>MADNESS OF METEOROLOGY: December-like start, Smog visible across Glasgow, it cooled and Now it’s warming!

Written by on December 4, 2009 in Rest of Europe with 1 Comment

>It was a stunningly beautiful morning after a clear, crisp and cool overnight, ideal for strong frost formation since our air is nice and “damp” from sunset to sunrise the radiational cooling machine drove daytime accummulated surface warmth back to space. We bottomed out at 8.15am with a respectable December-like 27 degree low here at the house when there is no snow on the ground.


Once again like Tuesday morning, the higher than normal soil moisture and runoff onto roadways created serious danger to drivers. Many untreated backroads today were dangerous throughout the country as temperature recovery was slow and therefore frost as well as ice forced me to drive ever more careful in the truck across Refrewshire and Ayrshire, high ground or not it was bad in some places.

As the day wore on and the sun shawn brightly under brilliant clear, blue skies and NO WIND this kept the air from warming since the December sun is weak and nearing it’s minimum, therefore many areas struggled to get above freezing for quite some time, places that didn’t see sunshine likely failed to crack freezing until clouds rolled in (explained below).


METEOROLOGY AND URBAN CONGESTION
Ground Level Ozone visible over Greater Glasgow this afternoon

As of around 10.30am this morning after leaving the Port Dundas district of Glasgow enroute to Ayrshire, skies were clear and around freezing with a lot of frost and ice on the ground. By the time I travelled across North Ayrshire and drove to the coast, clouds were already moving in off the Atlantic and therefore warming coastal communities to around 40 or greater. As of around 1pm under cloudy skies and mild temps I headed away from the Largs, Saltcoats and Stevenston area eastbound only to find a massive “sky contrast” ahead of me. The canopy of mid to high level cloud was pushing knifing it’s way across the horizon. An amazing sight with a soid canopy of cloud nudging it’s way across a sky that couldn’t have been clearer. The line frontrunning cloud line could not have been straighter and was almost directly north south oriented. This was the leader in a new appraoching Atlantic depression and it was pumping warmth west to east across Scotland at the 5,000ft level (my own estimate) and winds were likely strong. Little known to me was that as I progressed back towards Glasgow and as I crossed the Fenwick moor area (higher terrain) I drove out ahead of the cloud canopy and found myself just in front of the cloud line and back under clear skies. The clouds that were progressing towards Glasgow now created a shadow and with clear skies, temperatures were in fact forced to drop. Warm air flowing ABOVE a stable and untouched layer of cold at ground surface, unable to be warmed since there was no air movement meant an inversion had formed in low lying areas such as Glasgow. The overriding warm air actually acted like a lid in trapping this cold surface air, also aiding in the sun’s failure to warm up the surface, this combined with heavier Glasgow traffic on a Friday, lack of wind at the surface and warmth over top forced the formation of ground level ozone to form and as I drove down the steep decent of the M77 into the southside of the city, a brown haze was clearly visible across the Greater Glasgow area.

Glasgow is sheltered on all side by hills therefore air can at times become a little trapped.


TEMPERATURE FLUCTUATES FROM NORMAL DIURNAL PHYSICS BUT IS NOW BEING DISRUPTED AS INCOMING WEATHER SYSTEM REMOVES ONE AIR MASS OUT AND TRANSPORTS ANOTHER IN.


At around 2.30pm the temperature peaked at 35 degrees here at my house before beginning it’s decent. By 3.30pm it was down to 33 degrees as skies, though cloudier, were clear enough and the sun dropping rapidly for cooling to begin but since the daylong progression of incoming warmth in the mid-levels of the atmosphere off the Atlantic, this warmth was beginning to erode the cold surface air as clouds thickened and the mixing began to work down to earth. By 4pm we rose back to 35 degrees. Currently it’s the warmest we have been all day with a current reading of 37 as of 5pm under a solid cloud cover and now as I finish writing this as of 9pm it is 40 degrees and light rain is falling along with a slight breeze blowing. The cold air is gone now and oceanic air is now dominant.


Today experienced normal daily diurnal changes with a low and high ranging between 27 and 35, then the cooling began and we knocked on the door of freezing before the warmth aloft hit the surface and then jump went the thermometer…


Thanks for reading.

-Mark

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  1. Anonymous says:

    >Wonderful to hear a depression documented so vividly, perhaps you should work for the Glasgow tourist board. Spin? I don't detect a hint of it.

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