Astronomy, Photography and Weather

General Category => Weather & Atmospherics => Topic started by: brianb on September 12, 2009, 11:14:18 am



Title: Coastal frost - in summer!
Post by: brianb on September 12, 2009, 11:14:18 am
These clear skies are amazing, with no wind the temperature fell to 3.0C last night even as close as I am to the coast (200m). And there was genuine frost on the grass, and on the dew cap on my scope. Can't remember that happening whilst it was still (astronomically) summer before.

A couple of hours useful darkness before the Moon rose last night ... should be another hour tonight. Also, though the moon was too bright to tell for sure, the sky towards the NW horizon looked a bit brighter than I think it it should do in the early hours of the morning (12 Sep) ... just possibly auroral glow; certainly not a notable display. (There are a couple of street lights well hidden behind houses in that direction, then nothing more till the Faroes & Iceland!)


Title: Re: Coastal frost - in summer!
Post by: martinastro on September 12, 2009, 02:22:15 pm
Interesting stuff Brian.

On the night before last there was a definite air frost here, and I believe I saw some very light frost on the grass in the countryside. It has been very cool and sharp these nights, although last night seemed warm in comparison to the nights before.

That's interesting about the glow on the horizon, maybe it was a weak aurora.


Title: Re: Coastal frost - in summer!
Post by: rjgjr on September 12, 2009, 03:35:27 pm
Ah, the seasons are a changing!!


Title: Re: Coastal frost - in summer!
Post by: Paul on September 12, 2009, 04:35:20 pm
Well the seasons are pretty askew at the moment. Outside my work in Antrim we had dead leaves on the ground in August which seemed a little odd.


Title: Re: Coastal frost - in summer!
Post by: Roman White on September 12, 2009, 08:52:30 pm
Ah, the seasons are a changing!!
I agree with Paul, it sounds more like a question...
Today the daytime temperature was +24...+28C, and it will keep almost the same for next week. (I may astonish you, but on previous week the maximum here was +33C). So nothing tells about the autumn except of the shorter days and Orion which shines in the morning skies.  :)


Title: Re: Coastal frost - in summer!
Post by: rjgjr on September 12, 2009, 09:27:17 pm
Our entire summere here on the Southern Oregon Coast has been unusual, except for the temperatures that have run about normal. But growing season, my in-ground flowers and perennials, they didn't know when to start. My glads, iris, dahlias were 2-3 months late, the dahlias still haven't set bloom. Last year I picked 40 quarts of blackberries, I'll be lucky to get 5 this year. They're still trying to set flowers but they won't make it. Spring rains were a little lacking, but not much. Very strange indeed!


Title: Re: Coastal frost - in summer!
Post by: markt on September 13, 2009, 09:23:31 am
You certainly are lucky with a northerly aspect like that Brian! 

Whilst temperatures here are not as cool as you guys have been having in Norther Ireland the dew and fog of a morning certainly leans towards things more autumunal.  Here too leaves are starting to turn on the trees and the berries are early.

Metcheck reorted that Katesbridge, NI, recorded a temperature of -0.3c on thursday night.


Title: Re: Coastal frost - in summer!
Post by: brianb on September 13, 2009, 10:54:27 am
Quote
Metcheck reorted that Katesbridge, NI, recorded a temperature of -0.3c on thursday night.
Yeah, Katesbridge is the nearest NI has to a "frost hollow" - well inland & surrounded by gentle hills down which cold air flows when the wind is calm.

Last night was a bust. Breeze off the sea brought more or less solid stratocumulus once it was dark, min temp was 12.0C. Small breaks kept hopes up, I was catnapping with a 20 minute kitchen timer till 3 am in the hope that things would change but it was gradually thickening rather than the reverse .... Sun is at work on it now but with anticyclonic weather a southerly drift is better than a northernly one for astronomy.


Title: Re: Coastal frost - in summer!
Post by: martinastro on September 13, 2009, 02:10:28 pm
Last night was odd. The sky was clear here after sunset and in fine form. I got several hours comet hunting done then out of nowhere high level cloud comes racing in at tremendous speed from the north, this was after 23.00, then it remained overcast for the rest of the night. It was calm at ground level but the clouds seemed to be moving at breathtaking speed as if I was watching a real life time lapse movie. They seemed to arrive in an instant with no visual warning beforehand.