Fig. 1
Location of meteorological stations.
Fig. 2
Mean frequency of occurrence (%) of very strong and extreme cold stress according to the UTCI in Poland in the period November to March (A) and January (B), 1966/67 to 2018/19. UTCI, Universal Thermal Climate Index.
Fig. 3
Multiannual variability of seasonal (November–March) number of days with very strong or extreme cold stress according to UTCI in Suwałki (A) and Warszawa (B), 1966/67 to 2018/19. Solid lines represent respective trends. UTCI, Universal Thermal Climate Index.
Table 1
Selected characteristics of the number of days with very strong and extreme cold stress according to UTCI in Poland, 1966/67 to 2018/19: their maximum number and trend coefficient. Statistically significant (at 0.05 level) trend values are in bold.
| Station | Maximum number of days and season of their occurrence | Trend (days· decade−1) |
|---|---|---|
| Białystok | 42 1971/72 | −3.53 |
| Bielsko-Biała | 17 1967/68 | −0.91 |
| Borucino | 48 1969/70 | −2.33 |
| Chojnice | 7 1978/79 1986/87 | 0.00 |
| Elbląg | 19 1969/70 | −0.34 |
| Gdańsk | 15 1978/79 | 0.00 |
| Gorzów Wlkp. | 13 1978/79 | −0.57 |
| Hel | 16 1978/79 | −0.29 |
| Jelenia Góra | 10 1975/76 | −0.36 |
| Kalisz | 15 1986/87 | 0.00 |
| Katowice | 6 1978/79 | −0.31 |
| Kielce | 12 1984/85 | −0.24 |
| Kłodzko | 9 1969/70, 1977/78, 1983/84, 1984/85 | −0.34 |
| Kołobrzeg | 8 1978/79 | −0.53 |
| Koszalin | 9 1978/79 | −0.59 |
| Kraków | 14 1968/69 | 0.00 |
| Lesko | 15 1978/79 | −1.43 |
| Lublin | 13 1986/87 | 0.00 |
| Łeba | 19 1978/79 1986/87 | 0.00 |
| Łódź | 16 1969/70 | −0.99 |
| Mikołajki | 47 1971/72 | −4.62 |
| Mława | 28 1971/72 | −1.67 |
| Olsztyn | 12 1969/70 | 0.00 |
| Opole | 5 1978/79 | −0.31 |
| Poznań | 14 1978/79 | −0.49 |
| Racibórz | 10 1986/87 | 0.00 |
| Rzeszów | 21 1968/69 | −0.35 |
| Siedlce | 17 1986/87 | −0.81 |
| Słubice | 6 1978/79 | −0.29 |
| Suwałki | 34 1978/79 | −4.00 |
| Świnoujście | 16 1986/87 | −0.53 |
| Szczecin | 11 1978/79 | 0.00 |
| Terespol | 20 1968/69 | −0.59 |
| Toruń | 9 1978/79 | −0.53 |
| Ustka | 10 2010/11 | 0.00 |
| Warszawa | 19 1969/70, 1986/87 | −0.67 |
| Włodawa | 21 1978/79 | −0.48 |
| Wrocław | 9 1978/79 | −0.38 |
| Zakopane | 4 1967/68 | −0.18 |
| Zielona Góra | 9 1978/79 | −0.33 |
Fig. 4
Mean SLP [in hPa] (colour scale) and z500 hPa [in gpm] (dotted line) (A) anomalies of SLP [in hPa] (colour scale) and z500 hPa [in m] (dotted line) (B) and anomalies of T850 [in °C] (C) for days with very strong and extreme cold stress. SLP, sea level pressure.
Fig. 5
Mean SLP [in hPa] (colour scale) and z500 hPa [in gpm] (dotted line) (left column); SLP [in hPa] (colour scale) and z500 hPa anomalies [in m] (dotted line) (middle column); and anomalies of T850 [in °C] (right column) for the designated circulation types. SLP, sea level pressure.
Fig. 6
UTCI values (°C) in Poland on selected days: 31 December 1978 (A) and 30 January 2014 (B). UTCI, Universal Thermal Climate Index.
Fig. 7
Mean SLP [in hPa] (colour scale) and z500 hPa [in gpm] (dotted line) (top row); SLP [in hPa] (colour scale) and z500 hPa anomalies [in m] (dotted line) (middle row); and anomalies of T850 [in °C] (bottom row) for the selected days. SLP, sea level pressure.