Synopsis
A high-pressure area over the British Isles slowly moves northeast to the North Sea. Low-pressure Boris is above Eastern Europe and moving south. In between, we're dealing with northern currents. The remnants of a cold front are above the far southeast and are pulling back northwest over our country tonight and tomorrow morning as a weak heat front. The current, which is north today, then turns east to northeast. Meanwhile, an inactive heat front that pertains to low pressure Boris from Germany is getting closer and will pass westward in the evening. Both fronts are only recognizable by low clouds and of course in the moisture fields. We lay the second heat front at a dew point of about 15 degrees.

Model assessment
The stationary cold front remains recognizable by a strip of damper air, in which tonight and tomorrow morning low clouds could arise, above the east and southeast, helped by daily corridor and thrust. Tomorrow during the day, however, this resolves quite quickly. UWC and HAP2 will come to the passage of the diffuse heat front tomorrow morning with a chance at low Sc, which does not seem unrealistic. Behind the second heat front in the night to Wednesday, the chance of advtive stratus and fog increases. UWC is the most pronounced in this, other models, especially EC, are more relaxed in this. My impression is that UWC exaggerates a little bit, but that EC is far too rosy. Given the decreased solar power, the last stratus will probably not be resolved until the beginning of the afternoon, whether the west of the country has already been reached.Issues

Wind
Tomorrow afternoon and evening there is a chance of 6 Bft along the southwest coast.

Visibility
Tonight and tomorrow morning in the southeast and east there's a chance of fog. Wednesday in the night and morning mist, possibly even mist, behind the heat front of layer Boris, gradually resolving in the morning.

Temperature
No details.

Cloud
See model assessment on the risk of ST at the fronts. Further Sc and Cu on the daily corridor, a TCu seems no longer feasible.

Precipitation
Near the first diffuse cold/heat front until tomorrow morning chance of some light rain or drizzle, without any condition restriction. It's dry.

Synoptic development
A high is above the south of Scandinavia and consequently leads to a (northern) eastern flow of dry air. The current gradually becomes south-easterly due to an active layer moving from Italy to the south-west of Europe and the air brought in is getting warmer. Towards the weekend, this low is heading northeast towards our surroundings. On Monday, it'll probably move north through our country and then we'll get into a weak meandering current.

Model assessment and uncertainties
Until Saturday, the models are unambiguous. It's dry and the sun shines a lot. The midday temperature is between 22°C and 25°C. Sunday the current becomes south and later on the day probably a low with some (thunderstorm) showers coming from the south towards our country. The timing of these showers and how this layer develops is still uncertain. On Monday, September 23rd, this layer will move across our country, or just west of our country, northwards and the probability of precipitation is 70%. Then a weak meandering current causes slightly variable weather with precipitation potential around 50%. The sun shines occasionally, but sometimes also glitches with rain or showers. The current fluctuates between southwest and northwest, making the temperature forecast uncertain; the maximum temperature varies between 15°C and 23°C.

Multi-day Summary
Great periods with sun and dry. Sunday chance of some (thunderstorm) showers. Freely warm with maximum temperature between 22°C and 25°C.

EPS Period Summary
Slightly variable weather with occasionally sunshine, but also chance of some showers and temperatures falling to values around normal.

Valid from Wednesday 18 September to Monday 30 September