Forecast issued at 11 p.m. on Tuesday 11 August, just under 19 hours before totality

Forecast issued at 16:00 on Tuesday 11 August

The forecast period extends 26 hours ahead

A low-pressure system is expected to approach southern Iceland on Wednesday. The latest weather model runs indicate that it will be located just south of Reykjanes on Wednesday afternoon, with its associated fronts crossing most of the country. The low is then expected to move eastwards along the south coast.

Rainfall will mainly affect southern Iceland, while less rain is expected in Breiðafjörður and the Westfjords until the early evening, when the fronts appear likely to move across the area. These areas will therefore probably have the best chance of breaks developing in the cloud cover around the time of the solar eclipse. It is also expected to remain dry across northern Iceland for most of the day. More detailed forecasts for individual areas in western Iceland, with particular reference to the eclipse, are provided below.

Most models now place the low in a similar location, providing considerable confidence in its forecast position. However, there is still some uncertainty about the timing and extent of the fronts and how far north they will reach along Faxaflói Bay. This will significantly affect whether, and how clearly, the eclipse will be visible, particularly in northwestern Iceland.

The Icelandic Met Office’s high-resolution models provide forecasts for three cloud layers: high, medium and low cloud. High cloud has little effect on viewing the eclipse, as sunlight can pass through it relatively easily. Medium-level cloud is less transparent, although it may still be possible to view the eclipse. If low cloud covers an area, however, there is little chance of seeing the Sun or the eclipse.

The total cloud-cover forecast indicates that skies will be almost completely overcast across Iceland at 18:00, as shown in the green panel. For example, there is little chance of the cloud cover breaking up in southwestern Iceland. However, the low-cloud forecast shows more breaks in parts of western and northwestern Iceland, particularly in the Westfjords. The medium- and high-cloud forecasts show gaps in similar areas, although not in exactly the same locations. The upper image shows the latest run of the IG high-resolution model, while the lower image shows the DINI high-resolution model. The models do not fully agree, so the location of any breaks in the cloud cover remains uncertain.

Cloud-cover forecasts are generally among the most difficult forecast products to produce, as the underlying physics is highly complex. Small gaps in the forecast cloud cover should therefore be treated with caution. The forecasts primarily indicate that breaks may develop somewhere within the area, but their exact location cannot be determined.

The forecast for Iceland on Wednesday is as follows:

Easterly and northeasterly winds of 3–10 m/s, but somewhat stronger winds along the south coast. Cloudy in many areas with showers or intermittent rain, easing in northwestern Iceland during the evening. Temperatures of 8–18°C, coolest along the north and east coasts.

The precipitation forecast maps below from the Icelandic Met Office’s IG and DINI high-resolution models are valid at 18:00 on Wednesday. They show in much greater detail where rain is expected and the extent of the precipitation. The maps again demonstrate the difficulty of determining its precise location. The best chance of breaks in the cloud cover remains around Breiðafjörður, particularly in the Westfjords.

Weather outlook along the path of totality

Capital region

Light easterly or northeasterly winds, cloudy with showers. More persistent rain is expected for a time towards evening, before the precipitation begins to ease. There is little chance of breaks developing in the cloud cover around the time of the solar eclipse.

Reykjanes Peninsula

Similar conditions to the capital region, with northeasterly winds and showers. More persistent rain is expected for a time towards evening, before the precipitation begins to ease. There is little chance of breaks developing in the cloud cover.

Snæfellsnes

Easterly winds and generally dry conditions until after noon, followed by intermittent rain or showers. Skies will probably be cloudy, but as the fronts appear to be weakening around the time of maximum eclipse, there is a chance of local breaks developing in the low- and medium-level cloud around Breiðafjörður into the early evening.

Westfjords

Light northeasterly winds and mostly cloudy conditions. It will remain dry for most of the day, with isolated showers towards evening and somewhat more rain late in the evening. High cloud is expected, with little low cloud except mainly in western areas. Breaks may develop in the medium-level cloud, particularly in the northwest.