NOUS41 KWBC 021120 AAE

PNSWSH

 

Service Change Notice 17-59 Updated

National Weather Service Headquarters Silver Spring MD

720 AM EDT Mon Oct 2 2017

 

To:       Subscribers

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          -NOAAPORT

          Other NWS Partners, Users and Employees

 

From:     Dave Myrick

          NWS Office of Science and Technology Integration

 

Subject:  Updated: Slight adjustments to SBN and NOMADS

          transmission of National Blend of Models (NBM)

          guidance and bug fix effective on October 10, 2017

 

Updated to send more output for the 0500 UTC, 0600 UTC, 1700 UTC

and 1800 UTC cycles to provide information earlier for

Continental U.S. (CONUS) Weather Forecast offices (WFO) in the

Central and Eastern time zones.

 

Currently, the 0500 and 1700 UTC NBM runs are transmitted

through 84 hours on SBN. Based on feedback from CONUS

WFOs/Regions in Central and Eastern time zones, additional

Satellite Broadcast Network (SBN) transmissions through 

187 hours are needed for those two runs to be effectively used

in the primary forecasts issued by roughly 300 am/pm local time.

 

In addition, the 0600 UTC and 1800 UTC MaxT MinT MaxRH and MinRH

fields are transmitted currently to 72 hours. These will be

transmitted on the SBN to 264 hours, an hour earlier than

currently done on the 0700 UTC and 1900 UTC cycles. For

reference, SBN transmissions are roughly 1 hour later than the

NBM cycle times listed above (i.e., the NBM 0500 UTC run cycle

is available in the Advanced Weather Interactive Processing

System (AWIPS) via SBN by about 0600 UTC).

     

An error was also recently discovered, preventing blending of

88-h temperature and 94-h QPF06 on the 0200, 0800, 1400 and 2000

UTC NBM cycles. This error also impacted the 131-h wind gust at

0400, 1000, 1600, and 2200 UTC NBM cycles. With this error

corrected, the elements listed above will now begin populating

in GRIB2 data flow to Web Dissemination and NOAA Operational

Model Archive and Distribution System (NOMADS). There are no

changes to SBN/NOAAPORT with this fix. 

_______________

 

On or about Thursday, July 27, 2017, beginning with the 

1200 Coordinated Universal Time (UTC) model run, the NWS

Meteorological Development Laboratory (MDL) will implement an

update to the experimental NBM guidance over the CONUS, OCONUS

(Alaska, Hawaii, Puerto Rico), and Oceanic National Digital

Forecast Database (NDFD) domains.

 

1. Background

 

This upgrade will incorporate additional global and mesoscale

models over the CONUS and OCONUS domains.  The upgrade will

enable the NBM to routinely generate key aviation weather

elements for digital aviation services, fire weather and several

meteorological fields used to derive a predominant weather grid

at local Weather Forecast Offices. The location and cycle

availability of all NBM products is outlined in

Sections 4-6 below.

 

2. NBM Elements

 

A list of weather elements that will be available at hourly time

steps through 36 hours is provided below:

  

     1. 2-m temperature

     2. 2-m dewpoint

     3. 10-m wind speed

     4. 10-m wind direction

     5. 10-m wind gust

     6. Sky Cover

     7. Ceiling height (CONUS Only)

     8. Lowest cloud base height (CONUS Only)

     9. Visibility (CONUS Only)

    10. Precipitation potential index (CONUS Only)

    11. Quantitative precipitation amount (1-hour, CONUS Only)

    12. 2-m relative humidity (NDGD only, No SBN)

    13. 2-m apparent temperature (NDGD only, No SBN)

 

The following NBM weather elements will be available over the

CONUS and OCONUS domains at 3-hour time steps between 

39-192 hours and every 6 hours thereafter through 264 hours:

 

     1. 2-m temperature

     2. 2-m dewpoint

     3. Daytime 2-m Maximum temperature

     4. Nighttime 2-m Minimum temperature

     5. 10-m wind speed

     6. 10-m wind direction

     7. 10-m wind gust

     8. Sky Cover

     9. Precipitation potential index (6-hour)

    10. Probability of precipitation (12-hour)

    11. Quantitative precipitation amount (6-hour)

    12. 2-m Maximum relative humidity (12-hour)

