Wind forecast & weather Walchensee (Urfeld)

Walchensee

Urfeld · today

WindyØ13Gust 18 knCause: Inversion

measured now · 13:00

Ø12Gust 15 kn

Weather & wind by day

Per day the most likely wind level and its probability – plus weather, temperature, rain and the strongest wind at the best time of day. The coloured bar in each tile shows how the chances split across the levels.

Wind levels (mean wind or gust):
Calm below 6 kn · Light wind 6–10 kn mean wind · Windy from 11 kn mean wind or repeated gusts ≥ 20 kn · Big Day from 14 kn mean wind or repeated gusts ≥ 25 kn (a single gust doesn't make a wind day)

Wetterdaten: Open-Meteo.com (CC BY 4.0), Modelle u.a. DWD ICON – modifiziert (MOS-Windvorhersage) durch addicted-sports. · Open-Meteo.com

Wind over time

Hourly – mean and gust wind coloured by strength (local scale), plus the forecast of the key drivers. Two days side by side at full width, otherwise stacked; on mobile each day as rows.

Wind forecast & history

Solid lines are the forecast: mean wind (red) and gusts (anthracite), each with its spread. Once available, the measured values are added in the same colours but dashed. Use the arrows (day/month/year) to page through the days and compare forecast against reality. In knots (kn).

↔ swipe to page through the chart

The drivers behind the forecast

The most important inputs of our model for this spot – the same window as the history above. This shows which weather situation is behind the forecast (and, when paging, behind past days).

Thermal drive: air pressure Munich minus Innsbruck

On fine days the wind on Lake Walchensee is a thermal wind. It develops because the Alpine valleys heat up more during the day than the flat foreland. The slopes facing the sun receive the sun's rays more steeply and therefore heat up more than the plain. In addition, there is less air to heat in the narrow valleys. Pressure falls over the mountains and air from the foreland flows into the mountains. At Lake Walchensee it comes from north to northeast over Urfeld and usually starts around midday.

The chart shows the air pressure in Munich minus the air pressure in Innsbruck, a pressure gradient. If it is higher in Munich (light, top), the air is drawn into the mountains: favourable. In our measurements at Urfeld, from about +2.3 hPa there was wind in more than half of the hours between 11 am and 6 pm (dashed line). If the pressure is higher in Innsbruck (dark, bottom), it works against the thermal: then there is wind in only about 4% of the hours between 11 am and 6 pm.

Thermal drive: sunshine at the lake

Without sunshine there is no thermal wind: only the heating of the valleys builds up the pressure difference. Shown is the forecast solar radiation at the lake (area) and dashed the radiation that would be possible under a clear sky. The smaller the gap, the fewer clouds. Sunshine all day is the best condition. If clouds build up from midday, the thermal weakens. In our measurements at Urfeld, from about 90 % of the possible sunshine there was wind more than twice as often as with more cloud (dotted line).

Upper wind 850 hPa

Shown is the wind at about 1.5 km altitude (850 hPa) above the lake: the line shows the strength, the dots the direction (right axis).

For the thermal, the direction matters most. If the upper wind comes from north to east (green), it supports the north wind over Urfeld: our measurements then showed wind in about 60 to 65% of the hours between 11 am and 6 pm. From the northwest (grey) it was just under half. Upper wind from southeast to west (red) works against the thermal: only a good third of the hours.

South wind aloft is usually foehn and hinders the thermal. Only when it is very strong (over 15 knots) does the foehn itself reach the lake. Then it is windy, but from the south and gusty.

Stratification: a lid over the valley?

For a thermal wind the warmed air has to be able to rise. Shown is the temperature difference between the ground at the lake and about 1.5 km altitude (850 hPa). If it is much warmer below, the air rises well: favourable. If the difference is small or it is even warmer above (inversion), there is a lid over the valley.

What matters is where this lid lies. If the cold air lies only in the foreland below the Kesselberg, it often pushes a north wind over the Kesselberg to Lake Walchensee (see Inversion and fog in the foreland). If the lid lies at the height of the Herzogstand, it also sits over Lake Walchensee and slows the thermal. The weather model resolves this height only roughly, so the value is just an indication.

Inversion and fog in the foreland

Calculated and shown is the temperature difference between Lake Kochel (valley, about 600 m) and the Herzogstand (just over 1000 m), plus on the right axis how much cloudier the Alpine foreland is than the lake.

Normally the valley is warmer than higher up (value positive). If the value is below about 1 degree (dashed line), it is cold down below: an inversion. Then there is often fog or low stratus in the foreland while the sun shines on the lake.

If the inversion lasts until midday and the foreland is much cloudier than the lake, there is often a good north wind on Lake Walchensee, especially in autumn and winter. On such days the wind in the foreland usually comes from the east. If the inversion breaks up by midday, it becomes a normal thermal day.

Foehn

Calculated and shown is the air pressure in Bolzano minus the air pressure in Innsbruck, i.e. south minus north of the main Alpine crest. If the value is positive (top), pressure is higher in the south and the air pushes over the Alps from the south. On the northern side it drops into the valley as a warm, dry and gusty foehn.

From about +3 hPa (dashed line) the pressure difference is enough for foehn. Whether it breaks through to the lake also depends on the upper wind and on dry air. On real foehn days the value usually reaches about +5 hPa during the day.

At Lake Kochelsee the foehn is one of the main winds, usually early in the morning between about 3 and 9 am. At Lake Walchensee it reaches the water less often; there the chance of wind only rises clearly from about +7 hPa. If the value is negative (bottom), the higher pressure lies in the north: no foehn.

→ Wie gut ist unsere Vorhersage? (Auswertung gegen echte Messungen)

→ Windtag-Katalog seit 2022 (Ursachen-Einordnung, Modell v0)

Statistical forecast, no warranty – not an official weather forecast and no substitute for severe-weather warnings. Water sports at your own risk; judge the conditions on site. Terms of use