Version 4.3

NBM Version 4.3, which is tentatively scheduled to be implemented in April of 2025, will continue to fill existing product gaps requested by the Tropical, Fire Weather, and Aviation NWS Services. An overview of the changes/improvements being implemented is provided here.

PNS 24-75 Soliciting Comments on Upgrade 4.3 of the National Blend of Models through January 17, 2024

Version 4.2

Version 4.2 moved into operations on May 15, 2024. Information regarding changes proposed/included to NBM v4.2:

Version 4.1

NBM Version 4.1, which has been implemented as of Tuesday, January 17th, 2023, will continue to fill existing product gaps requested by the Aviation, Water Resources, and Marine and Tropical NWS AFS Service Program Office. Highlights associated with this upgrade include:


  • Regional Definitions:
    • CO - CONUS
    • AK - Alaska
    • HI - Hawaii
    • PR - Puerto Rico
    • GU - Guam
    • OC - Oceanic

  • Public: Added QMD-based probabilistic daytime maximum (MaxT) and nighttime minimum (MinT) temperatures in the form of percentiles and exceedance values (AK); Added 24h quantile mapped peak wind speed and wind gust percentile guidance for CONUS; Added NBM QMD PQPF percentile guidance (10th, 50th, and 90th) for 48h and 72h periods (CO, AK, HI, PR); Added Wet Bulb Globe Temperature (WBGT) (CO, HI, PR, GU); Added a 100 member 50km upper air quasi-Global blend product (85N to -85S) containing 100 members.

  • Winter Weather: Improved calibration of probabilistic and deterministic NBM winter weather guidance for snow, ice, freezing rain, and unconditional PTYPE using a 100 ensemble membership of Direct Model Output PTYPE; Added Snow Level percentiles.

  • Aviation: Added NCEP’s Aviation Weather Center’s 3-layer cloud product (cloud base, cloud top, and cloud coverage), High Cirrus Cloud Layer Base and Coverage and Icing product (CO); Added NCEP’s SPC’s calibrated Day-1 (4h and 24h) severe weather probabilistic products of hail, wind, and tornadoes (CO); Added Alaska deterministic aviation guidance through 84 hours; Added Thunderstorm coverage (CO, AK, HI, PR, and OC).

  • Fire Weather: Leveraged the Rapid Refresh (RAP) analysis for calibrating Mixing Heights for fire weather guidance (CO, AK, HI, PR).

  • Tropical: Added an innovative tropical cyclone feature matching technique to preserve the National Hurricane Center’s Gridded Tropical Cyclone forecast advisory Message (WTCM) wind field (CO, AK, HI, PR, OC).

  • Marine: Added 10th, 50th, and 90th percentile guidance for significant wave heights (CO, AK, HI, PR, GU, and OC); Added Sea ice concentration and thickness guidance to the AK domain.

It is anticipated that these upgrades will benefit the NWS in its mission towards better Impact Decision Support Services (IDSS). For additional information, please refer to the Service Change Notice and visit https://vlab.noaa.gov/web/mdl/nbm. NWS employees and affiliates are encouraged to visit the NWS Insider NBM Page and the NBM VLab Page.

 

Version 4.0

NBM Version 4.0, which was implemented on Tuesday, September 29th, 2020, will continue to fill existing product gaps requested by the Aviation, Water Resources, and Marine and Tropical NWS Service Program Offices. A few highlights associated with this release include:


  1. The continued infusion of cutting edge science advancements in the area of probabilistic quantitative precipitation forecasting (PQPF) and the addition of calibrated PQPF guidance for the Alaska, Puerto Rico, and Oceanic domains.

  2. The addition of probabilistic daytime maximum (MaxT) and nighttime minimum (MinT) temperatures in the form of percentiles and exceedance values for particular thresholds for the CONUS domain.

  3. Standard deviations for temperature, dew point temperature, percentage of sky cover, convective available potential energy (CAPE), and significant wave height for the CONUS, Alaska, Hawaii, and Puerto Rico domains.

