NOUS41 KWBC 201952 AAB

PNSWSH

 

Service Change Notice 17-63 Updated

National Weather Service Headquarters Silver Spring, MD

352 PM EDT Thu Jul 20 2017

 

To:      Subscribers:

         -NOAA Weather Wire Service

         -Emergency Managers Weather Information Network

         -NOAAPORT

         Other NWS Partners and NWS Employees

 

From:    Dave Myrick

         NWS Office of Science and Technology Integration

 

Subject: Updated: Extra-Tropical Storm Surge (ETSS) model

         upgrade and the first version of Probabilistic

         Extra-Tropical Storm Surge (P-ETSS) model:

         Effective TBD

 

Updated to change effective date to To Be Determined (TBD) from

August 8, 2017

 

On TBD, beginning with the 1200 Universal Coordinated Time (UTC)

cycle, the Extra-Tropical Storm Surge (ETSS) model will be

upgraded to:

 

  A. Create a single basin with overland information that covers

the Gulf of AK and the West Coast

  B. Create a new Tide version to resolve a tidal phase shift in

the Cedar Key (CD2), Tampa Bay (ETP3) and Apalachicola Bay (AP3)

Sea Lake and Overland Surges from Hurricanes (SLOSH) basins.

  C. Remove a wiggle seen in the station guidance from ETSS V2.1

  D. Experimentally generate a maximum storm tide above the

North American Vertical Datum of 1988 (NAVD-88) over the next

102 hours product

  E. Extend the guidance from 96 to 102 hours

  F. Discontinue the dissemination of the 5.0 km CONUS and 6.0

km AK grids

  G. Make general Enhancements / Bug fixes (e.g., make the CSV

files self-describing, add comments to the Standard Hydrologic

Exchange Format (SHEF) output and correct the linear

interpolation methods in the post-processing codes).

 

Also, on implementation day, the first version of Probabilistic

Extra-Tropical Storm Surge (P-ETSS) will be released.  It will:

  A. Run ETSS 2.2 with the 0.5 degree wind and pressure fields

from the Global Ensemble Forecast System's (GEFS) 21 members

  B. Equally weight the results to generate the probability

  C. Create products as detailed in the new P-ETSS products

section below:

 

The following ETSS products are available on the National

Centers for Environmental Prediction (NCEP) dissemination sites:

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

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

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

 

Or the NWS National Digital Gridded Database (NDGD)

dissemination sites:

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

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

http://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.slosh/AR.conus/

http://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.slosh/AR.alaska/

 

1. New ETSS products

 

- Generation of new maximum storm tide above NAVD-88 over the

next 102 hours products on NCEP servers:

  etss.tHHz.max.stormtide.con2p5km.grib2 for 2.5 km CONUS grid

  etss.tHHz.max.stormtide.con625m.grib2 for 625 m CONUS grid

  etss.tHHz.max.stormtide.ala3km.grib2 for 3.0 km Alaska grid

 

- The guidance will be extended from 96 to 102 hours on the NCEP

servers for:

  etss.tHHz.stormsurge.con2p5km.grib2

  etss.tHHz.stormtide.con2p5km.grib2

  etss.tHHz.stormsurge.ala3km.grib2

  etss.tHHz.stormtide.con625m.grib2

  etss.tHHz.tide.con625m.grib2

  etss.tHHz.stormsurge.ala3km.grib2

  etss.tHHz.stormtide.ala3km.grib2

  shef.etss.tHHz.totalwater.est

  shef.etss.tHHz.totalwater.gom

  shef.etss.tHHz.totalwater.wst

  shef.etss.tHHz.totalwater.ber

  shef.etss.tHHz.totalwater.goa

     where HH is the cycle hour

 

- New 2.5 km CONUS and 3.0 km Alaska surge plus tide grid

products on NDGD servers:

  ds.etss-stormtide-2p5.bin

  ds.etss-stormtide-3p0.bin

 

- New 625 m CONUS surge plus tide and tide only grid products on

NDGD servers:

  ds.etss-stormtide-625m.bin

  ds.etss-tide-625m.bin

 

2. ETSS Output Changes

 

- The NDGD directory structure for all ETSS CONUS and Alaska

products will be split into five new folders according to valid

period.  Users will now find the output stripped of super-

headers and routed into the appropriate day 1, day 2, etc. as

defined below:

  VP.001/ (day 1 guidance)

  VP.002/ (day 2 guidance)

  VP.003/ (day 3 guidance)

  VP.004/ (day 4 guidance)

  VP.005-007/ (day 5 through 7 guidance)

 

- The station text format product and SHEF product for Gulf of

Alaska are contained in a tar file "etss.tHHz.shef_tar" that

will be renamed on the NCEP servers as follows:

 etss.tHHz.stormsurge.gok.txt => etss.tHHz.stormsurge.goa.txt

 shef.etss.tHHz.totalwater.gok => shef.etss.tHHz.totalwater.goa

    where HH is the cycle hour

 

- The 2.5 km CONUS and 3.0 km Alaska surge only grid products

will be renamed on the NDGD servers as follows:

 ds.etss-2p5.bin => ds.etss-stormsurge-2p5.bin 

 ds.etss-3p0.bin => ds.etss-stormsurge-3p0.bin

 

- All GRIB2 encoding was changed to use meters to 3 decimals

instead of 5, which significantly reduces the file size.  No

precision was lost because the actual data is in tenths of a

foot, which can be recovered uniquely from meters with 3

decimals.