    13. 2-m Minimum relative humidity (12-hour)

    14. 2-m relative humidity (NDGD only, No SBN)

    15. 2-m apparent temperature (NDGD only, No SBN)

 

For CONUS only, the following NBM weather grid elements will be

available at hourly time steps between 1-36 hours, every 3 hours

between 36-192 hours, and every 6 hours through 264 hours:

 

     1. Maximum wet-bulb temperature aloft

     2. Bourgouin positive area/energy

     3. Bourgouin negative area/energy

     4. Probability of cloud ice present

     5. Conditional probability of rain

     6. Conditional probability of snow

     7. Conditional probability of freezing rain

     8. Conditional probability of sleet

     9. Conditional probability of refreeze sleet

    10. Snow-liquid ratio

    11. Snow level

    12. 3-h prob. of a thunderstorm (3-hourly, 3-78 hours)

    13. 6-h prob. of a thunderstorm (6-hourly, 84-180 hours)

 

3. This upgrade will incorporate additional global and mesoscale

models and statistically post-processed guidance over the CONUS

and OCONUS domains:

 

Current inputs:

 

    1. NAM (North American Mesoscale Forecast System - 12km)

    2. NAMNest (NAM 3km high resolution nest)

    3. GFS (Global Forecast System)

    4. GEFS (Global Ensemble Forecast System)

    5. GDPS (CMC - Environment Canada Global Deterministic –

        PoP12/QPF06 only)

    6. GEPS (CMCE - Environment Canada Global Ensemble)

    7. EKDMOS (Ensemble Kernel Density Model Output Statistics)

    8. Gridded GFS MOS (GMOS or MOSGuide)

 

New inputs:

 

    9. HRRR (High Resolution Rapid Refresh), CONUS only

   10. RAP (Rapid Refresh)

   11. Gridded LAMP (GLMP Localized Aviation MOS Product), CONUS

        only)

   12. HiResWindow ARW NCEP (High-Resolution Window Forecast

        System (HIRESW))

   13. HiResWindow NMMB NCEP (High-Resolution Window Forecast

        System (HIRESW))

   14. SREF (Short Range Ensemble Forecast) CONUS, Alaska,

        Puerto Rico sectors

   15. NAVGEME (Navy FNMOC Global Ensemble)

 

The CONUS NBM products will be disseminated on a 2.5-km Lambert

Conformal grid with dimensions NX=2345 and NY=1597.  This

represents an expansion to the west by 200 grid lengths compared

to the current operational NBM domain to provide coverage for

the Nearshore Wave Prediction Model (NWPS) along the

U.S. West Coast.

 

NBM products for Alaska will be produced on a 3-km Polar

Stereographic grid with dimensions NX=1649 and NY=1105. The

Hawaii NBM products will be produced on a 2.5-km Mercator grid

with dimensions NX=625 and NY=561. Products for Puerto Rico will

be produced on a 1.25-km Mercator grid with dimensions NX=353

and NY=257.

 

4. NBM Oceanic Products

 

NBM guidance for the Oceanic domain will now incorporate all

ensemble members from the Global Ensemble Forecasting System

(GEFS) and the Canadian Meteorological Centre Ensemble (CMCE).

This upgrade provides additional 10-m wind speed percentile

thresholds and a blended wind direction field using a clustering

technique. The Oceanic products will continue to be produced on

a 10-km Mercator grid with dimensions NX=2517 and NY=1817.

Guidance for the following elements will be available for the

0000 and 1200 UTC cycles at 3-hourly time steps between 3-192

hours and at 6-hourly time steps thereafter through 264 hours:

 

     1. 10-m wind speed 10th Percentile

     2. 10-m wind speed 25th Percentile

     3. 10-m wind speed 50th Percentile

     4. 10-m wind speed 75th Percentile

     5. 10-m wind speed 90th Percentile

     6. 10-m blended wind direction

 

Please note that these additional calculations are resource

intensive and results in a 40 minute runtime delay relative to

the current operational NBM oceanic product.

