Use of Medium and Extended Range Forecasts in Slovenia

1
Use of Medium and Extended Range Forecasts in
Slovenia

• Jure Cedilnik
• ARSO EARS Environmental Agency of Slovenia,
  Met. service

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Outline of the talk

• Introduction
• What is used for operational forecasting
• What are EC products used for
• Forecasting severe weather
• Experience with EC
• Conclusions

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Introduction

• EC cooperating member
• LACE and ALADIN member, LAM running locally up
  to 72 hours (already medium range)
• only few commercial customers (but well
  established contact with media mostly live
  radio interviews)
• quite small met. service

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What a forecaster uses daily

• short range
• mostly ALADIN-SI
• EC, MOS on EC, also NCEP
• DWD LM
• PEPS
• medium range
• EC deterministic EPS meteograms, clusters, MOS
• Multi analysis meteograms
• NCEP, mostly meteograms
• DWD GME
• extended range
• not tackled with on daily basis

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What is EC used for?

• media forecasts
• severe weather possibility
• temperature forecasts for power distribution
  companies
• maritime conditions forecast
• special forecasts (alpinistic expeditions,...)
• generally

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Extended Range Forecasts

• monthly meteograms
• no specific forecast products are created, no
  commercial use so far,
• only on verbal basis and upon customers' request
  (payphone, daily radio interviews, short
  newspaper texts,... and sometimes in tv weather
  forecast)

7
Seasonal forecasts

• mass medias interest
• sometimes too enthusiastic
• textual material for newspapers and web
• using all available forecast centres material
• no real experience yet

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Forecasting severe weather

• warnings for the media are issued only for the
  next day
• early warnings for civil protection up to three
  days ahead
• relies on EC for medium range, but including all
  other possible sources

warning thresholds - rain gt 100mm/24hrs (NW
Slovenia), gt 50mm/24hrs (elsewhere) -
snow gt 25 cm/12hrs - wind gt 25m/s (bora
regions), gt20m/s (elsewhere)
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Forecasting severe weather - plans

• downscale extended range EC forecast
• locally with a LAM
• only for the target period (e.g. day 7-8)
• upon forecasters request
• (downscaling on demand)

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Experience with medium and extended range EC
forecasts

• latest resolution improvement -gt impact of
  orography on precipitation has increased
• (EC going meso?)
• unsteadiness of meteograms through runs
  unfortunately with large impact
• also occurs with ensembles

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Flip-flopping?
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Situation on December 27, 05

• Mediterranean cyclone

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Mediterranean cyclone in last days of 05
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What about ensembles?
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Conclusions

• problems with Mediterranean lows very important
  for our service unsteadiness
• ensembles also unsteady not what one would want
  
• more and more interest for seasonal range by the
  media
• service difficult to imagine without EC