Australian Government Bureau of Meteorology
New South Wales
TOP PRIORITY FOR IMMEDIATE BROADCAST
Detailed Severe Thunderstorm Warning
for Heavy Rainfall
for parts of Greater Newcastle, Gosford/Wyong, Sydney and Blue Mountains/Hawkesbury areas.
Issued at 6:54 am Wednesday, 18 March 2026.
Slow moving thunderstorms are producing heavy rain along the central NSW coast.
HEAVY RAINFALL for the following areas:
Blue Mountains/Hawkesbury, Greater Newcastle, Gosford/Wyong and Sydney
The Bureau of Meteorology warns that, at 5:30 am, severe thunderstorms likely to produce heavy rainfall that may lead to flash flooding were detected near Budgewoi and Erskine Park. These thunderstorms are slow moving. They are forecast to affect Penrith, Cranebrook and Doyalson by 6:00 am and Blaxland, Glenbrook and Berkshire Park by 6:30 am.
93 MM WAS RECORDED AT MOSMAN IN 60 MIN TO 3:03 am
64 mm was recorded at Pearl Beach Reservoir in 60 min to 2:27 am
51 mm was recorded at Rose Bay in 30 min to 5:31 am
51 mm was recorded at Allambie in 30 min to 3:04 am
44 mm was recorded at Little Bay in 30 min to 5:07 am
42 mm was recorded at Wahroonga in 30 min to 3:13 am
36 mm was recorded at Shanes Park in 30 min to 6:32 am
Cancellation for the following areas:
New South Wales Anonymous Locale 1
The State Emergency Service advises that people should:
* Keep clear of creeks and storm drains.
* Don't walk, ride your bike or drive through flood water.
* If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue.
* Stay indoors away from windows, and keep children and pets indoors as well.
For emergency help in flood and storms, ring the SES on 132 500.
Stay updated on the Hazards Near Me NSW app or the ACT ESA website (https://esa.act.gov.au).
A more general severe thunderstorm warning is also current for parts of the Hunter, Metropolitan and Central Tablelands districts.
Other warnings may be current.
The next warning is due to be issued by 7:55 am.
Check https://www.bom.gov.au/weather-and-climate/warnings-and-alerts. Warnings are also available through TV and Radio broadcasts or call 1300 659 210. The Bureau and State Emergency Service would appreciate warnings being broadcast regularly.
Forecast
Merriwa (32.1394°S, 150.3557°E, 246m AMSL) set as my default location ›
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Seven day forecast
Today: Cloudy. Medium chance of showers, most likely this afternoon. The chance of a thunderstorm about the Lower Hunter this morning. Thunderstorms possibly severe with heavy rain which may lead to flash flooding near the coast this morning. Light winds becoming S/SE 15 to 20 km/h in the morning then becoming light in the late evening. Daytime maximum temperatures 23 to 28.
Forecast for Merriwa (32.1394°S, 150.3557°E, 246m AMSL) Wed Thu Fri Sat Sun Mon Tue Summary
Minimum 19° 18° 17° 16° 17° 16° 16° Maximum 29° 25° 28° 29° 26° 27° 29° Chance of rain 60% 70% 70% 60% 70% 60% 70% Likely amount 1-5mm 5-10mm 1-5mm 1-5mm 1-5mm < 1mm 1-5mm UV index Very High Very High Very High Very High Very High Very High Very High Fire Danger Rating Moderate Moderate Moderate Moderate - - - Frost risk Nil Nil Nil Nil Nil Nil Nil 9am 3pm 9am 3pm 9am 3pm 9am 3pm 9am 3pm 9am 3pm 9am 3pm Wind speed 15
(km/h)21
(km/h)4
(km/h)12
(km/h)6
(km/h)20
(km/h)6
(km/h)21
(km/h)12
(km/h)25
(km/h)10
(km/h)25
(km/h)10
(km/h)25
(km/h)Wind direction SSE SSE SSE S S S S S S SSE S SSE SSE SSE Relative humidity 87% 57% 98% 83% 94% 63% 89% 50% 91% 58% 90% 54% 94% 54% Dew point 21°C 19°C 20°C 21°C 19°C 19°C 18°C 16°C 18°C 16°C 18°C 16°C 18°C 18°C -
Warnings
- Detailed Severe Thunderstorm Warning (Heavy Rainfall) for Greater Newcastle, Gosford/Wyong, Sydney & Blue Mountains/Hawkesbury areas
- Detailed Severe Thunderstorm Warning (Heavy Rainfall) for Greater Newcastle, Gosford/Wyong, Sydney & Blue Mountains/Hawkesbury areas
- Severe Thunderstorm Warning (Heavy Rainfall) for parts of Hunter, Metropolitan and Central Tablelands
- Severe Thunderstorm Warning (Heavy Rainfall) for parts of Hunter, Metropolitan and Central Tablelands
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Sunrise and sunset times
Sunrise / Sunset for Merriwa (32.1394°S, 150.3557°E, 246m AMSL) First light Sunrise Sunset Last light Moon rise Moon set Moon phase New moon First quarter Full moon Last quarter 6:34am EDT 6:58am EDT 7:11pm EDT 7:36pm EDT 5:47am EDT 6:38pm EDT
Waning crescent
New moon Mar 19 First quarter Mar 26 Full moon Apr 02 Last quarter Apr 10 -
Temperature for next 5 days
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Rain for next 5 days