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Yesterday was the first day that really got me thinking winter is close.The temperature still reached a pleasant 19C, but RH was under 50%, so the 9C dew point was the lowest daytime dewpoint since about November -it felt chilly.
Interesting to note that the last several days have been cloudless and Nelson airport has recorded 9.7 hours of sunshine, compared to 11 hours between sunrise and sunset. I guess that's the standard everywhere?
Yesterday was the first day that really got me thinking winter is close.The temperature still reached a pleasant 19C, but RH was under 50%, so the 9C dew point was the lowest daytime dewpoint since about November -it felt chilly.
Interesting to note that the last several days have been cloudless and Nelson airport has recorded 9.7 hours of sunshine, compared to 11 hours between sunrise and sunset. I guess that's the standard everywhere?
Oak and Maples are a lovely red colour now.
With its manual equipment, you'd need a flat horizon to get 10.5 hours or so. But I know from a photo sent by a correspondent sent some years back that the exposure was pretty good then, probably enough to get close to the 10.5 mark. This tends to confirm my suspicion from intercomparisons that the exposure has deteriorated somewhat (fixed or growing obstructions) or that the equipment needs an overhaul. Picking a number nearer Appleby's values, as you suggested, is probably the most realistic assessment of local sunshine. Kelburn here recorded 10.1 hours a couple of days back when I'm pretty sure there was no cloud cover at all - the recordable max. for then would be about 10.4 hours according to tables which probably need updating.
With its manual equipment, you'd need a flat horizon to get 10.5 hours or so. But I know from a photo sent by a correspondent sent some years back that the exposure was pretty good then, probably enough to get close to the 10.5 mark. This tends to confirm my suspicion from intercomparisons that the exposure has deteriorated somewhat (fixed or growing obstructions) or that the equipment needs an overhaul. Picking a number nearer Appleby's values, as you suggested, is probably the most realistic assessment of local sunshine. Kelburn here recorded 10.1 hours a couple of days back when I'm pretty sure there was no cloud cover at all - the recordable max. for then would be about 10.4 hours according to tables which probably need updating.
To update - I looked at the numbers for April 2005 when Nelson set an all-time record for April sunshine - there was a reading of 10.6 hours early in the month (5th or so) and 10 hours on the 25th. I think the exposure would have been optimal then and any reduction from astronomical values (11.4 and 10.5 respectively) would be the standard 20-30 minutes for the equipment at start and end of day plus a small factor for hills etc. plus of course any sufficient cloud cover.
Location: João Pessoa,Brazil(The easternmost point of Americas)
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Southern Brazil is facing one of the most Warm April in many years,an High Pressure is keeping away Cool air masses,and the Cold fronts are stoped in Uruguay,it is the Cause of the Severe Storms of the Lasts days which even led to the occurrence of a tornado who Killed 4 Peoples.
While this in Ushuaia..
500mb Anomaly:
Last edited by ghost-likin; 04-16-2016 at 06:55 PM..
Fairly cool with a maximum of 23.5˚C. Mostly cloudy but good for riding, bits of rain. First road bike ride since October, I was quite unfit. Might post some photos in a few days if I time my camera next time. Quite cool for April but not awful yet.
To update - I looked at the numbers for April 2005 when Nelson set an all-time record for April sunshine - there was a reading of 10.6 hours early in the month (5th or so) and 10 hours on the 25th. I think the exposure would have been optimal then and any reduction from astronomical values (11.4 and 10.5 respectively) would be the standard 20-30 minutes for the equipment at start and end of day plus a small factor for hills etc. plus of course any sufficient cloud cover.
Just to confuse matters, Sunday recorded 10.1 hrs. Today has started out cloudless and hopefully stays that way for another comparison.
Might just be the local reporting at fault. Yesterday's newspaper showed the Sunday temperature range at 13.9C/17.5C, while I recorded 4.8C/21.1C.
Great snow photos marlaver.
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maybe a F3 judging by the damages
