NSW/ACT End of Holiday Heatwave - January 22-26, 2021

[Steve777]

The models and the BOM forecast are now lining up for heatwave conditions in much of SE Australia from this coming Friday January 22 and lasting up until Australia Day January 26. While not quite as intense as it looked a few days ago it will peak above anything so far this Summer. It is also fairly extended for a hot spell on the coast, with five consecutive 30+ days at Sydney OH. There will be some mid-level cloud about at times and thunderstorms are a 'slight' chance on some days.

The N-NW pattern is not that strong, so sea breezes should moderate conditions near the coast. The BOM's heatwave service rates this as a 'Severe Heatwave' for much of NSW, including Sydney. It gets an 'Extreme' rating for parts of Sourthen NSW and the ACT.
http://www.bom.gov.au/australia/heatwave/index.shtml

A weak Southerly arrives some time on the 26th. GFS suggests around mid-afternoon. There does not seem to be much in the way of storms or rain associated with the change, but it does look like an unsettled and potentially stormy pattern to follow. The 27th still looks warm.

Here are some forecast maxima for the January 22-26

Maitland : 34, 36, 37, 38, 37
Penrith : 36, 37, 40, 40, 39
Sydney OH : 32, 30, 32, 31, 32
Nowra : 35, 37, 31, 37, 34
Canberra : 34, 37, 38, 39, 37

 

[Lady Penelope]

The models and the BOM forecast are now lining up for heatwave conditions in much of SE Australia from this coming Friday January 22 and lasting up until Australia Day January 26. While not quite as intense as it looked a few days ago it will peak above anything so far this Summer. It is also fairly extended for a hot spell on the coast, with five consecutive 30+ days at Sydney OH. There will be some mid-level cloud about at times and thunderstorms are a 'slight' chance on some days.

The N-NW pattern is not that strong, so sea breezes should moderate conditions near the coast. The BOM's heatwave service rates this as a 'Severe Heatwave' for much of NSW, including Sydney. It gets an 'Extreme' rating for parts of Sourthen NSW and the ACT.
http://www.bom.gov.au/australia/heatwave/index.shtml

A weak Southerly arrives some time on the 26th. GFS suggests around mid-afternoon. There does not seem to be much in the way of storms or rain associated with the change, but it does look like an unsettled and potentially stormy pattern to follow. The 27th still looks warm.

Here are some forecast maxima for the January 22-26

Maitland : 34, 36, 37, 38, 37
Penrith : 36, 37, 40, 40, 39
Sydney OH : 32, 30, 32, 31, 32
Nowra : 35, 37, 31, 37, 34
Canberra : 34, 37, 38, 39, 37

Yuk. Some rain would be nice. At least the pool might justify the $$ I spend on it ....

 

[Homer]

And....to start off this heatwave, there have been some quite cool summer minimums around the metro this morning.
Down to low teens at "most" of the AWS's. 10.4 at Holsworthy and 10.8 at Richmond being the coolest.

 

[Jasper Schwarz]

Bom now ripping towards a heatwave later this week.

I don’t have the technical skills to check, but figured I pop this up now

 

[DidSurfNowSki]

Heatwave Situation for Saturday, Sunday, & Monday (3 days starting 23/01/2021)
Much of the severe to extreme heatwave conditions is now focussed on the southeast of the continent, with reprieve to southeastern WA and western SA. The region of extreme heatwave conditions expected has expended across southeastern NSW from western Sydney, through the ACT and into NE Vic. Severe heatwave conditions are expected in the surrounding regions across eastern SA, much of NSW (excluding the northeast), northern and eastern Vic, and an isolated area over northeastern Tas. Low intensity heatwave conditions are expected across much of Sa, southwestern Qld, southern Vic and much of Tas.

 

[Trail Blazer]

I have finally set up my weather station in the new rental, I was spurred on by the upcoming heat. It only reached 25.1C according to it today after a cool night of 14.2C, much closer to Terrey Hills (24.8C) than Obs Hill (28.2C), which at least gives me some confidence that it's in a good spot.

The elevation here is about 161m.

 

[CoastalStorm35]

The Oregon station I have can't do that so no, though the plan is to get a better Davis one like yours once I have done with moving (hopefully soon if we find somewhere).

ACCESS-C is saying this afternoon could be your stations baptism, good timing if to comes to fruition!

 

[Trail Blazer]

It'll be good if it can give things a bit of a drink before this heat.

You've got a great setup! Especially for clean wind data (that's the biggest challenge with anything at ground level with trees and buildings everywhere)

 

[connells]

CS35 I see you have a later model than mine with the newer rain bucket.

