Climatology of snow cover and snow water equivalent

• Chapter VI: Snow cover days in the Baltic States derived from satellite measurements
•  
• General remarks
• Validation with ground-based data
• Inter-annual variation in snow cover days
• Seasonal cycle of snow cover

Seasonal cycle of snow cover

Snow cover in the Baltic States starts to form in November and completely melts in April. The number of snow cover days is higher in the highlands and lower in lowlands and coastal areas. In most years the snow cover is permanent in January and February, meaning it builds up and does not melt (Fig. 5). During these months the average air temperature is well below 0 °C. In the southwestern part of the region the snows begin to melt in March, but in the northern parts the snow cover persists. In April, when the average air temperature starts to rise, the snow cover quickly melts and can cause major spring floods. The highest average number of SCDs (5–10 days) in April is observed in the northeastern part of Estonia (Fig. 5).

Figure 5: Mean monthly number of snow cover days in the Baltic states, 2000-2013. First snow in the region falls in November; snow cover builds up through December and stays permanent during January and February. Spring melt starts in March in the southwestern part of the region and by the beginning of April snow cover melts everywhere.