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 Making Decisions for the Next Season
Examples of Agricultural Forecasting
Applications Is there skill beyond climatology?
Ian Foster Miles Dracup WA Dept of
Agriculture Water Corporation
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Climate Risk Management

• The importance of climate risk management to many
  sectors is a given
• Seasonal forecasts potentially have a major role
• BUT (for example)
• 95 of farmers find seasonal forecasts
  interesting
• 25 of farmers find seasonal forecasts useful

Weeks (2005) Liebe Group Workshop, Wubin
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The Nature of Decisions

• A schedule of decisions
• Strategic vs Tactical decisions
• Negotiability of decisions (some may be locked in
  anyway)
• Capacity to respond to a forecast
• Information needs vary (eg, timeliness, means of
  delivery)

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Season Types - Eastern Wheatbelt
Extra from climate knowledge
Proportion of long-term profit
Condensed from 11 MUDAS season types (R Kingwell,
DAWA)
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Changes in Season Types - Merredin
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Schedule of Cropping Decisions
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A Targetted Forecast

• A forecast that was aimed at strategic
  agricultural decisions in WA would look like
• Long-lead (6 months)
• Likelihood of seasonal extremes (eg Tercile 1 vs
  Tercile 3)
• Available in summer/autumn
• Is communicated well
• Are we dreaming?

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Current Seasonal Outlooks

• Operational outlooks
• 0-1 month lead-time
• Driven by ENSO
• Autumn predictability barrier
• Statistical (issues of stationarity wrt climate
  trends)
• Expressed as probabilities
• Experimental outlooks
• To 6 months lead-time
• Rely on ENSO as a driver for seasonal memory
• Autumn predictability barrier
• Potential to adapt to climate trends
• Expressed as probabilities

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Analysis of Risk - Methods

• Historical climate data (BoM, DAWA, farmers own
  records)
• Historical production data
• Analysis tools (Rainman, Climate Calculator )
• Soil moisture (PYCAL, DAWA, APSIM)
• Crop Yield Estimates (STIN, APSIM, PYCAL )
• Combine season-to-date conditions with
  climatology and derived products
• Used more for tactical decisions within-season
• Need facilitated access (eg develop partnerships
  for delivery)

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Analysis of Risk - Rainfall
Observed to date
Future
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Analysis of Risk - Crop Yields
Source Horses for Courses Bulletin Aug 2005.
Site at West Morawa. Based on actual rain to 27
July 05, and historical finishes to the season.
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The Search for Predictability - 1
Correlation of May-Oct rain with SOI indices over
Feb-Apr. EPI derived in Nov of previous year
Source Telcik (2005)
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The Search for Predictability - 2
Correlation of May-Oct rain with SOI indices over
Mar-May. EPI derived in Nov of previous year
Source Telcik (2005)
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Correlations with SSTs
Correlation of MJJ rain with MJJ de-trended SST
Location at 32.5 S 177 E
Correlation of MJJ rain with JFM de-trended SST
Source Telcik (2005)
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SST Anomalies in Neutral Years
Av
Dry
May-Jul rainfall
Wet
Source Telcik (2005)
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Summary

• Climate risk management is important to many
  sectors. Seasonal climate forecasts form a part
  this.
• Current seasonal climate outlooks are not well
  matched to strategic decision making needs.
• Use of current conditions, climatology and
  derived products has practical application to
  tactical decisions.
• The search for predictability continues via
  enhancements to ENSO-based approaches and
  phenomena especially relevant to WA.