Flood E NSW SE QLD East Coast Rain Event 11 Dec - 20 Dec 2020

POW Hungry

Old n' Crusty
Moderator
Ski Pass
May 28, 2000
23,790
39,092
1,063
Eastern Burbs of Sydney
183.2mm fell here in the 24hrs to 9am. Some more showers fell overnight / early morning. A little bit of thunder about early this morning as well.

The year-to-date total currently stands at 2012.8mm. This now makes 2020 very slightly wetter than 2011 (which brought 2008.6mm). It is the wettest year since 2009 when 2110.0mm fell here.
The Macleay River at Sherwood bridge this morning:
221 (3).jpg


Moderate flood warning current for the Orara River.
Minor flood warnings current for the Wilsons, Richmond, Clarence, Bellinger, Nambucca, Macleay, Hastings, and Camden Haven Rivers.

Three wettest BOM gauges in the 24hrs to 9am were:
195mm Mundays Lane
192mm Maria River
171mm Seven Oaks
All of them being more-or-less under the same train of heavy rain that affected here.

The Severe Weather Warning was cancelled this morning.
A great example of 'mountain wave' action over the Sherwood Bridge!
Waterway imitating mid/upper-level Westerlies. Ironic.
 

Ken Kato

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Ski Pass
Jul 13, 2019
3,649
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Brisbane
Wettest December day on record for Lismore (Current AWS since 2002), previous daily record being 148.6mm.
I'm sure the old site would have a figure in the 2's.
Nah neither of the older sites have recorded any daily amounts in December in the 200's (Richmond Hill with 107.2mm and Centre Street site with 176.4mm).
 
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Big T

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Dec 1, 2019
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Albany Creek
It's a shame that Blair didn't migrate here from WZ.
depends where the shop is. If in cbd block , i think its gotta go over 9mt height to go through . still under 7m now but rising. If the rain backs off now they should be fine. The basin should be filling up though. Athough with the whiz bang levee , who knows , i think it protects the cbd at the expense of nth & sth lismore.

oops replied to wrong post.
 

Flowin

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Ski Pass
Jul 5, 2019
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Pinjarra Hills, QLD
just heard from a rellie in Lismore, the cbd now has water in it , rising water from the basin that the pumps cant handle rather than rising up from the wilson river.... dear oh dear...the council may have some questions to answer as i think this happened not that long ago.
I thought the levee overtopped in 2017 TC Debbie.. Did they rebuild the levee after Debbie?
 

Seabreezes

One of Us
Ski Pass
Jul 4, 2019
439
3,805
263
South West Rocks, NSW
The localised heavy rain today causing BOM to upgrade and reissue flood warnings, with a Major flood warning for the Orara River, Moderate flood warning for the Wilsons River, and also a Moderate flood warning for the Tweed River.

12.2mm here since 9am, which came from a bit of passing moderate to briefly heavy shower activity early this afternoon.

Rainfall Summary so far here at South West Rocks:
10th - 60.8mm
11th - 205.6mm
12th - 1.6mm
13th - 8.2mm
14th - 62.0mm
15th - 183.2mm

16th - 12.2mm so far ________
Event total so far: 533.6mm
 

Gleno71

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Ski Pass
Jul 4, 2019
1,184
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Gold Coast, Queensland
The normal NE flow over SE Qld is often ridge dominated as a high pressure system starts to weaken/move away. The next trough is approaching, but it will turn the winds NW by the time it gets close enough to clear the ridge's influence out. So generally quite fine conditions with broad scale descending air under the ridge. The surface might be quite muggy and humid, but descending air from dry uppers makes for a shallow layer of moisture.

In contrast we currently have the remants of an upper low and associated trough sitting in the region, so while the air is not particularly unstable anymore, it hasn't really stabilised. A clue to the difference from the sounding Ken posted is that the dew point drops away quite slowly with height. A more typical fine weather NE sounding would have the dew point drop far more rapidly as height increases, and the wind will usually turn westerly at a much lower level - maybe somewhere near 850hp. Rather unusual not to have any westerly component at all from 500hp and down.


