Skip to main content
U.S. flag

An official website of the United States government

Dot Gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Objective Verification Results From Forecasts Generated With The Arw and Nmm Dynamic Cores of The WRF Model


The Weather Research and Forecasting (WRF) model contains two dynamic cores: the Non-hydrostatic Mesoscale Model (NMM – Janjic 2003) core (developed at the National Centers for Environmental Prediction (NCEP) and the Advanced Research WRF (ARW – Skamarock et al. 2005) core, developed at the National Center for Atmospheric Research (NCAR). Each dynamic core corresponds to a set of dynamic solvers that operates on a particular grid projection, grid staggering, and vertical coordinate. The WRF model also contains a multitude of physical parameterizations, many of which can be used with both dynamic cores. This paper presents a comparison of temperature and precipitation forecast verification statistics for the ARW and NMM obtained as part of the Developmental Testbed Center (DTC, Bernardet et al. 2008) 2007 13- km Core Test. The main goal of this study is to determine if the inter-core differences increase with forecast lead times. This study is a follow up to the DTC 2006 Core Test (Brown et al. 2007), which compared ARW and NMM for 24-h forecasts and found no remarkable superiority in either core. The ARW and NMM dynamic cores were used to forecast 120 cycles divided into the four seasons. The models were initialized every 36 h, resulting in alternating 00 and 12 UTC cycles. Details of the experiment configuration, results, and conclusions are presented in sections II, III, and IV, respectively.

Article / Publication Data
Available Metadata
Fiscal Year
Published On
January 01, 2008

This publication was presented at the following:

9th WRF Users' Workshop
American Meteorolgical Society


Not available


Authors who have authored or contributed to this publication.