Beautiful morning here; 29/21 on my Vantage Pro 2 with barely a puff of wind and no clouds. And the promise of a string of similar days to follow. This is what Summer is all about.

 

[Billy Bob]

Another cool morning here, between 9 and 11 depending on what particular station you looked at. That is the seventh consecutive single figure morning for some stations: an excellent effort for January in the 21st century. I don't miss those 29/21 mornings in Sydney at all. Some of you might have guessed it- but I'm Drizzly Bear from the old forums. Kizz/connells can keep them as I know he prefers Japanese style summers.

The nights look to be reasonable here apart from Tuesday, when hot NW winds will possibly result in a minimum in the mid 20s in Canberra and about 23 here. That's to be expected the night before a change. Weak evening easterlies from the coast may give us a reprieve the other nights.

Fire is a bit of a worry, particularly with fresh westerlies forecast each day with temps in the mid to high 30s. There will be a lot of idiots around this weekend and as others have noted, it's as dry as chips around here with the husks of long dead grass from our wet spring. It won't take much to start a grass fire in these conditions.

A lot of people are getting nervous down here after what happened last summer; you won't find too many heat lovers down here at the moment. PTSD is real and I know of it through my involvement with the Braidwood community radio station. I only moved down in March so thankfully missed it all.

 

[Steve777]

A feature of this month in Sydney has been relatively cool nights. At OH the average minimum at 18.4° is tracking below the long-term (160 year) average of 18.8°, very unusual in any month these days. It’s 1.6° below the recent (1991-2020) average. There have been only a handful of 20+ minima, a contrast with recent years with featured long runs when it never dropped below 20° day or night.

===

Warm and humid here with a light NE’er. We might be getting sea gales later, like yesterday afternoon. On the coast, the NE’er didn’t stop all night, maybe part of the reason that sea temps off Sydney have cooled below 22° from 24° a couple of days ago.

Around Sydney, it’s reached 34° (rounded) at a few sites including the Airport and Olympic Park. Most of Sydney’s West is showing 32-33° and OH has just hit 30°.

 

[CoastalStorm35]

Temp peaked at 31.2c here is now falling in a light sea breeze, not sure yet if that will be the top of the day.

Humidity mixing with the heat now to make it feel soup kitchen like in the light winds...

 

[Steve777]

There are bubbly looking clouds about and small storm cells are developing around the edges of the Sydney Basin. Here’s the sky over Fiddens Wharf Oval (West Lindfield) around 3:00 PM.

The car thermometer was showing up to 34° a little while ago. It looks like OH has peaked at 31.8°, Bankstown at 35.0° and Penrith at 37.1°. Some stations may go higher. One of the storm cells is over Penrith now so maybe it won’t.

 

[POW Hungry]

Please stay on topic.
WX station discussion can move to another thread.

 

[Steve777]

Heard rumbling thunder for about 20 minutes or so from the cell passing over the upper North Shore.

A few Sydney stations have made late additions (after 4:00 PM) to their maxima. OH reached 32.9°, the warmest there since Nov 29. Olympic Park peaked at 35.4°. The hottest Sydney station seems to be Holsworthy Defence at 37.9° (100.2°F).

The latest GFS is now showing a persistent inland trough (‘Easterly Dip’) over SE Australia after the heatwave - warm, humid and wet.

 

[Homer]

The storm after it had passed this afternoon, heading towards the NE.
I received about 0.2 mm's from about 3 minutes of moderate rain.

 

[DidSurfNowSki]

 

[Steve777]

It’s a clear sunny morning with light winds and a bit of wispy high cloud. It was quite a warm night, with a low of 22.5° at OH, the warmest since Nov 29. The rest of Sydney was a bit cooler, mostly around 18-21°. Mount Boyce bottomed out at 18.1°, equivalent to about 25° at sea level - there’s warm air aloft.

There’s been a weak Southerly on the coast, not mentioned in the forecast but sort of implied in the lower forecast maximum for Sydney. The change passed through Sydney around 3:30. I expect that it will blow away quickly.

 

[DidSurfNowSki]

Yep, going to get warm.

 

[Steve777]

Sydney OH at 31.2° has already beaten its forecast by over 2°. It’ll probably drop back a bit soon once the wind shifts E-NE. Inland Sydney sites are into the low 30s. Sydney Airport, cool in a Southerly, is 4° cooler than OH.

Just looking at the dew points, there’s a lot of variation. OH is nearly 22° (58% humidity). It is warm and very humid so that might be about right. Nobbys is an incredible (i.e. I don’t believe it) 24.7° for 96% humidity. Is it foggy at Nobbys? Meanwhile, another coastal site, Bellambi, only has 17°. Most of inland Sydney is around 17-20° which seems about right.

