Two Category 3 Cyclones Pound Australia

Twin Category 3 tropical cyclones, Trevor and Veronica, pounded Australia’s north coast Friday and Sunday. The more destructive of the two storms was Tropical Cyclone Veronica, since it hit a more populated area and moved very slowly at landfall, subjecting the coast to an extended period of battering.

Cyclone #Veronica makes landfall on Western #Austraila, as seen by storm-centered MIMIC-TC microwave imagery. https://t.co/vyNFBXVKwK pic.twitter.com/f4qSLfdyEk

— UW-Madison CIMSS (@UWCIMSS) March 24, 2019

The southern eyewall of Veronica first moved over the coast at 18Z Saturday, when the Joint Typhoon Warning Center (JTWC) rated Veronica a Category 3 storm with 120 mph winds. Moving very slowly towards the coast at less than 5 mph, Veronica managed to keep its eye over water for the next 12 hours, taking advantage of low wind shear and very warm ocean waters of 30°C (86°F) to intensify into a Category 4 storm with 130 mph winds at 0Z Sunday. By 6Z Sunday, the eye was still over water, but land interaction and increasing wind shear had weakened Veronica to a Category 3 storm with 120 mph winds. Veronica slowly rumbled ashore on the northwest coast of Australia between 6Z and 12Z, weakening to a Category 2 storm with 100 mph winds. A section of coast between Roebourne (population 1000) and Port Hedland (population 14,000) took an extended pounding for more than 18 hours from winds in excess of hurricane force, which likely resulted in severe wind damage.

Veronica brought a wind gust of 96 mph east of Karratha at Roebourne Airport, and Port Hedland and Karratha recorded wind gusts in excess of 70 mph. Veronica is expected to dump total rainfall amounts in excess of 500 mm (20”) before the cyclone dissipates. On Monday morning, Veronica had moved back over water along the coast, and had top winds of 45 mph. Increasing wind shear and land interaction should cause the cyclone to dissipate by Tuesday. The cyclone has brought considerable tree damage and power outages, but there are no reports of major damage or injuries thus far.

5:30pm NZDT / 2pm ACST - #CycloneTrevor as seen via Himawari satellite: pic.twitter.com/UQr3ADAv21

— WeatherWatch.co.nz (@WeatherWatchNZ) March 23, 2019

Trevor makes two Australia landfalls

Tropical Cyclone Trevor brought double major trouble to Australia, making two landfalls as a Category 3 storm with 115 mph winds. Trevor’s first landfall came near 07 UTC Tuesday just south of Lockhart River (population 600) in Australia’s Queensland state, where wind gusts of up to 83 mph (133 km/hr) were measured. The cyclone caused considerable damage to trees and a few buildings, and up to 300 mm of rain (11.81”) fell along its path across the sparsely populated Cape York Peninsula.

After taking about a day to cross the Cape York Peninsula, Trevor emerged over the Gulf of Carpentaria as a disorganized tropical storm. Trevor reorganized over very warm 31°C (88°F) ocean waters, and headed south-southwest to make a second Category 3 landfall at 8 pm Friday evening (U.S. EDT) near Borroloola (population 900) in the Northern Territory.

Trevor was the first major tropical cyclone to hit Queensland since Nathan of 2015, which struck as a Category 3 storm with 115 mph winds on March 19, 2015. I could find just one other tropical cyclone in NOAA’s historical hurricanes database that made multiple landfalls in Australia at Category 3 or higher strength: Ingrid of 2005, which made three landfalls on the mainland as a Category 3 or 4 storm, plus several landfalls on islands along the north coast.

Figure 1. Radar image of Tropical Cyclone Trevor at 23Z Friday, March 22, 2019, one hour before the storm made landfall. Image credit: Australia BOM.

Fortunately, there were no sizable coastal towns in the sparsely settled area where Trevor came ashore. The Aboriginal population is widely dispersed in small communities in the region; approximately 1400 people were evacuated from the region before Trevor hit--the biggest evacation effort in fifty years, according to the BBC. No injuries or major infrastructure damage was reported in the region, though.

What's worse: three major cyclones in a week—or two major hurricanes in a day?

It's not every year that one nation experiences multiple Category 3 or stronger landfalls in a single week, as Australia just did. Incredibly, the United States once had to deal with two major landfalls in a 24-hour period—and it just happened to be on Labor Day. This occurred during the hyperactive 1933 Atlantic hurricane season.

At around 0500Z (midnight ET) on September 4, the Treasure Coast Hurricane stormed ashore near Jupiter, Florida, with top sustained winds of 125 mph, after having peaked at Category 4 strength. On the following night, at 10 pm CT on September 4, the Cuba-Brownsville Hurricane—at one point a Category 5 storm—struck far South Texas, also with top sustained winds of 125 mph. Thanks to Phil Klotzbach (Colorado State University) for this example.

Bob Henson contributed to this article. Thanks to Dr. Phil Klotzbach for details on the 1933 U.S. landfalls.