Visibility IV / V
At the 2.1.2016 i drove to Louekallio skiresort to check might be there diamond dust conditions for halos. Before i leaved i checked weather conditions at Louekallio. Temp was close to -20deg and wind was quite calm. So i decided to drive to Loekallio.
When i arrived to Louekallio about half kilometer long "sausage" leaved from the snowguns. Lot of icecrystals was floating from the sky, but no halos was visible. I drove farther from the skiresort, but there was same situation. I drove back to near skiresort to wait if the situation improves.
After long waiting i noticed that on the carlights icecrystals started to sparkle more and more. I went out to check might be there halos and i saw 22halo and possible upper tangent arc.
I took lamp and camera and went to near field. First exposure revealed that there might be wegener arc also. Best phase lasted maybe few minutes and after best phase display was unchanged whole evening.
I spent few hours driving around roads to find might be there better spot to see halos, but i didnt find.
Afterwards. During processing photos i noticed that there is tape arcs on both sides and no any mark of upper tangent arc. No supralateral arc or infralateral arc. Then i realised this is pure parry display. Helic arc was present and faint antisolar arc. So wegener was actually Hastings arc.
First photo is single frame from the best moment.
Second photo is stacked from 5frames. Together 150s exposure
Third photo is Stacked from 9frames, together 270s exposure.
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great catch, pure parry, no column, no plate. just a bit of random...
the crystals seem not that well oriented because of poor shape of upper sunvex and tape arc. though the helic is rather sharp
This is "The photo" for the much desired uppevex Hastings. Rovaniemi has seen already highly suggestive cases this winter, but this one is unequivocal. Well, one can not expect anything less from Mikkilä.