Evaluation Study Of The Tactical Atmospheric Modeling System Real Time Tams Rt At Npmoc San Diego

The U.S. Navy is aggressively pursuing mesoscale atmospheric modeling. The Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) has been developed by the Naval Research Lab in Monterey, California to meet this task. A forecast system employing COAMPS, called the Tactical Atmospheric Mesoscale System- Real Time (TAMS-RT), is currently being field tested at two of the Navy's major regional weather facilities in Manama, Bahrain and San Diego, California. Mesoscale modeling is a complex process that requires detailed knowledge of mesoscale forcing and responses, as well as a capable data display system to make the best use of this new capability. While the challenge of interpretation of forecasts on the mesoscale has increased, the time available for producing forecasts has, if anything, decreased. Optimal methods of evaluation and display are needed that enable a forecaster to rapidly, yet skillfully complete this process. This thesis illustrates analysis techniques to aid in rapidly evaluating the utility of any given mesoscale forecast and proposes optimal methods for 3-D visualization and interpretation of various weather parameters. Using these techniques and methods, TAMS-RT performance is then evaluated for critical mesoscale weather phenomena as defined by NPMOC San Diego, including the mesoscale weather effects associated with frontal passages and the Catalina Eddy.

The Tactical Atmospheric Modeling System/Reat Time (TAMS/RT) combines the high-resolution Coupled Ocean/Atmosphere Atmosphere Mesoscale Prediction System (COAMPS) and the Tactical Environmental Data Server (TEDS). In this study, we evaluate TAMS/RT sea level pressure, 10 meter (m) winds and 2 m air temperature fields generated at the Naval Pacific Meteorology Oceanography Center (NPMOC) in San Diego. We qualitatively compare outer nest (45 and 54 kms) sea level pressure 12 and 24-hour forecasts with model analyses. Then we quantitatively compare surface observations with inner nest (5 and 6 kms) model wind (u and v) and temperature forecast fields (00, 06, 12, 18, and 24-hour). Contrary to expectations, we found no error growth through the forecast cycle and relatively high error in the initial analysis for all variables. When examined by 0000Z and 1200Z model runs, we found a repetitive pattern related to the diurnal cycle which impact use by a forecaster. We link day to day error to the diurnal pattern and larger magnitude error to cold starts, background fields, and data assimilation problems. We observed high variability among observed and model values but still found various model trends that require further evaluation.

This report documents the culmination of a three-year development and testing effort on a two-dimensional (x-y plane) surface-layer windflow model for complex terrain. The model was acquired from the U.S. Army Atmospheric Sciences Laboratory (ASL) at White Sands, New Mexico in 1984. The version of the model described in this report has been adapted to run using real time data on both the Zenith-100 and IBM-compatible Zenith-248 computers. The model accepts input of a single surface observation (or forecast) of wind, temperature, and cloud cover, and uses this information along with terrain information and the date/time to diagnose the surface-layer stability. The model then performs a variational analysis of the windfield, adjusting the winds through a relaxation technique until the windfield conforms to effects of topography, stability, ambient flow conditions, and mass continuity. The model is designed to produce high-resolution wind analyses, typically running on domains on the order of 10 X 10 km, with horizontal grid spacing of 100 to 200 m. We present an overview of potential military and nonmilitary uses for the model, and describe the relevant physics and computer architecture of the model and its two utility plotting routines. A user's guide, included here as Section 4, is primarily aimed at providing operational users such as forecasters some guidelines for using the model and interpreting the output. Finally, we present the results of an operational test of the model in support of Army Special Forces operations at Ft. Devens, Massachusetts. The test results illustrate the model's potential as a tactical weather support tool for low-level aviation and paradrop activities.

This report documents the culmination of a three-year development and testing effort on a two-dimensional (x-y plane) surface-layer windflow model for complex terrain. The model was acquired from the U.S. Army Atmospheric Sciences Laboratory (ASL) at White Sands, New Mexico in 1984. The version of the model described in this report has been adapted to run using real time data on both the Zenith-100 and IBM-compatible Zenith-248 computers. The model accepts input of a single surface observation (or forecast) of wind, temperature, and cloud cover, and uses this information along with terrain information and the date/time to diagnose the surface-layer stability. The model then performs a variational analysis of the windfield, adjusting the winds through a relaxation technique until the windfield conforms to effects of topography, stability, ambient flow conditions, and mass continuity. The model is designed to produce high-resolution wind analyses, typically running on domains on the order of 10 X 10 km, with horizontal grid spacing of 100 to 200 m. We present an overview of potential military and nonmilitary uses for the model, and describe the relevant physics and computer architecture of the model and its two utility plotting routines. A user's guide, included here as Section 4, is primarily aimed at providing operational users such as forecasters some guidelines for using the model and interpreting the output. Finally, we present the results of an operational test of the model in support of Army Special Forces operations at Ft. Devens, Massachusetts. The test results illustrate the model's potential as a tactical weather support tool for low-level aviation and paradrop activities.

The FAAT List is not designed to be an authoritative source, merely a handy reference. Inclusion recognizes terminology existence, not legitimacy. Entries known to be obsolete are included bacause they may still appear in extant publications and correspondence.