GEPS and REPS#
This notebook demonstrates how to access Canada’s ensemble model data with Herbie:
model="geps"(Global Ensemble Prediction System)model="reps"(Regional Ensemble Prediction System)
These are lightweight access examples (URL discovery, source checks, and inventory).
[15]:
from herbie import Herbie
import pandas as pd
Pick a recent cycle#
GEPS and REPS are both ECCC models. We pick a recent 00/12 UTC cycle for examples.
[16]:
recent = pd.Timestamp("now", tz="UTC").floor("12h").tz_convert(None) - pd.Timedelta("12h")
recent
[16]:
Timestamp('2026-04-17 00:00:00')
GEPS example#
GEPS supports two products:
product="geps-prod"product="geps-raw"
[17]:
H = Herbie(
recent,
model="geps",
product="geps-raw",
fxx=24,
variable="TMP",
level="ISBL_0850",
)
H
✅ Found ┊ model=geps ┊ product=geps-raw ┊ 2026-Apr-17 00:00 UTC F24 ┊ GRIB2 @ local ┊ IDX @ None
[17]:
▌▌Herbie GEPS model geps-raw product initialized 2026-Apr-17 00:00 UTC F24 ┊ source=local
[18]:
# Candidate remote sources
H.SOURCES
[18]:
{'msc': 'https://dd.weather.gc.ca/20260417/WXO-DD/ensemble/geps/grib2/raw/00/024/CMC_geps-raw_TMP_ISBL_0850_latlon0p5x0p5_2026041700_P024_allmbrs.grib2'}
[19]:
H.PRODUCTS
[19]:
{'geps-prod': 'processed ensemble products (probabilities, means, etc.); files served from grib2/products',
'geps-raw': 'raw ensemble member output; files served from grib2/raw'}
[20]:
# Inspect GRIB inventory (if available for the selected source)
H.xarray()
Note: Returning a list of [2] xarray.Datasets because cfgrib opened with multiple hypercubes.
/home/kps5442/mapwall_dev/herbie-dev/src/herbie/core.py:1301: UserWarning: Will not remove GRIB file because it previously existed.
warnings.warn("Will not remove GRIB file because it previously existed.")
[20]:
[<xarray.Dataset> Size: 1MB
Dimensions: (latitude: 361, longitude: 720)
Coordinates:
* latitude (latitude) float64 3kB -90.0 -89.5 -89.0 ... 89.5 90.0
* longitude (longitude) float64 6kB 0.0 0.5 1.0 ... 359.0 359.5
number int64 8B 0
time datetime64[ns] 8B 2026-04-17
step timedelta64[ns] 8B 1 days
isobaricInhPa float64 8B 850.0
valid_time datetime64[ns] 8B ...
gribfile_projection object 8B None
Data variables:
t (latitude, longitude) float32 1MB ...
Attributes:
GRIB_edition: 2
GRIB_centre: cwao
GRIB_centreDescription: Canadian Meteorological Service - Montreal
GRIB_subCentre: 0
Conventions: CF-1.7
institution: Canadian Meteorological Service - Montreal
model: geps
product: geps-raw
description: Canada's Global Ensemble Prediction System (GEPS)
remote_grib: /home/meteo/kps5442/data/geps/20260417/CMC_geps-...
local_grib: /home/meteo/kps5442/data/geps/20260417/CMC_geps-...
search: None,
<xarray.Dataset> Size: 21MB
Dimensions: (number: 20, latitude: 361, longitude: 720)
Coordinates:
* number (number) int64 160B 1 2 3 4 5 6 7 ... 15 16 17 18 19 20
* latitude (latitude) float64 3kB -90.0 -89.5 -89.0 ... 89.5 90.0
* longitude (longitude) float64 6kB 0.0 0.5 1.0 ... 359.0 359.5
time datetime64[ns] 8B 2026-04-17
step timedelta64[ns] 8B 1 days
isobaricInhPa float64 8B 850.0
valid_time datetime64[ns] 8B ...
gribfile_projection object 8B None
Data variables:
t (number, latitude, longitude) float32 21MB ...
Attributes:
GRIB_edition: 2
GRIB_centre: cwao
GRIB_centreDescription: Canadian Meteorological Service - Montreal
GRIB_subCentre: 0
Conventions: CF-1.7
institution: Canadian Meteorological Service - Montreal
model: geps
product: geps-raw
description: Canada's Global Ensemble Prediction System (GEPS)
remote_grib: /home/meteo/kps5442/data/geps/20260417/CMC_geps-...
local_grib: /home/meteo/kps5442/data/geps/20260417/CMC_geps-...