 

5. SBN/NOAAPORT Dissemination

 

While the NBM will run every hour and produce output to 

264 hours with each run, only a subset will be sent across the

Satellite Broadcast Network (SBN) and NOAAPORT due to bandwidth

limitations. Products will be disseminated in GRIB2 format and

will contain individual WMO headers. On implementation day,

current NBM products going across the SBN/NOAAPORT will no

longer contain superheaders. The schedule for SBN/NOAAPORT

dissemination is as follows:

 

  NBM Window                  Disseminated Cycles (UTC)

  ----------------------      ------------------------------

 

  Short-term: 1-18h           0100, 0200, 0400, 0800, 1000,

1100,

                              1300, 1400, 1600, 2000, 2200, 2300

 

  Short-term: 1-36h           0300, 0600, 0900, 1500, 1800, 2100

                         

  Short-term and                    

  medium-range: 1-187h        0500, 1700

 

  Short-term and                    

  extended-range: 1-264h      0000, 0600*, 0700, 1200, 1800*,

1900

 

  Oceanic products -

  through 264h                0000, 1200

 

*For 0600 and 1800 UTC, only MaxT MinT MaxRH MinRH transmitted

to 264 hours; other elements just to 36 hours.

 

6. TGFTP/NDGD Dissemination

 

Output for the 0000, 0700, 1200 and 1900 UTC cycles will be

placed in the experimental area of the National Digital Guidance

Database (NDGD) in GRIB2 format at the following locations:

 

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.b

lend/AR.conus/  (CONUS)

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.b

lend/AR.alaska/  (Alaska)

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.b

lend/AR.hawaii/  (Hawaii)

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.b

lend/AR.puertori/  (Puerto Rico)

ftp://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.b

lend/AR.oceanic/  (Oceanic)

    

Each domain directory will contain subdirectories for each valid

period as follows:

 

     VP.001/      Day 1

     VP.002/      Day 2

     VP.003/      Day 3

     VP.004/      Day 4

     VP.005-007/  Days 5-7

     VP.008-450/  Days 8 and beyond

 

Each element-specific GRIB2 file will reside in the appropriate

valid period subdirectory and contain individual WMO headers.

On implementation day, NBM files residing in NDGD will no longer

contain superheaders.  A listing of GRIB2 file names for all NBM

elements that will reside on TGFTP is provided in Table 1 below.

 

Table 1: GRIB2 file names for NBM elements that will reside on

TGFTP/NDGD in the appropriate valid period subdirectory

 

   CONUS/ALASKA/HAWAII/PR PRODUCTS:

   GRIB2 FILE NAME     NBM ELEMENT NAME

   ---------------     -----------------------------

   ds.skymean.bin      Sky cover (mean)

   ds.wdirmean.bin     Wind direction (mean)

   ds.wspdmean.bin     Wind speed (mean)

   ds.pop12.bin        12-h probability of precipitation

   ds.tempmean.bin     2-m temperature (mean)

   ds.tdmean.bin       2-m dewpoint temperature (mean)

   ds.maxtmean.bin     Daytime maximum temperature (mean)

   ds.mintmean.bin     Nighttime minimum temperature (mean)

   ds.qpf06.bin        6-h quant. precipitation amount

   ds.rhmean.bin       2-m relative humidity (mean)

   ds.apptmean.bin     2-m apparent temperature (mean)

   ds.wgustmean.bin    Wind gust (mean)

   ds.ppi.bin          Precipitation potential index

   ds.maxrhmean.bin    12-h maximum relative humidity (mean)

   ds.minrhmean.bin    12-h minimum relative humidity (mean)

 

   CONUS-ONLY PRODUCTS:

   GRIB2 FILE NAME     NBM ELEMENT NAME

   ---------------     -----------------------------

   ds.pts03.bin        3-h Probability of a thunderstorm

   ds.pts06.bin        6-h Probability of a thunderstorm

   ds.vismean.bin      Visibility (mean)

   ds.cigmean.bin      Ceiling height (mean)

   ds.cldbsemean.bin   Cloud base height (mean)

   ds.qpf01.bin        1-h Quant. precipitation amount

   ds.cprbfzrain.bin   Cond. probability of freezing rain

   ds.cprbsnow.bin     Cond. probability of snow

   ds.cprbrain.bin     Cond. probability of rain

   ds.cprbsleet.bin    Cond. probability of ice pellets

   ds.prbrefzslt.bin   Probability of refreeze sleet

   ds.probcldice.bin   Probability of cloud ice present

   ds.negemean.bin     Bourgouin negative area/energy (mean)

   ds.posemean.bin     Bourgouin positive area/energy (mean)

   ds.slrblend.bin     Snow-liquid ratio (mean)

   ds.snowlvlmean.bin  Snow level (mean)

   ds.maxwbmean.bin    Maximum wet-bulb temp. aloft (mean)

