Use of Medium and Extended Range Forecasts in Slovenia

Jure CedilnikARSO [EARS – Environmental Agency of Slovenia, Met. service]

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

2/15

Outline of the talk

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

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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)

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Seasonal forecasts

mass media’s interest sometimes too enthusiastic

textual material for newspapers and web using all available forecast centres’ material

no real experience yet

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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: > 100mm/24hrs (NW Slovenia),

> 50mm/24hrs (elsewhere)- snow: > 25 cm/12hrs- wind: > 25m/s (bora regions),

>20m/s (elsewhere)

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

9/15

Forecasting severe weather - plans

downscale extended range EC forecast locally with a LAM only for the target period (e.g. day 7-8) upon forecaster’s request

(downscaling on demand)

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Experience with medium and extended range EC forecasts

latest resolution improvement -> impact of orography on precipitation has increased

(EC going meso?) unsteadiness of meteograms through runs

– unfortunately with large impact also occurs with ensembles

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Flip-flopping?

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Situation on December 27, 05 Mediterranean cyclone

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Mediterranean cyclone in last days of 05

Precipitation accumulation over event for different runs [mm]

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2012h

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Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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Precipitation accumulation over event for different runs [mm]

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10

20

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50

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2000h

2012h

2100h

2112h

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2400h

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2512h

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2612h

2700h

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What about ensembles?

Use of medium and extended range forecasts in SloveniaECMWF FPU Meeting, June 14-16, 06

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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