  4. Improvement in the deterministic aviation guidance routinely used in daily airport operational planning through 84 hours for Terminal Aerodrome forecasts (TAFs)).

  5. 6-h Probability of Thunder for the CONUS, Alaska, Hawaii, Puerto Rico, and Oceanic domains; (6) The addition of several new elements to the Guam domain.

  6. The addition of new weather elements in the NBM text product along with improvements to the probabilistic text message product. There will be over 2,000 new station text locations added (bringing the total to about 9,000), including most of the CONUS airports.

It is anticipated that these upgrades will benefit the NWS in its mission towards better Impact Decision Support Services (IDSS).

Version 3.2

NBM Version 3.2, implemented on February 19, 2020, continued to fill existing product gaps requested by the Aviation, Fire Weather, Water Resources, and Marine NWS Service Program Offices. A few highlights associated with this release include:

  1. The continued infusion of cutting edge science advancements in the area of probabilistic quantitative precipitation forecasting (PQPF) (especially in the mountainous West) and the addition of calibrated PQPF guidance for the Alaska and Puerto Rico domains.

  2. The addition of various percentile and exceedance thresholds for snowfall and ice amounts (CONUS and Alaska).

  3. The addition of probabilistic daytime maximum (MaxT) and nighttime minimum percentile (MinT) guidance for the CONUS domain.

  4. Uncertainty information in the form of standard deviations for MaxT, MinT, 10 m Wind Speeds, and 10 m Wind Gusts for the CONUS, Alaska, Hawaii, and Puerto Rico domains.

  5. The addition and improvement in aviation guidance routinely used in daily airport operational planning (including the extension of visibility and ceiling height guidance through 84 hours for Terminal Aerodrome forecasts (TAFs).

  6. The addition of new weather elements in the NBM text product along with a new probabilistic text message product. 

Version 3.1

NBM V3.1, implemented in October 2018 (AWIPS 18.1.1), continued to incorporate additional global models (i.e.., ECMWF (deterministic and ensemble)) and mesoscale models (i.e., HRRR-Extended (1-36h guidance)) into its suite of model guidance to cover the CONUS, OCONUS, and Oceanic domains. This upgrade enabled the NBM to fill existing product gaps requested by the Aviation, Fire Weather, Water Resources, and Marine NWS Service Program Offices. Prior to V3.1, NBM data was packaged in GRIB2 and only provided forecasts at gridpoints. NBM V3.1 introduced a new text product (similar to MOS-station bulletins) that provides NBM forecasts at stations. The data in these bulletins are the NBM’s nearest grid point forecast to the corresponding station. Four individual NBM text bulletin products are generated every hour, each covering different forecast horizons. For a complete discussion concerning these messages, along with an exhaustive listing weather elements added to NBM V3.1 and their dissemination times, please see NBM V3.1 SCN.

Version 3.0

Version 3.0, released July 27th, 2017 (AWIPS 17.3.1) incorporated additional global and mesoscale models for the CONUS, OCONUS, and Oceanic domains along with running hourly and providing 1-36h forecasts. Several new weather elements were added to this version such as calibrated Probability of Precipitation (6-hour) and QPF, ceiling height and visibility, and weather, snow, and ice forecasts to name a few. An exhaustive lists of weather elements added to V3.0 can be found in NWS SCN 17-59.

Versions 1.0 - V2.0

The first version of the NBM was released January 6, 2016 in CONUS AWIPS 16.1.1, after Congress mandated that the NWS develop a blended model approach following Hurricane Sandy in 2012. This first version used 3 models (GFS, GEFS mean, CMCE mean) and covered temperature, wind, and sky cover over the CONUS (Continental United States) region two times a day. Version 2, released November 15, 2016 in CONUS and OCONUS (outside-CONUS) AWIPS 16.2.2, added coverage over Alaska, Hawaii, and Puerto Rico.

NBM