Current ECMWF ensemble-based tools for forecasters 4.10... · using Typhoon Lupit and Hurricane Ike Examples. (Includes the possibilities of multimodel plots for Ike using ECMWF cxml

Slide 1

Slide 1

Current ECMWF ensemble-based tools

for forecasters

David Richardson

Head, Meteorological Operations Section

[email protected]

Thanks to Fernando Prates, Tim Hewson

HFIP Workshop 20-21 April 2010

mailto:[email protected]

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


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


Slide 4

Slide 4

Katrina forecasts (days from landfall)

•4 days •3 days

•1.5 days

Ensemble clearly shows

changing uncertainty in tracks


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


Slide 6

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)


Slide 7

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


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


Slide 10

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


Slide 11

Slide 11

Basin activity: monthly forecast


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



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



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


< 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



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



< -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


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


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

2009

Actual Lupit Track (source: wikipedia)


MOGREPS-15 general basin products from 12Z forecast on

21st October 2009


© 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

Slide 20

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


Slide 21

Slide 21

Extra-tropical feature tracking


User can click on any spot (= cyclonic feature)

to see how that feature evolves in the EPS

Slide 22


Slide 23

Extra-tropical feature tracking


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

see how that feature evolves in that member

Slide 24

Slide 24

Prototype: Forecasting tool

Interactivity: zooming, panning, …

Customisation:

Probabilities threshold, …

Show/hide, add/remove layers

Related products: Meteograms


Slide 25

Slide 25HFIP Workshop 20-21 April 2010

Probability of more

than 5mm precipitation

in 24 hours (T+ 84-108)

Slide 26


User can change

accumulation period

and threshold

Slide 27


Slide 28


New plot is generated

in real time

Slide 29

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


Documents

Current ECMWF ensemble-based tools for forecasters 4.10... · using Typhoon Lupit and Hurricane Ike Examples. (Includes the possibilities of multimodel plots for Ike using ECMWF cxml