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Re: Contact at NWS Gateway



Wayne,

Thanks for the additional information. We will begin investigation of the problem this week.

Regards,
Allan



Wayne Gibson wrote:
Allan,

Here's some background info and an example from Jan 2007.

We receive our weather data via the Internet Data Distribution from the National Center from Atmospheric Research. The Family of Services products are ingested into that feed and we "capture" data by specifying WMO product id's. That is how we get the standard airways observations (e.g. ASOS data). I've noticed that many of the Canadian station are reporting no precipitation. One example is station CXTO. That station's data is "captured" by the bulletin headers "SACN98 CWAO" (METAR format), and "SACN98 KWBC" (in the old standard airways format(SA) format). It is my understanding that some countries are still using SA rather than METAR format.

If you look at Jan 15, 2007 there are some specific examples where the SA data show rainfall but the values are missing in the METAR format of the data. Below are data extractions from that date. The string at the beginning of each record up to the ":" mark is the ASCII data file from which I've extracted the data. The file name also contains the specific year, month, day, and hour of the observation. For example, "2007011509_sao.wmo" refers to data for year 2007, month 01, day 15, and hour 09. Here are the extractions in the 2 formats.

SA FORMAT
---------------
2007011509_sao.wmo:XTO SA 0900 AUTO8 M M M 185/-01/-04/MMMM/M/0009 PCPN 0.9MM PAST HR
    PRESFR 8048 97MM=
2007011510_sao.wmo:XTO SA 1000 AUTO8 M M M 168/-01/-03/MMMM/M/0020 PCPN 1.1MM PAST HR
    8051 31MM=
2007011511_sao.wmo:XTO SA 1100 AUTO8 M M M 155/-02/-03/MMMM/M/0036 PCPN 1.6MM PAST HR
    /S+01/ 6055 57MM=
2007011512_sao.wmo:XTO SA 1200 AUTO8 M M M 143/-03/-04/MMMM/M/0053 PCPN 1.7MM PAST HR
    SOG 02 6042 43MM=
2007011513_sao.wmo:XTO SA 1300 AUTO8 M M M 130/-04/-05/MMMM/M/0017 PCPN 1.7MM PAST HR
    7038 76MM=
2007011514_sao.wmo:XTO SA 1400 AUTO8 M M M 131/-03/-04/MMMM/M/0030 PCPN 1.3MM PAST HR
    /S+01/ 5024 22MM=
2007011515_sao.wmo:XTO SA 1500 AUTO8 M M M 120/-03/-05/MMMM/M/0050 PCPN 2.0MM PAST HR
    6023 35MM=
2007011520_sao.wmo:XTO SA 2000 AUTO8 M M M 106/-03/-05/MMMM/M/0006 PCPN 0.6MM PAST HR
    5023 38MM=

METAR format:
----------------
2007011509_sao.wmo:METAR CXTO 150900Z AUTO M01/M04 RMK AO1 9PAST HR PRESFR 8048
    SLP185 P0000 T10091037 50009=
2007011510_sao.wmo:METAR CXTO 151000Z AUTO M01/M03 RMK AO1 1PAST HR 8051 SLP168 P0000
    T10131031 50020=
2007011511_sao.wmo:METAR CXTO 151100Z AUTO M02/M03 RMK AO1 6PAST HRS+01/ 6055 SLP155
    P0000 T10151027 50036=
2007011512_sao.wmo:METAR CXTO 151200Z AUTO M03/M04 RMK AO1 7PAST HR SOG 02 6042
    SLP143 P0000 T10341043 50053=
2007011513_sao.wmo:METAR CXTO 151300Z AUTO M04/M05 RMK AO1 7PAST HR 7038 SLP130 P0000
    T10371046 50017=
2007011514_sao.wmo:METAR CXTO 151400Z AUTO M03/M04 RMK AO1 3PAST HRS+01/ 5024 SLP131
    P0000 T10321042 50030=
2007011515_sao.wmo:METAR CXTO 151500Z AUTO M03/M05 RMK AO1 0PAST HR 6023 SLP120 P0001
    T10331045 50050=
2007011520_sao.wmo:METAR CXTO 152000Z AUTO M03/M05 RMK AO1 6PAST HR 5023 SLP106 P0000
    T10331048 50006=

As a further check on the daily precipitation totals, folks at the Ontario Climate Center referred me to this web page to check the observations:

http://climate.weatheroffice.ec.gc.ca/climateData/dailydata_e.html?timeframe=2&Prov=CA&StationID=31688&Year=2007&Month=1&Day=15

As you can see from that web page, the total for Jan 15 should be about 11.5mm,. The total from the SA data is 10.9mm, and 0.01 inches from the METAR data. Clearly the METAR form of the data is inaccurate.

So this is an example of the problem I've been chasing down. It actually has been that way since at least April of 2006 for some stations. Hope my explanation and example is sufficiently clear. If not, let me know what further information I can provide.

