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Service Change Notice 24-34 Updated

National Weather Service Headquarters Silver Spring MD

430 PM EDT Wed Apr 17 2024



To:	 Subscribers:

	 -NOAA Weather Wire Service

	 -Emergency Managers Weather Information Network

	 -NOAAPort

	 Other NWS Partners and NWS Employees



From:	 Ajay Mehta

	 Director, NWS Office of Observations



Subject: Updated: NOAA-21 NUCAPS Soundings to be Added to the

Satellite

	 Broadcast Network (SBN) on Near April 29, 2024



Updated for implementation date moved from April 29 to May 9, 2024.



On or near May 9, 2024, NOAA-Unique Combined Atmospheric Processing

System

(NUCAPS) soundings from the NOAA-21 polar-orbiting satellite will be

added

to the Satellite Broadcast Network (SBN).



NUCAPS estimates atmospheric temperature and moisture at 100 pressure

levels between the earth's surface and the upper atmosphere, about an

hour

after local solar noon in each location. NOAA-21 NUCAPS soundings

provide

insight into the early-afternoon pre-convective environment,

complementing

the mid-morning soundings of the Metop-C satellite.



Each NOAA-21 NUCAPS file (granule) spans about 30 seconds of time

(about

200 granules per orbit) and samples an area roughly 2100km by 200km

with

a

grid of 30 x 4 = 120 atmospheric soundings. Each of these soundings

estimates the following atmospheric parameters at 100 vertical

levels:



	Parameter		     Units

	—--------------------------  —----

	Pressure		     mb

	Air temperature 	     K

	Liquid water mixing ratio    g/g

	Water vapor mixing ratio     g/g

	Ozone mixing ratio	     ppb

	Sulfur dioxide mixing ratio  ppb



NOAA-21 NUCAPS soundings on SBN will amount to 1,800 files/day and

0.38

GB/day. They will be broadcast via the SBN NMC3 channel (Port 1205,

PID

105) using the following WMO header codes:



	IUTN11 KNES	IUTN14 KNES	IUTN17 KNES

	IUTN12 KNES	IUTN15 KNES	IUTN18 KNES

	IUTN13 KNES	IUTN16 KNES	IUTN19 KNES



Thes	e codes are also used for NOAA-21 NUCAPS. They correspond to

the

geographic regions previously detailed in SCN19-59

(https://www.weather.gov/media/notification/pdf2/scn19-

59nucaps_soundings.pdf)



Additional details on NUCAPS soundings from NOAA-21 and other

satellites

are available on the NOAA VLab at

https://vlab.noaa.gov/web/towr-s/jpss-

nucaps.



Critical weather, enhanced caution, or other factors may affect the

timing

of this change.



For questions pertaining to these changes, please contact:



    NOAA/NWS Office of Observations

    Silver Spring, MD

    Email: NWS-OBS-Satellites@noaa.gov

  or

    AWIPS Network Control Facility (NCF) Help Desk

    NOAA/NWS Office of Central Processing

    Silver Spring, MD

    Phone: 888-808-8624



For questions regarding the content or distribution of the products

listed

here please contact:



    Joseph V. Fiore Jr.

    NOAA/NESDIS/OSPO/Satellite Products and Services Division

    College Park, MD

    email: joseph.fiore@noaa.gov

    Google Voice: 240-622-5819



National Service Change Notices are online at:



https://www.weather.gov/notification/