Winter pilot season kicks off

Third pilot season of the CLIPS project has started. Pilot users get to try out our new winter six week forecasts, which help the general public to prepare for winter conditions as well as to get the best out of them.

CLIPS project develops novel extended-range forecasts that estimate the weather conditions during the upcoming six weeks. Six week forecasts of the winter season include Sweather weather outlook, Outlook for driving conditions, Outlook for winter outdoor activities, Heating degree day outlook and storm outlook. All the forecast products are unfortunately only in Finnish, but if that’s no problem you can still sign up for piloting on our website.

Is a beanie enough, do I need a quilted jacket?

Sweather weather outlook is a brand new six week forecast that brings mittens and winter boots on the weather charts. It estimates, based on the joint effect of temperature and wind speed, whether the weather conditions on the upcoming six weeks are mild, chill or freezing.

“Especially in winter the mere temperature is not enough to describe, how biting the cold weather and minus degrees can be. Therefore the Sweather weather outlook uses the Wind Chill Index, which means the joint effect of the temperature and wind”, explains researcher Natalia Korhonen from the Finnish Meteorological Institute.

Outlook for driving conditions estimates slippery conditions and snowfall

Outlook for driving conditions resembles greatly the autumn’s Winter tire outlook. In addition to the days with slippery conditions it takes into account the weekly amount of days with snowfall. In most cases when the Finnish winters challenge the drivers with difficult driving conditions, it has to do with especially slippery roads or heavy snowfall.

Is the snow cover thick enough for winter sports?

Approaching winter lures most of the Finns to dig up the skis, skates and sledges from the storage. Especially skiing and sledding are nevertheless very dependent on the snow cover. The time when a stable snow cover stays on the ground varies a lot from year to year –  particularly in the Western and Southern Finland, where the snow cover often doesn’t stay more permanently before the turn of the new year.

Outlook for winter outdoor activities looks at the weather conditions from the viewpoint of winter sports. It estimates weekly frosty winter days and amount of days with snowfall. Here, frosty winter day means a day, during which the daily temperatures stay mostly under zero degrees. Also, a six week forecast estimating possible periods of freezing temperatures is in the making.

Outlook also provides a map of the observed snow depth at the moment. Observations are sourced from the Finnish Meteorological Institute. The snow depth map acts as a starting point for estimating the conditions in the upcoming weeks. If the situation with the snow cover is poor to begin with and there is not much snowfall forecasted for the following weeks, chances are that the conditions won’t favour outdoor activities that require a thick layer of snow.

Familiarize yourself with heating degree day sums

In winter the need for heating in the buildings and properties increases particularly during periods of freezing temperatures. Heating degree day outlook includes forecasts of the accumulated heating degree day sum and frost sum in the following six weeks and helps in planning the heating of properties.

“The use of heating degree day values takes a bit of effort from the user as they need to familiarize themselves with the concept. In a nutshell: the higher the heating degree day sum and frost sum, more energy is needed and consumed to warm up the buildings”, summarize the researchers of the CLIPS project.

With heating degree day sum, it is possible to map the realized heating energy consumption of a building and compare it with values from different months or years or with typical needs of heating energy for buildings in different municipalities in Finland. Using heating degree day sum in evaluations is based on the assumption that the energy consumption of a building is approximately comparable to the difference between the indoor and outdoor temperatures. You can learn more about the concept of heating degree days on the website of the Finnish Meteorological Institute.

Wind gusts cause harm in land areas

Windstorm outlook is upgraded with two new forecast types in the winter pilot season. First of the new forecasts illustrates the maximum gusts for each upcoming week. In the forecast of weekly maximum gusts the scale starts from 8 m/s wind gusts and continues until 21 m/s, which is described as severe gale or “storm”.

The second forecast estimates the probability of near gale gusts on a weekly level. “Near gale gusts are minimum 14 m/s wind gusts, which can already make biking difficult or disturb the traffic and transportation. Gusts of this strength can also knock over trees or cause other kind of wind damage. Forecast map helps to estimate, how high is the probability that the following weeks bring along such strong gusts”, explains researcher Terhi Laurila from the Finnish Meteorological Institute. Also the forecast estimating the weekly means of atmospheric pressure, familiar from the autumn’s six week forecasts, continues as part of the Storm outlook.