5.1. RAPID UPDATE CYCLE 2
5.2. LOCAL ANALAYSIS AND PREDICTION SYSTEM
 

Numerical weather analyses from two regional atmospheric models will be collected and archived for the Large-Regional Study Area Domain during the experiment period. The principal purpose of these analyses will be to provide the large-scale meteorological context for the experiment. Analyses data sets will be collected from the Rapid Update Cycle model (RUC2; Benjamin et al, [1998]), run by the National Centers for Environmental Prediction (NCEP), and the Local Analysis and Prediction System (LAPS; Albers et al., [1996]), run by the NOAA Forecast Systems Laboratory (FSL).
 

5.1. RAPID UPDATE CYCLE 2

The RUC-2 is an operational atmospheric prediction system comprised primarily of a numerical forecast model and an analysis system to initialize that model. The RUC-2 provides high-frequency (every 1 h) 3-d objective analyses over the contiguous United States at 20-km resolution. It currently assimilates data from: 1) commercial aircraft (relayed through ACARS - Aircraft Communications, Addressing, and Reporting System), 2) wind profilers (404 and boundary-layer 915 MHz), 3) rawinsondes and special dropwinsondes, 4) surface reporting stations and buoys, 5) RASS (Radio Acoustic Sounding System) - experimental, 6) VAD (velocity-azimuth display) winds from NWS WSR-88D radars, 7) GOES total precipitable water estimates, 8) SSM/I total precipitable water estimates, and 9) GOES high-density visible and IR cloud drift winds.

Diagnostic outputs from the RUC include relative humidity, surface temperature, dewpoint, sea-level pressure, precipitation, snow accumulation, snow depth, categorical precipitation types, freezing levels, 3-hr pressure change, convective available potential energy (CAPE), convective inhibition (CIN), lifted index, helicity, precipitable water, soil moisture, tropopause pressure, vertical velocity, planetary boundary-layer height, gust wind speed, cloud-base height, cloud-top height, visibility, convective cloud top height, and equilibrium level height.

More information about the RUC-2 is available at http://maps.fsl.noaa.gov/.

The hourly RUC-2 analyses and 1-hr forecast data for the continental U.S. will be collected at the National Operational Hydrologic Remote Sensing Center (NOHRSC) and written to DVD media. All variables and levels will be archived. The 1-hr forecast data are necessary for precipitation fields. The data collection will begin in January, 2002 and continue through the end of the experiment (~18 months). The data rate will result in a data set consisting of approximately 36 DVDs.
 

5.2. LOCAL ANALYSIS AND PREDICTION SYSTEM

The LAPS combines numerous observed meteorological data sets into a collection of atmospheric analyses. LAPS has both analysis and prediction components. The analyses provide spatially and temporally continuous atmospheric and land-based fields over Colorado and parts of surrounding states, on a 10-km grid with hourly temporal resolution. LAPS makes use of a wide range of observational data sets as part of its analyses. These include: 1) surface observations at 22 local sites every 5 min, as well as hourly surface airways observations (SAO) from North America, 2) Doppler radar volume scans at 6-min intervals, 3) wind and temperature Radio Acoustic Sounding System (RASS) profiles from the NOAA Demonstration Profiler Network (60-min interval), 4) satellite visible data (30-min interval) and multi-spectral image and sounding radiance data (90-min interval), and 5) automated and voice reports from selected aircraft at random times.

Outputs from the LAPS analyses include hourly three-dimensional and surface distributions of temperature, surface u and v winds, vertical velocity, dew-point temperature, relative humidity, specific humidity, pressure, MSL pressure, cloud type, mean cloud drop diameter, cloud base, cloud top, fractional cloud cover, cloud liquid water, cloud ice, surface precipitation type, rain concentration, snow concentration, soil moisture, snow accumulation, snow water equivalent, and snowmelt over the Colorado domain.

More information about the LAPS is available at http://laps.fsl.noaa.gov/.

Staff at Colorado State University (CSU) will routinely retrieve the LAPS data sets from the NOAA FSL, where the model is run. CSU will transfer the data sets to the data management facility where they will be archived.