The Australian Weather Forum

The complexity of this synoptic bomb can't be underestimated. Each series of model runs are producing different severe to extreme scenario's over several days. I'm currently having a close look at the 18Z runs of GFS & Icon, just waiting on EC 18Z run to finish in an hour or so. GFS 18Z on late ...

00Z run - UK, EC, GFS, ICON, Access's & JMA all going for the multi surface low pressure 'fujiwhara effect' spawning from the cut off mothership upper tropospheric cyclonic vortex for Friday. Access G going for a 978 hPa cold core cyclone in Bass strait. The Spirit of Tassie will need to carry d...

The BoM would be using the EC ensemble for that map from the 12z run. You only have to wait for the next model run to get a different synoptic chart ;) At the moment on the latest 00Z runs so far, it seems like we may have a dual polar cyclone fujiwhara effect on our hands, with a backend Antarctic ...

Nice Nick! Some big fat flakes in that shot. Let's hope it holds.

yes Nick. The models are still holding onto the falls. When did it last snow in Canberra?

Polar vortex at both 70 & 10 hpa is elongated and twisted 30 deg clockwise from 70 up to 10: https://earth.nullschool.net/#current/wind/isobaric/70hPa/orthographic=-279.83,-89.46,689 https://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-279.83,-89.46,689 At 10hpa, it looks lik...

Nice summary HB. Thundersnow has never lined up for here locally but its definitely a chance on current projections. We probably should get another couple of downgrades and upgrades in the next 48 hours :) It's certainly entertaining! EC putting flurries on Frankston and 0.5 to 1cm of sleet and snow...

Another entertaining batch of runs with the cut off low scenario showing on virtually all models now. GFS keeps producing the bomb cyclone in Bass strait within 120 hours from now :) EC now onboard again with a similar bomb in western Bass strait but 2 days later. EC is a tad erratic from run to run...

This latest GFS 00Z run is truly remarkable. A dart board 968 hPa cold core destructive Bass strait cyclone. It can only downgrade from here BoM and Vic Emergency will need a war room if that comes off.

weekly temp highlights to 02/08 UT.

Top temp +54.3c Failakah, Kuwait. About 2c under the Death Valley 1913 record.

Min temp -75.6 Vostok, Antarctica

GFS is going quite feral GFS 0108 18Z run is going with a multi core lower tropospheric cyclonic vortex attack. Its an elongated King Rossby wave as seen by it's width across to NZ. The southerly fetch will put snow in places it doesn't normal fall if that verifies.

Time to pull the trigger on this event, as I’m sure there is some model fun along with projection downgrades and upgrades to be had. The stratospheric polar vortex disturbance which has been watched closely in the climate driver thread is commencing to propagate into lower atmosphere and mid latitud...

75 model runs across the American and European ensembles on the 12z run suggests a vigorous cold wave into the 2nd week of August. The stratospheric disturbance discussed in earlier posts is arriving at the surface

If the EC ensemble members verify in the next 2 week, this will be the first full scale sudden stratospheric warming event since 2002. Could be an interesting September for the mid latitudes of OZ.

Yes SB, the stratospheric disturbance that Crikey and Didjman have been following is propagating towards the lower levels. It's now all about the Rossby wave and I think NZ is first cab off the rank as Didjman suggests. Keeping an eye towards the middle of August when the block is broken down.

Squeezed in 0.5mm

Spencer creek snow depth update: Now 140cm

2mm on the last system, 16mm for the thread.

UK missed the 38.5c record but western Europe got slam dunked by the terrestrial heat bomb. The wavy jet took the Sahara into Germany and France especially with many heat records. The same wavy jet bringing an unseasonal cold records into the U.S overnight.

24 hour extremes to 2pm AEST 25 July

Mitribah, Kuwait +50.8c
Vostok, Antarctica -63.1c

Pago Pago / Int. Airport (American Samoa) 188mm


Attention turns to London today (Thursday) and the UK record of 38.5c set in 2003 maybe challenged.