Severe Tropical Cyclone Marcia crossed the coast at Shoalwater Bay (north northwest of Yeppoon) during the morning of 20th February 2015. Marcia crossed the coast at category 5 intensity in a largely uninhabited area, although significant damage was recorded at Yeppoon and Rockhampton as the system weakened after making landfall.
The tropical low that eventually became severe tropical cyclone Marcia was first identified in the Coral Sea on Sunday, February 15th 2015. Marcia was tracked over the next few days as it drifted eastward with little change in intensity (Figure 1).
During the afternoon of Wednesday February 18th, the low pressure system reached tropical cyclone intensity and was named Marcia, before beginning to move towards the southwest. Tropical cyclone Marcia continued to intensify during February 18th and was estimated to have reached category 2 intensity by that evening.
Thursday February 19th, saw tropical cyclone Marcia continue on a south-westerly track and undergo a period of extremely rapid intensification, increasing by two categories to a category 4 severe tropical cyclone in approximately 12 hours. This increase in intensity is well above the average rate of intensification for tropical cyclones anywhere in the world.
Late on February 19th, Marcia made a sharp turn towards the south and intensified even further, and was estimated to have reached category 5 intensity at 4am on Friday 20th February (Figure 2.)
Prior to landfall in the early hours of February 20th, the automatic weather station on Middle Percy Island recorded a maximum sustained (10 minute average) wind speed of 84 knots (156 km/h) and a maximum wind gust of 112 knots (208 km/h), or the equivalent of a strong category 3 system. This weather station was located to the west of tropical cyclone Marcia's core and would not have experienced the cyclone's maximum winds in its eye-wall. At that time, intensity estimates inferred from satellite imagery indicated Marcia was a category 5 system at its core. High resolution radar imagery (Figure 3) shows that Middle Percy Island was located just outside the eye wall of Marcia (represented by the strong reflectivity returns near the centre of the system).
Figure 1: Track of severe tropical cyclone Marcia, showing estimated areas affected by winds associated with categories of cyclone intensity.
- Map Legend:
- >= Category 3 Winds
- Category 2 Winds
- Category 1 Winds
Figure 2: Zoomed in track of severe tropical cyclone Marcia, showing estimated areas affected by winds associated with categories of cyclone intensity.
- Map Legend:
- >= Category 3 Winds
- Category 2 Winds
- Category 1 Winds
Figure 3: RADAR reflectivity (dBZ) image at 4:30am AEST on February 20th 2015, showing the eye of severe tropical cyclone Marcia moving in a southerly direction and passing to the east of the Middle Percy Island automatic weather station. Wind barb symbol indicates sustained winds in excess of 80knots (148km/h) from the southwest.
Based on all the evidence collected and detailed reanalysis of satellite imagery, severe tropical cyclone Marcia crossed the coast at Shoalwater Bay (north northwest of Yeppoon) as a category 5 system at around 8am AEST on February 20th. Severe tropical cyclone Marcia was a relatively compact system compared to other severe tropical cyclones such as severe tropical cyclone Yasi and weakened quickly as it moved over land during the day. It is believed that only a small part of the coastline within about 15km of the cyclone centre would have experienced category 5 strength winds.
As Marcia moved over land, the township of Byfield sustained major damage as did the surrounding pine forest plantations. Yeppoon also received significant damage with the automatic weather station recording a maximum sustained wind speed (10 minute average) of 65 knots (120 km/h), or the equivalent of a category 3 system, as the category 4 centre of Marcia passed to the west.
The eye of Marcia passed over the city of Rockhampton where a maximum wind speed (10 minute average) of 40 knots (75 km/h) was recorded at the automatic weather station at Rockhampton Airport. Analysis of radar imagery indicated that the strongest part of the eye wall missed the automatic weather station and it is concluded that parts of Rockhampton experienced winds of high-end category 2 strength.
Marcia then turned to the south-southeast and impacted the town of Biloela early that evening, where wind gusts to 85 km/h were recorded.
Marcia was downgraded to a tropical low at 2 am Saturday 21 February, located to the south of Monto. The low tracked further southeast during 21 February and crossed the Sunshine Coast back out to sea at 3 pm 21 February.
The area of Shoalwater Bay, where Marcia made landfall, had widespread areas of uprooted trees and evidence of storm surges and beach erosion, particularly along the coast north of Yeppoon. The Shoalwater Bay Training Area (SWBTA) is used for military training exercises by the Australian Defence Force and as a result is largely uninhabited with limited buildings. The eye of Marcia passed directly over Townshend Island (Figure 2) within the SWBTA and experienced the full force of winds when at category 5 intensity. Aerial photography taken very soon after the passage of Marcia shows almost complete defoliation of trees on Townshend Island (Figure 4). Access to the area is restricted but permission was granted to a team of Bureau of Meteorology and Queensland Department of Science, Information Technology and Innovation (DSITI) staff on the 8-9 March 2015. The coastline of Pearl Bay (Figure 2 and Figure 5) clearly shows extensive tree defoliation and soil erosion as it experienced the outer edge of the very destructive wind core generated by Marcia at its maximum intensity just before landfall.
