Sydney Weather Nerds

27/10/2025

27/10/2025

Mornin’ Nerd Fam! Sydney woke up in full post-change hangover mode — overnight temps dipped to 10–12°C, drizzle loitered like an uninvited guest, and everything outside currently feels like someone left the fridge door open.

🌦️ Today: Expect a day that looks worse than it is. Cloudy skies, isolated showers (mostly coastal), and temps that’ll hover around 15-16°C. Winds stay from the S/SE, so if you’re heading out, prepare for that “walking through soup made of wind” feeling.

🛰️ Satellite drama of the morning:
This morning’s imagery is chef’s kiss meteorology — a literal collision of air masses over eastern Australia.
* To the south: that polar air, speckled cloud tops marking cold instability, tumbling north like it’s late for work.
* To the north: a smooth, smeary band of tropical moisture, draped along an upper trough — that’s the humid stuff feeding in from the northwest.
* Where they meet? That’s the atmospheric equivalent of a mosh pit — a baroclinic zone that’s fuelling mid-level cloud and scattered rain bands over NSW and Queensland.

Radar check: Patchy showers flicking around the Sydney Basin early this morning. Further west, a second trough line is firing up over the Riverina, which may sneak east tomorrow.

💚 Health & lifestyle:
* Pollen: Low (the cold air’s bullying it into submission).
* Migraine / Arthritis: Pressure’s up, humidity’s down — expect twinges.
* Outdoor plans: Still breezy and cool — laundry may orbit back to the neighbour’s fence.

🌙 Tonight: As the upper trough deepens inland this afternoon, it starts dragging the northwest moisture plume toward the coast. Watch for low-level winds from S/SE to flip E–ENE between roughly 5–7pm, first along the coast then creeping inland through the evening. That shift is more than just a breeze change — it’s the handover between two air masses. Once that happens cloud will thicken from the west & showers will develop & increase. Heaviest rain will be where the colder air & the tropical system clash. Temps 13-14°C - warmer if the upper system pushes further south.

🧠 Summary:
Today’s basically meteorological theatre — polar air crashing the tropical party. We’ll stay chilly, cloudy and unsettled before things gradually warm back up toward the weekend. Sydney’s doing her best impression of Melbourne, and honestly, she’s nailing it.

27/10/2025

- light gusty showers pushing in as that very cold air starts arriving - anyone looking outside will note sudden & rapid dark low cloud pushing in over the last 45 mins. Hopefully we all get something.

27/10/2025

27/10/2025

Evenin’ Nerds! Sydney, she did it. The change hit bang on 12:17 pm, and my word, what an entrance — the kind that slams the door, knocks over the pot plants, and sends your washing into the neighbour’s pool.

☀️ Daytime recap: We peaked at 25–27°C just before the southerly bulldozed in, then boom — temps plummeting to 14–17°C and still dropping. Gusts clocked 85 km/h on the coast, 50 km/h out west, and that “mild spring day” turned into a scene from Frozen faster than you could say “where’s my hoodie.”

🌬️ The southerly saga: This wasn’t your average “sea breeze with opinions.” The core of this change came wrapped in a pressure drop below 1000 hPa, and it’s dragged in a slab of Antarctic air cold enough to make a magpie shiver. The coldest air is still pushing north, so if you thought it was chilly now — buckle up, this is just foreplay.

🥶 Regional chills: South of Sydney is freezing. The Illawarra’s been lashed by bitter winds, and Green Cape clocked just 9.7°C this arvo — yes, on the coast! Most towns between Nowra and Batemans Bay are sitting 11–14°C, and Sydney’s now colder than it was overnight. That’s meteorological disrespect.

🌧️ Radar & satpic sitch: A solid band of rain and showers is marching through the southern Illawarra, tied to a blob of 850 hPa air near -1°C — icy enough for graupel or hail in the higher bits. Expect that band to drift into Sydney tonight, especially the coast and south.

The real intrigue: the water vapour imagery. Moisture is streaming in from the northwest, colliding with this slab of polar air sweeping up from the Bight. If those two hook up over Sydney later tonight… boom. A burst of heavier showers or even a sneaky rumble isn’t off the table.

💚 Health & lifestyle:
* Sleep comfort: Good luck — it’s going to sound like your house is sighing under the wind.
* Pets & plants: Bring them in before they develop frost anxiety.
* Commuters: Expect slippery roads and low vis if showers hit overnight.
* Arthritis & migraine: The barometer’s having a meltdown; your joints are valid.

🌙 Tonight: Cloudy, windy, and properly cold. Temps hover around 8-14°C, with showers pushing up from the south. Wind chills near 8°C on the coast. By dawn, it’ll feel like someone accidentally set Sydney’s thermostat to “Canberra.”

