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URMA Winds over the Great Lakes

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DT
Dan Thompson, modified 4 Months ago.

URMA Winds over the Great Lakes

Youngling Posts: 3 Join Date: 4/29/14 Recent Posts

Hello, I had a couple of questions about URMA winds over the Great Lakes. I am basing some of these questions off the kml files of the sites used in RTMA/URMA for 20250828 at 0600Z.

1) Even after the GLERL "synthetic" obs were removed in March 2025, we are still noticing suspiciously low sustained wind values in the same location as before east of the Keweenaw Peninsula in Lake Superior in the NBM. The gusts do not look as bad. We are wondering if this is due to one of the synthetic obs still being in the URMA analysis: https://docs.google.com/presentation/d/1DSudKLNwZF676A6QBj-BTVlHFaKdgyPanK9Hykjjj9U/edit?slide=id.p#slide=id.p

2) If I understand correctly, wind observations at varying heights are supposed to be normalized to 10m. However, when I look at the obs in Google Earth for a site that has its anemometer at 46.9 m AGL (ROAM4), it looks like its sensor height is noted at 10m for the sustained file. Some other sites that show the same behavior: PILM4 (15.5m), DISW3 (25.3m), and STDM4 (35.1m). When I look at the gust file, it looks like the station height is listed as 20m. I may be missing something here.

3) Why are the NDBC buoys not used in the analysis (e.g., 45006)?

4) We have a pretty reliable site just offshore in Lake Superior (GISM4), can the winds and gusts be turned on at this site?

Thank you for your time.

Dan Thompson

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MM
Matthew Morris, modified 4 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 181 Join Date: 12/6/17 Recent Posts
Hi Dan,

Thanks for your questions.  We are still looking into questions 1) and 3), so we will need to follow-up with you on those once we learn more.

2) We currently don't perform a height adjustment for marine wind observations.  A similarity theory adjustment is used to normalize non-standard mesonet wind observations to a height of 10 m.  For example, all RAWS (CWOP) observations are assigned a height of 6 m (2 m).  The similarity theory adjustment is not currently set up to assign a sensor height to individual stations, so if a station's provider is not on the provider windheight list, then it would default to a height of 10 m.  I also don't believe we have any metadata indicating these stations aren't at the standard 10 m.  One key challenge is that we simply don't have good metadata for many of these stations, which makes it difficult to accurately account for these non-standard heights.

4) Mesonet wind observations are rejected by default in RTMA/URMA, unless the provider and/or individual station is trusted.  It would take a system implementation to change these uselists.  We might have an opportunity for a minor upgrade in the coming months, so we could include this request in that upgrade.  We will keep you posted.

Please let us know if you have any other questions.

Thanks,
Matt

On Wed, Sep 3, 2025 at 5:22 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Hello, I had a couple of questions about URMA winds over the Great Lakes. I am basing some of these questions off the kml files of the sites used in RTMA/URMA for 20250828 at 0600Z.

1) Even after the GLERL "synthetic" obs were removed in March 2025, we are still noticing suspiciously low sustained wind values in the same location as before east of the Keweenaw Peninsula in Lake Superior in the NBM. The gusts do not look as bad. We are wondering if this is due to one of the synthetic obs still being in the URMA analysis: https://docs.google.com/presentation/d/1DSudKLNwZF676A6QBj-BTVlHFaKdgyPanK9Hykjjj9U/edit?slide=id.p#slide=id.p

2) If I understand correctly, wind observations at varying heights are supposed to be normalized to 10m. However, when I look at the obs in Google Earth for a site that has its anemometer at 46.9 m AGL (ROAM4), it looks like its sensor height is noted at 10m for the sustained file. Some other sites that show the same behavior: PILM4 (15.5m), DISW3 (25.3m), and STDM4 (35.1m). When I look at the gust file, it looks like the station height is listed as 20m. I may be missing something here.

3) Why are the NDBC buoys not used in the analysis (e.g., 45006)?

4) We have a pretty reliable site just offshore in Lake Superior (GISM4), can the winds and gusts be turned on at this site?

Thank you for your time.

Dan Thompson


--
Dan Thompson RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/46678926VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758
MM
Matthew Morris, modified 4 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 181 Join Date: 12/6/17 Recent Posts
Hi Dan,

Please see below for the answer to your first question.  We are still looking into the missing buoy data (question 3).

