Cyclone Yasi (Feb 02, 2011)

Category 5 cyclone Yasi is going to land near Innisfail, Queensland around 11 pm tonight.  It is in the middle of Cairns to Townsville.  Government has ordered people in the region to evacuate to safer place instead of staying home.  I just hope that it won't cause too many severe damage, but the strong wind, heavy rain and tidal surge.  Sigh!

<Ref links>
1. Basic information about category 1 to 5 on wiki

Tropical systems are officially ranked on one of several tropical cyclone scales according to their maximum sustained winds and in what oceanic basin they are located. Only a few scales of classifications are used officially by the meteorological agencies monitoring the tropical cyclones, but some alternative scales also exist, such as Accumulated Cyclone Energy, the Power Dissipation Index, the Integrated Kinetic Energy Index, and Hurricane Severity Index.

Should a tropical cyclone form in the North Atlantic Ocean or the North-eastern Pacific Ocean, it will be classified using one of the categories in the Saffir-Simpson Hurricane Scale. In the Western Pacific, tropical cyclones will be ranked using the Japan Meteorological Agency's scale. The Regional Specialized Meteorological Centre (RSMC) in New DelhiIndia also uses a different scale to assess the maximum sustained winds of a tropical cyclone. In the Southern Hemisphere, the Météo-France forecast center on La Reunion uses a scale that covers the whole of the South West Indian Ocean. Both the Australian Bureau of Meteorology and the RSMC in Nadi, Fiji use the Australian tropical cyclone intensity scale.

Australian Region
Tropical Cyclone Intensity Scale
CategorySustained
winds
Gusts
Five>107 kt
>200 km/h
>151 kt
>279 km/h
Four86-107 kt
160-200 km/h
122-151 kt
225-279 km/h
Three64-85 kt
118-159 km/h
90-121 kt
165-224 km/h
Two48-63 kt
89-117 km/h
68-89 kt
125-164 km/h
One34-47 kt
63-88 km/h
49-67 kt
91-125 km/h
Tropical
Low
<34 kt
<63 km/h
<49 kt
<91 km/h

Australia

Any Tropical Cyclone that forms to the east of 90°E in the Southern Hemisphere, is monitored by either the Australian Bureau of Meteorology and or the Regional Specialized Meteorological Center in Nadi, Fiji.[4] Both warning centres use the Australian tropical cyclone intensity scale, which measures tropical cyclones using a six category system.[4] It is based on estimated maximum windgusts, which are a further 30-40% stronger than the 10-minute average sustained winds. This is different from the Saffir-Simpson Hurricane Scale, which uses 1-Minute Maximum Sustained winds.[1]

When a Tropical Cyclone that has wind speeds below 35 knots (65 km/h, 40 mph) forms east of 160°E it is labelled as either a Tropical Disturbance or a Tropical Depression by RSMC Nadi.[4] If it forms to the west of 160°E it is labelled as a Tropical Low by the Australian Bureau of Meteorology.[4] However if it forms to the north of 10°S and between 90°E to 125°E the low is labelled as a Tropical Depression by the Tropical Cyclone Warning Center in JakartaIndonesia.[18]

If a tropical depression should reach 35 knots (65 km/h, 40 mph), it will be named by the TCWC or RSMC and be classified as aTropical Cyclone.[19] Should the cyclone intensify further reaching maximum sustained winds of 65 knots (145 km/h, 75 mph) then the cyclone will be designated as a Category Three Severe Tropical Cyclone.[19] A Severe Tropical Cyclone will be classified as a Category Five Severe Tropical Cyclone should the cyclone's maximum sustained wind speed be greater than 110 Knots (200 km/h, 130 mph) and gusts be above 150 knots (280 km/h, 175 mph).[19]

(note) kt: The knot is a unit of speed equal to one nautical mile per hour, which is equal to exactly 1.852 km/h and approximately 1.151 mph.


(Issued at 6:04 pm EST Wednesday 2 February 2011. Refer to Tropical Cyclone Advice Number 18. )

Community ThreatPast Cyclone Details
 Warning Zone - Gales within 24 hours
 Watch Zone - Gales from 24 to 48 hours
 Past Location and Intensity Number
 Past Track and Movement
Current Cyclone DetailsForecast Cyclone Details
(at 24 and 48 hours from issue)
 Current Location and Intensity Number
 Very Destructive Winds
 Destructive Winds
 Strong Gale Force Winds
 Gale Force Winds
 Forecast Location and Intensity Number
 Very Destructive Wind Boundary
 Destructive Wind Boundary
 Strong Gale Force Wind Boundary
 Gale Force Wind Boundary
 Most Likely Future Track
 Range of Likely Tracks of Cyclone Centre

The outermost boundary of the winds shown in the Coral Sea represent strong gale force (41kt) winds. Elsewhere gale force (34kt) winds are shown.

