Atmospheric Pressure Question

jArgHA

I have a question on the changes that happen in atmospheric pressure - can anyone tell me whether there would have been a significant change in pressure over Ireland on Christmas Day / Christmas night into Stephen's Day?

I'm curious as on Christmas night I managed to suffer from something called spontaneous pneumothorax (basically where air leaks out of lung) and wound up in hospital for 2 days. The doctors were not able to explain why it happened to me but I was curious about something I saw on the Wikipedia entry

The symptoms usually start at rest. Tall males, especially smokers, are characteristically at a higher risk of PSP. It has been found that PSP occurs more commonly during changes in atmospheric pressure and during exposure to loud music, and this explains to an extent why episodes of pneumothorax may happen in clusters.

With the drastic change in weather overnight on Christmas night (with the rain finally arriving) I thought that there may have been a significant change in atmospheric pressure that day, can anyone confirm if this was the case?

maquiladora

Pressure dropped from about 1030 to 1020 from midday on the 25th to midday on the 26th, not a drastic change and nowhere near the kind of drop experienced during the periods of stormy weather we had earlier before the cold spells.

jArgHA

aha thanks maquiladora, that blows that theory out the window. funny I would have just assumed that the big change in temperature would have also meant a big change in pressure also but obviously not so.

riffmongous

Here's the full 'synop' list for that time, to read the pressure, go to the 7th set of numbers, it will start with a 4. This gives the corrected to sea level pressure values. To read the value, replace the 4 with a 1 and add a decimal point in front of the last digit, so

40262 -> 1026.2hPa
40275 -> 1027.5hPa
40296 -> 1029.6hPa

http://www.ogimet.com/display_synops.php?lang=en&lugar=03955&tipo=ALL&ord=DIR&nil=SI&fmt=html&ano=2010&mes=12&day=24&hora=16&anof=2010&mesf=12&dayf=27&horaf=16&send=send

The actual station pressure can be read from the 6th set of numbers, I did it for Cork Airport, hope this helps.

Here's a link to a full explanation of the synop code
http://www.rwic.und.edu/metresources/synop.html

jArgHA

thx riffmongus, very useful links there

edit: as a matter of interest what might a 'significant' 24 hour change in pressure amount to approx?

Deep Easterly

UK Fax synoptic analysis maps (PPVA89) attached from Christmas day noon up to St Steven's day, showing strong anticyclone over Ireland collapsing rapidly on Christmas night as a frontal zone approached from the SW. A fall of approximately 15 hPa within that 24 hr period.


Chart source: UK Met Office

riffmongous

jArgHA wrote: »

thx riffmongus, very useful links there

edit: as a matter of interest what might a 'significant' 24 hour change in pressure amount to approx?

I'm glad you found them useful, the synops are a great resource once you figure them out.

Now I'm not certain what's the answer to your question but I thought I'd dig up an example for you anyway. Here's the synops for the 24hrs when that storm hit back in November

http://www.ogimet.com/display_synops.php?lang=en&lugar=03953&tipo=ALL&ord=DIR&nil=SI&fmt=html&ano=2010&mes=11&day=07&hora=12&anof=2010&mesf=11&dayf=08&horaf=12&send=send

So it goes from 1012.7hPa to 965.6hPa, so thats a change of 47.1hPa in 24hrs. I'm guessing that's significant for Ireland