Sincerely,

Wayne

Wayne Gibson
Senior Research Assistant
Oregon State University
PRISM Group

Web Site: http://www.ocs.oregonstate.edu/prism
Office: 541.737.5696

----- Original Message ----- From: "Allan Darling" <address@hidden>
To: "Wayne Gibson" <address@hidden>
Cc: "Paul Noonan" <address@hidden>; "Walter Smith" <address@hidden>; "Linda Miller" <address@hidden>; "Fred Branski" <address@hidden>; "Unidata Support" <address@hidden>
Sent: Friday, January 26, 2007 8:25 AM
Subject: Re: Contact at NWS Gateway


Wayne,

Yes, samples of products with suspected problems would be the starting point for our investigation. Please send any examples you have. More current data is better.

Regards,
Allan



Wayne Gibson wrote:
Fred,

Sorry to have bothered you when you're away.

Walter and Allan, would you like me to provide some specific examples?

Wayne Gibson
Senior Research Assistant
Oregon State University
PRISM Group

Web Site: http://www.ocs.oregonstate.edu/prism
Office: 541.737.5696

----- Original Message ----- From: "Fred Branski" <address@hidden> To: "Linda Miller" <address@hidden>; "Allan Darling" <address@hidden>; "Walter Smith" <address@hidden>; "Paul Noonan" <address@hidden> Cc: "Wayne Gibson" <address@hidden>; "Unidata Support" <address@hidden>
Sent: Thursday, January 25, 2007 11:54 AM
Subject: Re: Contact at NWS Gateway


Wayne and Linda,

Wayne is correct we receive Canadian SA data in both METAR and AIRWAYs
formats.  both are made available in their native format and the
Canadian Airways reports along with a few remaining U.S. reports in
AIRWAYs code are converted to METAR here at the NWSTG. We are aware of
some translation problems which have been corrected. I'm not completely
sure if all the problems we were aware of fixed.  It is also possible
Wayne has identified a different problem.

Wayne should pass the details to Walter Smith and Allan Darling.
Allan's branch is responsible for the software and Walter for Data
Management.

Sorry I didn't get back to you sooner but I'm out of the office.

Cheers, Fred

Linda Miller wrote:
Hi Wayne,

FYI-Joe Irwin's email bounced. I believe he retired and I forgot about that, so we'll hope that Fred will get back to you on this question.

Thanks again,

Linda

Wayne Gibson wrote:
Linda,

That is a good question. If issued by the CWAO office, then the format is standard airways (SA) and the precipitation is correct. If issued by KWBC, then the format is METAR and the precipitation is incorrect. As another check, the METAR format can't be correct as the monthly precipitation totals for many of the Canadian sites starting in April 2006 are very low (2-11 mm) and those values are not realistic.

Thanks for tending to this quickly.

Wayne

--------------------------------------------------
- Wayne Gibson                                   -
- Senior Research Assistant                      -
- Oregon State University                        -
- Spatial Climate Analysis Service               -
-                                                -
- Email: address@hidden             -
- Web Site: http://www.ocs.oregonstate.edu/prism -
- Web Site: http://www.ocs.oregonstate.edu       -
- Voice: 541.737.5696                            -
--------------------------------------------------
On Wed, 10 Jan 2007, Linda Miller wrote:

Hi Wayne,

I've copied two people at the NWS, but when I read your email, I wondered if this is happening on the Canadian side or at the NWSTG. In any event, hopefully either Fred or Joe will get back to you.

Thanks!

Linda

Wayne Gibson wrote:
Linda,

Good morning.

Recently I was looking at some Canadian surface data that we receive via LDM. Apparently it is received in both SA (standard airways) amd METAR format. Correct me if I'm wrong, but the SA data is converted to METAR format at the NWSTG and retransmitted. In that process, precipitation is not being converted correctly. Do you know the appropriate contact at the NWS that would be responsible for the conversion process? I'd like to start a dialogue and see if the problem can be fixed.

Sincerely,

Wayne

--------------------------------------------------
- Wayne Gibson                                   -
- Senior Research Assistant                      -
- Oregon State University                        -
- Spatial Climate Analysis Service               -
-                                                -
- Email: address@hidden             -
- Web Site: http://www.ocs.oregonstate.edu/prism -
- Web Site: http://www.ocs.oregonstate.edu       -
- Voice: 541.737.5696                            -
--------------------------------------------------

--
Linda Miller - address@hidden
Community Services, Unidata
University Corporation for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307-3000
303-497-8646 fax: 303-497-8690


--
===============================================================
  Fred Branski, Operations Support, Performance Monitoring &
Data Management Branch, W/CIO11
                RTH Washington
                U.S. National Weather Service
                Office of the Chief Information Officer
                Telecommunication Operations Center

  Phone:       +301 713 0864 Ext. 146      Fax:  +301 713 1409
  Cell/Pager:  +240 355 4468
  E-mail:      address@hidden
===============================================================




--
Allan Darling
Chief, Telecommunication Software Branch
NOAA's National Weather Service, OCIO/TOC
(301)713-0882 x114

http://www.nws.noaa.gov/tg/




--
Allan Darling
Chief, Telecommunication Software Branch
NOAA's National Weather Service, OCIO/TOC
(301)713-0882 x114

http://www.nws.noaa.gov/tg/