[nws-changes] 20120330: HWRF model changes-Fwd: ADMIN NOTICE NOUS41 KWBC

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20120330: HWRF model changes-Fwd: ADMIN NOTICE NOUS41 KWBC
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 30 Mar 2012 06:43:23 -0600

-------- Original Message --------

231
NOUS41 KWBC 301136
PNSWSH

Corrected to increment number to TIN 12-19
Technical Implementation Notice 12-19
National Weather Service Headquarters Washington DC
705 AM EDT Fri Mar 30 2012

To:       Subscribers:
          -Family of Services
          -NOAA Weather Wire Service
          -Emergency Managers Weather Information Network
          -NOAAPORT
          Other NWS Partners, Users and Employees

From:     Timothy McClung
          Science Plans Branch Chief
          Office of Science and Technology

Subject:  Hurricane Weather and Research Forecast
          (HWRF) Model Changes: Effective May 15, 2012

Effective on or about Tuesday, May 15, 2012, beginning with the
1200 Coordinated Universal Time (UTC) run, the National Centers
for Environmental Prediction (NCEP) will upgrade the HWRF -
Princeton Ocean Model (POM) coupled system. The scientific
enhancements include the following:

      - Implement triple-nesting capability with a new centroid
        based nest movement algorithm
      - Configure the inner-most grid at cloud-resolving 3 km
        horizontal resolution with explicit representation of
        convective processes
      - Implementation of GFS Shallow Convection
      - Modifications to SAS deep convection, GFS PBL, GFDL
        surface physics and Ferrier microphysics
        parameterizations suitable for higher resolution and
        based on observational findings
      - Re-design of vortex initialization for 3 km resolution
        with improved interpolation algorithms and better
        representation of composite storm
      - Improved POM initialization in the Atlantic domain and
         new 1-D ocean coupling for Eastern Pacific basin
      - Upgrade the HWRF GSI to V3.5 and use of new Hybrid
        GSI/GFS for initial and boundary conditions once the
        Hybrid GSI/GFS has been implemented operationally
      - Improvements to HWRF Unified Post Processor to
        generate new SSM/I simulated microwave satellite imagery
        products
      - Very high-resolution (every 5 sec.) storm tracker output
        to support National Hurricane Center (NHC) operations

Test results from the combination of these upgrades showed
significantly improved track, intensity and structure forecast
skills and improved track, intensity and storm radius forecast
biases in both Atlantic and Eastern North Pacific basins.

Product Changes:

The following elements will be added to the HWRF model output
GRIB files:

     -simulated microwave satellite imagery products from SSM/I-S
      sensors

Additional products and their contents:

     - new intermediate grid output GRIB files (*hwrfprs_i.grb*
       and *hwrfsat_i.grb*) at a horizontal resolution of 0.1
       deg. lat/lon
     - nest (innermost domain) GRIB files (*hwrfprs_n.grb* and
      *hwrfsat_n.grb*) will now be at highest resolution of 0.03
       deg. lat/lon
     - new merged grid (innermost + intermediate) output GRIB
       files (*hwrfprs_m.grb* and *hwrfsat_m.grb*) for selected
       variables at a horizontal resolution of 0.03 deg. lat/lon
     - combined grid output GRIB files (*hwrfprs_c.grb* and
       *hwrfsat_c.grb*) will now be a combination of all three
       domains at highest resolution of 0.03 deg. lat/lon
     - parent grid output GRIB files (*hwrfprs_p.grb* and
       *hwrfsat_p.grb*) remain unchanged and will be at the same
       0.25 deg. lat/lon resolution.

A new very high temporal frequency (5 sec) tracker output product
(ascii text file) is added at the request of NHC.

There will be an increase of roughly 8GB in product size due to
high resolution output and additional elements.

These changes will result in about a 20 minute delay in product
dissemination time.  This change was proposed in an NWS Public
Information Statement issued February 1, 2012.  Based on the
responses received, NWS will move forward with this change in
dissemination time of the HWRF products.

The HWRF GRIB products are disseminated via the NCEP FTP server
and are not available on NOAAPORT or AWIPS.

More details about the HWRF-POM are available at:

http://www.emc.ncep.noaa.gov/HWRF/index.html

NCEP encourages users to ensure their decoders are flexible and
are able to adequately handle changes in content order, changes
in the scaling factor component within the product definition
section (PDS) of the GRIB files, and any volume changes which
may be forthcoming. These elements may change with future NCEP
model implementations. NCEP will make every attempt to alert
users to these changes prior to any implementations.

For questions regarding these model changes...please contact:

  Dr. Vijay Tallapragada
  NCEP/Environmental Modeling Center
  Hurricane Forecast Project
  Camp Springs, Maryland
  301-763-8000 x 7232
  vijay.tallapragada@xxxxxxxx

NWS National Technical Implementation Notices are online at:

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

$$