NOUS41 KWBC 111918 AAA
Technical Implementation Notice 12-19, Amended
National
Weather Service Headquarters Washington DC
318 PM EDT Fri May 11 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:
Amended: Hurricane Weather and Research Forecast
(HWRF) Model Changes: Effective May 24, 2012
Amended to reschedule implementation for Thursday, May 24,
2012. Also added clarification
about nest product filename.
Effective
on or about Thursday, May 24, 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
- Redesign 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
- 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 (Note: this change will result in a
filename
change on the NWS
FTP server. The current filename is
ns.{stormname}.YYYYMMDDHH_fh.00##_tl.press_gr.0p1deg. The
filename will change
from *press_gr.0p1deg to
*press_gr.0p03deg).
- 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
NWS
National Technical Implementation Notices are online at:
http://www.nws.noaa.gov/os/notif.htm
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