On Oct 26, 12:03 am, "Richard Dixon" wrote:
Dear All,

Does anybody know the most rapid recorded pressure rise during the
passage of an extratropical system? I just tried googling with little
success, I'm sure we've talked about it before on here.

"Lothar" in France had rises of 27mb/3hr - but this appears to be
surpassed by the "Greenhouse Low" - an extraordinary low that hit
Iceland in 1991 with sustained winds of 57m/s recorded and pressure
rises of 30.4mb/3hrs. I'd doubt the validity of those gusts!!

Anyhow - does anybody know of 3-hour pressure rises bigger than these?

Cheers,
Richard

p.s. If anyone wants to read more about this:

http://cat.inist.fr/?aModele=afficheN&cpsidt=2917156- abstract but no
contenthttp://folk.uio.no/jegill/publications.html - "Potential
vorticity-based interpretation of the evolution of 'The Greenhouse
Low', 2-3 February 1991" - probably a bit more technical !

In "Weather", March 1975, there is a short article (M W Stubbs)
on an unusually deep Low that passed more or less directly over OWS "D"
(44N, 41W) at 2025Z on 29 Jan 1972. The lowest pressure recorded was
947.5 mb. At 2000Z the pressure was 955.3, 3-hr tendency -35.0 mb.
From various other figures quoted one can deduce that the 3-hr tendency
at 2025Z was -41 mb. At 2025Z the pressure then rose 22.6 mb in 35
minutes(!), and the 2100Z ob shows 340°/85 kn, sky obscured, heavy
showers, pressure 970.1 mb. At 2300Z, the last ob quoted, the
pressure was 987.8 mb, tendency +32.5 in 3 hrs. Extrapolating to
2325Z, the 3-hr tendency would be +40 to +41 mb.

Tudor Hughes, Warlingham, Surrey.