The forecast path shown above is the Bureau's best estimate of the cyclone's future movement and intensity. There is always some uncertainty associated with tropical cyclone forecasting and the grey zone indicates the range of likely tracks of the cyclone centre.

Due to the uncertainty in the future movement, the indicated winds will almost certainly extend to regions outside the rings on this map. The extent of the warning and watch zones reflects this.

This product is designed for land-based communities; mariners should read the coastal waters and high seas warnings.


Remarks:

SEVERE TROPICAL CYCLONE YASI IS A LARGE AND VERY POWERFUL TROPICAL CYCLONE AND POSES AN EXTREMELY SERIOUS THREAT TO LIFE AND PROPERTY WITHIN THE WARNING AREA, ESPECIALLY BETWEEN CAIRNS AND TOWNSVILLE. 

DURING THE EVENING, THE VERY DESTRUCTIVE CORE OF CYCLONE YASI WILL CROSS THE COAST BETWEEN INNISFAIL AND CARDWELL, ACCOMPANIED BY A DANGEROUS STORM TIDE SOUTH OF THE CYCLONE CENTRE.

Tropical Cyclone Yasi, CATEGORY 5, will continue to move in a west-southwesterly direction and is expected to cross the coast near Innisfail close to midnight.

Coastal residents between Cairns and Ayr are specifically warned of an EXTREMELY DANGEROUS SEA LEVEL RISE [i.e. storm tide] as the cyclone approaches, crosses the coast and moves inland. The sea is likely to steadily rise up to a level which will be VERY DANGEROUSLY above the normal tide, with EXTREMELY DAMAGING WAVES, STRONG CURRENTS and FLOODING of low-lying areas extending some way inland. The storm tide will persist for many hours after landfall of the cyclone and secondary peaks may occur around high tide on Thursday morning. Higher than normal tides will exceed the high water mark with damaging waves and flooding in low lying areas in remaining warning areas to the south of Ayr. 

People living in areas likely to be affected by this flooding should take measures to protect their property as much as possible, and be prepared to follow instructions regarding evacuation of the area if advised to do so by authorities. 

DAMAGING WINDS with gusts to 90 km/hr are currently affecting the coast and islands, and are forecast to spread into the tropical interior overnight and west to Mt Isa during Thursday. 

Between Port Douglas and Ayr these winds will become DESTRUCTIVE with gusts in excess of 125 km/hr developing during the couple of hours, spreading into the eastern tropical interior overnight. VERY DESTRUCTIVE winds with gusts up to 290 km/hr are expected to develop between Cairns and Ingham during the evening as the cyclone approaches and crosses the coast. These VERY DESTRUCTIVE winds will also occur to the north of the cyclone and affect the Atherton Tablelands. 

Due to the large size of the cyclone, people in the path of the VERY DESTRUCTIVE WINDS are likely to experience these conditions for about 3 to 4 hours.

Winds are forecast to gradually ease about the east coast during Thursday morning as the cyclone moves inland.

FLOODING RAINS will develop from Cooktown to Sarina during this evening and then extend inland overnight.

People between Cape Flattery and Sarina and extending west across the tropical interior to the Northern Territory border, should complete preparations quickly and be prepared to shelter in a safe place.
- Boats and outside property should be secured.
- For cyclone preparedness and safety advice, visit Queensland's Disaster Management Services website (www.disaster.qld.gov.au)
- For emergency assistance call the Queensland State Emergency Service (SES) on 132 500 (for assistance with storm damage, rising flood water, fallen trees on buildings or roof damage).

Name:  Severe Tropical Cyclone Yasi

Details: 

 Time (EST)Intensity CategoryLatitude
(decimal deg.)
Longitude
(decimal deg.)
Estimated Position
Accuracy (km)
0hr6 pm February 2517.2S147.6E20
+6hr12 am February 3517.6S145.9E55
+12hr6 am February 3318.4S144.2E85
+18hr12 pm February 3219.1S142.5E110
+24hr6 pm February 3119.7S141.0E140
+36hr6 am February 4tropical low20.8S138.4E205
+48hr6 pm February 4tropical low21.8S136.2E260

The next Forecast Track Map will be issued by 7:00 pm EST Wednesday

Comments