 

- The process ID in the GRIB2 messages was changed from 12 to 16

to allow P-Surge (12), ETSS (16) and P-ETSS (18) to be

differentiated.

 

- Some station identifiers in the station text format products

(etss.tHHz.PROD.RGN.txt) are changing with this upgrade (e.g.,

CFWM1 CUTLER, ME is now 8411060 CUTLER, ME as we had not

previously associated its Center for Operational Oceanographic

Products and Services (CO-OPS) station ID to it).

 

- The following files will be created later than in ETSS v2.1,

due to the larger basin size for the West Coast:

  mdlsurge.HHw - 7 minutes delayed

  etss.tHHz.stormsurge.wst.txt - 11 to 12 minutes delayed

  etss.tHHz.stormtide.wst.txt - 11 to 12 minutes delayed

 

After implementation day, the following new P-ETSS products will

be found on the NCEP web dissemination sites:

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

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

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

 

Or the NWS National Digital Gridded Database (NDGD)

dissemination sites:

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

http://tgftp.nws.noaa.gov/SL.us008001/ST.expr/DF.gr2/DC.ndgd/GT.petss/AR.conus/

 

The P-ETSS directory structure will match the new ETSS directory

structure.  Files will be placed into the respective folders for

the valid period, such that:

  VP.001/ (day 1 guidance)

  VP.002/ (day 2 guidance)

  VP.003/ (day 3 guidance)

  VP.004/ (day 4 guidance)

  VP.005-007/ (day 5 through 7 guidance)

 

1. New P-ETSS products

 

- Station text format storm surge and storm tide products on

NCEP servers:

  petss.tHHz.NAME.stormsurge.RGN.txt

  petss.tHHz.NAME.stormtide.RGN.txt

 

Where NAME is the product type (e10, e90=storm tide height

exceeded by 10%, 90% of the ensemble members; max, mean and

min=maximum, mean and minimum storm tide heights of the ensemble

members), HH is the cycle hour and RGN is the region (est=East

coast, gom=Gulf of Mx, wst=West coast, ber=New Alaska Basin,

goa=Gulf of AK).

 

- Above NAVD-88 gridded products on NCEP servers:

 A) Incremental hourly groups to hour 102 products for CONUS:

  petss.tHHz.stormtide_NAME_1hr_inc_dat.con2p5km.grib2

  petss.tHHz.stormtide_NAME_1hr_inc_dat.con625m.grib2

 B) Incremental hourly groups to hour 102 products for Alaska:

  petss.tYYYYMMDDHHz.stormtide_NAME_1hr_inc_dat.ala3km.grib2

 C) Cumulative 6-hourly groups to hour 102 products:

 CONUS

  petss.tHHz.stormtide_NAME_6hr_cum_dat.con2p5km.grib2

  petss.tHHz.stormtide_NAME_6hr_cum_dat.con625m.grib2

 Alaska

  petss.tHHz.stormtide_NAME_1hr_cum_dat.ala3km.grib2

 

- Above ground level (AGL) gridded products on NCEP servers:

 A) Incremental 6-hourly groups to hour 102 products:

 CONUS

  petss.tHHz.stormtide_NAME_6hr_inc_agl.con2p5km.grib2

  petss.tHHz.stormtide_NAME_6hr_inc_agl.con625m.grib2

 Alaska

  petss.tHHz.stormtide_NAME_6hr_inc_agl.ala3km.grib2

 

 B) Cumulative 6-hourly groups to hour 102 products:

 CONUS

  petss.tHHz.stormtide_NAME_6hr_cum_agl.con2p5km.grib2

  petss.tHHz.stormtide_NAME_6hr_cum_agl.con625m.grib2

 Alaska

  petss.tHHz.stormtide_NAME_6hr_cum_agl.ala3km.grib2

 

Where NAME is the product type (e10, e20, e30, e40, e50,

e90=storm tide height exceeded by 10, 20, 30, 40, 50, 90% of the

ensemble members; max, mean, min=maximum, mean, minimum storm

tide height of the ensemble members; and gt1, gt2, gt3, gt4,

gt5, gt6, gt7, gt8, gt9, gt10, gt13, gt16 ft=Probability of

storm tide height greater than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

13, 16 feet above NAVD-88) and HH is the cycle hour.

