Cold,
with record rainfall in the Centre
Heavy
thunderstorm falls in WA KimberleyGiles Weather Station, just over the WA/NT border west of Alice Springs, has recorded 260.2mm in the 5 days ended 9am 10 December, with 76.2mm falling in the 24 hours to 9am on 6 December, and 119.0 in the day to 9am today. The previous record November one-day fall of 60.7mm in 45 years of record has therefore been broken twice in 3 days. Giles' average annual rainfall is 275.2mm, while their previous wettest December yielded only 116.8mm for the month. This morning, 89mm fell in just 6 hours to 3am. Other heavy 24 hour falls in the area are given below, along with some of the short-duration measurements at Giles and Uluru, where the airport recorded 46mm for the 24 hours to 9 this morning, but the ranger station reported 85.6mm.
The storms resulted when a sharp convergence or trough line developed last night in the SA/NT border area. Moist northerlies, which have been bringing heavy falls to the Kimberley, fed into the trough, which also marked the boundary of much cooler southern air being drifted across the area around a high pressure ridge to the south. Fitzroy Crossing, in the West Kimberley, recorded 83mm in 6 hours to 3am. Heavy cloud cover coupled with the intrusion of cooler southern air kept daytime temperatures 10 to 14° below average across central eastern WA, southern NT and the northern two-thirds of SA. Hawker, in SA's mid-north, recorded its coldest December minimum temperature in 34 years when the thermometer dropped to 5.0°.