Localized Aviation MOS Program

LAMP Change Notice




Attention LAMP users:

Effective August 23, 2006, a modification to the GFS-LAMP guidance for precipitation characteristics in BUFR format will be implemented. This modification is necessary to correctly reclassify the categories of the GFS LAMP precipitation characteristics guidance (drizzle, continuous, and showers) in BUFR format to be consistent with the BUFR definitions of this element.

Prior to this fix, the GFS LAMP precipitation characteristics in BUFR format were being categorized as:

1 = showers
2 = drizzle
3 = continuous

However, the correct definition for these categories of precipitation characteristics in BUFR format are:

1 = drizzle
2 = continuous
3 = showers

as specified in our documentation https://www.weather.gov/mdl/media/mdl/BufrLAMPCategory05.pdf (pdf).

If you have been using this BUFR field, and interpreting the categories as the documentation indicates, note that they were misaligned and not what they were documented to be. For example, if the guidance indicated "1" for a station, the documentation indicates that is drizzle, but the actual LAMP forecast was for showers. The LAMP software should have mapped the "1" to a "3" which would have correctly indicated showers according to the documentation.

Effective with the 2100 UTC cycle on August 23, 2006, the software will be modified to fix these categorizations so that they are consistent with the BUFR documentation. This web site will be updated to indicate the cycle with which the change takes place once that information is known.

This only affects the GFS LAMP BUFR product, and only the BUFR descriptor element of 0 60 092 Conditional Precipitation Forecast (categories)

We apologize for any inconvenience this might have caused. Please let us know if you see any problems or have any questions.

Thank you for your interest in LAMP.

Judy Ghirardelli