BY Cecilia Viloria Dominican Republic

CARICOF Probabilistic Rainfall Outlook April-May-June

CARICOF(Caribbean CLimate Outlook Forum ) Probabilistic Rainfall Outlook

April-May-June

CIMH Coordination – Cédric Van Meerbeeck,

Onamet Caridad Perez

NMHS’s acknowledged for rainfall data delivery! Antigua & Barbuda,

Bahamas, Barbados, Belize, Cuba, Dominica, Dominican Republic, Grenada, Guadeloupe, Guyana, Jamaica, Martinique, St. Lucia,

Trinidad and Tobago

CARICOF

CPT probabilistic AMJ rainfall forecast Two experiments: 1) Predictor is simulated SST over the tropical Pacific over AMJ (data source: CFS)

2) Predictor is observed SST over the tropical Atlantic and Pacific over JFM (data source: IRI data library)

Experiment 1 corresponds to the final experiment accepted during the CPT training 27-29 Feb 2012 and used for the CARICOF MAM rainfall outlook . Experiment 2 takes both the Atlantic and Pacific SSTs into account, as Atlantic SSTs are perhaps the second-most important driver of rainfall throughout the Caribbean.

CPT AMJ rainfall forecast – Experiment 1

Data: Predictor = AMJ SST model predictions 1982-2012

140E-90W and 30N-20S (i.e. tropical Pacific) [Source: CFS]

Predictand = AMJ rainfall for 94 Caribbean stations

1982-2011 Parameters: CCA modes: max = 3; optimum= 1 X modes: max = 5; optimum = 4 Y modes: max = 5; optimum = 2 Missing Y data threshold: 20% missing values, 10% missing stations, leading to 83 stations included in hindcast and forecast Goodness index (transformed Y) = 0.198

To run the statistical model Climate Prediction Tools (CPT), we are using the basis of 27 stations from Dominican Republic and Caribbean region.

Participate in the Caribbean region:Antigua & Barbuda, Bahamas, Barbados, Belize, Cuba, Dominica, Dominican Republic, Grenada, Guadeloupe, Guyana, Jamaica, Martinique, St. Lucia, Trinidad and Tobago

This model is being analyzed to determine approximately what good the predictions are, for which it makes a comparative analysis of total rainfall occurred and determine the behavior and compare it with the model. These may be below normal, within the normal or above the nomal which are reference standards.

We are using CPT from 2010 -2012

Dom. Rep.

Station Belo

w Norm

al Abov

e Station Belo

w Norm

al Abov

e Antigua_GCastle 18 31 51 Dominican_Rep_BARAHNA 25 32 43 Antigua_VCBIRD 19 31 50 Dominican_Rep_BAYAGNA 28 32 40

Dominican_Rep_CABRERA 31 32 38 Bahamas_LPIA 43 31 25 Dominican_Rep_CONSTAN 25 31 44

Dominican_Rep_GASPHEZ 26 32 42 Barbados_CIMH 19 32 50 Dominican_Rep_HOVALLE 25 31 45 Barbados_GAIA 18 31 51 Dominican_Rep_JIMANI 28 31 41

Dominican_Rep_LAMERIC 22 32 46 Belize_Belmopan 27 32 41 Dominican_Rep_LAVEGA 25 32 43 Belize_BigfallS - - - Dominican_Rep_LUNION 24 31 45 Belize_Cfarm 25 33 42 Dominican_Rep_MOCA 27 32 41 Belize_Melinda 31 32 37 Dominican_Rep_MONTCRI 34 32 34 Belize_MidSex - - - Dominican_Rep_PLCASAS 23 30 47 Belize_PG_Airport 32 32 36 Dominican_Rep_POLO 22 32 46 Belize_Pgorda - - - Dominican_Rep_PTACANA 27 32 41 Belize_Pomona - - - Dominican_Rep_RARRIBA 25 31 44 Belize_Savannah - - - Dominican_Rep_RIOSANJ 30 32 38 Belize_SpanishL 30 33 38 Dominican_Rep_SALCEDO 24 31 45 Belize_TowerHil - - - Dominican_Rep_SAMANA 26 31 43

Dominican_Rep_SANCRTB 24 31 46 Cuba_Cent 43 32 25 Dominican_Rep_SANPMAC 22 31 47 Cuba_East 38 33 29 Dominican_Rep_SBLMAR 24 31 45 Cuba_West 40 31 28 Dominican_Rep_SCRTBAL 28 31 41

Dominican_Rep_STGORDG 36 32 32 Dominica_TDCF 20 31 49 Dominican_Rep_STIGO 24 31 45 Dominica_TDPD 19 31 50 Dominican_Rep_STODGO 24 31 45

