Ilmaarhiiv
12th week 2010
In the beginning of the week (22.03) cold air streamed into Estonia following the low pressure area that retired beyond Lake Peipus. It brought air temperatures down below zero everywhere (0 - -4 °C) and turned the rain all over the country to slush and snow. In daytime a high pressure ridge stretched over Estonia, offering sunshine, but the degrees of warmth were meagre (up to +3 °C) because of the strong winds.
On 23.-24.03. Estonia was left on the edge of a low pressure area from Scandinavia that moved towards southeast across Latvia, with snow, slush and rain falling, and more cold brought by the wind that turned to northerly.
In this section of cold air another high pressure area developed over the Baltic countries bringing a calm, cold and foggy night on 25.03: in Jõhvi the week’s minimum was recorded: -12,4 °C. In daytime the sun had enough strength to dispel the fog and to raise the air temperature locally up to +6 °C.
The following days low pressure troughs moved from the sea over Estonia towards the northeast, bringing in humid and warm air with the help of the winds that turned southerly. 10 °C was recorded on Friday (26.03) in the northwestern corner of Estonia but on Saturday (27.03) the air temperature in Pärnu rose to +13,1 °C (the maximum of the week). On Saturday (27.03) thunderstorms appeared in southern as well as western Estonia, caused by quickly advancing warm air masses.
Jüri Kamenik’s story about the March 27 thunder.
http://www.ilm.ee/?47152
On Sunday night (28.03) Estonia, on the edge of a low pressure area moving towards northeast from near Stockholm, had temperatures above zero (+1..+6 °C), and rainy and windy weather (the southerly wind reached up to 15 m/s). During the day a depression was moving above Finland and swirled cold air back to Estonia from the north, so that in the afternoon rain turned into slush in western Estonia, and in the evening into snow in north Estonia. The southwesterly wind reached up to 16-18 m/s locally and the air temperature during the day rose with barely one degree.
Snow conditions.
The sun as well as the heavier rain on Saturday (27.03) melted the snow so forcefully that in some places the snow thickness meter stayed at zero. Mostly however it was up to 3 to 30 cm in western and southern Estonia, in northern Estonia 15 to 57 cm.
EMHI snow cover thickness chart:
29.03.2010 at 08:00
All spring processes advanced mightily during the week. In the nights there was some frost but in daytime an intense snow melting went on. In the mornings the roads were slippery. On Wednesday morning (24.03) the ground was covered by fresh, 5 cm thick snow. At the end of the week the nights became warm and it rained. The warmest day of the week turned out to be Saturday (27.03), with air temperature rising over 10 degrees and in the evening around 7 o’clock there was thunder. With seven days the snow thicknesss on open ground was reduced by 15-20 cm. In places water had collected under the snow. The frost depth in ploughed fields and winter rye fields was mostly 30-35 cm, under grass sward the ground was frozen to a depth of nearly 15 centimetres. At the depth of winter crop growth nodes the temperature during the week was around -0,2…-0,4. On the village roads breaking up of teh roads started. During the week starlings, lapwings and larks arrived in Jõgeva and the surroundings, and searched food on snowfree road verges. Around here mew gulls, white storks, goldeneyes, thrushes, the first tortoiseshell butterflies and yellow brimstones were seen. In the schoolhouse park a Ural owl was flying around. On the tealeaved willow and goat willow catkins became visible. The Pedja river lost its ice cover and mallards swam two by two along the river.
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