CIMSS Model Analyses and Forecasts

CIMSS Convective Development Nearcasting Model (CCDNM)

Last updated: Wed Feb 27 20:18:28 UTC 2013

Precipitable Water Two-Layer Difference (Low - Mid)
Theta-e Two-Level Difference (Mid - Low)
Low Layer Precipitable Water (900-700 mb)
Mid Layer Precipitable Water (700-300 mb)
Low Level Theta-e (780 mb)
Mid Level Theta-e (500 mb)


CCDNM AUTOMATED ADMINISTRATIVE MESSAGE
COOPERATIVE INSTITUTE FOR METEOROLOGICAL SATELLITE STUDIES MADISON WI
0818 PM UTC WED FEB 27 2013

GEMPAK IMAGE GENERATION FOR THE 20130227/19Z NEARCAST IS NOW COMPLETE.

.END

Under Development

The following derived products result from further calculations on the basic precipitable water fields above:


One-Day Archive

Previous Runs (within past 24 hours):
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A three-day archive of four-panel loops is also available.


5 Day Loops Updated Hourly

  • Upper left panel is Mid Level Theta-E, lower left is Low Level Theta-E, right is Theta-E Difference (Mid-Low)
  • Theta-E Analysis loop. Includes most recent 9 Hr nearcast at end.
  • Theta-E 03 HR Nearcast loop.
  • Theta-E 06 HR Nearcast loop.
  • Theta-E 09 HR Nearcast loop.

  • Model Comparisons (of Latest Nearcast cycle)

  • Comparisons and Tests

  • These computer forecasts are EXPERIMENTAL and are used by atmospheric scientists to assess the value of satellite observations in numerical weather prediction. Although the accuracy of these products is consistently good, forecast errors can occur due to non-receipt of data, observation errors, and computer problems. The forecasts are fully automated and are not always closely monitored by CIMSS scientists. The risk of using the CCDNM to plan weather-sensitive activities falls on the user. Feedback will help us improve deficiencies in the CCDNM. Please forward any comments to the CRASmaster using the contact form.


    About these Forecasts

    Information from the GOES-13 sounder water vapor channels help to define the regions most susceptible to convection on that day. This technique initializes a trajectory model with Rapid Update Cycle (RUC) winds and precipitable water at different levels as retrieved from the GOES-13 sounder. The retrieval uses the three water vapor channels:  channels 10 (7.4 microns), 11 (7.0 microns), and 12 (6.5 microns). The shorter wavelength energy typically is emitted from higher in the atmosphere. GOES sounder weighting functions from channel 10 typically peak around 600 or 700 mb; weighting functions from channel 12 peak closer to 400 mb. The exact level is, of course, a function of the air mass and the satellite viewing angle. These three channels can help to define the distribution of water vapor in the atmosphere at different levels:  the output of the retrieval that combines the brightness temperatures and initial guess soundings is precipitable water (mm) at different levels. Such a multi-layer description of the atmospheric water vapor is not possible with the single water vapor channel on the GOES imager; the multiple channels of the GOES sounder are required.

    This model can predict areas of destabilization (convective potential) if "low" level moisture moves underneath "upper" level drying. The fields are presented as moisture change with height. If a region shows the moisture change with height increasing with time, then that region is becoming more convectively unstable.

    The CIMSS Satellite Blog offers additional information about these forecasts and an example of their intended use in the "Short-term predictions of convective development" post. Also, see:

    * Nowcasting Analysis Project using the GOES sounder

    Background and Training


    Support for the National Weather Service

    * Convective Development Nearcasting Model in D-2D

    Numerical Weather Prediction Research at CIMSS

    * Real-time CIMSS Regional Assimilation System (CRAS)

    * 61 km CRAS Hurricane Track Prediction Project

    * 60-hour Simulation of the Edmund Fitzgerald Storm

    * Numerical Weather Prediction Concepts

    * Land Surface Energy/Water Budget Studies


    U. Wisconsin SSEC CIMSS NESDIS CoRP NESDIS STAR
    Please refer questions or comments to the CRASmaster using the contact form.

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