High Frequency Weather Forecasts

Last updated: Sat, Nov 23, 09:00:00 UT

Ronald J Maddalena (Retired) and Larry Morgan
Green Bank Observatory, Green Bank, WV

Overview of Cloud Coverage and Conditions Unsuitable for Continuum Observations:

Various colors codes depict different aspects of cloud coverage and other criteria for scheduling continuum projects.  In short, the times when conditions are best for continuum observing are those where blue extends from the top to the bottom of the figure.  Any shade of white, cyan, or magenta indicate less than perfect continuum conditions.

• Three thin bands at the top, with differing intensities of magenta, indicate when conditions are thought to be unsuitable for observing with the Mustang 90 GHz bolometer ( "The Effects of Weather on MUSTANG Data Quality" by Mason & Perera, 2010).   The three bands depict conditions for different elevations (30, 45, and 90º), as indicated on the plot.  The shades of magenta indicate the degree to which the conditions are unsuitable in the following way: 
  
• Dark Magenta:  the time lies between sunrise to sunset+3 hrs or the wind speed is greater than those specified in DSS memo 5.3 (J. J. Condon & D. S. Balser, Dynamic Scheduling Algorithms, Metrics, and Simulations, 2010);
  
• Medium Magenta: the atmospheric contribution to the system temperature exceeds 50 K at the labeled elevation.
• Light Magenta: the atmospheric contribution to the system temperature exceeds 35 K at the labeled elevation.
• Central thick band, which uses a color ramp that goes from blue through white, indicates percentage of optical cloud coverage.   As the legend shows, white represents full cloud coverage and blue represents clear skies.  Cloud cover forecasts are from the Green Bank Point Map forecasts.
• Cyan band at the bottom, if present, indicates those times when we believe conditions are unsuitable for continuum observing for receiver systems other than Mustang.  The criteria is based on a maximum downward long-wave irradiance (LWd) of 300 W/m², which is the upper limit per the accepted Dynamic Scheduling System guidelines for continuum observations (DSS memo 14.2; Dana S. Balser, Atmospheric Stability from GBT Continuum Observations, 2010).  LWd data are derived from the NAM and GFS3 model forecasts.
• Black, if present, show when forecasts do not exist for the indicated time.

• Full details and references.
• The original version of the overview plot that uses RESTs instead of the DSS algorithms.
• A version of the overview plot that uses the DSS algorithms.
• A version of the overview plot that uses the DSS algorithms except for the efficiency limit terms.

• 3.5-Day (NAM) Forecasts:
  • Ground Weather Condition
  • Clouds and Precipitation
  • Opacity
  • System Temperature
  • Relative Effective System Temperature (REST)
  • Atmospheric Temperature
  • Refraction
• 7.5-Day (GFS) Forecasts:
  • Ground Weather Condition
  • Clouds and Precipitation
  • Opacity
  • System Temperature
  • Relative Effective System Temperature (REST)
  • Atmospheric Temperature
  • Refraction
• Traditional (Ground-Level) Forecasts:
• Current Conditions
• Severe Weather Alerts
• Hourly Forecasts
• Daily Forecasts