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In them, the autumnal period is very short and winter in mid-latitudes begins already in October. In marine and transitional climatic zones (maritime to continental, including Lithuania), the autumn period is usually long and variable, with relatively warmer periods being replaced by colder ones, depending on large-scale atmospheric circulation, the ocean surface temperature anomalies in the region and other factors.
The last week in Lithuania was abnormally cold: the average daily air temperature for the last 7 days ranged from 6 degrees in the east and northeast of the country to more than 9 degrees on the coast. This temperature background is typical for mid-October. Although the average temperature was abnormally low, the slow movement of the old cyclone (over Ukraine and Russia) to the east and the wide bands of low clouds behind it prevented frost (at least in the air, as observed in places on the surface ground).
For this reason, the medium-term weather forecasts made in the middle of the month did not materialize either. The apparent advection of cold weather caused predictable frosts in many areas. The daily maximum air temperature was also abnormally low: in some eastern and northeastern regions it was only 4-7 degrees on September 19-22.
The aforementioned cooling weather is a big boost for the start of the golden autumn. The leaves of the trees began to turn yellow and red earlier, but the period of massive yellowing of the foliage will probably correspond to a perennial one – the first decade of October. Another question is how long that beauty will last. If a moderately warm climate prevails (without strong frosts), calm and, most importantly, dry, there will be no autumn storms; trees can still delight in color for 2-3 weeks.
Rainy, cool and windy weather can shorten this period from 1 to 1.5 weeks. By comparison, in the second half of September, the eastern Siberian lime taiga suddenly turns yellow due to the first frosts. And it occurs almost simultaneously over a large area (> 2 million square kilometers). If there is no significant cloud layer, it is visible even from Earth’s orbit.
If we have already started in Siberia, it is necessary to mention the snow. A permanent snow cover has already formed in the mountainous regions of the east (especially the northeast) of Siberia: the ridges of Čersky, Verkhoyansk and the Oimiakon and Chukchi mountains, the Putoran plateau and some areas of northern Krasnoyarsk Krai. Also in the eastern part of the Alaska Peninsula and in the upper reaches of the Makensee River.
During the first decade of October, permanent snow cover will form over much of eastern Siberia (excluding southern), much of Alaska, and northwestern Canada. At the end of September, the Arctic sea ice occupies the smallest areas of the year.
This year there was a heavy melting in the summer and it was projected to be a record year in terms of sea ice declines. The National Snow and Ice Data Center (NSIDC, USA) announced that this season’s low was set for September 16 at 4.72 million. kv. km. However, it took more than a million square kilometers to reach the 2012 record (3.41 million square kilometers).
It should be noted that in recent decades, due to autumn storms and thin ice, the seasonal minimum is sometimes reached even in October, although sea ice is already growing at that time. On Friday evening and morning, the rear of an active Atlantic cyclone (currently its center over southern Estonia) passed through Lithuania. As a result, it rained heavily throughout most of the country.
It has also warmed after a longer cooling period, as sea air masses are already getting warmer than continental air masses at this time of year. A storm broke out on the coast, according to data from the Klaipėda Meteorological Station (Melnragė), the strongest gusts reached 19 m / s, and according to data from the Klaipėda Port Automatic Station (North Pier), almost 25 m / s. Both stations registered maximum speed around midnight, but gusts that reached 17 m / s were observed from 9 p.m. Thursday to 9 a.m. Friday morning.
Another frontal system arrives in Lithuania on Saturday, so light rain is forecast, the air temperature is 2-3 degrees higher than on Friday. On Sunday, the high pressure core will open from the southwest to the Baltic region, so the pressure will increase, the night air temperature will drop (5 to 10 degrees) and the day will increase (14 to 19 degrees).
At the beginning of next week, the Baltic anticyclone will retreat to the northern part of Russia and intensify, so no precipitation is expected, we will get more sun, and the wind direction will change towards the eastern rhubarb. On Wednesday, a slow-moving frontal system will approach from the west: pressure will begin to drop, cloud cover will increase, and light rains are expected.
No significant frosts are expected at night and in the morning, and during the day the air temperature will rise to 11-16 degrees. In early October, Iceland’s low-pressure zone will strengthen, but its position is expected to be slightly south of the perennial, with transmission predominantly to the southwest in Europe. The warmest will be in southern and central Europe, and the rainiest in western and northern Europe.
