Results of weather forecasts
On this page the results of weather forecasts are shown, constantly updated, so that anyone can know the quality of the service offered.
Since the accuracy of a prediction can be understood in different ways also, depending on the users' goals, Lungimira indicates some reference intervals and considers proper or accurate a prediction when the distance from the observation is less than the interval set. A correct prediction is often not enough if it is not too precise and therefore useful in helping to make choices. Lungimira considers useful or precise a prediction when its variability interval does not exceed the range set for each of the three atmospheric variables.
| Evaluation of: | Precision | ||
| Accuracy | Forecast: | Likely (very precise) | Unlikely (not precise) |
| Correct (very accurate) | A | B | |
| Incorrect (not accurate) | C | D | |
Square correctness-utilities.
A – Reliable and correct forecast (precise and accurate): with a narrow range of variability and a small deviation from the recorded data.
B – Unreliable but correct forecast (imprecise but accurate): with an excessive variability interval but a small deviation from the recorded data.
C – Reliable but incorrect forecast (precise but inaccurate): with a limited range of variability but excessive deviation from the measured data.
D – Unreliable and incorrect forecast (neither precise nor accurate): with an excessive range of variability and a large deviation from the recorded data.
Lungimira took into account the majority of human activities to determine what are the sufficient conditions to define a good level of accuracy and precision.
The following list defines the ranges of accuracy and precision of a
forecast of a period of ten days for the three main atmospheric variables:
| Variables | Accuracy: Difference between observation and median expected | Precision: Interval between percentile 5 and 95 expected |
|---|---|---|
| Temperature | |ΔT| < 3 °C | ΔT > 8 °C |
| Rainfall | |ΔR| < 20 mm | ΔR > 60 mm |
| Atm. Pressure. | |ΔP| < 7 hPa | ΔP > 15 hPa |
From the statistics of the predictions of Lungimira, available at the end of the page, result the following mean statistical indices that describe the level of quality of the service for the three main atmospheric variables: (Preliminary values to be updated)
| Reliable and accurate forecasts ([A] / [A+B+C+D]) | Accuracy Index ([A+B] / [A+B+C+D]) | Precision Index ([A+C] / [A+B+C+D]) | Mean Error (ME) | Mean Absolute Error (MAE) | Mean Squared Error (MSE) | Root Mean Squared Error (RMSE) | |
|---|---|---|---|---|---|---|---|
| Temperature | 76.0 % | 80.4 % | 92.1 % | 0.06 °C | 1.52 °C | 4.27 °C^2 | 2.06 °C |
| Rainfall | 68.3 % | 71.5 % | 91.9 % | 0.10 mm | 12.40 mm | 474.83 mm^2 | 21.64 mm |
| Atmospheric pressure at sea level | 69.7 % | 75.2 % | 93.1 % | 0.51 hPa | 3.80 hPa | 29.23 hPa^2 | 5.32 hPa |
From the following list you can check out the annual tables with percentages of correct predictions for the three atmospheric variables considered, estimated by means of a control sample. To view the tables select a year among those present, and will open another window. By clicking on the data in the table it appears the maps of the corresponding forecasts.
| Index of years with available data: (in update) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 2015 | 2016 | 2017 | |||||||
