Page History

Note: HRES and Ensemble Control Forecast (ex-HRES) are scientifically, structurally and computationally identical.  With effect from Cy49r1, Ensemble Control Forecast (ex-HRES) output is equivalent to HRES output shown in the diagrams.   At the time of the diagrams, HRES had resolution of 9km and ensemble members had a resolution of 18km.

Tropical Cyclone Diagrams - new TCs

Tropical storm strike probability charts.

Charts are available to show the potential tropical cyclone activity at different time ranges throughout the forecast.  They encompass both tropical cyclones that are present at analysis time and those that come into existence during the forecast.  These are an experimental product in which TC assignation, for cyclonic features, is based on identifying a warm core. 

...

• all tropical cyclones (wind speeds >8m/s),
• tropical storms (wind speeds >17 m/s),
• hurricanes/typhoons (wind speeds > 32m/s). 

Web charts

Tropical storms are identified by the existence of a warm core isobaric depression.  The charts show the probability of the passage of storms identified in this way (some possibly not yet developed) within a 300km radius of a given location. 

...

Fig8.1.16.2-4: Web charts tropical storm strike probability charts from ensemble probability charts data time 12UTC 03 January 2018 verifying at  T+144 (12UTC 09 January 2018) and T+192 (verifying 12UTC on 11 January 2018).   Forecast from ensemble, data time 00UTC 8 January 2018.    The charts show probabilities associated with tropical storm force winds indicated to increase from a weaker pre-existing tropical cyclone near the northwest coast of Australia.

ecCharts

Tropical cyclone, tropical storm, and hurricane strike probability charts are also available on ecCharts.  These are an experimental product based upon identification of the warm-core circulation during the forecast period.  They are useful during and after extra-tropical transition of these features as they move into mid-latitudes.  ecCharts have the advantage that boundary layer (or any other) winds can be superimposed.

...

Fig8.1.16.2-5: ecChart tropical storm strike probability chart from ensemble with 100m winds (m/s) from HRES for T+96 verifying at 00UTC 12 January 2018.  Forecast from ensemble, data time 00UTC 8 January 2018.  With effect from Cy49r1, HRES

Note: HRES and Ensemble Control Forecast (ex-HRES) are scientifically, structurally and computationally identical.  With effect from Cy49r1, Ensemble Control Forecast (ex-HRES) output is equivalent to HRES output shown in the diagrams.   At the time of the diagrams, HRES had resolution of 9km and ensemble members had a resolution of 18km.

RSMC official forecasts of tropical cyclones take precedence

Note: IFS products on these pages regarding tropical cyclones are generated automatically without any editing by forecast experts.   RSMCs (Regional Specialized Meteorological Centres) have ultimate responsibility for official forecasts of tropical cyclones within their respective regions (ECMWF is one of a number of centres that provide data to them).  Up-to-date information is available by direct access to official RSMC forecasts through the WMO Severe Weather Information Centre.  For up-to-date forecast information for their own local area users should refer to forecasts from their own National Meteorological Service.

Additional Sources of Information

(Note: In older material there may be references to issues that have subsequently been addressed)

• Read more on ECMWF presentation of tropical cyclones (with up-to-date locations of TCs).

(FUG Associated with Cy49r1)