Belgrad nov. 2013

SEECOF-10Forecasts for DJF

Christian Viel

Météo-France

2

Outline

Ocean analysis

Ocean forecasts

General Circulation forecasts

Impacts (T, RR)

Summary

3

Oceanicanalysis

SSTOct. 2013

Ocean analysis

From MERCATOR, reference GLORYS 1992-2009

4

Ocean analysisAugust September October

Equatorial PacificEquatorial AtlanticEquatorial Indian

Kelvin waves

time

5

Weak SST anomalies in equatorial regions :

– Atlantic : ~neutral

– Pacific : weak positive anomaly in the western part, becoming neutral in the eastern part (warming) ENSO phase : neutral

– Indian : west neutral, east positive IOD still negative (but now ~0)

Ocean analysis

Niño3.4

6

Outline

Ocean analysis

Ocean forecasts

General Circulation forecasts

Impacts (T, RR)

Summary

7

Ocean forecasts

SST forecasts

Météo France

ECMWF

8

Niño3.4

Ocean forecasts – Central Pacific

9

Ocean forecasts - Atlantic

Northern tropical Atlantic (TNA) :

10

Tropics : Pacific : weak positive anomaly around the Warm Pool; ENSO neutral Indian : IOD ~0 Atlantic : warmer than normal conditions in Northern sub-tropics

Ocean forecasts

11

Ocean forecasts

12

NAO- NAO+

Atlantic ridge

Blocking

SST Composites of November (standardized anomalies) vs winter regime occurrences in DJF (MF model)

Lower Tercile

Upper Tercile

UpperTercile

Lower Tercile

(significance threshold 70 %)

Previous oceanic conditions to winter weather regimes

13

Reg

ime

et m

ean

TT

,RR

in

win

ter

14

Outline

Ocean analysis

Ocean forecasts

General Circulation forecasts

Impacts (T, RR)

Summary

15

Tropical response and forcing - DJF

Shaded areas : velocity potential anomalies (divergent circulation anomalies)

green <-> upward motion anomaly

pink <-> downward motion anomaly

Isolines : stream function anomalies (rotational circulation

anomalies)

blue lines <-> cyclonic (in NH)

red lines <-> anticyclonic (in NH)

Upper troposphere circulation fields (200 hPa)

++

+ -

--

16

Mid-Latitude Response - DJF

17

Mid-Latitude Response - DJF

18

Relatively good consistency in tropical response to SST forcing But no trace of teleconnection from tropics to NH mid-latitude

limited predictability related to tropical forcing

General Circulation forecasts - DJF

19

Outline

Ocean analysis

Ocean forecasts

General Circulation forecasts

Impacts (T, RR)

Summary

21

Temperature probabilities : DJF

Skill (1987-2001)

22

Precipitation probabilities : DJF

Skill (1987-2001)

Skill (1987-2001)

outer-quintile categories

24

Summary for DJF

- close to normal conditions in equatorial waveguides , despite ofwarming of SST anomalies over the central part of Equatorial Pacific ENSO : neutral conditions

- limited predictability over mid-latitudes (Europe)

- some signal (for T) over the Mediterranean basin : slightly enhanced probabilities of warmer than normal conditions

25

Temperature and rainfall scenarios for Europe : DJF

Skill (1987-2001)

T

MODELS

CEPabove

normal

above

normal

no

privileged

no

privileged

no

privileged

MFabove

normal

above

normal

above

normal

above

normal

above

normal

Met Officeno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

CPC normalabove

normal

no

privileged

no

privileged

above

normal

JMA

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

synthesisno

privileged

above

normal

no

privileged

no

privileged

no

privileged

LC-MMEabove

normal

above

normal

above

normal

above

normal

above

normal

Eurosipabove

normal

above

normal

above

normal

above

normal

above

normal

no privileged scenario

above normal

Northern Europe Southern Europe Central Europe Eastern Europe SEE Region

privileged scenario by

RCC-LRF node

no privileged scenario

above normalno privileged

scenario

MODELS

CEPno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

MFAbove

normal

no

privileged

Above

normal

Above

normal

Above

normal

Met Officeno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

CPCAbove

normal

no

privileged

no

privileged

JMA

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

no

privileged

scenario

synthesisno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

LC-MMEno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

Eurosipno

privileged

no

privileged

no

privileged

no

privileged

no

privileged

privileged scenario by

RCC-LRF node

no privileged scenario

no privileged scenario

no privileged scenario

no privileged scenario

no privileged scenario

Northern Europe Southern Europe Central Europe Eastern Europe SEE Region

RR

http://elaboration.seasonal.meteo.fr

Not yet available Not yet available

26

27

NAO- NAO+

Atlantic ridge

Blocking

SST Composites of November (standardized anomalies) vs winter regime occurrences in DJF (MF model)

Lower Tercile

Upper Tercile

UpperTercile

Lower Tercile

(significance threshold 70 %)

Previous oceanic conditions to winter weather regimes

28

Reg

ime

et m

ean

TT

,RR

in

win

ter