Oct 09, 2025

Meteorological Development Laboratory’s Localized Aviation MOS Program and Gridded LAMP upgraded to Version 2.7

An important upgrade to the Localized Aviation Model Output Statistics (MOS) Program (LAMP) and Gridded LAMP (GLMP) systems was implemented into NWS operations on Tuesday, September 16, 2025. 

LAMP is a statistical system, developed by the Meteorological Development Laboratory, that provides forecast guidance for sensible weather elements and updates the Global Forecast System-based MOS on an hourly basis (every 15 minutes for C&V elements). LAMP provides guidance for over 2000 stations in the CONUS, Alaska, Hawaii, and Puerto Rico, as well as gridded observations and gridded forecast guidance out to 38 hours (for most elements). GLMP  serves as an important input to the National Blend of Models in the first 36 hours of the forecast. 

Federal Aviation Administration (FAA) Traffic Flow Managers require precise forecasts of the time of onset and cessation of flight categories at core airports. Traditional LAMP guidance has provided forecasts of ceiling and visibility (C&V), but not for specific aviation flight categories (e.g. Instrument Flight Rules - IFR). MDL’s LAMP Team was tasked by the FAA’s Aviation Weather Research Program to develop a product to forecast the time of onset and cessation of flight categories at the Core 30 airports, which leverages the sub-hourly (15-minute) LAMP/GLMP “High Impact Weather (HIW)” C&V guidance that was implemented with the LAMP/GLMP v2.6 upgrade in September 2024. The HIW guidance provides forecasts of the lowest ceiling height and lowest visibility condition that is expected during a 15-minute period, out to six hours. 

The v2.7 upgrade includes the addition of several new text bulletin products that provide the forecasted start and end times of aviation flight categories as well probabilistic information which previously was only available “under the hood.” 

1. An expanded sub-hourly bulletin containing guidance valid for 15-minute periods out to six hours, updating every 15 minutes (96 cycles per day). An example is shown below for station KCDJ (Chillicothe, OH). The forecasted flight category is indicated in row “FLT”, followed by indicators of onset (“+”), prevailing (“---”), and cessation (“/”) of a flight category condition. Rows that begin with “CP” contain cumulative probabilities of flight categories with respect to ceiling height, and rows that begin with “VP” contain cumulative probabilities of flight categories with respect to visibility.
   
   
    
2. Extended flight category bulletin containing guidance for hourly projections (valid at the top of the hour) out to 38 hours, updating hourly. The format of this bulletin is identical to the example shown above for station KCDJ. 
3. A “simplified” bulletin that indicates the start day/time and end day/time in UTC for each flight category, produced every 15 minutes (96 cycles per day) covering the first six hours, and produced hourly (24 cycles per day), providing coverage out to 38 hours. An example simplified bulletin is shown below for station KCDJ.
   
   
    

The flight category bulletins described above are produced not only for the “Core 30” airports but for all CONUS LAMP stations (1818). Users can access the new flight category bulletin products on NCEP Web Services (NOMADS).
Other upgrade highlights include:

1. Updated hourly categorical visibility guidance at stations to improve over-forecast biases.
2. Addition of ceiling height and visibility guidance for 335 stations in the “LAV” and “LEV” text bulletins and BUFR message.
3. A bug fix to correct a misrepresentation of unlimited ceiling height in the Alaska GLMP ceiling grids.

Additional details about the upgrade can be found in the Service Change Notice. For questions about this model upgrade, please contact the LAMP Team at nws.lamp@noaa.gov.