Station Belo

w Norm

al Abov

e Station Belo

w Norm

al Abov

e Grenada_MB 23 31 47 Jamaica_BECKFORD 30 32 38

Jamaica_MANLEY 32 33 36 Guadeloupe_BAIE_MAHAUT 17 31 52 Jamaica_SANGSTER 34 32 34 Guadeloupe_DESIRADE 18 31 51 Jamaica_SAV 31 32 36 Guadeloupe_LE_MOULE 18 31 50 Jamaica_SERGE 31 32 37 Guadeloupe_PETIT_BOURG 19 31 50 Guadeloupe_PORT_LOUIS 19 31 50 Martinique_FDF_DESAIX 19 30 50 Guadeloupe_RAIZET 18 31 51 Martinique_FDF-DONIS 19 30 51

Guadeloupe_ST_FRANCOIS 20 31 49 Martinique_FOND-DENIS-CADET 18 31 51

Guadeloupe_STE_ANNE1 20 31 50 Martinique_GRANDRIVIERE 19 31 50 Guadeloupe_STE_ANNE4 19 31 50 Martinique_LAMENTIN-AERO 17 30 53

Martinique_ROBERT-DUCHESNE 18 31 51

Guyana_#73Village 32 32 36 Martinique_STE-MARIE-GEND 19 31 50 Guyana_Albion_Ft 27 32 41 Martinique_ST-ESPRIT-GEND 18 31 52 Guyana_Annai - - - Martinique_ST-PIERRE 20 31 49 Guyana_AnnaReg - - - Martinique_TRINITE-SPOUTOU 19 31 50 Guyana_Blairmont 31 32 37 Martinique_TROIS-ILETS 18 31 51 Guyana_Charity - - - Martinique_VAUCLIN 18 31 51 Guyana_Gtown 27 32 41 Guyana_Lethem - - - St_Lucia_GC 17 31 52 Guyana_Mards 27 32 41 St_Lucia_Hew 19 31 51 Guyana_New_Amsterdam 30 32 38 Guyana_PortK - - - Trinidad_and_Tobago_CrownPt 22 31 47

Guyana_Skeldon 29 32 39 Trinidad_and_Tobago_Hillsborough 20 31 49

ROC area maps

Odds of valid above normal rainfall forecast: ROC = 50-80% in E and S Caribbean islands ROC = 20-50% in other areas.

Odds of valid below normal rainfall forecast: ROC = 50-80% in E Caribbean islands; ROC = 20-50% in the Greater Antilles, Bahamas, Belize, southernmost islands and Guyana for seasons with below normal rainfall.

CCA modes

AMJ Rainfall Forecast Tercile maps

NORMAL

BELOW

ABOVE

CPT AMJ rainfall forecast – Experiment 2

Data: Predictor = JFM SST observations 1979-2012

140E-20W and 30N-20S (i.e. tropical Pacific & Atlantic) [Source: IRI data library]

Predictand = AMJ rainfall for 94 Caribbean stations 1979-2012

Parameters: CCA modes: max = 3; optimum= 2 X modes: max = 5; optimum = 5 Y modes: max = 5; optimum = 5 Missing Y data threshold: 20% missing values, 10% missing stations, leading to 82 stations included in hindcast and forecast Goodness index (transformed Y) = 0.205

Station Belo

w Norm

al Abov

e Station Belo

w Norm

al Abov

e Antigua_GCastle 37 32 31 Dominican_Rep_BARAHNA 46 30 24 Antigua_VCBIRD 39 31 30 Dominican_Rep_BAYAGNA 33 31 36

Dominican_Rep_CABRERA 39 30 31 Bahamas_LPIA 43 30 27 Dominican_Rep_CONSTAN 39 31 30

Dominican_Rep_GASPHEZ 32 31 37 Barbados_CIMH 39 34 28 Dominican_Rep_HOVALLE 31 30 40 Barbados_GAIA 38 31 31 Dominican_Rep_JIMANI 33 29 37

Dominican_Rep_LAMERIC 37 29 34 Belize_Belmopan 34 31 34 Dominican_Rep_LAVEGA 37 31 32 Belize_BigfallS - - - Dominican_Rep_LUNION 34 31 36 Belize_Cfarm 41 33 26 Dominican_Rep_MOCA 42 28 30 Belize_Melinda 31 30 38 Dominican_Rep_MONTCRI 41 31 28 Belize_MidSex - - - Dominican_Rep_PLCASAS 39 30 31 Belize_PG_Airport 36 29 35 Dominican_Rep_POLO 37 32 31 Belize_Pgorda - - - Dominican_Rep_PTACANA 37 28 35 Belize_Pomona - - - Dominican_Rep_RARRIBA 33 30 37 Belize_Savannah - - - Dominican_Rep_RIOSANJ 34 30 35 Belize_SpanishL 43 32 25 Dominican_Rep_SALCEDO 35 30 36 Belize_TowerHil - - - Dominican_Rep_SAMANA 38 29 32

Dominican_Rep_SANCRTB 37 31 32 Cuba_Cent 48 30 22 Dominican_Rep_SANPMAC 42 30 29 Cuba_East 49 31 20 Dominican_Rep_SBLMAR 38 31 31 Cuba_West 50 30 20 Dominican_Rep_SCRTBAL 29 33 37

