Brian Blaylock 🌐 Webpage

Brian's High-Resolution Rapid Refresh code: HRRR-B

HRRR-B, or "Herbie," is a python package for downloading recent and archived High Resolution Rapid Refresh (HRRR) model forecasts. I created a lot of this during my PhD and decided to organize what I had into a more coherent package. It will continue to evolve at my leisure.

HRRR model output is archived by the MesoWest group at the University of Utah on the CHPC Pando Archive System. The GRIB2 files are copied from from NCEP every couple hours. Google also has a growing HRRR archive. Between these three data sources, there is a lot of archived HRRR data available.

This package demonstrates how to download those HRRR files with Python.

• Download full or partial HRRR GRIB2 files. Partial files are downloaded by GRIB message.
• Three different data sources: NCEP-NOMADS, Pando (University of Utah), and Google Cloud.

  • The Pando HRRR archive is in process of moving to Amazon Web Services as a public Earth dataset. It will be available in zarr format that will allow for more flexibility for chunked data requests.

• Open HRRR data as an xarray.Dataset.
• Other useful tools (in development), like indexing nearest neighbor points and getting a cartopy crs object.

Goals

This package is still being developed. I want to make it so you can do this:

import hrrrb.archive as ha

or

from hrrrb.archive import get_hrrr

And I want to publish this on PyPI.

🌹 What's in a name?

How do you pick the right name? For now, I settled on the name HRRR-B, pronounced "Herbie," because this package helps you get data from the High-Resolution Rapid Refresh (HRRR) model, and the B is for Brian. Is it a little pretentious to attach your own name to a package? Maybe the B stands for something else someday. I'm also thinking about just naming this "Herbie" and you would import with import herbie.archive as ha

Contributing Guidelines (and disclaimer)

The intent of this package is to serve as an example of how you can download HRRR data from the Pando HRRR archive. Since this package is a work in progress, it is distributed "as is." I do not make any guarantee it will work for you out of the box. Any revisions I make are purely for my benefit. Sorry if I break something, but I usually only push updates to GitHub if the code is in a reasonably functional state (at least, in the way I use it).

With that said, I am happy to share this project with you. You are welcome to open issues and submit pull requests, but know that I may or may not get around to doing anything about it. If this is helpful to you in any way, I'm glad.

🐍 Conda Environment

These examples use Python 3. The environment.yml file lists all the packages you will need, plus a few useful extras. If you have Anaconda installed, create this envrionment with

conda env create -f environment.yml

Then activate the hrrrb environment with

conda activate hrrrb

If conda environments are new to you, I suggest you become familiar with managing conda environments.

📝 Detailed Jupyter Notebooks

These notebooks show practical use case of the hrrrb package:

• Package Examples

These notebooks offer a bit of discussion on how the download package works. They aren't as practical, (and have probably changed a little), but helps illustrate the download method.

• Part 1: How to download a bunch of HRRR grib2 files (full file)
• Part 2: How to download a subset of variables from a HRRR file
• Part 3: A function that can download many full files, or subset of files
• Part 4: Opening GRIB2 files in Python with xarray and cfgrib

⚠ The functions in hrrrb.archive slightly different than (and better than) these discussion notebooks.

👨🏻‍💻 hrrrb.archive -- All the useful functions in one module

If you are looking for a no-fuss method to download the HRRR data you want, use the hrrrb.archive module. Feel free to edit/improve it to fit your needs. If you write a useful function, send me a .py file or make a pull request to share your script.

Requires xarray, cfgrib, cartopy, requests

👉 Click Here For Some Examples

How do I import these functions? That depends on where you put the module and where the script you are running is located.

Install via PyPiI(coming soon)

pip install hrrrb

If hrrrb is in your current working directory or if it is in a directory included in your PYTHONPATH, then simply import the functions with

from hrrrb.archive import download_hrrr, get_hrrr

If hrrrb is in a different directory, you will need to tell your Python script where to find it. You can do that by appending the sys.path in your script.

import sys
sys.path.append('/directory/location/of/hrrrb')

from hrrrb.archive import download_hrrr, get_hrrr

Function arguments

download_hrrr(DATES, searchString=None, fxx=range(0, 1), *,
              model='hrrr', field='sfc',
              download_dir='./', dryrun=False, verbose=True)

get_hrrr(DATE, searchString, *, fxx=0, DATE_is_valid_time=False, 
         remove_grib2=True, add_crs=True, **download_kwargs):

• DATES Datetime or list of datetimes representing the model initialization time.
• searchString See note below
• fxx Range or list of forecast hours.
  • e.g., range(0,19) for F00-F18
  • Default is the model analysis (F00).
• model The type of model.
  • Options are hrrr, alaska, hrrrX
• field The type of field file.
  • Options are sfc and prs
  • nat and subh are only available for today and yesterday.
• download_dir The directory path the files will be saved in.
  • Default downloads files into the user's home directory ~/data/hrrr.
• dryrun If True, the function will tell you what it will download but not actually download anything.
• verbose If True, prints lots of info to the screen.

Specific to get_hrrr:

• DATE_is_valid_time For get_hrrr, if True the input DATE will represent the valid time. If False, DATE represents the the model run time.
• remove_grib2 For get_hrrr, the grib2 file downloaded will be removed after reading the data into an xarray Dataset.
• add_crs For get_hrrr, will create a cartopy coordinate reference system object and append it as a Dataset attribute.

The important searchString argument

searchString is used to specify select variables you want to download. For example, instead of downloading the full GRIB2 file, you could download just the wind or precipitation variables. Read the docstring for the functions or look at notebook #2 for more details.

searchString uses regular expression to search for GRIB message lines in the files .idx file. There must be a .idx file for the GRIB2 file for the search to work.

For reference, here are some useful examples to give you some ideas...

Are you working with precipitation fields? (e.g., APCP)
A lot of users have asked why the precipitation accumulation fields are all zero for the model analysis (F00). That is because it is an accumulation variable over a period of time. At the model analysis time, there has been no precipitation because no time has passed.

• F00 only has a 0-0 hour accumulation (always zero)
• F01 only has a 0-1 hour accumulation
• F02 has a 0-2 hour accumulation and a 1-2 hour accumulation.
• F03 has a 0-3 hour accumulation and a 2-3 hour accumulation.
• etc.

Best of luck 🍀
- Brian

🌐 HRRR Archive Website: http://hrrr.chpc.utah.edu/
🚑 Support: atmos-mesowest@lists.utah.edu
📧 Brian Blaylock: blaylockbk@gmail.com
✒ Citation this details:

Blaylock B., J. Horel and S. Liston, 2017: Cloud Archiving and Data Mining of High Resolution Rapid Refresh Model Output. Computers and Geosciences. 109, 43-50. https://doi.org/10.1016/j.cageo.2017.08.005

Thanks for using HRRR-B