Pressure – What exactly is it?

You will have heard a million times forecasters talking of high or low pressure systems, but what exactly are they, and how do they affect our weather?  A huge amount of air is pushing down on us at all times, the gases in the air are made of tiny molecules that although we can’t see them, are taking up space and have weight.  The reason we can’t feel this is because our bodies also have air, which pushes outwards and this creates a balance between the two.  Warm air molecules move quickly and push each other apart, meaning the air gets lighter and rises.  Cooler air molecules move slowly, and they take up less space than the warm air molecules, and as the air becomes denser and heavier it sinks.  Air pressure is the weight of the air pushing down on the earths surface, when air warms up it rises, when air cools and sinks there is high pressure.  Air pressure varies all over the planet as different areas receive different amounts of the suns warmth.  Pressure is measured with a barometer, and is recorded as millibars (mb).  There is a difference between absolute pressure and sea level pressure.  You can find your sea level pressure with a quick google search by typing in your location.  My weather station records the actual pressure where I am, and will be different to those nearer the sea.  Where there are hurricanes/typhoons the pressure at sea will drop very low, as these storms from from low weather systems.

High Pressure

As stated, when the air cools it sinks, and this means there is more air pushing down on the earths surface, thus the air pressure rises.  As the air sink it becomes warmer and drier and the clouds disappear, so areas of high pressure usually bring warm dry weather with clear skies.  In weather maps, high pressure will be depicted as red.

Low Pressure

When the air warms it rises, leaving less air pushing down on the earths surface, and this leads to the pressure going down.  Areas of low pressure, which are usually described as a depression, bring rain, wind and storms, and changeable temperatures.  As high pressure is shown as red on weather maps, low pressure is shown as blue.

So generally, high pressure = good, low pressure = bad.  Here in Britain, when we have typical weather for the seasons, we will have high pressure in spring/summer, and low pressure in autumn/winter.  The reason we haven’t had the typical weather patterns lately is because of the jet stream, because it has been sat to the south of the UK for much of the past 18 months it has allowed low pressure to sweep right across the UK, usually in summer it sits above us, therefore drawing away low pressure above us and allowing high pressure to build.  This is the kind of weather we have been seeing lately, the jet stream is in its more typical place for this type of year so the low pressure is being dragged north of us.  Let’s all hope it will stay there throughout July and August!

 

 

Hottest day recorded, and broken 3 times this week! will it last?

So Saturday saw the hottest temperature I have recorded at 27.6c, Tuesday then broke that record at 28.7c, and today we have reached 29.8c, with a good chance we will top 30!  The question everyone is asking is will it last?  The answer is yes, it certainly could, potentially until the end of July believe it or not.  This has been the longest real summer weather we have experienced since 2006, and many have welcomed it with open arms, myself included.  The reason as I have explained previously is the Jetstream (Jetstream is explained elsewhere on the site) is currently situated well to the north of the UK, pushing away all low pressure and allowing high pressure to pretty much dominate the entire country.  Northern Ireland has recorded the hottest temperatures of this current spell, reaching 29.9c, which is only just under a degree hotter than the hottest ever record.  The chances are that will be well beaten this weekend though.  Some coastal areas, South Tyneside included will find temperatures dropping over the weekend with some cloud rolling in off the North Sea, that is not to say it will be cold by any means, it will still be in the 20s and will feel very warm in the sunshine.

The rest of the month appears for now to remain largely warm and dry, there is the chance of a few showers, which you would expect this time of year, but by no means a washout.  All in all enjoy the weather, make sure you wear suncream mind even in cloudier conditions, I can testify how easy it is to get caught out by the Rudolf look I am currently sporting after strolling yesterday morning in cloudier conditions!

Summer arrives in style!

