KEYNOTE: Changes in Weather Conditions and Predicting Weather Conditions in the FutureKeliolosuhteiden muuttuminen ja niiden ennustaminen tulevaisuudessa

Meteorologist Kerttu Kotakorpi

Changing road conditions and predicting them in

the future

Climate changes –globe is warming

• Year 2017 was globally one degreewarmer than the pre-industrial era

• Year 2017 was the second warmest in history – warmest without el Niño

Picture: Ed Hawkins, University of Reading, UK

Climate changes –globe is warming

• In Finland the climate is already 2,3 degreeswarmer!

Weather in Finland after 100 years

• Temperature in Finland will rise more and fasterthan the global average

• Climate changes more in the winter than summer

• Temperatures rise

• Precipitation grows

Seasons change• Dry periods shortens in winter and spring

• Downpours strengthens in spring and autumn

• Mean temperatures rise by 3 to 5 degrees by the end of the century

Seasons changing in Pikku-Huopalahti, Helsinki

Climate is warming– winter weather is changing

• Temperatures rise• Less freezing temperatures• Less frost in the ground• More temperatures close to zero

• More precipitation • More snow in the northern parts of Finland • More rain• More slippery conditions• More darkness

Winter temperatures rise

• Warming is fastest in the north

• By the end of the century climate in the centralFinland is similar to Poland or Hungary today

• In the south freezing temperatures get moreunusual

New Year2011 in Helsinki

Winter temperatures rise

By the end of the century the winter temperatures can rise by 6 to 8 degrees in Finland

Similar temperatures now in November

+8 °C

+7 °C

+6 °C

Very cold temperatures go down in history

• Less cold winter days

• Less very cold freezing temperatures

• At first there will be more temperatures close to zero in the wholecountry, later only in the nortern and eastern parts of the country

• Because of the shorter winters and warming, temperatures will be lessoften close to zero at the end of the century

Hrrr….

Precipitation increases

• Precipitation increases and downpours getstronger

• Change is relatively bigger in the winter than in the summer and stronger in the north than in the south

• In the winter the heaviest rain intensifiesrelatively most

• Because of the rising temperatures, bigger partof the precipitation is rain

Precipitation increase in winter

Precipitationincreases by 40 % by the end of the century!

Amount is the same as in England today!

+40 %

+30 %

+20 %

Freezing rain

• Freezing rains disturbing traffic will decrease by couple of days duringnext decades

• In the northern parts of Finland freezing rains can get a little morefrequent as temperatures are more often close to zero

ONLY LAPLAND WILL HAVE SNOW COVER AT THE END OF THE CENTURY

Shorter period of snow

• In the southern and western parts of Finland the snowydays will decrease by 50 %

• In the north snowy days willdegrease by 20-30 %

• Blizzards increase – stillthere can be mass of snowat once

• The need for snow plow willnot change a lot

Winter road conditions change

• Mild and rainy winters will increase the erosion of roads

• Need for removing ice and spreading salt on the roads willdecrease in the south

• Winter road maintenance will concentrate in the north

• Need for preventing slipperiness will grow in the north

NEED FOR SPREADING SALT AND SAND ON THE ROADSCAN EVEN INCREASE

CYCLINGPERIOD

LENGTHENS, BUT AT THE SAME TIME

RAINYNESS AND WINDINESSINCREASES

Weather predictions become more precise

• Computation capacity of the weather prediction models will grow in the future

• Weather prediction models become more exact

• It will be possible to plan even more detailed operations for roads

Thank you for your attention!

Source: ilmasto-opas.fi and fmi.fikerttu.kotakorpi@yle.fi