current ecmwf ensemble-based tools for forecasters 4.10... · using typhoon lupit and hurricane ike...

Slide 1

Slide 1

Current ECMWF ensemble-based tools

for forecasters

David Richardson

Head, Meteorological Operations Section

david.richardson@ecmwf.int

Thanks to Fernando Prates, Tim Hewson

HFIP Workshop 20-21 April 2010

Slide 2

Slide 2

Summary

ECMWF EPS: 50 members, 32km resolution to day 10 then 50

km to day 15. Runs twice per day

If a TC is reported at analysis time then perturbations are

generated targeted on TC (using singular vectors)

All TCs reported at analysis time are tracked in each EPS member

Current products:

• Individual tracks (all members, control, high resolution model)

• Strike probability

• Feature-specific “EPSgrams”: EPS distribution of maximum

wind and minimum pressure following the TC track

Under test:

• Include TC genesis

• More interactivity on web products

HFIP Workshop 20-21 April 2010

Slide 3

Slide 3

TC products available on web for WMO users

TC track from each

ensemble member

(thin lines)

Strike probability

(shading)

Shows which areas

are more at risk

HFIP Workshop 20-21 April 2010

Slide 4

Slide 4

Katrina forecasts (days from landfall)

•4 days •3 days

•1.5 days

Ensemble clearly shows

changing uncertainty in tracks

HFIP Workshop 20-21 April 2010

Slide 5

Slide 5

TC products: Lagrangian EPSgram

Feature-based

Shows max wind and central

pressure along the TC track

Box-whisker: EPS distribution

Green line: EPS control

Blue line: high-resolution

deterministic forecast

In this example clear impact of

resolution on intensity; EPS still

gives useful information on

associated uncertainty

Deterministic Forecast and EPS Distribution 26 August 2005 12 UTC

Tropical Cyclone KATRINA (12L) starting from 25.2 N 81.9 W

EPS Lagrangian Meteogram

0

10

20

30

40

50

Number of EPS Members Tracked

0

10

20

30

40

50

60

10m Wind Speed (m/s)

940

960

980

1000

1020

FRI SAT SUN MON TUE WED26

AUGUST2005

27 28 29 30 31

Mean Sea Level Pressure in Cyclone Centre (hPa)

min

25%

median

75%

max

HFIP Workshop 20-21 April 2010

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Slide 6

TC genesis

Increasingly ECMWF forecasts pick up tropical cyclones

before they are officially reported

In 2008, Atlantic hurricanes were predicted 5-7 days before

they were observed

TS/Hurricane 1st Observed date Forecast detection

Fay 16-Aug D+6 (run: 10-Aug)

Gustav 25-Aug D+5 (run: 20-Aug)

Hanna 28-Aug D+5 (run: 23-Aug)

Ike 02-Sep D+7 (run: 26-Aug)

Josephine 03-Sep D+5 (run: 29-Aug)

HFIP Workshop 20-21 April 2010

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Slide 7

L

LL

L

L L

L

L L

1016

1016

1016

5°N5°N

10°N 10°N

15°N15°N

20°N 20°N

25°N25°N

30°N 30°N

85°W

85°W 80°W

80°W 75°W

75°W 70°W

70°W 65°W

65°W 60°W

60°W 55°W

55°W 50°W

50°W 45°W

45°W 40°W

40°W 35°W

35°W 30°W

30°W 25°W

25°W 20°W

20°W

Tuesday 26 August 2008 12UTC ECMWF Forecast t+120 VT: Sunday 31 August 2008 12UTC Surface: Mean sea level pressure

L

LL

L

LL

L

L

L

1008

1016

1016

1016

5°N5°N

10°N 10°N

15°N15°N

20°N 20°N

25°N25°N

30°N 30°N

85°W

85°W 80°W

80°W 75°W

75°W 70°W

70°W 65°W

65°W 60°W

60°W 55°W

55°W 50°W

50°W 45°W

45°W 40°W

40°W 35°W

35°W 30°W

30°W 25°W

25°W 20°W

20°W

Sunday 24 August 2008 12UTC ECMWF Forecast t+168 VT: Sunday 31 August 2008 12UTC Surface: Mean sea level pressure