 

   OCEANIC PRODUCTS:

   GRIB2 FILE NAME     NBM ELEMENT NAME

   ---------------     -----------------------------

   ds.wdirmean.bin     Wind direction (mean)

   ds.wspd10p.bin      Wind speed - 10th percentile

   ds.wspd25p.bin      Wind speed - 25th percentile

   ds.wspd50p.bin      Wind speed - 50th percentile

   ds.wspd75p.bin      Wind speed - 75th percentile

   ds.wspd90p.bin      Wind speed - 90th percentile

 

 

7. NCEP Web Dissemination

 

On implementation day, the NBM output for all cycles, elements,

and projections will now be made available on NCEP web 

services sites:

 

http://nomads.ncep.noaa.gov/pub/data/nccf/com/blend/prod/

http://ftp.ncep.noaa.gov/data/nccf/com/blend/prod/

ftp://ftp.ncep.noaa.gov/pub/data/nccf/com/blend/prod

 

8. WMO Headers

 

Unique originating center IDs have been assigned to each

geographic region. A listing of the originating center IDs is

given in Table 2 below. WMO headers for all NBM elements and

discontinued superheaders are listed below in Tables 3 and 4,

respectively. 

 

A document outlining the new WMO header scheme for NBM products

can be found here:

 

  http://www.weather.gov/media/mdl/NBM_WMO_header.pdf

 

Table 2: List of originating center IDs (CCCC) for NBM products

 

Two IDs are assigned to each geographic region to accommodate

all weather elements. Oceanic products are disseminated under KWEA.

 

   Geographic Region      Originating Center (CCCC)

   -----------------      ------------------------

   CONUS and Oceanic      KWEA and KWEB

   Alaska                 KWEC and KWED

   Hawaii                 KWEE and KWEF

   Puerto Rico            KWEG and KWEH

 

Table 3: WMO headers for all NBM products that will be

disseminated over the SBN/NOAAPORT and placed on TGFTP/NDGD

 

Listed below are representations of the WMO headers where xxx is

a placeholder for the forecast valid day and hour (see header

document linked above for further details).

 

   CONUS Products (CCCC=KWEA)

   WMO Header        Element Name

   ----------        -----------------------------

     YAAxxx          Sky cover (mean)

     YBAxxx          Wind direction (mean)

     YCAxxx          Wind speed (mean)

     YDAxxx          12-h Probability of precipitation

     YEAxxx          2-m temperature (mean)

     YFAxxx          2-m dewpoint temperature (mean)

     YGAxxx          Daytime maximum temperature (mean)

     YHAxxx          Nighttime minimum temperature (mean)

     YIAxxx          6-h Quant. precipitation amount (mean)

     YJAxxx          6-h Probability of a thunderstorm

     YMAxxx          Precipitation potential index

     YPAxxx          Visibility (mean)

     YQAxxx          Ceiling height (mean)

     YRAxxx          Relative humidity (mean) - NDGD only

     YTAxxx          Apparent temperature (mean) - NDGD only

     YVAxxx          1-h Quant. precipitation amount (mean)

     YWAxxx          Wind gusts (mean)

     YYAxxx          3-h Probability of a thunderstorm

 

   CONUS Products (CCCC=KWEB) 

   WMO Header        Element Name

   ----------        -----------------------------

     YAAxxx          Cond. probability of freezing rain

     YBAxxx          Cond. probability of snow

     YCAxxx          Cond. probability of rain

     YDAxxx          Cond. probability of ice pellets

     YEAxxx          Probability of refreeze sleet

     YGAxxx          12-h Maximum relative humidity (mean)

     YHAxxx          12-h Minimum relative humidity (mean)

