Tropical Cyclone Imogen was the first tropical cyclone of the season to form within Australian waters for the summer season 2020/21. The storm just reached a Category one storm on the Saffir Simpson Scale and barely lasted 18 hours in the southern part of the Gulf of Carpentaria of Queensland before crossing the coastline near Karumba.
Tropical Cyclone Imogen’s lifespan was short due to the storm forming so close to the Queensland coast. At landfall, the storm had wind gusts to 100 km/h and sustained winds of 65 km/h.
Accumulative rainfall totals reached 300 to 400 mm resulting in flooding and swelling of local rivers.
The attached image from NASA Worldview 3/1/2021 is showing the storm making landfall near Karumba.
As shown in the plot below taken from the Bureau of Meteorology “Water and the Land”, the heaviest rainfall totals for Queensland for the week ending the 7/1/2021 is shown to be across northern Queensland and the general path of this storm / raindepression across the southern part of Cape York Peninsula can easily be depicted.
During the course of Monday afternoon 4 January 2021, a squall line swept across Sydney that brought significant wind gusts, heavy rain, small hail at Blacktown and a significant number of lightning strikes.
One media report suggested that there were 38,000 lightning strikes around and within 100 km of Sydney during the event.
While I could not chase the Monday event due to work commitments, it is noted that the storm swept rights across Sydney.
At Auburn where I work, there were at least 2 lightning strikes very close to the Cumberland City Council office building where I work and one may have struck the car park building due to the noise that was generated.
On the way home that afternoon, I noted that a drain became blocked on the corner of Kerr Parade and Marion Street which resulted in significant flooding of that section of road and a set of traffic lights were blacked out on Blacktown Road which suggested a local power failure.
The Monday afternoon storm brought peak wind gusts of 74 km/h at Camden between 3.42 pm and 3.47 pm, 85 km/h at the airport between 4.25 pm and 4.30 pm and rainfall of between 14 and 22 mm around Blacktown. Shanes Park in Sydney's West received 33 mm during the event being the highest rainfall total. Other suburbs had lower rainfall totals.
Late afternoon on the 5/1/2021, further showers and storms occurred across Sydney. I was able to take numerous photos of interesting cloud towers, cloud bases, cumulo congestus clouds and Cumulonimubus calvus cloud formations. Some of the cloud formations were impressive for the late afternoon sky.
One Particular storm occurred late evening over Blacktown that produced a heavy downpour of rain but little wind. While there was lightning, it was sporadic.
This event concluded the two day storm event for Sydney and all activity had cleared by 11 pm that evening.
The cloud images attached to this post are from 3 storm cells that formed over Western Sydney during the event.
The system that brought rain and storms to much of eastern New South Wales at the end of December 2020 has continued into the first 3 days of January 2021. One positive is that large areas of the inland has now received some rainfall from the system as expected.
Some notable storm events have occurred over recent days which has caused disruption, localized flash flooding and or wind damage. Some affected towns and cities include:-
1 - Warrnambool (SW Victoria) - Rare storm events have resulted in heavy rainfall totals of 53 mm for the 24 hours to 9 am 3/1/2021.
2 - Broken Hill (Western New South Wales). Reported in the media 2/1/2021 that a number of thunderstorms occurred some of which brought hail of between 2 cm and 4 cm including flash flooding of low lying areas.
3 - Parkes (Central West of NSW) - 2/1/2021. A thunderstorm impacted the town between 4.41 pm and 4.58 pm that brought wind gusts to 158 km/h. The local weather station recorded the peak wind gusts between 4.43 pm and 4.48 pm as well as rainfall being - 4.41 pm (0.0 mm), 4.43 pm (4.4 mm) - (That is 4.4 mm of rain in 2 minutes), 4.48 pm (21.6 mm). This is 17.2 mm in approximately 5 minutes or 21.6 mm in 7 minutes. By 4.58 pm, 31 mm had fallen from the same storm.
Other notable rainfall events within the Central West slopes and plains include 38 mm at Dubbo 115 km to the north.
Isolated rainfall totals of 65 mm fell at Portable in the Riverina of New South Wales, 62 mm at Okeh in north west New South Wales, 53 mm at Glenorchy (North west of Glenn Innes) as well as falls of 29 to 61 mm around Wollongong and Kiama on the Illawarra coast.
Last week, it was stated that there was elevated fire risk at Albury and a fire was observed on a hillside in the distance. Overnight falls of 20 mm here as well as 28 mm at Hume Dam would have been beneficial to suppress the fire danger for the short term.
The rain events and recent storms has contributed to much of New South Wales receiving average to better than average rainfall totals for the year 2020 as shown in the plots below produced on the Bureau of Meteorology “Water and The Land” site although when reviewing the Rainfall anomalies for 2020, it becomes clear that much of western and southern New South Wales is only receiving average to slightly below average rainfall. While no part of New South Wales is currently in drought, there is a risk of these areas falling back into drought for the longer term if further rainfall is not received.
Given that the plots are for the period 1 January 2020 to the 31 December 2020, the rain and storms that impacted Broken Hill and surrounds on the 2/1/2021 will benefit the region further and the local water supply.