🔭 The week ahead: updated around 8pm with the freshest data this side of 31/Atlas

So yes, Sydney just went from spring flirtation to Antarctic slap in six hours. Classic.

27/10/2025

- the initial bow wave of the change has now pushed across the whole Sydney Basin (you can see it in the image - like a snake). You’re probably rolling your eyes - “it’s cool, yeah, but not that cold….FIZZA” despite the fact that the Coast is now colder than it was overnight, and most places have cooled by over 5ºC, some 7-8ºC already…

Well there’s a very good reason it’s not ultra cold *just yet*. As I told you this AM, super cold air is very dense, fat, heavy and takes its sweet ol’ time. Our special Nerds Rainbow infrared sat-pic tells the story - the dark blues/purples is warmer air, the aqua/green/yellows is super cold air. You can see that super cold air slowly marching up the coast - Kiama is now only 13, Bellambi 15, and the South Coast 11-13ºC! The outer edges of that has to get over the Royal National Park and coast line to get into the Sydney Basin, and then it’ll start to damming up like me with too many carbs - and then watch temps drop. That is starting to happen now, so keep an eye on those coastal temps.

27/10/2025

- change is officially through the Airport, with temps dropping 5ºC in 10 mins and humidity jumping 40%! Meanwhile Jervis Bay 15ºC and Kiama 16ºC, and places on the South Coast 11 - 14ºC! 🥶 Enjoy Hunter Weather ❤️

27/10/2025

- HERE IT COMES! Right on time. Wattamolla 60km/h southerlies, and on radar you can see 2 light blue ‘arcs’ or curves moving towards Sydney AP and the Shire - that’s the change! Hunter Weather your turn next - PS Kiama now only 16ºc!!!

27/10/2025

- change is through Kiama, which puts it into the Sydney Basin around 12pm as forecast. Already kicking off showers just off the coast and also near Kiama. The coldest air still lags behind the initial leading edge, slowly working its way up the South Coast - most of the coast south of Jervis Bay is only 11 - 13ºC!!!!! Ouch.

26/10/2025

- change is between Kiama and Jervis Bay, so far 6-8ºC temp change, coldest air on the South Coast with Merimbula only 12ºC, almost 13ºC colder

26/10/2025

26/10/2025

Morning Nerd Fam! Happy Monday 🫠❤️
Sydney’s had a surprisingly restless night with 11–17°C and a few rogue light showers. And yes, none of the models saw it coming — which tells us that mid-level moisture was thicker and stickier than models guidance allowed for. That sneaky onshore layer’s flexing, and she’s not in the model spreadsheets.

🌡️ Today’s Forecast:
This morning is the appetizer — the main course arrives around late morning to lunchtime, when the southerly change barrels through.
* Timing: Based on radar, the front’s near Batemans Bay (~225km out) and trucking north around 60km/h.
* Colder, denser air like this often underperforms on speed due to friction and depth drag, so we’re leaning more towards midday for most of the metro, maybe 12:30ish for the CBD, later for the Hawkesbury.
* Before the change: warm and smug with 24-25°C on the coast, 25-27°C in the west west, NW winds occasionally gusty.
* When it hits: the mercury plummets faster than your motivation on a Monday — a 10–12°C drop in 90 minutes. Winds swing sharply S/SE 40–60 km/h, gusty near the coast, cloudy skies thickening right behind it.
* After: light patchy drizzle or coastal showers, maxes capped around 16–18°C post-change.

🛰️ Satpic Situation:
The IR and WV loops show the front’s cold core punching north, with a strong dry slot behind — classic upper-level intrusion. You can see the cold conveyor belt wrapping around the southern flank.

💧 Rain & radar outlook:
Radar’s already showing light returns west of the ranges, and another weak band pushing off the Shoalhaven coast. Once the southerly arrives, expect scattered light showers for a few hours, then easing.

💚 Health & lifestyle forecast:
* Pollen: Moderate today, but the southerly will clear it nicely by this arvo.
* Migraine/arthritis: Rough morning — falling pressure + wind shift combo special.
* Outdoor plans: Morning jog? Fine. Lunch outdoors? Only if you enjoy being exfoliated by sand and regret.
* School pick-up: cold, miserable, gloomy & windy, and that’s just the kids. Showers near the coast

🌙 Tonight:
Cloudy and cool, lows 12–14°C & windy.

🧠 Summary:
The southerly change lands late morning to lunch, and she’s not here to play. Expect a fast temp drop, messy winds, and a taste of autumn in October. The midweek system’s looking far juicier — the models may have missed today’s drizzle, but they’re all in on Wednesday’s rain event.