MOS Verification

This site contains some basic verification results for a few weather elements from MDL's NGM-,AVN-,and MRF-based MOS packages. We are still working on these pages... Please see the bottom of this page for email addresses to send your comments and suggestions to.

1. Click on your choice for each of the categories along the left side of the page, namely, "Variable", "MOS Pkg", "Date", and "Region".
2. If a graph is not immediately displayed, click on the region of interest on the map.  Subsequent requests can be made by either selecting an entry from the regions menu or clicking on the region of interest on the map.
3. A default graph is now displayed along with additional menus at the top of the page, namely "Graph Type" and "Projection".
4. Click on your choice from each of these new menus.
5. Click on the graph for more information about the scores and contents of the graph.
6. To print a graph, click the print button at the bottom of the page.
7. Send us your comments by clicking on the "comments" button, located at the bottom of the page. We welcome your suggestions!

---

Definitions: Top of Page

Variables:
Max Temp: Daytime maximum temperature is defined as 7 AM to 7 PM LST. Note that maximum temperature is associated with the 24-h projection from 0000 UTC, 36-h projection from 1200 UTC, 48-h projection from 0000 UTC, and so on.
Min Temp: Nighttime minimum temperature is defined as 7 PM to 8 AM LST. Note that minimum temperature is associated with the 24-h projection from 1200 UTC, 36-h projection from 0000 UTC, 48-h projection from 1200 UTC, and so on.
POP: Probability of Precipitation (PoP) for 12-h periods, specifically, 0000-1200 UTC and 1200-0000 UTC.

MOS Packages:

• NGM:
• Available for the 0000 and 1200 UTC cycles
• Variables are available for the 24-, 36-, 48-, and 60-h projections.
• NGM-based guidance is not available for Hawaii and Puerto Rico.
• AVN:
• Available for the 0000 and 1200 UTC cycles
• Variables are available for the 24-, 36-, 48-, 60-, and 72-h projections.
• MRF:
• Available for the 0000 UTC cycle only.
• Variables are available for the 24-h through 192-h projections.


Regions:
We present verification results for 335 stations in the conterminous U.S., Alaska, Hawaii, and Puerto Rico. The "national" statistics are for all available stations combined. See the map for regional definitions.

Graph Type:
Scatter Plot
Error Histogram
Error by Groups
MAE
Bias
Reliability
Brier Score

Projections
See MOS packages and variables above for the available projections.

References:
• Glahn, H. R., A. H. Murphy, L. J. Wilson, and J. S. Jensenius, Jr., 1991: Lectures Presented at the WMO Training Workshop on the Interpretation of NWP Products in Terms of Local Weather Phenomena and their Verification.  Wageningen, The Netherlands, 29 July-9 August 1991.  World Meteorological Organization.
• Stanski, H. R., L. J. Wilson, and W. R. Burrows, 1989: Survey of Common Verification Methods in Meteorology.  Research Report No. (MSRB) 89-5, Forecast Research Division, Atmospheric Environment Service, Environment Canada.
• Wilks, D. S., 1995: Statistical Methods in the Atmospheric Sciences.  Academic Press, 259-267pp.

Acknowledgments:
Data Acquisition

• MDL Statistical Modeling Branch

Graph Style/Content
• MDL Evaluation Branch

Software Development
• Arthur Taylor

Web Page Development Arthur Taylor Mark Stram

National Weather Service 1325 East West Highway Silver Spring, MD  20910 (301)713-1613

Valery Dagostaro (valery.dagostaro@noaa.gov), Arthur Taylor (arthur.taylor@noaa.gov), Wilson Shaffer (wilson.shaffer@noaa.gov), Mark Stram (mark.stram@noaa.gov)