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High wind bias in north-central AL

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KM
Kathleen Magee, modified 2 Years ago.

High wind bias in north-central AL

Youngling Posts: 2 Join Date: 10/11/16 Recent Posts

Good afternoon!

 

At NWS Huntsville, we have noticed a high wind bias for north-central Alabama from the experimental NBM (v4.1). When posting this data there, it was explained that it was likely a result of station AR191 on Monte Sano in Alabama, a station at 1600 ft AGL. While the rest of north Alabama is at a much lower elevation (~900 ft AGL), the influence of this station extends far beyond locations at a similar elevation. Is there a way we can work to reduce its influence on nearby winds?

 

Thanks!
Katie Magee

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KM
Kathleen Magee, modified 2 Years ago.

RE: High wind bias in north-central AL

Youngling Posts: 2 Join Date: 10/11/16 Recent Posts

Forgive the slides, heights denoted as AGL should be elevation above sea level.

Jeffrey Craven, modified 2 Years ago.

RE: High wind bias in north-central AL

Youngling Posts: 90 Join Date: 9/24/12 Recent Posts
The experimental NBM v4.1 24 hour Prob 24 Max Wind and Max Gust products have some hot spots related to consistently high values in URMA.   A sampling of them are found on this example from today (with black circles).   HSV area is one of them that we have noticed.  The most prominent is in Central IL.  

There tends to be one high observation in all those areas, but the influence spreads over a broader area. 





JPC

Jeff Craven
Chief, Statistical Modeling Division (SMD)
Vice Lead, Innovation, Science & Technology (Evolve PMO)
National Weather Service, W/STI-12
Meteorological Development Laboratory (MDL)
Room 10410, SSMC2
Silver Spring, MD 20910
(816) 506-9783 cell/text
(301) 427-9475 office
@jpcstorm


On Thu, Mar 3, 2022 at 4:30 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Forgive the slides, heights denoted as AGL should be elevation above sea level.


--
Kathleen Magee RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/20984845VLab.Notifications@noaa.gov

Attachments:

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MM
Matthew Morris, modified 2 Years ago.

RE: High wind bias in north-central AL

Youngling Posts: 158 Join Date: 12/6/17 Recent Posts
Hi Katie,

Please see the attached slide deck for figures valid 14Z February 3rd.  The location of AR191 is indicated by a red circle.  Slide 2 reveals that the region of localized stronger winds at this time is originating in the background fields (i.e., HRRR 1-hr forecast) rather than from the assimilation of wind observations from AR191.  This is corroborated by the analysis increments figure on slide 4.  Thus, this is likely a result of a systematic high bias in the HRRR-forecasted winds at this location.

 URMA Wind Speed Case Study - Huntsville, AL

Please let us know if you have any other questions.

Thanks,
Matt

On Thu, Mar 3, 2022 at 4:30 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Forgive the slides, heights denoted as AGL should be elevation above sea level.


--
Kathleen Magee RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/20984845VLab.Notifications@noaa.gov
BM
Brian Miretzky, modified 2 Years ago.

RE: High wind bias in north-central AL

Youngling Posts: 47 Join Date: 1/8/13 Recent Posts
Katie if you see more examples in the NBM please continue to provide them so we can compare with the URMA at the same time.

Many thanks,
Brian Miretzky

On Fri, Mar 4, 2022 at 4:06 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:
Hi Katie,

Please see the attached slide deck for figures valid 14Z February 3rd.  The location of AR191 is indicated by a red circle.  Slide 2 reveals that the region of localized stronger winds at this time is originating in the background fields (i.e., HRRR 1-hr forecast) rather than from the assimilation of wind observations from AR191.  This is corroborated by the analysis increments figure on slide 4.  Thus, this is likely a result of a systematic high bias in the HRRR-forecasted winds at this location.

 URMA Wind Speed Case Study - Huntsville, AL

Please let us know if you have any other questions.

Thanks,
Matt

On Thu, Mar 3, 2022 at 4:30 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

Forgive the slides, heights denoted as AGL should be elevation above sea level.


--
Kathleen Magee RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/discussions-forums-/-/message_boards/view_message/20984845VLab.Notifications@noaa.gov

--
Matthew Morris RTMA/URMA Discussion Group Virtual Lab Forum http://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/21010843VLab.Notifications@noaa.gov
JS
Jack Settelmaier, modified 1 Year ago.

RE: High wind bias in north-central AL

Youngling Posts: 23 Join Date: 11/2/12 Recent Posts

So, is the takeaway from this month's old NBM, RTMA/URMA review that the too-high winds/gusts evident in the NBM v4.1 over WFO HUN's area were the result of the NBM's use of HRRR retaining some too-high observations, and spreading them over too large an area?

 

It appears that the URMA correctly did not keep the higher wind speeds to the northeast of Huntsville that were evident in the RTMA GES.

MM
Matthew Morris, modified 1 Year ago.

RE: High wind bias in north-central AL

Youngling Posts: 158 Join Date: 12/6/17 Recent Posts
Hi Jack,

In this particular case, the high wind speeds in URMA were originating in the background fields (i.e., the 1-h HRRR forecast).  In order to determine whether particular observations were assimilated in the HRRR, I would suggest reaching out to the HRRR developers [for instance, Guoqing Ge and Terra Ladwig] for assistance.

Thanks,
Matt

On Tue, Jun 21, 2022 at 4:54 PM VLab Notifications <VLab.Notifications@noaa.gov> wrote:

So, is the takeaway from this month's old NBM, RTMA/URMA review that the too-high winds/gusts evident in the NBM v4.1 over WFO HUN's area were the result of the NBM's use of HRRR retaining some too-high observations, and spreading them over too large an area?

 

It appears that the URMA correctly did not keep the higher wind speeds to the northeast of Huntsville that were evident in the RTMA GES.


--
Jack Settelmaier RTMA/URMA Discussion Group Virtual Lab Forum https://vlab.noaa.gov/web/715073/home/-/message_boards/view_message/23022724VLab.Notifications@noaa.gov

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