6am analysis this morning shows no fronts in the area, just a low to
the southwest. The T+24 forecast however shows fronts "appear" over
northern areas --- what's happened here? This would be this low's
*second* set of fronts.

Surprisingly cold temperatures forecast for tomorrow and Friday. True,
the wind goes round to a west-north-westerly point on Friday but IMX
both winds from a northerly point and *strong* winds are required to
produce below-normal temps in summer. The isobars don't seem that
close on Friday.

Thankfully the weekend looks warm in the south, if perhaps on the
cloudy side due to that front embedded in the high. Still, as long as
it's warm and not gloomy, no complaints...

"Nick Whitelegg" wrote in message
om...
6am analysis this morning shows no fronts in the area, just a low to
the southwest. The T+24 forecast however shows fronts "appear" over
northern areas --- what's happened here?

Nick, the charts are subjective but I suspect it's a frontogenetic situation
with the area of 'weather' eventually taking on the properties of the more
conventional warm/cold/occlusion. In saying that if you look at the 06Z
analysis it doesn't take much imagination to link the troughs together to
resemble the system on the 06Z T+24, as strange as it may seem.

Jon.

"John Whitby" wrote in message
news:%EuSc.1766$7E3.536@newsfe5-
snip

Obs, radar, satpics and 1200Z Camborne still suggest very little *frontal*
about the weather effecting the SW. Looks as if the rain will be patchy
...basically an area of showers with some thunderstorms. As Jon suggests
though things may change. Still likely to give plenty of rain to some
places
which have already had more than enough. Mainly shower cloud on this
afternoons satpic .....

http://www.sat.dundee.ac.uk/abin/pro...roject.ch2.jpg
Cheers
John

There's a bit more organisation to the precipitation in the far south now
but admittedly it's still largely a showery/convective mass. The 18Z
analysis on the MetO Aviation (subscription pages) put the occlusion roughly
Rosslare through Plymouth with a narrow warm sector over NW France. The 12Z
(unmodified mesoscale) carries a more organised band of rain north (perhaps
overdone in terms of coherence) to lie roughly where the occlusion is placed
on the 12Z T+24 http://imkpc3.physik.uni-karlsruhe.de/pics/brack0.gif .

I'd hazard a guess it's all roughly tied in with the 16 theta-w plume that
can be seen here :-
http://meteocentre.com/models/ukmet_...W_12_panel.gif
the occlusion extending back further west through the 14 theta-w over
Ireland.

Jon.


Jon.

"Jon O'Rourke" wrote in message
...

"Nick Whitelegg" wrote in message
om...
6am analysis this morning shows no fronts in the area, just a low to
the southwest. The T+24 forecast however shows fronts "appear" over
northern areas --- what's happened here?

Nick, the charts are subjective but I suspect it's a frontogenetic
situation
with the area of 'weather' eventually taking on the properties of the more
conventional warm/cold/occlusion. In saying that if you look at the 06Z
analysis it doesn't take much imagination to link the troughs together to
resemble the system on the 06Z T+24, as strange as it may seem.

Jon.
Obs, radar, satpics and 1200Z Camborne still suggest very little *frontal*
about the weather effecting the SW. Looks as if the rain will be patchy
....basically an area of showers with some thunderstorms. As Jon suggests
though things may change. Still likely to give plenty of rain to some places
which have already had more than enough. Mainly shower cloud on this
afternoons satpic .....
http://www.sat.dundee.ac.uk/abin/pro...roject.ch2.jpg
Cheers
John

There's a bit more organisation to the precipitation in the far south now
but admittedly it's still largely a showery/convective mass. The 18Z
analysis on the MetO Aviation (subscription pages) put the occlusion roughly
Rosslare through Plymouth with a narrow warm sector over NW France. The 12Z
(unmodified mesoscale) carries a more organised band of rain north (perhaps
overdone in terms of coherence) to lie roughly where the occlusion is placed
on the 12Z T+24 http://imkpc3.physik.uni-karlsruhe.de/pics/brack0.gif .

I'd hazard a guess it's all roughly tied in with the 16 theta-w plume that
can be seen here :-
http://meteocentre.com/models/ukmet_...W_12_panel.gif
the occlusion extending back further west through the 14 theta-w over
Ireland.

Jon.

I'm not clear about what's exactly going on.
The WV is complex-
http://www.sat.dundee.ac.uk/pdus/BW/...11800BW1_g.jpg
with a striking dry intrusion like feature along the jet streak into the showers off the SW coast.
Is there a baroclinic zone in the English channel with a notional triple point off the SW coast?Is
the trough / shower feature to Sw nr Biscay expected to interact with this and set off a sort of
'Instant Occlusion ' which then moves NE?
If the jet overruns the convection at the triple point is this likely to provide enough shear for
tornado formation on the south coast?
http://www.sat.dundee.ac.uk/abin/pro...roject.ch2.jpg
shows the anvils 'pluming out' in the winds aloft.
Anybody got a clear analysis?
--
regards,
david
(add 17 to waghorne to reply)

The 18Z
analysis on the MetO Aviation (subscription pages) put the occlusion roughly
Rosslare through Plymouth with a narrow warm sector over NW France.
20Z radar certainly shows a more organised warm front (?)-
http://www.met-office.gov.uk/weather..._PS_latest.GIF

--
regards,
david
(add 17 to waghorne to reply)

The 12Z analysis http://imkpc3.physik.uni-karlsruhe.de/pics/bracka.gif
a pretty good fit then with yesterday's 12Z T+24.

Jon.