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An ECMWF reforecast request for all the available hindcastDates of an ECMWF model version date

 

Info
  • The objective of this example is to demonstrate how to iterate efficiently over all the available hincastDates for an ECMWF model version date.
  • To start writing your request you firstly need to select a model version date and to find the corresponding Hindcast Dates. Please  check ECMWF availability
    (lightbulb) Keep in mind that the ECMWF reforecast configuration is "on the fly". For more information read a brief description of reforecasts.
  • The requests below can be used as a starting point, however you need to keep in mind that you have to adapt it to your needseg to set the keyword values according to your requirements ("param", "levtype", "step" etc).
  • In this way you can extend this request to download the whole S2S ECMWF reforecast. Don't forget to check ECMWF availability (warning)

(smile) You can use the variable target to organise the requested data in files as you wish.

Code Block
languagepy
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
origin = "ecmf"
modelVersionDate = "2015-12-03"
hindcastDates = ["1995-12-03", "1996-12-03", "1997-12-03", "1998-12-03", "1999-12-03", "2000-12-03",
                 "2001-12-03", "2002-12-03", "2003-12-03", "2004-12-03", "2005-12-03", "2006-12-03", "2007-12-03",
                 "2008-12-03", "2009-12-03", "2010-12-03", "2011-12-03", "2012-12-03", "2013-12-03", "2014-12-03"]
def retrieve_ECMWF_reforecast():
    """
       A function to demonstrate how to iterate efficiently over all hindcastDates
       for a particular ECMWF reforecast model version.
       Change the variables below to adapt the iteration to your needs
    """
    # Please note that the "sfc" and "pl" requests below could run in parallel
    # Step 1: Get pressure level data
    pfplTarget = "%s_%s_%s.grb" % (origin, "pfpl", modelVersionDate)
    ECMWF_reforecast_pf_pl_request("/".join(hindcastDates), pfplTarget)
    # Step 2: Get surface data
    pfsfcTarget = "%s_%s_%s.grb" % (origin, "pfsfc", modelVersionDate)
    ECMWF_reforecast_pf_sfc_request("/".join(hindcastDates), pfsfcTarget)
def ECMWF_reforecast_pf_pl_request(hindcastDate, target):
    """
       A ECMWF reforecast, perturbed forecast, pressure level, request.
       The cost of this request is fields and  Gbytes 
       Change the keywords below to adapt it to your needs.
    """
    server.retrieve({
        "class": "s2",
        "dataset": "s2s",
        "date": modelVersionDate,
        "expver": "prod",
        "hdate": hindcastDates,
        "levtype": "pl",
        "levelist": "10/50/100/200/300/500/700/850/925/1000",
        "origin": origin,
        "param": "130/131/132/133/135/156",
        "step": "24/to/768/by/24",
        "stream": "enfh",
        "target": target,
        "time": "00",
        "number": "1/2/3/4",
        "type": "pf",
    })   
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
origin = "ecmf"
modelVersionDate = "2015-12-03"
hindcastDates = ["1995-12-03", "1996-12-03", "1997-12-03", "1998-12-03", "1999-12-03", "2000-12-03",
    "2001-12-03", "2002-12-03", "2003-12-03", "2004-12-03", "2005-12-03", "2006-12-03", "2007-12-03", 
    "2008-12-03", "2009-12-03", "2010-12-03", "2011-12-03", "2012-12-03", "2013-12-03", "2014-12-03"]

def retrieve_ECMWF_reforecast():
    """
       A function to demonstrate how to iterate efficiently over all hindcastDates
       for a particular ECMWF reforecast model version.
       Change the variables below to adapt the iteration to your needs
    """
           
    #Please note that the "sfc" and "pl" requests below could run in parallel
           
    #Step 1: Get pressure level data
    pfplTarget = "%s_%s_%s.grb" % (origin, "pfpl", modelVersionDate)
    ECMWF_reforecast_pf_pl_request("/".join(hindcastDates), pfplTarget)
           
    #Step 2: Get surface data
    pfsfcTarget = "%s_%s_%s.grb" % (origin, "pfsfc", modelVersionDate)
    ECMWF_reforecast_pf_sfc_request("/".join(hindcastDates), pfsfcTarget)

def ECMWF_reforecast_pf_pl_request(hindcastDate, target):
    """
       A ECMWF reforecast, perturbed forecast, pressure level, request.
       The cost of this request is fields and  Gbytes 
       Change the keywords below to adapt it to your needs.
    """
    server.retrieve({
        "class": "s2",
        "dataset": "s2s",
        "date": modelVersionDate,
        "expver": "prod",
        "hdate": hindcastDates,
        "levtype": "pl",
        "levelist": "10/50/100/200/300/500/700/850/925/1000",
        "origin": origin,
        "param": "130/131/132/133/135/156",
        "step": "24/to/768/by/24",
        "stream": "enfh",
        "target": target,
        "time": "00",
        "number": "1/2/3/4",
        "type": "pf",
    })

def ECMWF_reforecast_pf_sfc_request(hindcastDate, target):
    """
       A ECMWFreforecast, perturbed forecast, sfc request.
       The cost of this request is 383,040 fields and 7.1 GB
       Change the keywords below to adapt it to your needs.
    """
    server.retrieve({
        "class": "s2",
        "dataset": "s2s",
        "date": modelVersionDate,
        "expver": "prod",
        "hdate": hindcastDate,
        "levtype": "sfc",
        "origin": origin,
        "param": "1/33/34/59/121/122/134/136/146/147/151/165/166/167/168/169/175/176/177/179/180/181/235",
        "step": "24/to/744/by/24",
        "stream": "enfh",
        "target": target,
        "time": "00",
        "number": "1/2/3/4",
        "type": "pf",
    })

if __name__ == '__main__':
    retrieve_ECMWF_reforecast()


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