So after forecasts of a heatwave for over a week, the good weather began on Friday as high pressure built over the UK, and yesterday we hit this years high, in fact, the highest I have recorded since having my weather station (records began December 11 2011).  The top temperature was 27.6c and was reached at 14.30, and it was by anybody’s reckoning a glorious summers day, we had wall to wall sunshine and not a cloud in the sky.  Many are in agreement that this will be our best weather since July 2007, and although there are signs that the weather may break down by the 15th this is not a certainty, and also even if it does it will not be a washout like we have had in recent years, and the weather should stay around average for the time of year.  All will become clearer as we get closer to the time, all forecasts and models are more reliable a few days before hand.  Check back for more info on what to expect over the next few weeks

Summer ready to arrive?

After much debate over whether we will have to endure another washout summer, and it did actually look like a bit of a damp squib until recently, it is now fairly certain that from the end of this week at least we shall experience some glorious summer weather.  All charts now seem to be in agreement that from around Friday temperatures will rise and blue skies and sunshine are on they way, and could actually stick around for a while.  Some say we could have the hottest July temperatures since 2006, which I have to say would be very welcome after last years washout.  The chart below gives a brilliant indication of what is to come:

A brilliant sight to see :)

 

That chart is for the 10th July, so you can see how well the UK is looking for this time.  Let’s just hope it continues until autumn, and is followed by a nice snowy winter!

The reason the weather is set to improve is again down to the position of the jet stream, which is set to head well north of the UK, allowing high pressure to build from the continent.  This picture is taken from Matt Hugo, and shows the position of the jet stream and how it allows the high pressure to reach us:

In summer, high pressure from the continent brings warmth and summery weather, whereas in winter it brings cold and snow.  Weather systems from the Atlantic (low pressure), regardless of season bring with them  wind and rain, and while we would expect these kind of weather systems to dominate through autumn or springtime, the position of the jet stream over the past few years has meant we have had Atlantic weather a lot more than usual, and this caused a lot of the flooding throughout last year.  In short, if everyone blows north we may be able to keep the jet stream well clear of us, and the summery weather will remain!

Things on the up!

Well, despite my best intentions this website has totally been left to its own devices lately.  A new laptop is being delivered in the coming week and the broadband, after 6 months of complaint, is finally being fixed tomorrow, so fingers crossed with reliable internet and a computer that isnt constantly overheating I should be able to keep this site much better updated. Even just the data from the weather station isn’t being uploaded properly as the laptop is crashing so much, so fingers crossed all problems will be resolved within the next week :)

Let it snow, let it snow, let it snow…….

Well the forecast snow certainly showed up!  Sunday saw the first flurries, although we didn’t really have any lying snow until Monday/Tuesday, when we had around 2-3cms.  After that we had a dry and very cold week, temperatures in NE32 fell as low as -6.6, before the snow made a huge return yesterday!  If you follow us on twitter you will have seen our predictions from as early as last Monday that South Tyneside would see heavy snow on Friday night, and we certainly did.  Around 6 inches fell yesterday, giving a lovely covering with snow that was just perfect for snowballs!  Ireland/Wales and the Mildlands were forecast significant amounts of snow from a front coming in from the west, and a lot of people thought as this was not going to reach as far as us then we would not be in for snow; this was not the case, as our snow all came in from the North Sea.   When the North Sea machine kicks off we tend to do really well snow wise, if the conditions are right the warm sea and the cold air make a great combination for us.  We tend to do less well from frontal snow, (coming from the west) as by the time it gets over the Pennines there isn’t a lot left for us at times!

This weeks forecast will be put up tomorrow on the website, and we will also be returning to photo of the day, so if you have any photos of snow/sun whatever feel free to send them in to info@southtyneweather.co.uk

Wet and mild gives way to cold and snow?

