Great Rain…but now what?

Some great rain last night – at least enough to reduce the fire risk in the short term across our area. Much less rain inland however and numerous lightning strikes did start new fires. According to the RFS update on our local (Bees Nest) fire: “Storm cells moved across the fireground yesterday afternoon. Lightning strikes were detected across the area and a number of new fires have been reported. Make sure you report any unattended fires to Triple Zero (000) immediately. Although there was some rainfall across the fireground it has not been enough to extinguish the fire.”

Here’s the totals according to BoM gauges – you can see the (well forecast) good totals across our region:

One BIG reason why we’ve seen an increase in humidity and rain close to the coast is because the Southern Oscillation has gone positive. Here’s where it sits at the moment (with the forecast for the week ahead):

You can clearly see where it went negative in July – the start of the big dry for us near the coast – and remained that way until yesterday. Positive on this index means the high pressure cells are further south – letting onshore winds and higher humidity levels move in across our region. It’s forecast to stay positive for at least the next week, which means more likelyhood of onshore winds and the risk of showers. There has been a LOT of discussion about the Sudden Stratospheric Warming that took place at the south pole over the last month. The following chart shows the temperatures (top chart) and temperature anomolies (bottom chart) above the south pole – pretty dramatic:

We would usually expect to see one significant impact from this event – the development of a strongly negative Southern Oscillation – which means high pressure cells a lot further north and westerly winds blasting across our region. So far we’ve been blessed with that not eventuating – but these events last over months rather than days, so there is still the potential for that to happen over the next couple of months. If it does we will quickly see a return of fire weather…so something I’ll keep a close eye on over the next couple of months. Meanwhile for the inland – they’ll likely need to wait for the Indian Ocean patterns to change before they see much rain – and that is likely some time away.

Smoke then rain…

An animation of the last 24 hours of the Grafton radar shows smoke plumes developing over out of control fires to our North (that were at Emergency Warning level again yesterday). That smoke cleared last night as fire activity died down. You can then see rain developing to our south and a southerly change sweep north across the region – and then an even more extensive area of rain develop to our south through today. Of more interest to us is the band developing to our west:

We’ll likely see that sweep through later on today and into tonight…with hopefully some showers to follow. Still some reasonable totals being forecast by the models between now and the end of the week. Here’s the current forecast from the top three models:

Now a case of watching the radar and seeing what happens. If we get some good rain fantastic – but if you find you get a quick moving storm come through but not much to follow it’s worth keeping an eye out for lightning-started fires. Fingers crossed we don’t see any of them.

Stormy Tuesday?

We’ve got that long promised change coming through tomorrow. It looks like we’ll be sitting to the north of the low – and that means more chance of a stormy change coming in from the south west. Those lucky folk to the south of the low will be looking at onshore winds with showers and longer rain periods.

Below is animation I’ve just put together with images from Meteologix. It shows from 1pm Tuesday through 1am Wednesday. The first half of the animation shows the forecast lightning for tomorrow. You can see storms develop on the hills and then expand rapidly and move northeast into the late arvo – so there could be quite a lightning display to our north tomorrow evening. The second half of the animation is the forecast radar image for the same period. Again you can see the storms develop and move north east…but then the ‘radar’ image shows showers and rain hanging around once the storms move through. This is good news – with the ground so dry there is the risk of new fires from lightning strikes…so having some soaking rain come through afterwards would be a good thing. There is NO guarantee of this event happening as forecast – but with the forecasts in it’ll be interesting to compare what happens in real time compared to the forecast below.

Rain Coming Up?

Not going to be posting every day…but had to post these images – actually starting to look fairly decent for some rain over the next couple of weeks…and not just for in the valley but also up on the hills as well. Here’s the Bello rain forecast across a range of models for the next 10 days:

A good combination – multiple models showing rain coming – and across a number of days as well. We might not see huge totals but to clear the air and bring the fires under control will do for now. Also looking decent on the hills – here’s the forecast 10 day rain for the Billys Creek / Mount Hyland area:

Worth noting that even if we don’t get rain every day, the low chances indicated mean higher humidity levels and the chance for firefighters to get on top of the fire. Now here’s hoping it comes together – will believe it when I see it.

Temperature wise we’ll be on a downward trend once we get through today – here’s how the temperatures look across the next 10 days:

One more hot and dry (and smoky) day to get through before the change comes through – then radar watching to see what falls where….

Rain This Week?

