Plan for Removal of NGM-LAMP


August 09, 2007

Updated November 05, 2007 to correct ftp directory name


1. Introduction

The Local AWIPS MOS System (LAMP) system currently updates the Nested Grid Model (NGM) Model Output Statistics (MOS). The LAMP system is being redeveloped to update the Global Forecast System (GFS) MOS instead of the NGM MOS, and has been renamed the Localized Aviation MOS Program. Currently, the new GFS-based LAMP system is running operationally with the same number of cycles as the NGM-based LAMP system and will eventually provide updated guidance every hour of the day. In addition, the number of stations for which forecasts are generated in the new GFS-LAMP system has significantly increased from its predecessor the NGM-LAMP system and is now on the order of the station-based GFS-MOS system.

The NGM-LAMP system runs at the National Weather Service (NWS) Weather Forecast Offices (WFOs) in the Advanced Weather Interactive Preparation System (AWIPS), as well as in a non-operational jobstream at NCEP for internal archiving, product generation for the NWS LAMP web page, and to send products to the NWS FTP server. The NGM-LAMP system is being removed from AWIPS in the OB8.1 release of AWIPS. This removal is in accordance with the approved OB8.1 content of the System Recommendation & Evaluation Committee (SREC). With the AWIPS OB8.1 release, the NGM-LAMP software will no longer run locally at CONUS WFOs in AWIPS, and the NGM-LAMP guidance will no longer be available in AWIPS.

In concert with planning to discontinue the outdated NGM-LAMP guidance, the non-operational system can no longer be supported as new systems are developed and maintained. Therefore the NWS plans to remove the NGM-LAMP products from the NWS LAMP web site and also from the NWS FTP Server

A Public Information Statement has been issued to request comments on the planned removal of the NGM-LAMP products from the web site and the NWS FTP server. You can access the Public Information Statement at:


2. Background

The NGM-MOS based LAMP system was implemented locally at NWS WFOs in AWIPS in the late 1990's. In time, difficulties became evident with locally implementing such a system. As AWIPS was updated, it was found that the coordination and maintenance of the local implementation of the LAMP system with each AWIPS upgrade or release created an unnecessary shift in resources from other LAMP projects. In addition, the system could fail at a WFO for reasons unrelated to the LAMP software, such as lack or delay of receipt of the observations, the model data, the MOS, in addition to the inadvertent deletion of critical files that could negatively affect the system. This created an unforeseen maintenance issue in terms of resources necessary to support the local system.

As more modern MOS systems were being developed at MDL, the NGM-LAMP system became outdated. The original development of the NGM-LAMP was for eight cycles of guidance for less than a thousand stations in the CONUS. The system was driven by the NGM model and updated the NGM MOS. The NGM model and NGM MOS are not only outdated, they are "frozen" in that they are not being updated, and therefore are not realizing any benefits from NCEP modeling improvements. The NGM model has not been modified since 1991, and the NGM MOS has not been updated since 1995. Consequently, the opportunity existed to update the LAMP system based on more modern NCEP models and newer MOS guidance

Based on the maintenance issues found, it was decided that centralizing the LAMP system would allow for a more easily updated and maintained system. In addition, a science opportunity existed to update the LAMP system based on more modern NCEP models and newer MOS guidance. It was decided to utilize the GFS and GFS MOS for this purpose. By removing the system from AWIPS and the WFOs, and implementing on NCEP central computers, the dissemination could be centralized and the maintenance more manageable. This upgrade to the system has made it possible to develop the system as an update to the more modern GFS MOS, to provide guidance for many more stations (upwards of 1500) and more cycles (eventually 24 cycles) than was realistically possible with the older NGM-LAMP.

