Severe Tropical Cyclone Monica

17 - 25 April 2006

Summary

A tropical low was analysed in the far northern Coral Sea on 16 April. The low moved towards the southwest under the influence of a weakening ridge to the south. There it reached cyclone intensity on 17 April and began a more westward track toward Cape York Peninsula. The system intensified to hurricane-force strength before making landfall 40 km south of Lockhart River on the afternoon of 19 April. The system weakened over land, before entering the Gulf of Carpentaria as a weak cyclone early the following day.

Monica began to intensify rapidly as it tracked to the northwest over the Gulf of Carpentaria reaching 56 m/s (110 knots) intensity at 0600 UTC 22 April then attaining maximum intensity of 69 m/s (135 knots) 24 hours later about 120 km to the northeast of Nhulunbuy. This is the highest intensity of any cyclone in the Australian region. At this time, Monica had an eye diameter of around 30 km but the effects of the very destructive core were very much confined near to the eye wall. The Cape Wessel AWS recorded a mean wind of 36 m/s (70 knots) prior to failing as Monica 's maximum winds approached to an estimated 15 km of the station. The convective structure of Monica maintained its intense nature until it made landfall at 0900 UTC 24 April at Junction Bay, 35 km west of Maningrida.

Increasing shear and being over land contributed to the weakening process but it appears the entrainment of mid-level dry air was the most important factor. Just 12 hours after landfall the system had weakened to below cyclone intensity, and passed to the north of Darwin as a tropical low during the afternoon of 25 April.

Fortunately Monica crossed Cape York Peninsula at a remote location, avoiding the local townships of Lockhart River and Coen. However there was widespread tree damage and moderate damage to infrastructure along the Arnhem Land coast, extending as far west as the township of Jabiru. Maningrida community received substantial damage as the cyclone passed just to the north of the township, with several houses damaged by fallen trees. The uninhabited coastal crossing point suffered severe vegetation damage, with 50-70 per cent of all trees felled, as well as evidence of a 5-6 m storm surge zone in Junction Bay.

Track and intensity

All times in UTC - add 10 hours to convert to EST and 9.5 hours to convert to CST.

Best Track of Severe Tropical Cyclone Monica

Observations summary

Maximum Winds
109 km/h gust at Lockhart River at 15:00 EST 19 April.
130 km/h mean wind at Cape Wessel, 8 pm CST 23 April.
148 km/h gust at Maningrida, 6:40 pm CST 24 April.
118 km/h gust at Jabiru, 3:02 am CST 25 April.
Lowest Reported Pressure
986.0 hPa at Lockhart River.
970.2 hPa at Cape Wessell.
986.2 hPa at Maningrida.
986.6 hPa at Jabiru Airport.

Daily Rainfall

Rainfall - Queensland
215 mm at Lockhart River in the 24 hours until 9am on 19 April.
239 mm at Violet Vale in the 24 hours until 9am on 20 April
282 mm at Musgrave in the 24 hours until 9am on 21 April
Rainfall - Northern Territory
190 mm at Ngayawili in the 24 hours until 9am on 25 April
340 mm at Majestic Orchids (near Darwin River Dam) in the 24 hours until 9am on 26 April
261 mm at Kidman Springs in the 24 hours until 9am on 27 April

Figure 1. Rainfall during the week ending 23 April, 2006

Rainfall map

Figure 2. Rainfall during the week ending 29 April, 2006

Rainfall map

Satellite and radar Images

Figure 3. TC Monica near the Queensland coast, 19/04/2006, 12:30pm EST. Image from MTSAT satellite.

Satellite image

Figure 4. TC Monica near the NT coast, 24/04/2006, 3pm CST. Image from MTSAT satellite.

Satellite image

Figure 5. Weipa radar at 4pm EST on 19 April 2006.

Weipa Radar image

Figure 6. Gove radar at 9:20pm CST on 23 April 2006.

 Gove Radar image