# Joint Hurricane Testbed (JHT) Program

For the

*Environmental Modeling Center/National Centers for Environmental
Prediction*

*5200 Auth Rd*

*Camp Springs, Md. 20746*

### Hurricane Model Transitions to Operations at NCEP/EMC

Robert E. Tuleya, Weixing Shen, and Hua-Lu Pan (EMC/NCEP)

### 

### January 2004 Progress Report

This proposal calls for the continuation of funded work on the GFDL
hurricane model upgrades as well as the initiation of a prototype
Hurricane forecast system. The second area of work is the commencement
of the transition from the GFDL to WRF model that is scheduled to become
the next operational hurricane model in \~2006. The progress toward
these tasks and goals are indicated in bold italic directly in the
original Time Line given for this project. Some of these results were
presented at EMC at the modeling workshop in early December. The results
will be given in more detail at the upcoming 58^th^ IHC meeting.

Time Line

Year One: July to December, 2003

1)  Code and begin to test bulk microphysics packages in collaboration
    with GFDL. ***Code has been implemented into GFDL system for the
    Ferrier scheme. We will work with GFDL(Bender) in making comparisons
    with the Lin scheme which may be more complicated. We anticipate
    problem areas of how to blend the microphysics package with other
    convective parameterizations and also with large scale
    concdensation. The basic programming approach to handle microphysics
    in the GFDL model has been designed and coded by Bender and Tuleya
    over the last two years. Bender has already upgraded an earlier
    version to successfully run the Lin micrpphysics.***

2)  Run parrallel version of GFDL model with NOAH LSM for 2003 season
    for significant landfalling storms. Identify and address problem
    areas. Also run historic cases from 1995 to present. ***Weixing has
    successfully coded and run the Noah LSM for several cases of 2003
    including Isabel. In addition some 2002 cases were also run. One
    complication is that the operational GFDL model code has changed ,
    so the Noah LSM code had to be integrated into the 2003 GFDL model
    which includes new physics and increased vertical resolution. These
    problems have been rectified so that the GFDL model can be run with
    the NOAH LSM using the 2003system . Basically results have shown
    some improvements in the quality of the forecast especially
    precipitation. The LSM has led to less spurious low rainfall amounts
    away from the storm center. Historic cases are also planned in order
    to get a more compete picture of the skill of the LSM. We now have
    initial conditions for \~25 landfalling cases from 1995-2002 with
    the 2003 GFDL initial condition. The initial land condition will be
    taken directly from a separate land analysis system run at EMC, the
    LDAS. Coding is underway to allow the use of LDAS as a land
    condition for the GFDL model system.***

3)  In collaboration with GFDL install test versions of GFS surface
    parameterizations into GFDL model and run several real data cases.
    ***This project has been delayed with more emphasis on an early
    start of Hurricane WRF task item sl***

4)  ***ated for the second half of year one and year two. EMC has
    assigned additional personnel for this task. A prototype Hurricane
    WRF system has been initiated. This system includes the same NMM-WRF
    dynamic core that will be used for the extratropical mesoscale
    forecasts that will replace the ETA model. The NMM WRF code has been
    assimilated into the WRF software structure and includes the
    traditional pre-prossessing and interpolation of model initialial
    conditions (i.e. WRF SI) and WRF model integration. Some
    integrations have already been performed, including cases of Isabel
    and Claudette.***

5)  In collaboration with URI and GFDL, investigate the feasibility of
    using updated topography and land-use data set. Insure land-sea
    masks for ocean, land, and atmospheric model are consistent. ***New
    in-house topographical data sets have been identified at EMC. We are
    presently comparing them to the present GFDL topography field. It is
    hoped that the new data will resolve islands that were not resolved
    in the GFDL model like the Bahamas. The design of this upgrade was
    discussed at a recent EMC meeting and Tuleya indicates that this can
    be handled in the pre-processing step before the GFDL model system
    is started. These new high resolution global fields can be redefined
    based on the new topography.***

Year One: January to July, 2004

6)  Investigate feasibility of installing test versions of GFS shallow
    convection and radiative packages into GFDL model. Continue to test
    and evaluate the upgrades started in first half-year.

7)  Install WRF physics packages into GFDL model and compare results
    with operational codes.

8)  Begin to design and develop Hurricane WRF forecast system by linking
    proto-type model to GFDL initial conditions.

9)  In collaboration with Bender determine whether and which model
    upgrades should be made operational for 2004 season.

Year Two: July 2004 to July 2005

1)  Run bulk microphysics packages for test suite to test forecast
    performance

2)  Evaluate Hurricane WRF proto-type model and forecast system. Compare
    Hurricane WRF to GFDL model with WRF physics packages.

3)  Begin testing nested and movable nest WRF model when available.

4)  In collaboration with Bender, determine feasibility of installing
    GFDL model upgrades into the 2005 operational suite.\<

5)  Determine the feasibility of running operationally a Hurricane WRF
    proto-type forecast system for the 2005 season.