We’ve got a change moving through early this week that has the potential to bring some rain. It actually looks like it will bring a lot of rain to the south of us, but more touch and go for our region. Some models show reasonable totals but others show very little. It doesn’t look like drought breaking rains for us – and almost definitely not drought breaking for up on the ranges where a number of very large fires are burning. However….it’s better than we’ve seen for some time so having a look in more detail, here’s the ECMWF forecast for what will be happening at the surface and up high over the next few days. The forecast hour is at the top:

You can see a cold pool moving up from down south, combined with a trough moving across at the surface. That cold air moving through up high generates a tight but transient surface low on the east coast…anywhere to the south of that low will see some decent rain from this event….but sadly for us it looks like we’ll be to the north so will see much lower totals. You can see this reflected in the totals forecast until 10pm Wednesday from 4 keys models:

…If only that low was another 200km north! Beyond that there is not much rain in the short term outlook, but the good news is that once we get this Monday out of the way the fire danger levels look less elevated than they have recently – at least in the short term….until we get good rain across NE NSW every dry change will bring the risk of significant fire.

Longer Term Dry, Shorter Term Wet?

Shorter term we could see some rain, but longer term the outlook is weighted towards drier than average.

Mixed messages about the weather right now…and that comes from the mix of longer term and shorter term forecasting….so best to start with my perspective of the differences between the two.

Shorter term forecasts use the current state of the atmosphere and ocean and then project forwards with that information to forecast what will happen over the next one to two weeks. They’re getting better and better at this – but the problem is small miscalculations in the short term magnify quickly – so once you get beyond a few days the outlooks can change wildy from run to run.

Longer term forecasts look at the current state of the atmosphere and ocean and use this data to try to work out what that means for the coming season. They don’t forecast so much from day to day, but try to average out what they think that means for the season.

A good way of looking at how they work together is to think of a dice being thrown. If 1,2 or 3 means rain and 4,5 or 6 means dry, the shorter term forecasts will try to project which numbers will come up over the next week or two. The longer term forecasts don’t do that – they instead look at how the dice will be weighted…so for example if weighted towards 4,5 or 6 then they’ll forecast that it will likely be drier than average as we’ll likely see more 4, 5s or 6s than 1, 2 or 3. It does NOT mean that we won’t see a 1, 2 or 3 – just that we’ll likely see less of them. In weather terms that means that the longer term (seasonal) forecasts might indicate drier than normal – but that doesn’t mean we won’t see wet spells. We could be lucky and see a couple of bigger wet spells come up, even though the longer term forecasts were weighted towards drier than average.

Hope that makes sense – because you’ll need that to understand what is forecast right now 🙂

Shorter term forecast:

The current 10 day forecasts across Eastern Australia are finally showing the potential for some rain. The last few changes have been dry, but the next one coming up early next week looks like it could capture some moisture off the Pacific. Here’s the 10 day outlooks from 4 of the top models:

There are some significant differences between them in terms of who gets what – but the key take out from it is that a more unsettled spell is likely for many parts of NSW. Would be great to see some good rains across the tablelands to help with the huge fires up there. The change will be moving through early next week before it then dries up again. The next change might also bring some rain – but a long way off and I’ll post more about that as we get closer to the time.

Longer term forecast:

The outlook is pretty bad. Even if we get some rain over the next couple of weeks we’re unlikely to be out of fire season yet. Here’s the forecast from the EC model for October through January. This shows rainfall anomolies…so how much more of less than normal we will likely see. As we head into summer our average rainfall increases signficantly, so slightly drier than normal can still mean decent falls for us…but right now November would be a significant concern. The outlook is a result of the forecast temperatures and weather patterns in the Indian Ocean (positive forecast until end of the year – much drier than normal across SE Aus), Pacific Ocean (neutral for now – much less of an impact) and Antarctic Oscillation (how far north the westerlies come – and right now this one has the potential to head into record negative territory through October and November – which is not good for us at all).

Rain is coming…

We’ve got a dynamic and likely quite wet spell of weather coming up. This animation shows the weather forecast for the next 10 days – you can see that once the change moves through on Wednesday we get into a pattern of onshore winds with showers and longer spells of rain:

There could be some decent falls coming up – but this event will likely be categorised by how long it lasts rather than a huge fall on one day. The accumulated rainfall for the next 10 days shows it well, with the totals increasing day by day rather than a huge fall on any one day:

I’ve selected late next week to show some of the totals forecast by the models. You can see it more dramatically in these forecast rain totals from ECMWF:

…and GFS:

Both show some BIG totals looking likely…but don’t focus on the numbers – more on the indication of wet weather ahead and some decent rain totals likely, which over a week or so could accumulate into some higher end totals by the time it clears through. Usually when we see these totals forecast it is from an event lasting a couple of days – and over a short period of time such totals would likely bring some flooding. With this event forecast to last for a significant period of time it means the ground has more time to absorb the rain, meaning lower fast river rises…but also worth noting that a couple of models show a low forming offshore across SE Qld or NE NSW – and if that happened we could see some bigger totals if it formed just to our north.

