Category Archives: Tropical Cyclones

A large circulation sproducing heavy rainfall, very strong winds and storm surges

Tropical Cyclone Ula – 1 January 2016

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During the New Year period, a tropical storm within the south Pacific Ocean south, south east of Western Samoa has transitioned into the first tropical Cyclone of the season. The transition has occurred at latitude 16.1 degrees south and 169.9 degrees east.

The storm is expected to track south west towards north east Australia over the next 48 hours then slowly weaken. The storm is expected to remain well out to sea, at least for the short term.

Synoptic charts throughout the next 7 days will show the tropical storm encroaching towards Australian waters or making an approach towards north east Queensland but it is far too early at this stage to verify what occurs in the longer run as the storm continues to track south west.

It is identified that:-

1 - The storm is formally named Ula.
2 - The storm is forecast to reach a Category 3 Tropical Cyclone within 24 hours with projected wind speeds of 110 knots (204 km/h) with stronger wind gusts to 135 knots or 250 km/h. This makes it an intense storm.
3 - The storm is not threatening any population centre.

Should the storm approach north east Queensland, it would intensify the south easterly winds onto the coastline especially during the latter part of the forecast period.

The models from CIMSS and dated 1 January 2016 shows the storm in its early stages. The core is relatively small and compact but a small eye is visible in the imagery. The storm will be watched over coming days to determine what it does.

Strong monsoon low and possible tropical cyclone Top End NT 25/12/2015

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A strong and vigorous monsoon low across the inland or base of the top end of the Northern Territory has forecasters concerned. On Christmas Eve, the low pressure cell was inland but south of Darwin.

It is forecast to move east then south east. There is the possibility of the low crossing the coast and transitioning into Australia's first tropical cyclone of the season.

If it does not it will certainly cause heavy to very heavy rainfall and certain flooding in low lying areas of the Gulf Country of Queensland and Northern Territory.

Rainfall models are forecasting in excess of 400 mm of rain from the event across some regions.

During Thursday and Friday, the monsoonal trough and low signaled its early intentions across the Top End where heavy rain and flooding occurred. Fortunately other than Darwin, most of the top end is uninhabited and hence the flooding is occurring across rural areas and within creek and river crossings.

Up until 9 am 24/12/2015, 119.4 mm of rain fell at Darwin International Airport. A weather station at Dum In Mirrie recorded 235.8 mm. Other big rainfall totals include:-

Charles Point - 242 mm.
Adelaide River - 198 mm.
Wagait Beach - 175 mm.

Up until 3.00 am 25/12/2015, the following rainfall had been recorded:-

Upper Adelaide River 164 mm.
Port Keats 155 mm.
Dum In Mirrie 139 mm.

For Dum In Mirrie, this is 375 mm when combined which is easily enough for major flooding to occur.

The next four days will be difficult weather wise across the top end and Darwin. In particular, storms and very heavy rain is being forecast for large areas. For Darwin 30 to 80 mm is forecast for Christmas Day but heavier totals of 170 mm is not being ruled out during thunderstorm events.

The development of any tropical cyclone will also create further issues in coming days across the eastern top end. The storm has not been named at the present time but it is receiving very close attention.

To support this article, the following is provided:-

1 - Rainfall plot for Darwin to 9 am 24/12/2014 (Bureau of Meteorology).
2 - Forecast rainfall plot for the top end (Northern Territory) for the 26/12/2015 (Bureau of Meteorology Water and the Land).
3 - Position of the monsoon low for 3.30 pm Saturday 26/12/2015 (BSCH).
4 - Forecast position of the low (Possible tropical cyclone) 3.30 pm 27/12/15 (BSCH).
5 - Forecast position of the low (Possible tropical cyclone) 9.30 pm 28/12/15 (BSCH).

Typhoon Melor makes landfall Philippines 15/12/2015

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Melorfrom NASA


Typhoon Melor (Nona) has made landfall passing over portions of Mindoro, a portion of Luzon Island (Southern tip), northern part of Samar Island, Mashbate and Tico Islands (Philippines).

The storm has intensified significantly and its strength is well in excess of earlier forecast models.

The storm has reached a powerful Category 4 on the Saffir Simpson Scale with sustained winds in excess of 125 knots or 231 km/h with higher wind gusts reaching or approaching 150 knots or approximately 278 km/h. This makes it a powerful storm especially for mid December.

The storm at 4pm 15/12/2015 was located at 13.2 degrees north and 120.8 degrees east and appears to have reached maximum intensity. According to PAGASA, the storm at 4 pm was over Santa Cruz Oriental Mindoro but its speed had slowed.

Over the next 12 hours, this storm should make its closest approach to the capital city of Manila but should stay to the south of the capital. The storm is then expected to travel back over over open water and slowly decay.

On December 14, the storm was sustaining winds close to the core of 127 knots or 235 km/h with peak gusts to 135 knots or approximately 250 km/h.

At 5 pm December 15, PAGASA was warning of moderate to heavy rain within 250 km of the eye with flash floods and landslides expected for areas under Signals 2 and 3. Storm surges of two metres were also in the forecast warnings issued.

Metropolitan Manila is under Signal 1 for the duration of the storm and hence significant damage across the city is not expected.

At 4 pm 15/12/2015, there were regions under Signal 3 including Santa Cruz with warnings for property damage, flooding and damage to crops.


The images of the storm are provided as follows:-

1 - CIMSS (Image and forecast plot acquired 15/12/2015) - It clearly shows its location and strength. The eye is not visible but an eye was identifiable on the satellite photos of the 14/12/2015.

2 - NASA (Images acquired from MODIS Worldview dated 14/12/15 with overlays) - The images show the storm commencing landfall over the far northern edge of Samar Island. The eye is clearly seen in the pictures.

3 - Radar image (Acquired from PAGASA 15/12/2015) - This is from the Tagaytay radar unit. The precipitation shield is impacting the capital city of Manilla.