.. _extracthrrr:

Extract HRRR data
===============================

Data source
-------------------------------

The HRRR (High-Resolution Rapid Refresh) is a NOAA real-time 3-km resolution, hourly updated, cloud-resolving, convection-allowing atmospheric model, 
initialized by 3km grids with 3km radar assimilation based on the WRF model. It covers the USA.
Radar data is assimilated in the HRRR every 15 min over a 1-h period adding further detail to that provided by the hourly data assimilation from the 13km radar-enhanced Rapid Refresh.
The forecst lead time is 48 hours.

Data, tutorial, licence and informations can be found here https://registry.opendata.aws/noaa-hrrr-pds/

The official website is https://rapidrefresh.noaa.gov/hrrr/

Historical mode
*******************************

Browse the bucket here https://noaa-hrrr-bdp-pds.s3.amazonaws.com/index.html

Data are stored since 2014-07-30.

Download surface grib2 and pressure-level grib2 files with these commands:

.. note ::
    wget -c -nd https://noaa-hrrr-bdp-pds.s3.amazonaws.com/hrrr.${YYYYMMDD}/conus/hrrr.t${RR}z.wrfsfcf${HH}.grib2

    wget -c -nd https://noaa-hrrr-bdp-pds.s3.amazonaws.com/hrrr.${YYYYMMDD}/conus/hrrr.t${RR}z.wrfprsf${HH}.grib2

    cat hrrr.t${RR}z.wrfprsf${HH}.grib2 hrrr.t${RR}z.wrfsfcf${HH}.grib2 >> hrrr.${YYYYMMDD}${RR}z.${HH}.grib2

With YYYYMMDD and RR are the date and assimilation start date of the run. HH is the forecast lead time.

Example YYYYMMDD=20260924 RR=12, HH=06 <==> forecast of 20260924 18 UTC based on the 13UTC run.

Operational mode
***********************************

Files are updated hourly. HRRR runs a cycle every hour.

Using the files
------------------------------------
Only available since MNH-V6-0-0.

Simply fill the HATMFILE field in PRE_REAL1.nam with the file name hrrr.tRRz.wrffHH.grib2.