About the Regional Spectral Model

NCEP's global spectral model (GSM) provides the starting point for all of the forecasts. The GSM has a global computational grid of 384x184 or a resolution of about 1 degree. The regional spectral model (RSM), which is embedded within the global computational grid has higher resolution but only operates over selected regions. Over Hawai`i, the resolution is about 1/10 degree. All models have 28 levels in the vertical. This GSM/RSM modeling system is quite versatile and can easily be adapted to any regional domain. For more information, please go the National Center for Environmental Prediction's RSM Homepage.

References
Juang, H. and M. Kanamitsu, 1994:
Chen, S.-C., J. Roads, H. Juang, M. Kanamitsu, 1996:
Wang, J.-J, H.-M H. Juang, K. Kodama, S. Businger, Y. -L. Chen and J. Partain, 1998:
Juang, H.-M H, 2000:

The RSM plots are produced twice daily by the Honolulu Weather Service Forecast Office. Each model run starts with a 12 hour forecast and extends to 48 hours in three hour increments. An identifier is located at the bottom of each plot, stating the valid date, valid forecast time, forecast projection, and type of plot. An example might be:

RSM 970619/1200V012 10 METER WINDS (KTS)

The first part (RSM) identifies the plot as a Regional Spectral Model. The first six digits (970619) identify the year, month and day. The next four digits (1200) identify the valid forecast time in Greenwich time. For Hawai`i, subtract 10 hours to obtain local time. The final three numbers (012) after the "V" identify the forecast projection. Finally, the type of plot is given. The example identifies a RSM 12-hour forecast of 10 meter winds for June 19, 1997 at 1200 Greenwich time (2:00 AM local Hawai`i time).