Figure 4: The eye of severe tropical cyclone Marcia passed directly over Townshend Island while at category 5 intensity. (Source: J. Bowman)
Figure 5: Extensive defoliation and soil erosion at Pearl Bay due to severe tropical cyclone Marcia. Photo taken on March 9th 2015. (Source: Bureau of Meteorology and Queensland Government Department of Science, Information Technology and Innovation(DSITI)). Transport provided by Queensland Department of National Parks, Sport and Racing.
Figure 6: Sandy Creek Road, Byfield before (upper photo) and following (lower photo) severe tropical cyclone Marcia, February 2015 showing widespread tree damage. (Source: Fugro ROAMES)
There was structural damage to houses, uprooted trees, downed power lines and evidence of storm surge elsewhere in parts of the Capricornia district, including (but not limited to) the towns of Byfield (Figure 6), Yeppoon (Figure 7 and 8) and Rockhampton.
Figure 7: Image of roof damage in Yeppoon from severe tropical cyclone Marcia. (Source: 7 News Brisbane)
Figure 8: Image of significant structural damage in Yeppoon from severe tropical cyclone Marcia. (Source: ABC News)
Storm Tides and Waves
A large storm surge was recorded across the Capricorn coastline, with significant beach erosion and structural damage impacting Great Keppel Island in particular (Figure 9). Fortunately, the storm surge from Marcia along the coast near and to the south of Yeppoon coincided with a falling tide and did not produce significant inundation or damage. The DSITI storm tide gauge at Rosslyn Bay recorded a storm surge of 0.6m producing a storm tide height of only 0.06m above highest astronomical tide (HAT) (Figure 10). There was however evidence of significant erosion and large deposits of pumice stone indicative of much higher water levels being reached on beaches to the north of Yeppoon between One Mile Beach and Farnborough Beach, and particularly at 9 Mile Beach.
The DSITI storm tide gauge at Port Alma observed a storm surge of 2.0 metres (Figure 11) while the wave rider buoy at Emu Park registered a significant wave height of 4.1m and peak height of 7.0 metres with waves coming from the northeast and a peak period of 9 to 10 seconds (Figure 12). The storm tide gauge at Port Alma almost recorded water levels close to but not exceeding HAT as the surge coincided with low tide. It is believed that the storm surge at Port Alma is likely to have been enhanced by the shape of the coastline relative to the track of the cyclone.
For further detail see the DSITI Coastal Impacts Unit fact sheet 'Severe tropical cyclone Marcia: storm tide and wave monitoring data'.
Figure 9: Great Keppel Island holiday cabins toppled onto the beach from severe tropical cyclone Marcia. (Source: ABC News)
Figure 10: Sea level measurements from the Qld State Government (DSITI) storm tide gauge at Rosslyn Bay. (Source: DSITI Coastal Impacts Unit fact sheet 'Severe tropical cyclone Marcia : storm tide and wave monitoring data')
Figure 11: Sea level measurements from the Qld State Government (DSITI) storm tide gauge at Port Alma. (Source: http://www.qld.gov.au/tides)
Figure 12: Significant wave height and direction measurements from the Qld State Government (DSITI) wave rider buoy at Emu Park. (Source: www.qld.gov.au/waves)
Rainfall and Flooding
Heavy rainfall associated with tropical cyclone Marcia affected catchments extending from the far eastern parts of Fitzroy River catchment south to the Queensland - New South Wales border. The heaviest rainfall was recorded over the Don and Dee Rivers and Callide Creek in the Fitzroy River catchment area, where up to 300 mm of rainfall was recorded in 6-8 hours during the afternoon and evening of 20 February as tropical cyclone Marcia tracked through the region.
Flooding above the major flood level occurred in the following basins:
- Don and Dee Rivers and Callide Creek in the Fitzroy River catchment
- Burnett River and Three Moon Creek in the Burnett River catchment
- Mary River, Six Mile Creek and Tinana Creek in the Mary River catchment
For more information on the flooding that was produced by severe tropical cyclone Marcia see here.
Coastal Crossing Details
Extreme Values During Cyclone Event (estimated)
February 18 00:32UTC - February 10 14:32UTC
February 19 01:00UTC - Febraury 20 03:00UTC
MSLP Chart Loop
February 16 00:00UTC - February 22 18:00UTC