Before we kick off the rain we’ve got another two days of storms likely. Some around today, much as yesterday, but a significant increase likely tomorrow as the change moves up and turns winds more onshore. The forecast temps over the next 10 days show it well – much higher daytime peaks forecast today and tomorrow, with much lower totals to follow as cloud and showers increase and winds turn more onshore:

So an interesting spell of weather coming up. I’ll post more, both here and on the Facebook page, as we head into it.

Gratitude: Many thanks as always to weather.us and tropicaltibdits for the charts and images.

Chance of storms then cooler

We’ve got a warm day today, with temps heading up towards 30C:

Once again this is ahead of a cool change which will move through overnight. That change moving up will likely trigger some storms over the ranges to our west through this afternoon. Those storms will then move south east towards the coast. We’re at the edge of the risk area with most storms likely to our south and west, but still a chance we’ll see something kick off. Storm forecast for today like this – you can see how close to the edge we sit with storms much more likely inland and to our south:

After that change moves through tomorrow looks a LOT cooler with the chance of showers – a completely different day to today. Here’s forecast max temps for tomorrow afternoon:

Once we move through tomorrow we’ve got another few drier and sunnier days coming up again, though this time we’re unlikely to see so much of the warmer weather before the next change moves through on Monday. That next change will combine with some decent cold air up high to increase instability and the chance of showers and storms. Total forecast rain over the next 8 days looks like this:

…however some models are showing totals higher than those shown here. With the cold air up high the potential for higher rain totals and a more dynamic surface pattern are certainly there – I’ll post more over the weekend.  Beyond that it looks like a similar pattern ahead – changes coming through but with the ongoing risk of showers and storms, so dry at times but by no means dry right though.

Lots to talk about…

There is a lot happening in the weather world at the moment so going to post here as we can mix images and posts…

We’ve had some good rain over the last couple of weeks – and now with temperatures climbing and the sun shining everything is starting to grow quickly. This image shows how much of our usual September total NSW has received so far:

Only a third of the way into the month but already over our total September average…

The rain so far could be good news – there is still the chance of an El Nino forming…and we have also got the Antarctic Oscillation likely to head back into the negatives over the next couple of weeks:

The AAO is a rough measure of how far north or south winter weather systems and high pressure systems sit. Through August the AAO sat in the negative, and we had bush fires and dry weather as a result. It then turned strongly positive in early September and we saw some really good rains as a result. The AAO is very hard to predict but right now it looks like it could head back into the negative again later this month – which increases the chance (but no guarantee) of drier weather once again. The recent rains should help alleviate the impact of a drier spell – it will take some time before fire risks increase again.

Looking over the next week we should see a lot of dry weather across our region with just a few showers or storms, more likely on the hills. Here’s the forecast rainfall from a couple of the top models through this weekend:

Forecast rain from the ECMWF model
Forecast rain from the German model

With Spring now well established drier weather means it will warm up quickly. Each day from now through Saturday will be warmer than the one before…so by the time we hit the weekend we’ll likely be in the low 30s:

Forecast Maximum Temps Saturday

All pretty usual Spring like weather coming up for us….but right now the Northern Hemisphere tropics are in overdrive. There are numerous significant storms around – including Florence which is likely to hit the US later this week. Here’s the (beautiful but scary) current view of the tropical Atlantic:

…and here is the forecast rainfall across parts of the east coast of the USA over the next 10 days – if this comes off they will be facing some devastating flooding:

That’ll do for now – I’ll come back with an update in the next few days. I’ll be retweeting the most interesting posts on Florence on the Bello Weather twitter feed if you want to keep up with what is happening on the other side of the world, otherwise look forward to sharing more local weather news with you soon!

Rain Coming?

** Longer article – click on the link to see all images if reading this on Facebook **

We had one change move through overnight bringing us a little rain – only 1.2mm recorded in town. The next change moves through over the weekend and once again it will bring some bigger falls inland. As this one moves towards the coast there are some signs however that we could be in sweeter spot this time around, with winds turning onshore temporarily late Sunday and through Monday. With a cold change moving through up high there will be some decent instability around. Combine that instability with a whole heap of moisture moving in from the north west and onshore winds at low levels…and we could see some decent falls. It is still some time off so there is time for us to move back out of favour but right now we’ve got the models looking like this:

European Model – the best of the bunch:

American model – next best model around:

German model:

…and the Australian model – this is the only one not so keen right now…but was also the best at predicting the last system so definitely worth giving it a consideration:

I’ll post more as we get closer, but we are sitting below average right now and this is a good time to get some rain into the earth. Fingers crossed it comes together.