NOUS41 KWBC 231912
PNSWSH

Public Information Statement, Comment Request

National Weather Service Headquarters, Washington, DC

312 PM EDT Mon May 23 2011

To: Subscribers:

-Family of Services

-NOAA Weather Wire Service

-Emergency Managers Weather Information Network

-NOAAPORT

Other NWS Partners, Users and Employees

From: Geoff DiMego

Chief, Mesoscale Modeling Branch

NCEP/Environmental Modeling Center

Subject: Soliciting Public Comments through June 30, 2011,

On the Removal of NCEP’s Regional Spectral Model

for Hawaii

The National Centers for Environmental Prediction (NCEP) is proposing to stop running the Regional Spectral Model (RSM) and discontinue all output products from this model. The RSM is currently only run for a domain over the Hawaiian Islands. NWS Pacific Region has agreed to discontinue the RSM run after NCEP added a Guam domain to its HiResWindow suite in March 2011. Output of the HiResWindow suite includes the Hawaiian Islands and provides an alternative source of information for the RSM. NWS is seeking comments on this proposed change through June 30, 2011.

The RSM is a limited-area atmospheric model using a spectral method for horizontal advection. The model uses hydrostatic dynamics; it is run for Hawaii with the equivalent of 10 km horizontal resolution, at 20 North, using a grid of 97x76 points on 42 levels. Runs are made twice daily from 00z and 12z and range to 48 hours.

The RSM has been run operationally since June 1997 to provide numerical guidance for use by NWS Weather Forecast Offices in Hawaii. The Hawaii RSM products (211 fields per output time) are only disseminated via the NWS and NCEP FTP servers. These products are not available on NOAAPORT. At this time, the NWS no longer has a requirement to produce these runs or products because newer products have been introduced that meet the needs of forecasters.

The table below lists characteristics of the RSM and other current (and imminent) NCEP Operational Products, all of which are based on nonhydrostatic dynamics, that provide similar or better guidance than the Hawaii RSM. More details about the exact grids and products available for each of the items listed in the table below are available at:

http://www.nco.ncep.noaa.gov/pmb/changes/rsm_removal.shtml

Product Runs/day Range Resolution Grid

RSM 2 48hr 10km/42lev see URL above

NAM 4 84hr 12 km/60lev grid #182

NAM nest* 4 60hr 3 km/60lev grid #196

HiResWindow

WRF-ARW 2 48hr 5 km/35lev see URL above

WRF-NMM 2 48hr 4 km/35lev see URL above

* NAM nest is planned for implementation in July 2011. See NWS

TIN 11-16 for more details on the NAM nest.

NWS will evaluate all comments to determine whether to proceed with this change. If approved, a TIN will be issued containing implementation dates.

Send comments on this proposal to: