While the usual fear of failure applies this far out, the models seem to be holding for half decent to decent rain across a fair bit of the state, and maybe cold enough for alpine snow at the end.
I think we're all wise to the fact that these week-out models don't really mean anything, other than to predict 'something may happen'
I can see the sensational News.com.au articles already
It's going to be one of those cases where a few locales nudge 40mm but falls way below expectation. If it really happens over a two-day period, it may end up better, but Melbourne will probably see flooding. I mean, f***, if it 10mm hammers down fast enough part of the city look like Venice.
It’s interesting as at times the models hold a long way out and very reliable but right now seem to be overestimating rainfall events. I wonder why that is.
In my opinion, not too much point looking at rainfall totals at this stage as models will find it impossible to pin point where the cyclonic bombing gyre will form, until maybe within 24 hours.... and maybe not at all. I've seen models get this wrong within 6 hours of the surface cyclone forming. EC in April 2017 missed a developing low centre centre by 200 km in Bass strait and a 80 to 120mm convergence zone was sent west of Melbourne and into the Macedon Ranges when no rain was projected.
For now, its all about the fracturing polar jet stream, upper cold core cyclone, Rossby wave, atmospheric river from the tropics and how warm the Tasman currently is. If the upper low moves into S.A, the chances of bombogenesis in Bass Strait increase
Progs look very good this morning. Widespread 50-100mm the next seven days. Not a lot of difference between them. Expecting widespread showers, rain and storms, then a very wet and windy cyclonic swly spell. Could well be some very heavy falls in the Yarra Ranges and a decent storm surge if the progs come off. I’ve seen these systems easily deliver 100mm plus in the Dandenongs, though details matter a lot.
NW won’t do so well, but rest of Vic should do ok to good.
Models have been very consistent with regard to the Jet and polar vortex
Now looking forward to minor details which will hopefully deliver
Interestingly the Tasman is up to 4c above ave
The size of this projected upper low is not normal. For this time of year, I can't remember seeing a cold breach into the tropopause this size over mainland Australia before. Almost hard to believe it will happen. The upper low that penetrated S.A, Vic and NSW last December was about a third of the size. The initial trough on Tuesday night will have a tropical water slide running into it. Then this could go completely nuclear in eastern Bass strait on the surface when the moisture advection machine kicks in from the Tasman on Thursday. As expected, models just can't lock in an agreement on where the cyclonic bombing gyre will reside.
JasmineStorm wrote: ↑Sat Nov 17, 2018 9:51 am
The size of this projected upper low is not normal. For this time of year, I can't remember seeing a cold breach into the tropopause this size over mainland Australia before. Almost hard to believe it will happen. The upper low that penetrated S.A, Vic and NSW last December was about a third of the size. The initial trough on Tuesday night will have a tropical water slide running into it. Then this could go completely nuclear in eastern Bass strait on the surface when the moisture advection machine kicks in from the Tasman on Thursday. As expected, models just can't lock in an agreement on where the cyclonic bombing gyre will reside.
Incidentally, the Nov 1988 system dropped a mere 9mm in Bendigo, but 30mm in Melb CBD. My gut feel is that it could be very similar.
Another system in the ballpark is early-Dec 1987. 60mm in Melbourne, but a generous 50mm in Bendigo. I well remember it as a school kid on a camp in South Gippsland that got well and truly washed out. And that was a 'wetter than average' El-Nino year.
I hope I find a decent amount of rain in the gauge when I come back home! I know it’s off topic but I am about to be hit with a
huge thunderstorm here on the Tweed Coast. Apparently it’s droping larger than golf ball size hail...