In the first ten days of January 2017, various active meteorological processes determined the weather conditions in Ukraine. A series of cyclones coming from the west and south-west brought frosts and active weather phenomena to Ukraine - snowstorms, glaze ice, ice-crusted ground, etc. Many oblasts demonstrated rather difficult snow deposits and slush build-up, frosts, etc. Rushing mighty winds dominated for several days. In the second half of the reporting period, snow covering significantly increased (and formed in many fields). There was observed untraditional distribution of air temperature figures as for January - eastern oblasts had warmer temperature figures compared with western and southern ones.
In western, northern, central, southern oblasts (except for Zaporizhia oblast), the average air temperature varied within the average regional range of -3.5…-8.5°C, down 1-4° compared with the standard; in mountainous raions of the Carpathians - -10…-13.5°C, down 3-6°. In southern raions of Kharkiv, Luhansk, Donetsk and Zaporizhia oblasts, the average temperature was somewhat higher - from 0° (Azov Sea) to -2.5°, up 1-3.5° compared with the standard. On the coldest days (January 8-9), deviations from the average daily air temperature in northern, western and Odessa oblasts reached 11-16°.
In the coolest nights, the minimum air temperature decreased to -15…-22°C, but in Luhansk, Zaporizhia, Donetsk, Kharkiv and Dnipropetrovsk oblasts the minimum indices reached -8…-14°C. The lowest temperature figures were observed in the Carpathian Mountains and south-eastern raions of Odessa oblast - -23…-26°C.
In the warmest days, the maximum air temperature reached +1…4°C, but in southern, south-eastern and south-western oblasts the maximum temperatures grew to +5…8°C.
In the coldest nights, the snow surface temperature decreased to -12…-17°C in eastern oblasts and Priazovye region, but in the remaining regions - to -20…-27°C. In the beginning of the first ten-day period, the soil surface temperature even grew to +1…6°C, but in southern oblasts - to +7…12°C.
Ukraine faced precipitations in the form of snow and sleet for 4-6 days throughout the whole territory of the country. The lowest average level of precipitations was observed in Ternopil, Volyn, Zakarpattia, Ivano-Frankivsk, Lviv, Rivne and Luhansk oblasts - at 50-90% of the standard (5-17 mm). In the other oblasts, the average level of precipitations exceeded the standard, and varied within 111-190% (20-36 mm). During cyclone movements, there were observed heavy precipitations, which daily maximum figures in Sumy, Zaporizhia, Mykolaiv, Kherson, Odessa oblasts reached 15-22 mm, or 1-1.5 ten-day standards.
Relative humidity of the air varied within the range of 68-94%. In some raions of Zakarpattia oblast and Prykarpattia region the relative humidity varied below 30% for 1 day, which is not typical for January.
As of January 10, the snow cover depth at 10-30 cm was observed throughout the whole territory of the country, but in northern and western oblasts, Donetsk, Luhansk, Zaporizhia oblasts the indices mainly varied within 3-20 cm. In some raions of Khrakiv and Sumy oblasts, and the Carpathian mountains, the snow cover depth reached 35-43 cm.
At the end of the ten-day period, the depth of soil freezing varied within 5-50 cm.
During 1-5 days, there was observed some strengthening of wind velocity throughout the whole territory of the country (except for Luhansk, Zhytomyr and Sumy oblasts) to 15-24 m/s, and in mountainous raions of the Carpathians - 27 m/s.
Despite significant decreasing of the average air temperatures in the second half of the reporting period (mostly in western and northern oblasts), overwintering of winter crops developed in quite satisfactorily rates. Sufficient level of snow covering prevented reduction of the soil temperature at the tillering node depth. In the period of the minimum air temperatures, the minimum soil temperature at the depth of tillering zone of winter crops (3 cm) varied within -2…-9°C. In some raions of western oblasts, where the snow depth was less than 5 cm (Rivne, Ternopil, Ivano-Frankivsk oblasts), the temperature decreased to -10…-12°.
In some fields of Sumy and Kharkiv oblasts ice crust remained for nearly one month with thickness of 5-19 mm, its rate of expansion reached 40-60% of the field. In eastern raions of Kherson oblast ice crust formed in the first ten-day period of January, with thickness of 7-38 mm, covering 40-90% of the field.
The weather conditions for further development of field works in January 2017 in Ukraine will be good and satisfactory.
According to data of the Ukrainian Hydrometeorological Center
