Numerical Weather Prediction

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MSAS/RSAS
Mesoscale Analysis and Prediction System (MAPS)
Surface Assimilation System (MSAS)

• Operational on AWIPS

Rapid Update Cycle (RUC) Surface Assimilation
System (RSAS)

• Operational at NCEP
• Backup Services Provided by the FSL Central
  Facility

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MSAS/RSAS

• Goals To provide timely and detailed analyses of
  surface variables and accurate quality control of
  surface observations
• Analysis Technique
• Univariate Optimal Interpolation
• configurable background

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MSAS/RSAS

• Observations Ingested
• METARs, buoys, ships, mesonet, automated COOP
• Quality Control Checks
• validity, temporal consistency, internal
  consistency, spatial consistency
• Subjective Intervention QC Capabilities
• accept and reject lists

In association with the AWIPS Quality Control
and Monitoring System
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MSAS/RSAS Common Features

• Station Monitoring Statistics
• frequency of failure, rms error, mean error to
  detect persistent failures and biases
• Stratified by station, observation type, and data
  provider

In association with the AWIPS QCMS Browser
and the ASOS Operations and Monitoring Center
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Meteorological Assimilation Data Ingest System
(MADIS) National Mesonet (5/26/04)

• http//www-sdd.fsl.noaa.gov/MADIS

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MSAS/RSAS

• Analysis Variables
• potential temperature
• (u, v) components of wind
• dewpoint temperature
• dewpoint depression
• altimeter change
• altimeter
• NWS sea-level pressure
• MSAS/RSAS pressure reduction

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Correlation Functions
Pressure Potential Temperature Winds,
Humidity
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MSAS/RSAS

• MSAS Derived Fields
• temperature
• lifted index
• moisture convergence
• equivalent potential temperature
• relative humidity
• temperature advection
• relative vorticity
• potential temperature advection
• equivalent potential temperature advection
• RSAS Derived Fields
• temperature
• specific humidity
• equivalent potential temperature

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MSAS/RSAS
MSAS AWIPS Configuration

• 1-Hour Analysis Cycle
• Default Domains
• CONUS (60 Km)
• Alaska (30 Km)
• Puerto Rico (30 Km)
• Site Configuration Options
• domain size and location
• grid resolution
• analysis background
• pressure change interval
• pressure reduction level

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MSAS/RSAS
RSAS NCEP Configuration

• Analysis Updated Twice/Hour (Four Times/Hour at
  FSL)
• 15 Km North American Domain

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MSAS/RSAS Advantages for the AoR

• Years of Experience Working with Forecasters
• Existing Operational Implementations on AWIPS and
  at NCEP
• Speed
• 3 minutes at NCEP for 317,840 grid points
• 1 to 3 minutes on AWIPS HP platforms
• Utilize ALL Surface Observations
• Close Fit to the Observations