These are the current air pressure maps for the Netherlands and the North Sea, the hourly forecast is based on the Harmonie-Arome weather model from the KNMI.
Weather models are algorithmic computer approaches that attempt to predict the future state of the atmosphere. To do this, a weather model places a grid of points over the map, for each point the forecast is drawn up based on the current starting situation - with parameters such as wind, air pressure, relative humidity and temperature. The calculations are performed 4 times a day to always take the new current values as a starting point.
Multiple variants
The KNMI uses several weather models, the High Resolution Limited Area Model (HIRLAM), in use since 1993. The HARMONIE (HIRLAM ALADIN Research on Mesoscale Operational NWP in Euromed), since 2012. And Harmonie-Arome has been the latest version of this model since 2019, a combination with the Arome weather model from Météo-France. These weather models provide hourly forecasts for the North Sea, the Netherlands and the rest of the Benelux.
Hyperlocal
The nice thing about Harmonie in particular is that it has a very high data resolution with grid points that are less than 2.5 kilometers apart. This model therefore provides a hyperlocal wind forecast that has a high degree of probability for the Netherlands. Hence the Water Map Live servers generate series of maps four times a day with the most recent output of the weather model.
Netherlands
Wind forecast nodes
Beaufort wind forecast
Wind forecast + air pressure
Wadden Sea
Wind forecast nodes
Beaufort wind forecast
Wind forecast + air pressure
IJsselmeer and Frisian Lakes
Wind forecast nodes
Beaufort wind forecast
Wind forecast + air pressure
Zeeland
Wind forecast nodes
Beaufort wind forecast
Wind forecast + air pressure
Knots |
Beaufort |
m/s |
km/h |
1 |
0 |
0 - 0,2 |
1 |
1-3 |
1 |
0,3-1,5 |
1-5 |
4-6 |
2 |
1,6-3,3 |
6-11 |
7-10 |
3 |
3,4-5,4 |
12-19 |
11-15 |
4 |
5,5-7,9 |
20-28 |
16-21 |
5 |
8,0-10,7 |
29-38 |
22-27 |
6 |
10,8-13,8 |
39-49 |
28-33 |
7 |
13,9-17,1 |
50-61 |
34-40 |
8 |
17,2-20,7 |
62-74 |
41-47 |
9 |
20,8-24,4 |
75-88 |
48-55 |
10 |
24,5-28,4 |
89-102 |
56-63 |
11 |
28,5-32,6 |
103-117 |
64-71 |
12 |
32,7-36,9 |
118-133 |