>Another 100 bagged in Downtown L.A. yesterday, whilst the 60s in Denver will be 80s Saturday!

Written by on September 25, 2009 in Rest of Europe with 3 Comments

>A topsy turvy weather pattern exists across the Western US where a strong upper ridge is forcing the blowtorch to continue across much of California and up into the Pacific Northwest and Western Canada. According to Accuweather, Both Edmonton and Calgary in Alberta topped 90 degrees Wednesday and this was the first time they recieved 90 AFTER the autumnal equinox.

A weak east to northeast flow allowed more strong warming across Southern California where it got to a blistering 105 in Riverside in San Bernardino County, a typical warm spot, tucked away between the Santa Ana range in a flat urban clustered valley that endures a more continental climate rather than Mediterannean climate with less cloudcover and cooling daytime maritime breezes. Despite a slight increase in coastal cloud and fog penetration along the coast, downtown Los Angeles, only 12 miles from the beaches of Santa Monica and Redondo Beach yet again managed to warm to 100-degrees yesterday whilst the beaches of Santa Monica remained a touch cooler as the shallow inversion allowed overnight fog and stratus to part ways for late morning burnoff but natural AC kicked in, in the form of a seabreeze as the sun heats up the land. Onshore flow’s tend to be weakened depending on the strength of the inland high pressure cell, when it stays a little further east like we have now, it can allow a weak marine layer to get to the coast but in a situation like present we see enough pressure height over LA and near enough to the coast but not too much so that the marine influenbce is shut down, we are seeing collection of ingredients come together where we see a weak E, NE pressure gradient which creates the downslope, compressional warming effect off the San Gabriel and San Bernardinos and coastal mtns as well as enough pressure height and thickness to towards the coastm, that we are seeing 100s reach downtown LA and even to Long Beach but a cooling marine influence from Redondo to Santa Monica up to Oxnard and Santa Barbara. However when pressure heights are stronger than what they are now nearer or on the coast, the cloud, fog and afternoon Pacific breezes are non existent and even the beaches can feel like coastal valleys and there is no relief from the blowtorch.

I have always been facinated by Southern California’s weather. Some think it’s boring as it appears to only be morning clouds and fog along the coast and sunny and hot inland. But when you look deeper into the dynamical drivers which streer and control LA and Southern California’s atmosphere it’s a lot more complex and interesting than one would think, The Southland region from desert to beaches, like up in the San Francisco Bay area, which I have visited both of have probably got some of the most inpressive microclimates, these two regions of California have either thee greatest or one of the greatest contrasts in temperature and weather anywhere in the world for such short distances.

As for Denver where the mountains in it’s back drop recieved heavy snow and Denver struggled to warm up at all, we have another chilly day today but as the high pushes east as the large trough in the interior West shunts east, the trough of low pressure and it’s very chilly air aloft will move east and the same high roasting California and the West Coast will finally bring late season warmth back to Denver…

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  1. JamieD5 says:

    >I am doing fine Mr Vogan. I appreciate your warmth at what could be a particularly chilly time of the year. The weekend has brought pleasant sunshine to East Scotland today and I hope you enjoy your weekend also, and that there's warmth to be had over the great city of Glasgow.
    I was in York on Thursday and some of the leaves had browned and been discarded by the trees.
    So are we likely to see 18 degrees C over Aberdeen this January? I would put my money on a warm winter considering the warm summer that we have experienced in the UK and the previous 30 years of warming.

    Thanks Mr D

  2. Mark'sWxWorld says:

    >warm late sept days doesn't portray a milder winter ahead! Aberdeen has seen 18 degrees in January. Leaves here Jamie are almost completely off certain trees, others have almost complete coverage still but days are sure crisper here than what your saying in Fife.

    Hope your doing well and you enjoy your weekend.

  3. JamieD5 says:

    >I thought I may as well give you a picture of the temperature trend here in sunny Scotland. Despite less hours of sunlight, the temperatures are holding up nicely to set the scene for a mild winter to come. Here in deepest, darkest Fife, the temperatures are peaking at around 16 degrees C and drop off to around 11 to 12 degrees C during the early morning. Pretty average apart from night time minima, which are actually a few degrees above average. this may be due to all this CO2 thats in the air, creating a warm blanket effect to keep the residents of Lochgelly warmer than usual. The trees support this warm theme, as the leaves are still green and holding up well.

    Today the temperature peaked at 19 degrees C in Aberdeen. Thats surely good reason to be optimistic for low heating bills this summer. It is predicted that Aberdeen will peak at 21 degrees C tomorrow. Isn't that just amazing. COme November, we could expect something nearer 9 degrees C daytime.

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