Thanks @Michael Hauber and @Ken Kato for the in depth explanation. Also i believe ( i think Ken has posted a chart a few times in the past ) of a chart that shows rising and descending air that could also explain the set up , but unsure if its publicly availiable
 

Dylan Kearney

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May 27, 2019
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I hope everyone is staying safe in the areas being impacted by flooding through northern NSW.
A sharp rise in the Upper Condamine River at The Head. This is due to the near stationary storm over the area. Goes to show just how unstable this moist NE wind flow is. BOM have also issued a warning for the Scenim Rim and Darling Downs for these storms.
 

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Big T

One of Us
Dec 1, 2019
284
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Albany Creek
Knee deep inside my friends shop, waist deep at the servo across the road, power gone out.
I’m guessing that’s down the bottom end of woodlark st? If so that makes sense, would be a few feet lower than most of the block, it’s a kick in the guts for them for sure. Re the levee, I’m sure it’s all rebuilt, but it hasn’t been topped this time around,river still a few metres below doing that.
 

Seabreezes

One of Us
Ski Pass
Jul 4, 2019
439
3,805
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South West Rocks, NSW
Compare the EC precip forecast that @Bello Weather posted in the very first post of this thread to what ended up falling:
accurate_model.png

2020121020201216.gif

It ended up being quite accurate!
- Correct with the placement of the heaviest rain (the far NENSW corner / Gold Coast hinterland, the Coffs-Dorrigo Plateau-South West Rocks triangle, and also the Comboyne inland of Port Macquarie)
- Correct with predicting an area of higher totals for the Sunshine Coast, and the Brisbane area getting lesser amounts.
- Correctly predicting a zone of higher totals stretching westward along the NSW/QLD border
- Correctly predicting the southern extent of the heavier rain (around the Taree area).
 

MegaMatch

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Ski Pass
Jul 3, 2019
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where
Compare the EC precip forecast that @Bello Weather posted in the very first post of this thread to what ended up falling:
accurate_model.png

2020121020201216.gif

It ended up being quite accurate!
- Correct with the placement of the heaviest rain (the far NENSW corner / Gold Coast hinterland, the Coffs-Dorrigo Plateau-South West Rocks triangle, and also the Comboyne inland of Port Macquarie)
- Correct with predicting an area of higher totals for the Sunshine Coast, and the Brisbane area getting lesser amounts.
- Correctly predicting a zone of higher totals stretching westward along the NSW/QLD border
- Correctly predicting the southern extent of the heavier rain (around the Taree area).

Definitely well modelled. Although I feel as though I've seen this exact event at least 20 times in the last 10 years. You'd want to hope the models would get it right by now when 9 times out of 10 that's where all these troughs/ECLs always seem to end up.
 

Kazza47

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Ski Pass
Jul 28, 2019
548
2,773
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Weirdest thing I've seen; the rain came creeping up on us but the lightning stayed on the mountains. So we've ended up with a constant shower , hardly strong enough to be classed as rain.
But it's constant so can't complain about that.
In a way, it's what a lot of us want - just some soaking rain, not too intense; no whiz bang storm; no damage.
:)
There is a Santa Claus after all.
I can see Lani getting a little bit down at Bell ; not as 'blanketing' as here but hopefully a soaking anyway (fingers crossed)
 

Trail Blazer

Part of the Furniture
Ski Pass
Jun 8, 2000
11,121
1,502
813
Jimi on Weatherzone. Pymble, Sydney
Seeing this thread is covering a large area, a decent storm approaching Putty North of Sydney, heading either towards the Blue Mountains or the North west part of Greater Sydney.

It is dying in the arse unfortunately. Too late I suppose. We have a couple more days of fun here at least
 

Falling_Droplet

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Ski Pass
Jul 7, 2019
2,055
11,403
363
Ferny Grove, QLD
fernygroveweather.com
Light showers in the late afternoon and during tonight. Near average temperature during the morning and afternoon and was variable while rising and falling many times from the mid morning to the mid afternoon. During tonight the temperature became slightly warm and warm later in the evening while the temperature fell slowly tonight. Dew point was stable in the morning and afternoon moderately high, fell a little later in the afternoon before becoming stable tonight while being slightly above average or moderately high.