LL

L

L

L

L

L

L

L

L

L

L

L1016

1016

1016

5°N5°N

10°N 10°N

15°N15°N

20°N 20°N

25°N25°N

30°N 30°N

85°W

85°W 80°W

80°W 75°W

75°W 70°W

70°W 65°W

65°W 60°W

60°W 55°W

55°W 50°W

50°W 45°W

45°W 40°W

40°W 35°W

35°W 30°W

30°W 25°W

25°W 20°W

20°W

ECMWF Analysis VT:Sunday 31 August 2008 12UTC Surface: Mean sea level pressure

5°N5°N

10°N 10°N

15°N15°N

20°N 20°N

25°N25°N

30°N 30°N

85°W

85°W 80°W

80°W 75°W

75°W 70°W

70°W 65°W

65°W 60°W

60°W 55°W

55°W 50°W

50°W 45°W

45°W 40°W

40°W 35°W

35°W 30°W

30°W 25°W

25°W 20°W

20°W

Surface: Mean sea level pressureTuesday 26 August 2008 00UTC ECMWF EPS Control Forecast t+120 VT: Sunday 31 August 2008 00UTC

5

10

20

30

40

50

60

70

80

90

101

Gustav

Gustav

IKE

Hanna

Hanna

IKE

Hanna

Gustav

IKE

5 day

forecast

Strike probability for 24 hrs centred T+132

Probability passing within 120 km

Active Atlantic hurricane season 2008

7 day

forecast

analysis5 day EPS

forecast

HFIP Workshop 20-21 April 2010

Slide 9

Slide 9

Cyclones ULUI & TOMAS

VT: 11-13 March 12-12Z

EPS

Strike Probability for

48hrs

03@12 D+10

07@12 D+606@12 D+705@12 D+8

04@12 D+9

10@12 D+309@12 D+408@12 D+5

ULUITOMAS

HFIP Workshop 20-21 April 2010

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Slide 10

TC genesis: monthly forecast

Once a week the 15-day EPS is extended out to 1 month ahead

Same TC tracker is run throughout the forecast

Genesis probability maps are produced for 7-day periods

Probabilities are presented as anomalies – i.e. is a TC more or

less likely to occur compared to the climatological frequency

The EPS re-forecasts are used to generate a model climatology

of TC activity

Re-forecasts are 5-member EPS run for current date for last 18

years, all run using operational model configuration

HFIP Workshop 20-21 April 2010

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Slide 11

Basin activity: monthly forecast

HFIP Workshop 20-21 April 2010

80°S80°S

70°S 70°S

60°S60°S

50°S 50°S

40°S40°S

30°S 30°S

20°S20°S

10°S 10°S

0°0°

10°N 10°N

20°N20°N

30°N 30°N

40°N40°N

50°N 50°N

60°N60°N

70°N 70°N

80°N80°N

20°E

20°E 40°E

40°E 60°E

60°E 80°E

80°E 100°E

100°E 120°E

120°E 140°E

140°E 160°E

160°E 180°

180° 160°W

160°W 140°W

140°W 120°W

120°W 100°W

100°W 80°W

80°W 60°W

60°W 40°W

40°W 20°W

20°W

0 00 00 0.060.2 0.060 0

0.02 0.22 0.64 0.44 0.01 0.17

Not Significant Significant at 5%

Ensemble size = 51,climate size = 90

Forecast start reference is 18/03/2010

Tropical Storm Frequency

ECMWF Monthly Forecast

Climate = 1992-2009

22/03-28/03/2010

DAY 05-11

Forecast mean Climate median

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Slide 12

Basin activity: monthly forecast

HFIP Workshop 20-21 April 2010

80°S80°S

70°S 70°S

60°S60°S

50°S 50°S

40°S40°S

30°S 30°S

20°S20°S

10°S 10°S

0°0°

10°N 10°N

20°N20°N

30°N 30°N

40°N40°N

50°N 50°N

60°N60°N

70°N 70°N

80°N80°N

20°E

20°E 40°E

40°E 60°E

60°E 80°E

80°E 100°E

100°E 120°E

120°E 140°E

140°E 160°E

160°E 180°

180° 160°W

160°W 140°W

140°W 120°W

120°W 100°W

100°W 80°W

80°W 60°W

60°W 40°W

40°W 20°W

20°W

0 10 13.04 15.13 10.17 1

4.31 1 0.49 1 0.01 1

Not Significant Significant at 5%

Ensemble size = 51,climate size = 90

Forecast start reference is 18/03/2010

Accumulated Cyclone Energy

ECMWF Monthly Forecast

Climate = 1992-2009

22/03-28/03/2010

DAY 05-11

Forecast mean Climate median

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Slide 13

Basin activity: monthly forecast

HFIP Workshop 20-21 April 2010

80°N

70°N

60°N

50°N

40°N

30°N

20°N

10°N

0°N

10°S

20°S

30°S

40°S

50°S

60°S

70°S

80°S

80°N

70°N

60°N

50°N

40°N

30°N

20°N

10°N

0°N

10°S

20°S

30°S

40°S

50°S

60°S

70°S

80°S

340°E320°E300°E280°E260°E240°E220°E200°E180°E160°E140°E120°E100°E80°E60°E40°E20°E

340°E320°E300°E280°E260°E240°E220°E200°E180°E160°E140°E120°E100°E80°E60°E40°E20°E

< 10% 10.. 20 20.. 30 30.. 40 40.. 50 50.. 60 60.. 70 70.. 80 80.. 90 > 90%

Probability of a TS passing within 300km radius

Weekly mean Tropical Storm Strike Probability. Date: 20100318 0 UTC t+( 96-264)

