bhutan presentation 2016 win sascof 9 - rimes.int · country presentation sascof 9 27-29 september...

CountryPresentation

SASCOF927-29September2016

Myanmar

Tayba BuddhaTamangDepartmentofHydroMetServices

MinistryofEconomicAffairstbtamang@moea.gov.bt

OutlineofPresentation• CountryIntroduction

• WintermonsoonforBhutan

• Climatologyofwinterseason(Oct’15toFeb’16)

• CurrentPredictionSystem/Verification

• Predictionfor2016-17winterseason

• Conclusion

CountryIntroduction

• Totalarea:38,394Sq.Km• Population:750,000• 79%ofpopulationisfarmer• Location:SouthernAsia,between

China&India• Altitude:100minthesouthto

7500mtotheNorthabovemsl• ForestCoverage:72.5%- Policyisto

ensureatleast60%foralltime• Topography:95%Mountainterrain

MonsooninBhutan

BhutanClimaticisgenerallydominatedbymonsoonwindswithdrywinterandwetsummermonsoon

DJF MAM JJAS ON

2% 19% 73% 6%

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecRain 10 21 50 123 197 372 434 361 236 97 8 6

050

100150200250300350400450500

Rainfallinm

m

MeanMonthly RainfalloverBhutan(1996-2015)

32

370

1402

110

0

500

1000

1500

JF MAM JJAS OND

Raininm

m

BhutanSeasonalRainDistribution

ForecastandobservationforwintermonsoonOctober2015-February2016(ONDJF)

Concencus from Winter South Asian Seasonal Climate Outlook Forum (Win SASCOF-1) OND

- First Winter SASCOF was conducted from 14-16th October at Chennai, Tamil Nadu, India

Concencus from WinSASCOF

- Normal to above normal is likely during the North East Monsoon (Oct-December) in southern parts of South Asia (Peninsular India, Sri Lanka and Maldives)

- Above Normal is likely over the northern parts of the region

- Others areas that receive very little rainfall (Including Bhutan) during the season are likely to receive normal rainfall

- Above normal temperature is predicted over most parts of the region in Bhutan

- Prevailing strong El Nino condition in the equatorial pacific is near certain to continue in the season

Concencus from Winter SASCOF- OND

Winter (OND) Rainfall Predicted to be normalfor Bhutan

Winter (OND) temperature Predicted to be above normal with El Nino predicted to persist

Prediction for 2015-16 winter

- CPT forecast using SST for JAS to predict ONDJF

- Goodness index =0.47

- Predicted normal for 2015-16 Winter for Bhutan

WinterRain

• NormalrainONDJF=142mm• JJAS(~1400mm)

• ONDrainwasbelownormal• Overalllastwintermonsoonwasbelownormal

29

-31 -31

52

-43

2912

79

5466

7 6

-5

30

-29

-55-41

-1

-69-58-80

-60-40-20020406080100

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

2014

2015

%DeviationONDJF

Findings

• 2015-16WinterONDJFrainfallforecastnotaccurate

• Possiblereason:Rainfallcontributionisveryminimalcomparedtoannual.Smallamount,largevariation.

DJF MAM JJAS ON

2% 19% 73% 6%

32

370

1402

110

0

500

1000

1500

JF MAM JJAS OND

Raininm

m

BhutanSeasonalRainDistribution

CurrentPredictionSystem/Verification

• ClimatePredictabilityTools(CPT)

• SASCOF(winterandsummermonsoon)

• FODAS(trial)

Predictionfor2016-17winterseason

• CPT• ObservedSSTAugust(1982-2016)

• GoodnessIndex=0.442• ForecastofabovenormalONDrainfall

Predictionfor2016-17winterseason

• FODAS–ForecastsystemOnDynamicalandAnalogueSkills

• DevelopedBCC• UsesBCC_GCMandGPCP• PostProcessing

1. Systematicerrorcorrection2. Dynamic-statisticcombinedforecasting3. Averageforsystematicerrorcorrectionand

dynamicstatisticcombinedforecast

FODASresult

Forecastofabovenormalrainfall

Forecastofnormaltoabovenormalrainfall

Conclusion• Forecastofnormalrainfallinwinter2015,recordedbelownormalrainfallinBhutan

• Thiswinter2016-17forecastofabovenormalrainfall

CHALLENGES• Thecoeff.ofvariationforwinterprecipitationisverylarge,makingdifficulttopredict

• Challengesinpredictionduetocomplexterrainsandlocalizedclimate

• Requirementofexploringnewtoolsandmethodsofpredictingwinterclimateoutlook

THANKYOU