 

[oldgeezer]

Yuk. Some rain would be nice. At least the pool might justify the $$ I spend on it ....

Yep. Bleeding money on the pool at the moment. The various components have all been replaced and configuring the pump speeds to satisfy the gas heater min flow rate requirements and not have the pressure wreck the cartridge is tricky. And water rates for the plants.

 

[oldgeezer]

South coast looks beautiful for the weekend. About 30C tops right on the coast with the sea breeze but the heatwave keeping humidity under control.

 

[POW Hungry]

Some good lift out Colo heights way. Doesn’t look overly threatening but good to see some lift out West.

 

[Eddy]

Just looking at the dew points, there’s a lot of variation. OH is nearly 22° (58% humidity). It is warm and very humid so that might be about right. Nobbys is an incredible (i.e. I don’t believe it) 24.7° for 96% humidity. Is it foggy at Nobbys? Meanwhile, another coastal site, Bellambi, only has 17°. Most of inland Sydney is around 17-20° which seems about right.

I was in Newcastle around lunchtime it certainly wasn't foggy, but humid with a moist light easterly blowing. Nobby's being surrounded by water I am not surprised by those numbers, certainly not representative of Newcastle.
A little further north, here its 33c dewpoint 23c humidity 53%.


Surf Cam for Nobby's
https://www.coastalwatch.com/surf-cams-surf-reports/nsw/nobbys-beach

 

[ShavedBadger]

No fog this morning in Newcastle, beautiful sunrise, but it warmed up quite quickly. No breeze to speak of until just after lunchtime, though there’s a north-easterly coming through now. Warm night predicted though.

 

[Steve777]

Nobby’s beach certainly looks beautiful today. I often go there when in Newcastle, walking along the beach and breakwater. In Summer the air is often so humid you can cut it. Or maybe like Newman (Seinfeld character) said of Hawaii: “The air is so dewy-sweet you don't even have to like the stamps.” Even so, I’d question 25.4°/24.7° (96% humidity). At 2:00 PM it was reported as 25.5 / 25.5° (100%) which doesn’t seem right. The ocean temp would be about 22-23°.

=====

A number of sites in NSW, all in the far West and Riverina, topped 40°. The hottest looks to have been 42.5° at Smithville, about 200 km NNW of Broken Hill on the SA border. Around Sydney, OH peaked at 31.9° early in the afternoon and slowly drooped back once the wind turned E. Penrith was hottest, reaching 38.1° before the Easterly arrived, it reached about 36-37° at other outer West sites while middle ring suburbs reached about 31-34°.

There are three more hot days to come, although the main heat won’t reach the coast. The BOM is forecasting warm and wet after the heatwave.

EDIT: storm cells have popped up near Penrith and the lower Blue Mountains. Also a couple East of Putty.

 

[Donza]

Beautiful in merimbula this morning after a southerly and associated roll cloud yesterday arvo.
Now in Jindy. Its around 32 degrees with a hot sun and moderate breeze.
Thankfully no humidity to sweat ....

 

[Homer]

Hearing quite a few rumbles from that Penrith cell. Maxed at 38.4 here today.

 

[Sideny]

Looks like its potentially severe with how slow moving it is.

 

[Northwesterly]

It is quite severe, I am surprised the BOM have not issue warnings for this storm.
Currently in Dharruk near Penrith working.
Very strong winds, at one stage leaves and branches were flying through the air.
Torrential rain. Very lightning active with lots of CG’s. Not getting out of the truck!!!
Wind is blowing the work truck from side to side while parked. Winds are still quite hot.

 

[Homer]

Some weird shit happening overhead at the moment.
I'm quite a distance to the east of that cell but some crazy development overhead. Lower clouds are moving quickly and developing then collapsing. Outflow perhaps? Higher cloud has no rain falling. There is almost constant rumbling.

 

[POW Hungry]

Radar says put a fork in it.

 

[POW Hungry]

Some weird shit happening overhead at the moment.
I'm quite a distance to the east of that cell but some crazy development overhead. Lower clouds are moving quickly and developing then collapsing. Outflow perhaps? Higher cloud has no rain falling. There is almost constant rumbling.

Just your garden variety 'scud' cloud.
If it were any more developed you'd prolly see that as the formation of Wall/Arcus cloud.

 

[Steve777]

t’s a calm, sunny morning after another warm, humid night. The part of the sky I can see is clear but City webcams show patches of low cloud. Minima across Sydney were around 19-22°. Winds are calm or very light and all over the place. Humidity levels around Sydney are in the 90s, at or near 100% at some sites.