search: None]
[21]:
# View level names
H.AVAILABLE_LEVELS
[21]:
['DBLL_100',
'DBLY_10',
'EATM_0',
'ISBL_1',
'ISBL_10',
'ISBL_100',
'ISBL_1000',
'ISBL_1015',
'ISBL_150',
'ISBL_175',
'ISBL_20',
'ISBL_200',
'ISBL_225',
'ISBL_250',
'ISBL_275',
'ISBL_30',
'ISBL_300',
'ISBL_350',
'ISBL_400',
'ISBL_450',
'ISBL_5',
'ISBL_50',
'ISBL_500',
'ISBL_550',
'ISBL_600',
'ISBL_650',
'ISBL_700',
'ISBL_750',
'ISBL_800',
'ISBL_850',
'ISBL_875',
'ISBL_900',
'ISBL_925',
'ISBL_950',
'ISBL_970',
'ISBL_985',
'ISBY_1000-500',
'MSL_0',
'NTAT_0',
'PVU_1',
'PVU_1.5',
'PVU_2',
'SFC_0',
'TGL_10',
'TGL_120',
'TGL_2',
'TGL_40',
'TGL_80']
[22]:
# View variable names
H.AVAILABLE_VARIABLES
[22]:
['ABSV',
'ACPCP',
'ALERT',
'APCP',
'CAPE',
'CIN',
'CWAT',
'DEPR',
'DLWRF',
'DPT',
'DSWRF',
'GUST',
'HEATX',
'HGT',
'HPBL',
'KX',
'LHTFL',
'MU-VT-LI',
'NLWRS',
'NSWRS',
'PRATE',
'PRES',
'PRMSL',
'PTYPE',
'RH',
'SHWINX',
'SKINT',
'SNOD',
'SPFH',
'TCDC',
'TMAX',
'TMIN',
'TMP',
'UGRD',
'ULWRF',
'VGRD',
'VVEL',
'WCHIL',
'WDIR',
'WEAFR',
'WEAPE',
'WEARN',
'WEASN',
'WIND']
REPS example#
REPS files are organized under the 10-km product path:
product="10km/grib2"
[23]:
H = Herbie(
recent,
model="reps",
product="10km/grib2",
fxx=6,
variable="ASNOW",
level="SFC",
)
H
✅ Found ┊ model=reps ┊ product=10km/grib2 ┊ 2026-Apr-17 00:00 UTC F06 ┊ GRIB2 @ local ┊ IDX @ None
[23]:
▌▌Herbie REPS model 10km/grib2 product initialized 2026-Apr-17 00:00 UTC F06 ┊ source=local
[24]:
# Candidate remote sources
H.SOURCES
[24]:
{'msc': 'https://dd.weather.gc.ca/20260417/WXO-DD/ensemble/reps/10km/grib2/00/006/20260417T00Z_MSC_REPS_ASNOW_SFC_RLatLon0.09x0.09_PT006H.grib2'}
[25]:
# The resolved remote file name from the selected model/date/fxx/variable/level
H.PRODUCTS
[25]:
{'10km/grib2': 'regional 10 km ensemble domain'}
[26]:
# Looks like you get both the ensemble members and the control run in the same file?
H.xarray()
Note: Returning a list of [2] xarray.Datasets because cfgrib opened with multiple hypercubes.
/home/kps5442/mapwall_dev/herbie-dev/src/herbie/core.py:1301: UserWarning: Will not remove GRIB file because it previously existed.
warnings.warn("Will not remove GRIB file because it previously existed.")
[26]:
[<xarray.Dataset> Size: 17MB
Dimensions: (y: 960, x: 908)
Coordinates:
latitude (y, x) float64 7MB ...
longitude (y, x) float64 7MB ...
number int64 8B 0
time datetime64[ns] 8B 2026-04-17
step timedelta64[ns] 8B 06:00:00
surface float64 8B 0.0
valid_time datetime64[ns] 8B ...
gribfile_projection object 8B None
Dimensions without coordinates: y, x
Data variables:
tsnowp (y, x) float32 3MB ...
Attributes:
GRIB_edition: 2
GRIB_centre: cwao
GRIB_centreDescription: Canadian Meteorological Service - Montreal
GRIB_subCentre: 0
Conventions: CF-1.7
institution: Canadian Meteorological Service - Montreal
model: reps
product: 10km/grib2
description: Canada's Regional Ensemble Prediction System (REPS)
remote_grib: /home/meteo/kps5442/data/reps/20260417/20260417T...
local_grib: /home/meteo/kps5442/data/reps/20260417/20260417T...
search: None,
<xarray.Dataset> Size: 84MB
Dimensions: (number: 20, y: 960, x: 908)
Coordinates:
* number (number) int64 160B 1 2 3 4 5 6 7 ... 15 16 17 18 19 20
latitude (y, x) float64 7MB ...
longitude (y, x) float64 7MB ...
time datetime64[ns] 8B 2026-04-17
step timedelta64[ns] 8B 06:00:00
surface float64 8B 0.0
valid_time datetime64[ns] 8B ...
gribfile_projection object 8B None
Dimensions without coordinates: y, x
Data variables:
tsnowp (number, y, x) float32 70MB ...
Attributes:
GRIB_edition: 2
GRIB_centre: cwao
GRIB_centreDescription: Canadian Meteorological Service - Montreal
GRIB_subCentre: 0
Conventions: CF-1.7
institution: Canadian Meteorological Service - Montreal
model: reps
product: 10km/grib2
description: Canada's Regional Ensemble Prediction System (REPS)
remote_grib: /home/meteo/kps5442/data/reps/20260417/20260417T...
local_grib: /home/meteo/kps5442/data/reps/20260417/20260417T...
search: None]