 

- Output will also be available on the NDGD server. A full

description of the directory/file structure is available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/NDGD-PETSS.pdf

 

NOAAPORT/SBN Changes

 

1. ETSS Gridded Data Removal

 

- Once the NWS Advanced Weather Interactive Processing System

(AWIPS) program is ready, the surge only CONUS 5 km and Alaska 6

km will be discontinued because higher resolution 2.5 and 3.0 km

replacement products are available. The surge only CONUS 5 km

and Alaska 6 km World Meteorological Organization (WMO) headers

are as follows:

 

     WMO Heading         Region

     LHU... KNHC         NDFD CONUS 5 km surge only grid

     LHR... KNHC         NDFD Alaska 6 km surge only grid

 

The "..." in the WMO heading is replaced by DHH where D is the

day of the forecast (A=Day 0, B=Day 1, ..., F=Day 5) and HH is

the hour of day when the forecast is valid.  A full description

of WMO header combinations per forecast cycle is available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/ETSS_removal_headers.pdf

 

2. ETSS Gridded Data Additions

 

- The surge only CONUS 2.5 km and Alaska 3.0 km gridded products

are being extended from 96 hours to 102 hours.  Their WMO

headers are as follows:

     WMO Heading       Region

     MHU... KNHC       NDFD CONUS 2.5 km surge only grid

     MHR... KNHC       NDFD Alaska 3.0 km surge only grid

 

The "..." in the WMO heading is replaced by DHH where D is the

day of the forecast (A=Day 0, B=Day 1, ..., F=Day 5) and HH is

the hour of day when the forecast is valid.  A full description

of WMO header combinations per forecast cycle is available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/ETSS_headers1.pdf

 

- The surge plus tide CONUS 2.5 km and Alaska 3.0 km gridded

products are being added for 0 to 102 hours.  Their WMO headers

are as follows:

     WMO Heading       Region

     MPQ... KNHC       NDFD CONUS 2.5 km surge plus tide grid

     LPQ... KNHC       NDFD Alaska 3.0 km surge plus tide grid

 

The tide only and surge plus tide CONUS 625 m gridded products

are being added for 0 to 102 hours.  Their WMO headers are as

follows:

     WMO Heading       Region

     MPU... KNHC       NDFD CONUS 625 m surge plus tide grid

     LPU... KNHC       NDFD CONUS 625 m tide only grid

 

The "..." in the WMO heading is replaced by DHH where D is the

day of the forecast (A=Day 0, B=Day 1, ..., F=Day 5) and HH is

the hour of day when the forecast is valid.  A full description

of the header combinations per forecast cycle is available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/ETSS_headers2.pdf

 

3. P-ETSS Gridded Data Addition

 

- The following P-ETSS surge plus tide gridded products are

being added for 0 to 102 hours:

 

 A) CONUS 625 m, CONUS 2.5 km and Alaska 3.0 km resolution 

cumulative 6-hourly groups for 10%, 20%, 30%, 40%, 50%, and 90%

exceedance above NAVD-88 and AGL

 B) CONUS 625 m, CONUS 2.5 km and Alaska 3.0 km resolution 

incremental 6-hourly groups for 10%, 20%, 30%, 40%, 50%, and 90%

exceedance AGL

 C) CONUS 2.5 km and Alaska 3.0 km resolution incremental hourly

groups for 10%, 50%, and 90% exceedance above NAVD-88

 D) CONUS 625 m, CONUS 2.5 km and Alaska 3.0 km resolution

cumulative 6-hourly groups for probability of Surge > 1, 2, 3, 6

and 10 ft above NAVD-88 and AGL

 E) CONUS 625 m, CONUS 2.5 km and Alaska 3.0 km resolution

incremental 6-hourly groups for probability of Surge > 1, 2, 3,

6 and 10 ft AGL

 F) CONUS 2.5 km and Alaska 3.0 km resolution incremental hourly

groups for probability of Surge > 1, 2, 3, 6 and 10 ft above

NAVD-88

 G) CONUS 625 m, CONUS 2.5 km and Alaska 3.0 km resolution

incremental 6-hourly groups of ensemble Min, Mean and Max AGL

 H) CONUS 2.5 km and Alaska 3.0 km resolution incremental hourly

groups of ensemble Min, Mean and Max above NAVD-88

 

Their WMO header scheme is available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/P-ETSS_WMO_Header_Scheme.pdf

 

A full chart of the header combinations per forecast cycle is

available here:

http://www.nco.ncep.noaa.gov/pmb/changes/docs/P-ETSS_headers.pdf

 

As part of NCEP's standard 30-day parallel testing, the updated

products will be available here:

 

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

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

 

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 changes and additions to the Extra-Tropical Storm Surge

guidance, please contact:

 

     Arthur Taylor

     Meteorological Development Laboratory

     Phone: 301-427-9444

     E-Mail: Arthur.Taylor@noaa.gov

 

or

     Huiqing Liu

     Meteorological Development Laboratory

     Phone: 301-427-9464

     E-mail: Huiqing.Liu@noaa.gov

 

For questions regarding the data flow aspects, please contact:

 

     Carissa Klemmer

     NCEP/NCO Dataflow Team

     College Park, MD

     301-683-0567

     E-Mail: ncep.list.pmb-dataflow@noaa.gov

 

NWS Service Change Notices are available here:

 

   http://www.nws.noaa.gov/os/notif.htm

 

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