Relative humidity fell rather slowly during the day and was a little variable and was moderately high in the morning and afternoon and became high later in the afternoon. Tonight the relative humidity stabilised while easing to slightly above average later tonight. Light WNW to SSW winds in the morning became ESE to SE from the late morning, became E to SE in the afternoon before ESE to ENE winds later in the afternoon. Light E to NE winds tonight while gradually backing to N to NE later tonight.

Last 24 hours:
rain 2020-12-16.PNG
temp 2020-12-16.PNG
hum 2020-12-16.PNG
wind dir 2020-12-16.PNG
 

Timbuck

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Jul 4, 2019
167
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Highland park
Ok miss la ninnny naa we had enough of the wet stuff on the GC , how about you use your amazing weather skills and steer it somewhere further west and north..... :D:D:D

what a great event and rain event for a lot of the east coast , pretty much all night Drizzle/light rain here and more heavy showers this morning. Sure is nice to. Lay in bed in the cooler temps listening to the rain.

had a family friend driving up from kyogle to get a car part I picked up for him as they are going to Fraser Friday. They made the right calls and and checked trafficlive site for flood closers etc He was driving though really heavy rain near kungur and uki and got the the bridge and it was under..bugger. Turned around and started to drive home and came the the bridge he just crossed and it was under.... that was maybe 15 mins time. Just goes to show once ground is wet those imbedded heavy showers make those smaller mountain streams rise fast. Some SES guys and council guys got caught as well. They all waited there for a bout 2 hrs and creek went down and he was able to make it home
Cheers

Tim
 

Artisan

Hard Yards
Dec 8, 2020
487
213
63
North West of Brisbane
Ok miss la ninnny naa we had enough of the wet stuff on the GC , how about you use your amazing weather skills and steer it somewhere further west and north..... :D:D:D

what a great event and rain event for a lot of the east coast , pretty much all night Drizzle/light rain here and more heavy showers this morning. Sure is nice to. Lay in bed in the cooler temps listening to the rain.

had a family friend driving up from kyogle to get a car part I picked up for him as they are going to Fraser Friday. They made the right calls and and checked trafficlive site for flood closers etc He was driving though really heavy rain near kungur and uki and got the the bridge and it was under..bugger. Turned around and started to drive home and came the the bridge he just crossed and it was under.... that was maybe 15 mins time. Just goes to show once ground is wet those imbedded heavy showers make those smaller mountain streams rise fast. Some SES guys and council guys got caught as well. They all waited there for a bout 2 hrs and creek went down and he was able to make it home
Cheers

Tim

Just south of me farm there’s a little creek in moderately steep country where about 140 years ago a wagon driver and his horses drowned. The story from his kids who were following along on foot were as the wagon got mid stream a flush of water came down and overturned the lot.
 

Falling_Droplet

One of Us
Ski Pass
Jul 7, 2019
2,055
11,403
363
Ferny Grove, QLD
fernygroveweather.com
3.4 mm since 9am yesterday. Event total of 124.8 mm.

Some light showers in the early hours. The temperature was stable or fell slowly in the early hours with a warm night. During this morning the temperature returned to near average. Dew point fell slightly in the early hours, and then rose from the early morning and have remained moderately high, though was briefly slightly above average in the early morning. Relative humidity have been near average that was stable in the early hours and have started to fall this morning. Light N to NNE winds with some NE winds and was calm at times in the early hours and this morning.
 

TweedStorm

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Jul 6, 2019
513
3,940
263
Banora Point
Morning gang, been absent for a while down on the Central Coast attending to family issues. (Thanks for the welfare check Mega ) Left the day before the 1 in 100 year flood arrived (the 2nd one for this year around the Tweed) and just can't believe that after that prolonged dry we were all so distressed about it, will go down as one of our wettest years.I see its still teeming down up there this morning.
Anyway, got a nice rumbly treat fr
IMG_20201217_094847.jpg
om this almost stationary storm over the hills just west of Gosford yesterday.
Have a goody folks.
 

GBerg

One of Us
Jul 28, 2019
72
872
233
Intercepted this beauty just outside of chinchilla last night at about 6.30pm. Was very suprised with the structure seeming there was a lack of shear. It dumped 45mm in 30mins and caused some minor flooding in town. I will post the edited pic later when i get home.
16081607304197822216679371570184.jpg
 
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