Pressure tendency evaluation

Just noticed this today as the cold front of some storm depression on the North sea was passing during the night, as one can also see nicely in the barograph.

As you can see in the screenshot Trail Sense gives an improving soon based on the 1.9hPa/3h increase. However, the increase over the last 3h was more like 1002-997 = 5 hPa which conforms a bit better with the current wind situation and current coastal strong wind warning for the Elbe (Hamburg-Cuxhaven 5-6 Bft, squalls up to 7 Bft) and measurements at a nearby meteorological station of 5 Bft (~16 kts).

So, I wonder if the tendency is calculated not for 3 real hours (if available) thus averaging, but just as the gradient between the last two points measured. Then it may fall in this situation for the slightly flatter increase in the last measurements and under-estimate the situation. (This would be erring on the dangerous side.)

Here’s the screenshot from Trail Sense from 11:14 CEST (UTC+2)

And just for comparison the relevant part of the analysis chart from Deutscher Wetterdienst, issued Thu, 2020-09-24, 06:00 UTC (isobars are 5hPa apart, the low (marked T) is moving in NE direction):

isRelatedTo: #179

[aw-bib]

Seems to be fixed indeed. Thank you 😃

[aw-bib]

Again a passing front during the night.

Without correction for sea level:

Switch on the correction for sea level by given altitude: