Best regards,
----
Miguel Tremblay
National coordinator, commercial data services
Canadian meteorological centre (CMC)
Environment Canada
http://www.ec.gc.ca/
2121 Trans-Canada N. Suite 201 Phone: 514-421-4729
Dorval, Qu?bec Fax: 514-421-4679
CANADA H9P 1J3 email: miguel.tremblay(a)ec.gc.ca
====================================
Chers usagers GRIB,
Le syst?me de pr?vision r?gional GEM ? aire limit?e (LAM) a ?t? d?ploy?
op?rationnellement au CMC le 20 octobre 2010. La grille de ce mod?le
?tant diff?rente de celles des mod?les pr?c?dents, un grand nombre de
modifications aux produits en avals ont d? ?tre effectu?.
Malheureusement, une de ces modifications n'a pu ?tre faite avant la
date d'impl?mentation.
La diff?rence entre ces 2 grilles cause des valeurs erron?es sur environ
50 points de la grille basse r?solution et sur 100 points sur la grille
haute r?solution. Ces valeurs erron?es se retrouvent dans l'extr?me
nord-est de la grille des produits du mod?le r?gional.
Cette implique que nous devons l?g?rement diminuer le domaine des
donn?es GRIB de la mani?re suivante;
1- Le domaine des donn?es basse r?solution passeront de 135x95 ? 132x95
points, ?liminant ainsi les 3 colonnes les plus ? l'est.
2- Le domaine des donn?es haute r?solution passeront de 501X399 ?
493x399 points de grille, ?liminant ainsi les 8 colonnes les plus ? l'est.
3- Le domaine de la grille haute r?solution du mod?le global en
coordonn?es polaires st?r?ographiques sera ?galement chang? afin de
maintenir la correspondance avec le domaine du mod?le r?gional. Il
passera de 251x200 ? 247x200 points de grille, ?liminant ainsi les 4
colonnes les plus ? l'est.
Les modifications aux donn?es GRIB1 seront effectu?es le 15 f?vrier 2011.
Les donn?es GRIB2 ont d?j? ?t? modifi?es.
La documentation sera mise ? jour le 13 janvier 2011. Les fichiers pour
les nouvelles latitudes et longitudes seront ?galement disponible ? ce
moment. Pour l'instant, les usagers peuvent apporter un correctif en
?liminant les colonnes appropri?es sur les fichiers pr?sent sur le datamart.
Des ?chantillons pour les nouveaux domaines sont disponibles ici:
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/reghires
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/reglores
http://collaboration.cmc.ec.gc.ca/cmc/cmoi/GRIB1_samples/psglb
Nous nous excusons pour les inconv?nients que peuvent causer cette
modification, mais nous croyons qu'il important d'apporter cette
correction afin d'?viter aux usagers du domaine entier d'utiliser des
donn?es erron?es.
D'autre part, nous tenons ? vous rappeler que les donn?es GRIB1 seront
retir?es le 26 avril 2011, tel qu'annonc? sur la liste de diffusion. On
peut trouver plus d'information ? ce sujet ? cette adresse:
http://dd.weatheroffice.ec.gc.ca/model_gem_global/WARNING_retrait_GRIB1_w...
Cordialement,
--
Miguel Tremblay
Coordonnateur national des services commerciaux de donn?es
Centre m?t?orologique canadien (CMC)
Environnement Canada
http://www.ec.gc.ca/
2121 Trans-Canada N. Suite 201 T?l?phone: 514-421-4729
Dorval, Qu?bec Fax: 514-421-4679
CANADA H9P 1J3 courriel: miguel.tremblay(a)ec.gc.ca
------------------------------
_______________________________________________
dd_info mailing list
dd_info(a)lists.ec.gc.ca
http://lists.ec.gc.ca/mailman/listinfo/dd_info
End of dd_info Digest, Vol 15, Issue 1
**************************************