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Slide 14

Basin activity: monthly forecast

HFIP Workshop 20-21 April 2010

80°N

70°N

60°N

50°N

40°N

30°N

20°N

10°N

0°N

10°S

20°S

30°S

40°S

50°S

60°S

70°S

80°S

80°N

70°N

60°N

50°N

40°N

30°N

20°N

10°N

0°N

10°S

20°S

30°S

40°S

50°S

60°S

70°S

80°S

340°E320°E300°E280°E260°E240°E220°E200°E180°E160°E140°E120°E100°E80°E60°E40°E20°E

340°E320°E300°E280°E260°E240°E220°E200°E180°E160°E140°E120°E100°E80°E60°E40°E20°E

< -40% -40..-30 -30..-20 -20..-10 -10.. 10 10.. 20 20.. 30 30.. 40 > 40%

Probability of a TS passing within 300km radius

Weekly mean Anomaly of Tropical Storm Strike Probability. Date:20100318 0 UTC t+( 96-264)

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Slide 15

Cyclones ULUI & TOMAS

Monthly Forecast

Weekly Mean anomaly of tropical Storm

Strike probability

TC observations 11-13 March

25th Feb days 12-18

04th Mar days 12-1804th Mar days 5-11

VT: 8th to 14th Mar 2010 VT: 15th to 21st Mar 2010

HFIP Workshop 20-21 April 2010

General MOGREPS-15 Products using Typhoon Lupit and Hurricane Ike Examples. (Includes the possibilities of multimodel plots for Ike using ECMWF

cxml data.)

Richard Swinbank and Piers Buchanan

HFIP Workshop 20-21 April 2010

Lupit: MOGREPS-15 12Z forecast from 21st October

2009

Actual Lupit Track (source: wikipedia)

HFIP Workshop 20-21 April 2010

MOGREPS-15 general basin products from 12Z forecast on

21st October 2009

HFIP Workshop 20-21 April 2010

© Crown copyright Met Office

September 5th 2008 at 12Z

• Test of multi-model product

• Combined strike probability for ECMWF and MOGREPS

• Uses CXML files from TIGGE

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Slide 20

EPS products – general developments

Growing use of forecast products on the web

Users request more tailored products and interactivity

this requires on-demand plot production

No specific applications for TCs (yet)

Few examples:

Extra-tropical cyclonic feature tracker

Clickable extreme forecast index (EFI)

New interactive on-demand web

HFIP Workshop 20-21 April 2010

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Slide 21

Extra-tropical feature tracking

HFIP Workshop 20-21 April 2010

User can click on any spot (= cyclonic feature)

to see how that feature evolves in the EPS

Slide 22

HFIP Workshop 20-21 April 2010

Slide 23

Extra-tropical feature tracking

HFIP Workshop 20-21 April 2010

User can click on any spot (= cyclonic feature) to

see how that feature evolves in that member

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Slide 24

Prototype: Forecasting tool

Interactivity: zooming, panning, …

Customisation:

Probabilities threshold, …

Show/hide, add/remove layers

Related products: Meteograms

HFIP Workshop 20-21 April 2010

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Slide 25HFIP Workshop 20-21 April 2010

Probability of more

than 5mm precipitation

in 24 hours (T+ 84-108)

Slide 26

Slide 26HFIP Workshop 20-21 April 2010

User can change

accumulation period

and threshold

Slide 27

Slide 27HFIP Workshop 20-21 April 2010

Slide 28

Slide 28HFIP Workshop 20-21 April 2010

New plot is generated

in real time

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Slide 29

Summary of products

Current products (available to WMO members):

Individual tracks (all members, control, high resolution model)

• On GTS, also CXML for TIGGE

Strike probability

Feature-specific “EPSgrams”: EPS distribution of maximum wind

and minimum pressure following the TC track

Under test:

Include TC genesis

Basin activity summary (TCs, ACE)

• Already operational for seasonal forecasts

More interactivity on web products

Use of re-forecast EPS for reference/calibration

HFIP Workshop 20-21 April 2010