1) We currently receive observations from BIGM4 through three separate feeds.  The latitude/longitude for each version is listed below:

Mesonet: LAT = 46.82722N, LON = 87.72472W
CMAN marine: LAT = 46.94000N, LON = 87.43000W
BUFR marine: LAT = 46.82694N, LON = 87.72694W

However, we are not currently using the observations from the BUFR feed, as the elevation data is missing and the obs are not dumped for use in RTMA/URMA.  The metadata for the mesonet and BUFR reports is encoded in the input data, while it is read in from NCEP decoder tables for the CMAN feed.  From our investigation, we have determined that the metadata for the CMAN report is incorrect in the decoder tables, thereby misplacing the observations over Lake Superior instead of along the coastline.  This incorrect lat/lon information can be updated in an upcoming decoder update (timeline TBD).  While we await this fix, our recommendation is to flag the misplaced observations (wind speed and temperature) via the SDM reject list.  This will hopefully help address some of the low wind speed bias you have observed east of the Keweenaw Peninsula.  Please let us know if you agree with this approach.

Thanks,
Matt

On Fri, Sep 5, 2025 at 3:52 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:
Hi Dan,

Thanks for your questions.  We are still looking into questions 1) and 3), so we will need to follow-up with you on those once we learn more.

2) We currently don't perform a height adjustment for marine wind observations.  A similarity theory adjustment is used to normalize non-standard mesonet wind observations to a height of 10 m.  For example, all RAWS (CWOP) observations are assigned a height of 6 m (2 m).  The similarity theory adjustment is not currently set up to assign a sensor height to individual stations, so if a station's provider is not on the provider windheight list, then it would default to a height of 10 m.  I also don't believe we have any metadata indicating these stations aren't at the standard 10 m.  One key challenge is that we simply don't have good metadata for many of these stations, which makes it difficult to accurately account for these non-standard heights.

4) Mesonet wind observations are rejected by default in RTMA/URMA, unless the provider and/or individual station is trusted.  It would take a system implementation to change these uselists.  We might have an opportunity for a minor upgrade in the coming months, so we could include this request in that upgrade.  We will keep you posted.

Please let us know if you have any other questions.

Thanks,
Matt

On Wed, Sep 3, 2025 at 5:22 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Hello, I had a couple of questions about URMA winds over the Great Lakes. I am basing some of these questions off the kml files of the sites used in RTMA/URMA for 20250828 at 0600Z.

1) Even after the GLERL "synthetic" obs were removed in March 2025, we are still noticing suspiciously low sustained wind values in the same location as before east of the Keweenaw Peninsula in Lake Superior in the NBM. The gusts do not look as bad. We are wondering if this is due to one of the synthetic obs still being in the URMA analysis: https://docs.google.com/presentation/d/1DSudKLNwZF676A6QBj-BTVlHFaKdgyPanK9Hykjjj9U/edit?slide=id.p#slide=id.p

2) If I understand correctly, wind observations at varying heights are supposed to be normalized to 10m. However, when I look at the obs in Google Earth for a site that has its anemometer at 46.9 m AGL (ROAM4), it looks like its sensor height is noted at 10m for the sustained file. Some other sites that show the same behavior: PILM4 (15.5m), DISW3 (25.3m), and STDM4 (35.1m). When I look at the gust file, it looks like the station height is listed as 20m. I may be missing something here.

3) Why are the NDBC buoys not used in the analysis (e.g., 45006)?

4) We have a pretty reliable site just offshore in Lake Superior (GISM4), can the winds and gusts be turned on at this site?

Thank you for your time.

Dan Thompson


--
Dan Thompson RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/46678926VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758

--
Matthew Morris RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/46728524VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758
DT
Dan Thompson, modified 3 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 3 Join Date: 4/29/14 Recent Posts

Hi Matthew, thank you for looking into these questions. Yes, I agree that flagging the BIGM4 ob via the SDM reject list would be a good course of action. Can you point me to where the list is, or will you take care of that on your end?

Also, thank you for considering our request for turning on mesonet site GISM4 in a future upgrade.

Dan

 

MM
Matthew Morris, modified 3 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 181 Join Date: 12/6/17 Recent Posts
Hi Dan,

I will coordinate this request with the SDM, and I will let you know once the station has been added to the list.  For future reference, information pertaining to RTMA/URMA station QC requests can be found on our VLab page, which includes a Google form to submit QC requests, as well as a spreadsheet documenting these requests.  There is no need for you to fill out the form for this station; I will take care of it.

Thanks,
Matt

On Mon, Sep 15, 2025 at 12:05 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Hi Matthew, thank you for looking into these questions. Yes, I agree that flagging the BIGM4 ob via the SDM reject list would be a good course of action. Can you point me to where the list is, or will you take care of that on your end?

Also, thank you for considering our request for turning on mesonet site GISM4 in a future upgrade.

