Ensemble forecast from Harmonie#

An ensemble weather forecast is a set of forecasts that present the range of future weather possibilities. Multiple simulations are run, each with a slight variation of its initial conditions and with slightly perturbed weather models. These variations represent the inevitable uncertainty in the initial conditions and approximations in the models. They produce a range of possible weather conditions.

Temporal and spatial resolution#

The forecast provides data for the next 2 days with a 24h time step.

The spatial resolution is 2.5 km.

Update frequency#

The data is updated four times a day following the model runs:

  • 00h UTC.

  • 06h UTC.

  • 12h UTC.

  • 18h UTC.

Available variables#

The following variables are available on the platform:

Probability of Precipitation of at least 1/5/10/20 mm#

This variable gives the probability (in %) that total precipitation will be 1/5/10/20 mm or above. It is derived from the range of possible outcomes as predicted by the Harmonie ensemble forecasting system. A higher probability indicates that more ensemble members are predicting total precipitation of 1/5/10/20 mm or above.

Currently, the platform displays a different layer for each of the available thresholds: * Precipitation of at least 1mm * Precipitation of at least 5mm * Precipitation of at least 10mm * Precipitation of at least 20mm

The units used are %.

Probability of Wind speed of at least 10/15 m/s#

This variable gives the probability (in %) that the wind speed will be 10/15 m/s or above. It is derived from the range of possible outcomes as predicted by the Harmonie ensemble forecasting system. A higher probability indicates that more ensemble members are predicting a wind speed of 10/15 m/s or above.

Currently, the platform displays a different layer for each of the available thresholds: * Wind speed of at least 10 m/s (Displayed as 36 km/h) * Wind speed of at least 15 m/s (Displayed as 54 km/h)

The units used are %.

Probability of Wind gust of at least 10/15 m/s#

This variable gives the probability (in %) that the wind gust will be 10/15 m/s or above. It is derived from the range of possible outcomes as predicted by the Harmonie ensemble forecasting system. A higher probability indicates that more ensemble members are predicting a wind gust of 10/15 m/s or above.

Currently, the platform displays a different layer for each of the available thresholds: * Wind gust of at least 10 m/s (Displayed as 36 km/h) * Wind gust of at least 15 m/s (Displayed as 54 km/h)

The units used are %.

Visualization#

Probability of Wind speed > 10 m/s (36 km/h)

Data sources#

Data provided directly by Met Éireann.