     YIAxxx          Probability of cloud ice present

     YNAxxx          Bourgouin negative area/energy (mean)

     YPAxxx          Bourgouin positive area/energy (mean)

     YQAxxx          Cloud base height (mean)

     YRAxxx          Snow-liquid ratio (mean)

     YSAxxx          Snow level (mean)

     YWAxxx          Maximum wet-bulb temp. aloft (mean)

 

   AK/HI/PR Products (CCCC=KWEC,KWEE,KWEG)

   WMO Header        Element Name

   ----------        -----------------------------

     YAAxxx          Sky cover (mean)

     YBAxxx          Wind direction (mean)

     YCAxxx          Wind speed (mean)

     YDAxxx          12-h Probability of precipitation

     YEAxxx          2-m temperature (mean)

     YFAxxx          2-m dewpoint temperature (mean)

     YGAxxx          Daytime maximum temperature (mean)

     YHAxxx          Nighttime minimum temperature (mean)

     YIAxxx          6-h Quant. precipitation amount (mean)

     YMAxxx          Precipitation potential index

     YRAxxx          Relative humidity (mean) - NDGD only

     YTAxxx          Apparent temperature (mean) - NDGD only

     YWAxxx          Wind gusts (mean)

 

   AK/HI/PR Products (CCCC=KWED,KWEF,KWEH)

   WMO Header        Element Name

   ----------        -----------------------------

     YGAxxx          12-h Maximum relative humidity (mean)

     YHAxxx          12-h Minimum relative humidity (mean)

 

   Oceanic Products (CCCC=KWEA) 

   WMO Header        Element Name

   ----------        -----------------------------

     OBAxxx          Wind direction (mean)

     OCCxxx          Wind speed - 10th percentile

     OCMxxx          Wind speed - 25th percentile

     OCGxxx          Wind speed - 50th percentile

     OCNxxx          Wind speed - 75th percentile

     OCKxxx          Wind speed - 90th percentile

 

Table 4: List of WMO superheaders that are being discontinued

 

Listed below are representations of the superheaders where “ii”

represents the valid period of the forecasts (ii=93-98)

 

   CONUS (CCCC=KWEA):

     LAAZii LBAZii LCAZii LDAZii LEAZii LFAZii

     LGAZii LHAZii LIAZii LRAZii LTAZii LWAZii

 

   Alaska (CCCC=KWEA):

     MAAZii MBAZii MCAZii MEAZii MFAZii

     MGAZii MHAZii MRAZii MTAZii MWAZii

 

   Hawaii (CCCC=KWEA):

     ZAAZii ZBAZii ZCAZii ZEAZii ZFAZii

     ZGAZii ZHAZii ZRAZii ZTAZii ZWAZii

 

   Puerto Rico (CCCC=KWEA):

     YAAZii YBAZii YCAZii YEAZii YFAZii

     YGAZii YHAZii YRAZii YTAZii YWAZii

 

   Oceanic (CCCC=KWEA):

     HCAZii

 

Users may find parallel NBM data for download:

 

http://para.nomads.ncep.noaa.gov/pub/data/nccf/noaaport/blend/

http://para.nomads.ncep.noaa.gov/pub/data/nccf/com/blend/para/

 

Feedback will be collected through October 27, 2017 via comments

provided on the electronic survey at:

 

  http://www.nws.noaa.gov/survey/nws-survey.php?code=EXPNBM

 

Any questions, comments or requests regarding this

implementation should be directed to the contacts below. We will

review any feedback and decide whether to proceed.

 

For questions regarding the implementation of NBM guidance

please contact:

 

  David Rudack

  MDL/Silver Spring, Maryland

  301-427-9456

  David.Rudack@noaa.gov

or

  Jeff Craven

  MDL/Silver Spring, Maryland

  301-427-9475

  Jeffrey.Craven@noaa.gov

 

For questions regarding the data flow, please contact:

 

  Carissa Klemmer

  NCEP Central Operations

  301-683-0567

  ncep.list.pmb-dataflow@noaa.gov

 

A web page describing the NBM can be found at:

 

  http://w2.weather.gov/mdl/nbm_home

 

NWS National Service Change Notices are online at:

 

  http://www.weather.gov/os/notif.htm

 

NNNN