Dominican_Rep_STGORDG 49 29 22 Dominica_TDCF 38 31 31 Dominican_Rep_STIGO 35 29 35 Dominica_TDPD 40 31 29 Dominican_Rep_STODGO 40 30 30

Station Belo

w Norm

al Abov

e Station Belo

w Norm

al Abov

e Grenada_MB - - - Jamaica_BECKFORD 48 30 22

Jamaica_MANLEY 51 29 19 Guadeloupe_BAIE_MAHAUT 40 31 29 Jamaica_SANGSTER 42 30 28 Guadeloupe_DESIRADE 40 32 28 Jamaica_SAV 39 29 32 Guadeloupe_LE_MOULE 41 31 28 Jamaica_SERGE 49 30 21 Guadeloupe_PETIT_BOURG 40 31 29 Guadeloupe_PORT_LOUIS 35 31 34 Martinique_FDF_DESAIX 38 30 32 Guadeloupe_RAIZET 41 31 28 Martinique_FDF-DONIS 33 32 35

Guadeloupe_ST_FRANCOIS 40 30 30 Martinique_FOND-DENIS-CADET 37 31 31

Guadeloupe_STE_ANNE1 38 30 32 Martinique_GRANDRIVIERE 38 30 31 Guadeloupe_STE_ANNE4 40 31 29 Martinique_LAMENTIN-AERO 40 31 29

Martinique_ROBERT-DUCHESNE 42 31 27

Guyana_#73Village 28 30 42 Martinique_STE-MARIE-GEND 39 32 29 Guyana_Albion_Ft 21 30 49 Martinique_ST-ESPRIT-GEND 42 32 26 Guyana_Annai - - - Martinique_ST-PIERRE 38 32 29 Guyana_AnnaReg - - - Martinique_TRINITE-SPOUTOU 42 30 28 Guyana_Blairmont 19 30 51 Martinique_TROIS-ILETS 36 31 33 Guyana_Charity - - - Martinique_VAUCLIN 42 31 27 Guyana_Gtown 20 29 51 Guyana_Lethem - - - St_Lucia_GC 34 34 32 Guyana_Mards 24 31 45 St_Lucia_Hew 35 33 31 Guyana_New_Amsterdam 21 30 49 Guyana_PortK - - - Trinidad_and_Tobago_CrownPt 30 32 37

Guyana_Skeldon 28 30 41 Trinidad_and_Tobago_Hillsborough 28 34 38

ROC area maps

Odds of valid below normal rainfall forecast: ROC = 50-70% in most E Caribbean; ROC = 20-50% in other areas.

Odds of valid above normal rainfall forecast: • ROC = 50-80% in E and S Caribbean; • ROC = 20-50% in other areas.

CCA modes

AMJ Rainfall Forecast Tercile maps

NORMAL

BELOW

ABOVE

Supporting probabilistic AMJ rainfall forecasts Four data sources: 1) IRI multi-model probability forecast 2) UK Met Office GCM (UKMO) probability forecast 3) European Center for Mid-range Weather Forecast GCM (ECMWF) probability forecast 4) APEC Climate Center (APCC) model probability forecasts.

Rainfall tendencies for supporting models: 1) Southern Caribbean tends to be more likely wetter than average. 2) Northern Caribbean tends to be more likely dry than average. 3) Near climatology rainfall expected across the remainder of the Caribbean. Rainfall outlooks are generated next to T2m outlooks for AMJ

CPT probabilistic AMJ rainfall forecast CONCLUSIONS Rainfall tendencies for April, May and June from the CPT experiments and supporting models: 1)Southern Caribbean tends likely to become wetter than average. 2)Northern Caribbean tends likely to become dryer than average. 3)Near climatology rainfall expected across the remainder of the Caribbean. 4)Compared to the previous (MAM) outlook, the area of above average rainfall is fading and retreating southward. The emerging drying is likely due to the disappearing La Niña (as seen in observed tropical Pacific SSTs), corroborated by a positive NAO phase this winter, enhancing trade winds, lowering tropical Atlantic SSTs, and thus rainfall over the eastern Caribbean.

Rainfall April 2012 RAINFALL mm

Analysis of rain according to the Percent of Normal

During the month of April 2012 the cumulative rainfall was above normal across the country. The positive deviation was 140.9%, which compared with the month of March was 30% higher.

Lluvia de abril 2012 de las regiones climáticas comparadas con la normal

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Región SE

Región SO

Región O Región NE

Región NO

Región N

Lluv

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Total mm Desvío mm Normal 1971-2000

Forecast Prepared by CariCOF Caribbean CLimate Outlook Forum

The result for Belize from the Central American and Caribbean Forum 35% likelihood of above normal rainfall 40% likelihood of normal rainfall 25% likelihood of below Normal rainfall

Thank you for your

attention