Dan

 


--
Dan Thompson RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/46892465VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758
MM
Matthew Morris, modified 3 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 181 Join Date: 12/6/17 Recent Posts
Hi Dan,

The mislocated marine observations from BIGM4 are now being rejected through the SDM reject list.  This change took effect with yesterday's 12Z URMA.

P.S. We are still looking into the missing buoy observations over the Great Lakes and hope to have an update for you in a couple of days.

Thanks,
Matt

On Mon, Sep 15, 2025 at 4:37 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:
Hi Dan,

I will coordinate this request with the SDM, and I will let you know once the station has been added to the list.  For future reference, information pertaining to RTMA/URMA station QC requests can be found on our VLab page, which includes a Google form to submit QC requests, as well as a spreadsheet documenting these requests.  There is no need for you to fill out the form for this station; I will take care of it.

Thanks,
Matt

On Mon, Sep 15, 2025 at 12:05 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Hi Matthew, thank you for looking into these questions. Yes, I agree that flagging the BIGM4 ob via the SDM reject list would be a good course of action. Can you point me to where the list is, or will you take care of that on your end?

Also, thank you for considering our request for turning on mesonet site GISM4 in a future upgrade.

Dan

 


--
Dan Thompson RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/46892465VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758

--
Matthew Morris RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/46897756VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758
MM
Matthew Morris, modified 3 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 181 Join Date: 12/6/17 Recent Posts
Hi Dan,

Thank you for your patience as we investigated the missing NDBC buoy observations (e.g., 45006) over the Great Lakes.  These buoy observations arrive at NCEP in two separate feeds: a TAC/CMAN feed (dumped into tank b001/xx003) and a BUFR feed (dumped into tank b001/xx103).  The BUFR reports have a 7-digit ID instead of the 5-digit ID associated with the TAC reports (e.g., 4500006 vs. 45006).  The station metadata is encoded in the incoming BUFR data, whereas it is read from station tables for the TAC feed.  A duplicate check is then performed that gives precedence to the BUFR observations when the lat/lon and timestamp for these reports match.  Then, QC is performed on the remaining observations.  The BUFR observations do not include station elevation information, so the QC tosses the BUFR observations over the Great Lakes.  Note: Over the Atlantic, Pacific, and Gulf, the station elevation can be assumed to be 0 m, but this is not the case for the Great Lakes, hence why the QC tosses these observations.  The end result is that we don't receive any of the Great Lakes buoy observations over US waters.  We are currently exploring options to restore the buoy observations over the Great Lakes.  Please stay tuned for updates.

While performing this investigation, we also observed that buoy observations over the Canadian waters are being used in RTMA/URMA.  The reason for this is differing timestamps in the TAC and BUFR data feeds.  The observations in the TAC feed generally have a valid time of the top of the hour, whereas the BUFR observations have a valid time of 5 minutes past the top of the hour.  The duplicate check code does not identify these as duplicate reports, so the TAC observations are used in this case.

Thanks,
Matt

On Wed, Sep 24, 2025 at 1:39 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:
Hi Dan,

The mislocated marine observations from BIGM4 are now being rejected through the SDM reject list.  This change took effect with yesterday's 12Z URMA.

P.S. We are still looking into the missing buoy observations over the Great Lakes and hope to have an update for you in a couple of days.

Thanks,
Matt

On Mon, Sep 15, 2025 at 4:37 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:
Hi Dan,

I will coordinate this request with the SDM, and I will let you know once the station has been added to the list.  For future reference, information pertaining to RTMA/URMA station QC requests can be found on our VLab page, which includes a Google form to submit QC requests, as well as a spreadsheet documenting these requests.  There is no need for you to fill out the form for this station; I will take care of it.

Thanks,
Matt

On Mon, Sep 15, 2025 at 12:05 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Hi Matthew, thank you for looking into these questions. Yes, I agree that flagging the BIGM4 ob via the SDM reject list would be a good course of action. Can you point me to where the list is, or will you take care of that on your end?

Also, thank you for considering our request for turning on mesonet site GISM4 in a future upgrade.

Dan

 


--
Dan Thompson RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/46892465VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758

--
Matthew Morris RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/46897756VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758

--
Matthew Morris RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/47038048VLab.Notifications@noaa.gov


--
Matthew Morris
SAIC at NOAA/NWS/NCEP/EMC
5830 University Research Ct., Rm. 2038
College Park, MD 20740
301-683-3758
DT
Dan Thompson, modified 3 Months ago.

RE: URMA Winds over the Great Lakes

Youngling Posts: 3 Join Date: 4/29/14 Recent Posts

Thank you for looking into this, much appreciated.