Originally Posted by lab man
I'm living right on the shannon estuary about 50 / 100 above sea level yes a rough guide is all I want there is a skrew on the back
Thanks for your help
Okay so your barometer at present should be reading 1001 mbs or 29.55" ... and if you happen to check a bit later, it should be slowly rising to reach a peak around 29.8" tomorrow mid-day, then it should fall to around 29.3" late Friday night. If you seem to be in that range you don't need to adjust.
At your elevation your actual air pressure is just slightly lower than sea level pressure. All the weather stations and weather maps you might see anywhere are converted to sea level pressures. Somebody living high up on a hill could have as much as an inch or 30 mbs lower "actual" pressure but if their instrument is set at the actual pressure it will range lower than the design values for "fair, change and stormy" or whatever they show.
Meanwhile, had a look at latest guidance ... Zeta was whistling along even a bit faster than yesterday's model guidance had shown, the ragged centre just left the U.S. mainland around Ocean City MD ... model consensus seems to be that the core of Zeta's energy will remain intact for 48-60 hours and zoom past Donegal Bay late overnight Saturday into Sunday morning, probably leading to a peak in wind speeds from midnight to 0600h on the west coast. Before that, the low forming up in the middle of the Atlantic now will be bringing an interval of strong winds Saturday morning, these will veer westerly for a time, and some clearing will develop later Saturday, a brief break in the strong winds could mark the passage of a very weak ridge before Zeta's remains arrive.
The supporting upper low is trying to keep up but is falling behind and will force a secondary low to form in the same zone as Zeta runs through, that second low will never totally develop and will remain a trailing wave but we need to keep an eye on that plus the final stage of low pressure dropping southeast on Monday.
Still some potential for any of these to develop an intense band of strong winds as the jet stream is quite compressed. Will probably just be a long term disturbed period of weather with mostly level one alert conditions and the occasional localized level two (or orange alert if you prefer).