GREarth Mesoanalysis Details

GREarth displays several severe weather and standard surface/upper air mesoanalysis fields. There are three rendering methods: color-filled graphical underlays, contour line overlays, and iconic overlays. All mesoanalysis fields are derived from the 13 km RUC hourly model using the virtual temperature correction.


Color-Filled Graphic Underlays

GREarth 1.00 can display one of 16 color-filled underlay graphics:

  1. MLCAPE - mixed layer CAPE (lowest 100mb mean)
  2. MUCAPE - most unstable CAPE
  3. EBWD - effective bulk wind difference
  4. ESRH - effective storm relative helicity
  5. SCP - supercell composite parameter
  6. STP - significant tornado parameter
  7. SVRH - severe thunderstorm hazard level
  8. TORH - tornado hazard level
  9. 2 meter temperatures
  10. 2 meter dewpoints
  11. 850 mb temperatures
  12. 850 mb dewpoints
  13. 700 mb temperatures
  14. 700 mb vertical velocity
  15. 500 mb relative vorticity
  16. 3 Hour snowfall accumulation forecast

Descriptions of many of these parameters are available on the Storm Prediction Center's excellent Mesoanalysis Help page.

It's important to note that the severe weather parameters will be close to but not exactly the same as those shown on the SPC Mesoanalysis pages. GREarth uses just the RUC model output for all calculations while the SPC combines the RUC with observations, which can lead to differences when the lower levels of the atmosphere are not adequately captured by the RUC model. 


Contour and Iconic Overlays

GREarth 1.00 can display several mesoanalysis overlays simultaneously:

  1. Surface MSLP contours
  2. 10 Meter Wind icons
  3. 850 mb Height contours
  4. 850 mb Wind icons
  5. 700 mb Height contours
  6. 700 mb Wind icons
  7. 500 mb Height contours
  8. 500 mb Wind icons
  9. 300 mb Height contours
  10. 300 mb Wind icons



GREarth's Severe and Tornado Hazard color fills are proprietary graphical fields that show where the RUC model indicates the potential for severe weather in the next three hours. The GREarth server calculates the SCP and STP for three forecast hours and combines those fields with the RUC forecast reflectivity. The result are fields showing where there will be both the right forecast environment and high forecast reflectivity. Here is a real-time example showing the TORH underlay with existing tornado warnings overlaid (radar data not displayed):

Note how the tornado warnings and tornado/funnel cloud LSRs are within the hazard areas indicated by the higher TORH values.