As a result, a more maintainable and updated product (GFS-LAMP) is now available. This product replaces the NGM-LAMP, and is in numerous regards a superior product. However, the NGM-LAMP elements of Quantitative Precipitation Forecasts (QPF) and the three layers of cloud guidance (height and amount) have not yet been replaced in the new GFS-LAMP system. Strong consideration was given to retaining these forecast elements. However, with regard to the QPF, we have found that the observations of precipitation amounts contained in the METARs are not adequate to help update the MOS because not all stations reliably report observed precipitation amounts. Therefore more robust observational data is desired. Currently we do not have a database of observations that will skillfully update the QPF in the GFS-based LAMP system, but we are investigating acquiring such data. Moreover, any new LAMP QPF development will be based upon a newly developed gridded GFS-MOS QPF product, which to date, has not been implemented. Once these two factors are no longer an issue, it is anticipated that a LAMP QPF product will be implemented. Cloud layers were not included in the new LAMP system because they were found to be of questionable skill. In the future, if it is determined that this element demonstrates any beneficial skill, it will likely be implemented in the new GFS-LAMP system. We are also investigating other cloud elements that might be beneficial to our users, such as guidance for a lowest cloud layer that is neither broken nor overcast. (Note: the GFS-LAMP does already provide ceiling height and total sky cover guidance).

Alternatives to the termination of the NGM-LAMP are not feasible because of limited resources within the NWS and the higher priority of further development of the replacement GFS-LAMP system.


3. Affected Products

If the NGM-LAMP were removed, the NGM-LAMP products listed below would no longer be available on the NWS FTP server

  • NGM-LAMP ASCII text bulletins located on the NWS FTP server in the following directory with the following filenames:


    where HH is the cycle of the NGM-LAMP guidance in UTC, and can be any of 02, 05, 08, 11, 14, 17, 20, or 23.

  • NGM-LAMP GRIB1 quantitative precipitation forecasts located on the NWS FTP server in the following directory with the following filenames:


    where YYYY is the current year in 4 digits, MM is the current month in two digits, and DD is the current day in two digits.

    HH is the cycle of the NGM-LAMP guidance in UTC, and can be any of 02, 05, 08, 11, 14, 17, 20, or 23.

The new GFS-LAMP guidance is currently available and is intended to be used as a replacement for the NGM-LAMP. Information concerning the GFS-LAMP, including the real-time GFS-LAMP guidance, is available at the web site

For your reference, key differences between the NGM-based LAMP system and the GFS-based LAMP system are summarized below. Please note that the GFS-LAMP does not currently provide guidance for either Quantitative Precipitation Forecasts (QPF) or Cloud Layer Amounts and Heights for 3 layers of clouds. In the future, these elements may be developed for GFS-LAMP. The new GFS-LAMP will provide guidance for categorical Ceiling Height and Total Sky Cover.

Category Current (NGM-based) LAMP New (GFS-based) LAMP
Runs Locally in AWIPS Centrally on NCEP computers
Distribution Within AWIPS, NWS ftp server, experimentally on web Across NOAAport, SBN, NWS ftp server, on website, National Digital Guidance Database, received in AWIPS and at NWS National Centers
Cycles Every 3 hours Every hour (planned)
Projections Hourly out to 20 hours Hourly out to 25 hours
Coverage CONUS CONUS, Alaska, Hawaii, Puerto Rico (Thunderstorm guidance available over CONUS only)
Stations ~ 1000 stations > 1500-1600 Stations (depending on the cycle)

Key differences between the NGM-based LAMP forecast elements and the GFS-based LAMP forecast elements are summarized below:

Element Current (NGM-based) LAMP New (GFS-based) LAMP
Temperature Yes Yes
Dewpoint Yes Yes
Wind Direction Yes Yes
Wind Speed Yes Yes
Wind Gusts No Yes
Probability of Precipitation Occurring on the hour Yes Yes
Best Category (yes/no) for Occurrence of precipitation on the hour Yes Yes
Probability of Precipitation Occurring in a 6-h period Yes Yes
Probability of Precipitation Occurring in a 12-h period Yes Yes
Probability of Thunderstorm Occurring in a 20-km gridbox in a 2-h period No Yes
Best Category (yes/no) for Occurrence of Thunderstorm in a 20-km gridbox in a 2-h period No Yes
Precipitation Type Yes Yes
Precipitation Characteristics No Yes
Sky Cover Yes Yes
Ceiling Height Yes Yes
Conditional Ceiling Height No Yes
Visibility Yes Yes
Conditional Visibility No Yes
Obstruction to Vision Yes Yes
Quantitative Precipitation Forecast Yes Planned
Three Cloud Layers Yes Planned

For more details about the new system, please visit our web site

Thank you for your interest in LAMP.

Judy Ghirardelli