Just start a log and write down every few hours or so what your barometer reads... and do not move its location, meaning do not change its elevation above sea level.
Then by end of week end you can look up the local pressure reported for your nearest location and compare the two.
We expect a drop from about the present 1024 down to 993 tomorrow around 4 to 6 pm.
|GFS forecast for Seattle Area
You can also use custom pressure links we have set up at www.starpath.com/local.
Or check "UW meteograms" from link at www.starpath.com/insidepassage for another prediction. Note their statement that these take a few minutes to build once requested.
For those away from Seattle, find your closest reference station at www.starpath.com/barometers
Here is the latest weather map, from 5 am this morning.
Here is our main reference for barometer use and calibration