CLIMATE SIGNAL: Between the morning of Friday 25 and that of Saturday 26, intensification of the northeast winds that will result from tense to strong in the highest peaks of the Dolomites, in the pre-Alpine ranges, on the coast (in particular the southern central) and in the southern plain; sometimes Foehn reinforcements also in some valleys and in the foothills, especially in the west.
General evolutionToday, Christmas Eve, a cold front will cling to the Alps, preceded by southwesterly currents of very humid air, so the sky will be overcast and very weak scattered precipitation will occur in a thermal environment that is not particularly cold for the period. On Christmas Day the aforementioned front will pass over the Triveneto with the return of some snow in the mountains above 500/700 m. On Saturday and Sunday the establishment of a ridge will favor the entry of very cold and dry air into the Alps, before the arrival of a deep Atlantic cavity, responsible for a significant snow episode, initially down to low altitude.
Afternoon / night of Thursday 24Overcast skies, associated with very weak scattered precipitation (40/60%), snow above 1400/1600 m in the Dolomites, locally up to 800/1100 m in some northern valleys; in the snow of the Pre-Alps at 1700/1800 m. Exhaustion of phenomena in the next few hours and evening clarifications. Dull and cool atmosphere with peaks of 5/6 ° C in the pre-Alpine valley and 1/3 ° C at 1000/1200 m. Moderate / tense winds from the southwest at high altitudes, moderate winds from the northwest at night; in the weak valleys of variable direction.
Friday 25Expected time: Climate slightly altered until mid-afternoon with very cloudy skies, associated with little rainfall. The flow from the northeast could generate orographic shading situations and partially reduce disturbance in some valleys, especially in certain soils of pre-Alpine valleys. The atmosphere will get colder and colder as the hours go by until it becomes winter all over the Venetian mountain at night.
Rain: High probability (70/90%) of low rainfall, sometimes generalized. The snow limit will drop from 1000/1200 m at night to 500/600 m at the end of the episode, it does not seem to affect the soils of the pre-Alpine valleys due to the absence of pre-existing cold air, except for some flakes in the usually colder sectors. . Cessation of phenomena between afternoon and night. 4-10 mm are expected with as many cm of snow above 1000/1200 m, locally up to 15 cm in the sectors exposed to the northeast and at high altitude for soft snow.
Temperature: In general descent with minimums observed at dusk at all altitudes. Maxima of 2/3 ° C are expected in the soils of the pre-Alpine valley and -2 / 0 ° C at 1000/1200 m. In Prealps at 1500 m min -5 ° C max 0 ° C, at 2000 m min -8 ° C max -3 ° C. In the Dolomites at 2000 m min -9 ° C max -4 ° C, at 3000 m min -16 ° C max -10 ° C.
Twenty: In the weak valleys of variable direction, except for some episodes of Foehn; at moderate / tense altitude from the northwest in the morning, from the northeast in the afternoon / evening, strengthening until strong on the Dolomite peaks and on the pre-alpine ridges, at 10-35 km / h at 2000 m, 30-60 km / h at 3000 m.
Saturday 26Expected time: Wonderful winter day. Sun, clear skies, clean air and excellent visibility, except fogs in the coldest hours in Valbelluna. Frosty day in almost all the Veneto mountains, except for a temporary passage above 0 ° C on some sunnier valley floors.
Rain: Absent (0%).
Temperature: Another slight decrease with strong night frosts in the snowy sectors (-8 / -12 ° C in the Dolomite valleys and in the pre-Alpine plateaus). Maxima of 1/2 ° C are expected in the soils of the pre-Alpine valleys and -3 / -1 ° C at 1000/1200 m, even lower in shady areas. In Prealps at 1500 m min -9 ° C max -5 ° C, at 2000 m min -11 ° C max -9 ° C. In the Dolomites at 2000 m min -13 ° C max -9 ° C, at 3000 m min -17 ° C max -14 ° C.
Twenty: In the weak valleys of variable direction, with the exception of the Foehn residue; in moderate / tense northeastern altitude in the early hours, especially in the highest peaks and in the pre-alpine ranges, in attenuation until moderate in the afternoon, at 10-35 km / h at 2000 m, 20-50 km / h at 3000 m .
Sunday 27Sun, clear sky and clear air until mid-afternoon, except fogs in the coldest hours in Valbelluna. In the second part of the afternoon, a gradual increase in cloud cover to overcast skies at night, when the first light snowfalls will occur down to low altitude from the western Pre-Alps. The temperatures in a new general slight decrease with strong frosts in the snowy areas (down to -10 / -15 ° C in the Dolomite valleys and in the pre-Alpine plateaus) and a slight recovery of the high altitude. Weak northeast winds in the morning and moderate / tense southwest winds starting in the afternoon; weak variable direction in the valleys.
Monday 28Very altered climate with widespread snowfalls, abundant above 600/800 m and significant in the pre-Alpine valley bottoms. The snow limit will remain on the valley floors, including the pre-Alpine, except for a slight rise in the sectors closest to the foothills due to the mitigating effect of the flow from the southeast. Temperatures generally rise, especially the lower ones in the valleys. Strong / very strong winds from the south at high altitude, weak of variable direction in the valleys, except reinforcements from the southeast near the foothills. Forecaster: RLTh.