EDIT: beach webcams are showing distinctly foggy beaches, including Maroubra and Bondi. WZ layers is showing what looks like sea fog off Southern Sydney.

 

[Steve777]

A feature of this event is not so much high temperatures as the high humidity that’s coming with them. This makes it feel a lot hotter but I think that it’s putting a cap on fire danger, which is only ‘high’, not ‘very high’ or ‘severe’ - that’s no reason for complacency of course.

Some temps and dew points: OH 32 / 21; Penrith 37 / 20; Bankstown 38 / 15.

Western Sydney is moving into the high 30s, including Badgerys Creek at 38.3° and Bankstown at 38.0°. Sydney OH has peaked at 32.5° so far.

There are some interesting-looking clouds to the South and South West.

 

[POW Hungry]

Decent cell just sitting on Katoomba & Surrounding BM Range.
7.5C temp drop in the last hour for Katoomba. Sans rain (yet).

 

[Steve777]

Decent cell just sitting on Katoomba & Surrounding BM Range.
7.5C temp drop in the last hour for Katoomba. Sans rain (yet).

Like yesterday’s cells it’s very slow-moving. There are also cells over the Southern Highlands.

Badgerys and Camden reached 40° before the seabreeze arrived there. Other outer Western Sydney sites went close. Sydney OH reached 34.2° and most of Sydney maxed in the mid to high 30s.

 

[ecowain]

Decent cell just sitting on Katoomba & Surrounding BM Range.
7.5C temp drop in the last hour for Katoomba. Sans rain (yet).

Lots of rain on Mount Victoria. Lovely!

 

[ecowain]

All the storm water drains overflowing.

Looks like three probable lightning strike fires in the mid mountains.

 

[Steve777]

All the storm water drains overflowing.

Looks like three probable lightning strike fires in the mid mountains.

Those storm cells brought some heavy falls in the Blue Mountains and Southern Highlands/Illawarra hinterland, including 41 mm at Wentworth Falls and an isolated 68 mm at Avon Fire Tower: http://www.bom.gov.au/nsw/flood/greatersydney.shtml

 

[connells]

Dew points have plummeted. Air has that inland smell now.

 

[Lady Penelope]

38 degrees here in Canberra today; just a little warmer than yesterday. Still feels quite sultry. Hope the week of rain/showers forecast comes off. We need that moisture.

 

[Donza]

Beautiful easterly in jindy.
Cooling down nicely.
Started with a cool 14 degrees.

 

[Steve777]

…don't miss those 29/21 mornings in Sydney at all. Some of you might have guessed it- but I'm Drizzly Bear from the old forums…

Welcome back Billy / Drizzly. I see that you have moved to climes more to your liking, with cold Winters (by Australian standards) and cool Summer nights.

The fire danger certainly hasn’t gone away. In spite of La Nina and a lot of cloudy days with rain recorded (near the coast anyway), there hasn’t really been that much rain in total. In particular, Canberra has only had 21 mm in January to date after 41 mm in December. Even Sydney is now tracking below average rainfall for January with only light falls forecast to the end of the month. Sydney has recorded 1.4 mm in the last 17 days.

——

It’s now 28/21 in Sydney, 30/19 at Olympic Park. Early high cloud has dispersed for another sunny day. The NE’er is up and running but still fairly light.

 

[davidg]

Penrith on track to record 6 days > 37c in a row. That's a pretty significant heatwave in anyone's books.

In fact last years summer from hell didn't come close to that sort of run of hot days, despite the extremes of course being far more extreme. I suspect the thick blanket fo smoke and constant dusts storms had a bit to do with that as well.

Its been a very dry start to the year as Steve notes above, only 20mm in the gauge for Jan half of which came on the 5th and hardly any storms at all.

Southerly doesn't look like it arrives tomorrow until after midnight. Yay.

 

[Trail Blazer]

22.0C - 35.5C here today assuming it goes no higher (currently 34.3C).

36.5C yesterday.

Penrith has just touched 40C, the first in the Basin today. I continue to be impressed at the new Obs Hill site keeping up with the Airport. Definitely a more representative location.

 

[davidg]

First 40c of Summer for the Sydney Metro?

39.9c at Penrith was damn close yesterday!

 

[Homer]

First 40c of Summer for the Sydney Metro?

39.9c at Penrith was damn close yesterday!

For Summer, technically yes.
Don't forget that there was 2 consecutive days of 40 in November, both for Penrith and OH.

 

[davidg]

Yeah but they were in Spring

 

[Homer]

Yeah but they were in Spring

Yes. I know! That's why I said "For Summer, technically yes."

 

[davidg]

Just messing with you. Only going to be 22c on Thursday, such extremes!