Well we began the new year the same as we left the old one, damp, mild and quite frankly a bit depressing!  All that is set to change over the coming days as we are set for quite a cold spell.  The hold the Atlantic has had over us for quite some time has finally given way to colder air from the east, which will result in freezing temperatures, and snow is possible for most regions.  I think as this winter has been mild for the majority we will really feel the difference as the temperatures begin to drop.  Already the past 2 days have shown lower temperature readings on my weather station, after balmy temperatures 10-12c that we have regularly saw over the past weeks we are now seeing 5c, and that is set to drop to minus figures before long.  Saturday is looking to be the first chance of snow, with more possible on Sunday, and then a higher chance again on Monday.  Remember though, snow is really hard to predict, as the model runs nearer the time give us their output I will be able to predict a bit better where it will fall and how much.  Because the cold air is coming from the east/north-east it will interact with the relative warmth of the North Sea (I say relative warmth, you wouldn’t want to go for a dip!!) which can cause significant snow showers along the east coast, so i think a lot of radar watching will be taking place to see where exactly the moisture is and whether or not it will blow as far inland as to hit us.  You may have heard or read recently about the “ssw event”, ssw stands for Sudden Stratospheric Warming, and is a factor in the cold weather, a good explanation on this can be found here:

http://metofficenews.wordpress.com/2013/01/08/what-is-a-sudden-stratospheric-warming-ssw/

Also, for anybody who would like to know what exactly “the models” are that forecasts are based on, a really good explanation can be found in the info bible that is Wikipedia:

http://en.wikipedia.org/wiki/Ensemble_forecasting

For now I am personally getting the sledges and windscreen scrapers out, and looking forward to hopefully out first real snow in quite a while.  I will leave the weather station on as much as I can over the next few days so the temperatures etc are available for anybody who would like to view them, but I am still having problems with the laptop over heating so I won’t be able to leave it on 24/7

 

First Snow of Winter

Well the first snow of this winter has fallen, and boy did it seem to take people by suprise, despite being talked about for days previously.  My personal experience of the roads wasn’t too bad, there did seem to be a lack of grit about as the roads were sheets of ice, but some people’s journey home from work yesterday were of epic proportions – some journeys took over 5 hours by all accounts.  I think questions have to be asked why as a country we seem quite unable to cope with any kind of extremeties in the weather; not that yesterday was extreme, it is winter after all, therefore generally it will be cold with the possibility of snow.  The massive rainfall we have had this year has been extreme, and I think people are starting to realise we need to be better prepared for these kinds of weather patterns.

With the cold weather looking set to last, and with more snow forecast this winter is looking set to be colder than average, which after last years quite mild one may seem out of the ordinary, but it isn’t!

 

Service resumes!

So after quite a long break hoping to get back into regular updates on here, especially over the coming months where I will be on constant snow watch!  It’s unbelievable that we are now in autumn, in all honesty I am still waiting for summer to begin…..This year’s summer was a complete washout pretty much throughout the entire UK, apart from a few days it mostly involved rain, wet and downright miserable weather.  The jet stream has been a much bandied about word this year, but this really is why we have had such unsettled conditions – the position of the jet stream has been dragging low pressure across the UK and blocking high pressure from the continent.  A recent press article on the BBC News site acknowledged that this has been the weirdest year for weather – http://www.bbc.com/news/science-environment-19995084

Closer to home there were several more incidences of flooding in the borough after heavy/persistent rain, although less than there could have been, it was good to see workmen out clearing the drains and gulleys of leaves and debris, I am sure it made a difference to some households.  The council and Highways Agency seem to be more on the ball than they previously have with this kind of thing so hopefully this will continue and the flooding of houses will occur less.  I think it is getting to the stage now where for some people their hearts sink the minute a drop of rain falls.

Looking ahead, next week is looking dry and settled with warmer weather looking to dominate, before a blast of much cooler air hits by next weekend.  It will be quite a shock to the system to go from so warm to so cold, there is even talk of snow!!!! but confidence is quite low at the moment – a week is a very long time in the world of forecasting.  What is looking very likely as I said is for it to be very cold by next weekend, so now could be the time to get out the winter coats and the hats and gloves!