For downloadable Cyclone Tracking Maps, click here. The maps cover the Australian region and the South China Sea/West Pacific region.
In Australia (those in other areas need to know their own local forms of the following), if you hear via the media that your area is included in a Tropical Cyclone Watch, this means that gale force winds may be experienced in your area within the next 24 to 48 hours, or a Tropical Cyclone Warning, which means that gale force winds may be experienced in your area within the next 24 hours, follow these simple steps:-
By following the steps above, you can see the progress of the cyclone, and can better judge the likelihood of being affected. Be aware that cyclones can change direction at any time, and can also intensify or weaken over time, and, gale force winds can sometimes be experienced hundreds of kilometers out from the cyclone centre, becoming more severe closer to the centre, so listen carefully to the cyclone advices.
Of course, be prepared, make sure you have read and understand the information publicly available from local authorities concerning preparing for cylones before a cyclone threat emerges. A pamphlet called "Surviving Cyclones", issued by the Australian Bureau of Meteorology, is a good place to start. The second paragraph was adapted from information in this pamphlet.
Whilst it is true that the various weather authorities can usually only give estimates of both the position of cyclone and the wind distribution zones around them, this is the best method I now of for home users to use to display a cyclone on a tracking map, as at a glance you can see the extent of the cyclone. If you combine a set of the resulting maps in a Slide Show or GIF animation, you can readily assess the degree of threat a cyclone poses to your area as the wind zone image progresses from map to map.
This method may seem a little involved at first sight, however the results are well worth it! After practising a few times, you will find that you can do it quite quickly.
The Wind Distribution Scaling Tool (Nautical Mile version only at this time, the Kilometer version will appear here soon) enables drawing idealised elliptical wind strength zones around the centre of a cyclone or typhoon on any tracking map of 30 pixels to the degree scale, so giving an instant appreciation of the extent of a cyclone or typhoon, and the degree of threat posed to any location in or near it's path. Correction for Latitude is also included as a table on the right hand side of the Wind Distribution Scaling Tool.
To use this method, you will first need to download the The Wind Distribution Scaling Tool, Nautical Mile version, Kilometer version will appear here soon. Open it in a Drawing program (you may need to convert it from GIF to PICT or whatever format is appropriate for your drawing program first), and Save it as a template. This means that you can open a fresh page each time you use it, and you can save the result under an appropriate name if you want.
You will also need need to dowload an appropriate cyclone tracking map, which should also be saved as a stationary pad.
Note: The following assumes that you have a working knowledge of your particular drawing program, and the tools within it. If you are not familiar with your drawing program, experiment for a while, until you know how to:- use the line and ellipse tools, group objects together and ungroup them, rotate objects to any desired angle, rescale objects, copy objects to the clipboard and paste from it, and save the result. You should also know how to convert images from one format to another, and how save a document as a stationery pad.
You can now view your Slide Show or GIF animation to readily assess the degree of threat a cyclone poses to your area.
Note: the following section has not yet been rewritten for the new 30 pixel per degree maps, and doesn't exactly follow the above instructions. The principles are the same, so I will leave this section until I have drawn all the screen sized maps and uploaded them.
To work through the examples shown below, you will need to download the Wind Distribution Zone Scaling Tool. You will also need to download two maps, the cyclone tracking map used in the first example is the Port-Hedland to Exmouth local map (click here to download), and the typhoon tracking map used in the second example is the Hong Kong Easterly Aspect local map (click here to download)(this map has been updated to a newer version).
In this section there will be two examples, one with a very intense cyclone, Tropical Cyclone Vance, the other with an intense typhoon Typhoon Maggie, to show the use of the Wind Distribution Zone Scaling Tool in practical situations. Whilst, at first glace this method may seem complex, once you have practiced a few times it can be done quite quickly. There are links to all example images both at the appropriate places in the document and as a list at the bottom of the page.
To get set up - open the cyclone tracking map you are going to plot on in a drawing program (you may need to use a graphics program to convert it to a PICT or PIC first), and save it as a stationery document, repeat with the Wind Distribution Zone Scaling Tool. By saving these documents as stationery pads, you can open fresh sheets each time you want to update your cyclone information.
Note: The example images linked to through some of the steps below are quite large, so it may be best to download them and use an image viewer to show them on your screen or print them. You could also save this page as a text or html file.
Here is an extract of a warning downloaded from theWeather Warnings page of the Australian Bureau of Meteorology Website:-
IDW50W19 40:0:2:24:18S115E999:11:00 PANPAN HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE PERTH AT 1700 UTC 21 MARCH 1999. HURRICANE WARNING FOR WESTERN AREA SITUATION Severe tropical cyclone VANCE with central pressure 915 hPa located at 1600 UTC within 20 nautical miles of Latitude nineteen decimal seven south (19.7S) Longitude one hundred and fourteen decimal five east (114.5E) moving southsouthwest at 09 knots. AREA AFFECTED Cyclone causing 30/50 knot winds and very rough to high seas, heavy swell within 140 nautical miles of centre, increasing to 50/70 knots very high seas heavy swell within 90 nautical miles of centre, and reaching 80/110 knots phenomenal seas within 20 nautical miles of centre.
In this case, if you look under "AREA AFFECTED", you will notice 3 zones of wind speed listed, and, as there is no directional information specified with any of these zones, we can assume that the cyclone is more or less circular. The 3 zones are 30/50 knots within 140 nautical miles (nm), 50/70 knots within 90 nm, 80/110 knots within 20 nm.
We can now draw 3 circles using the Wind Zone Scaling Tool to represent these 3 zones, beginning with the largest area zone (Steps 2 to 6 above - see example v1, example v2, example v3).
These 3 circles can now be stacked on top of each other and grouped (Step 7 - example v4).
The image is rescaled, the vertical axis at 100 percent, and the horizontal at 106 percent according to the table for a Latitude between 18.9 and 20.4 degrees (Step 9 - example v5).
A direction vector arrow is drawn pointing to the left, and rotated 67.5 degrees, so that the arrow is pointing SSW, the base of the arrow is placed in the centre, grouped with the image, and the result is copied to the clipboard (Steps 10 and 11, example v6).
A fresh sheet is opened from the Port Hedland - Exmouth local tracking map pad and the result is pasted near but not covering the correct location of TC Vance (Steps 12 and 13).
Horizontal locater lines are drawn at the appropriate Latitude and Longitude on the grid, for more precission, a small 'x' spanning 0.1 degrees is made and dragged so the top left of the 'x' touches the intersection of the 2 locater lines (Step 14, example v7).
The cyclone wind zone image is dragged so that it's centre aligns with the centre of the 'x' (Step 15).
In this case, the cyclone wind zone image covers the locations of several towns, so it is dragged off the area where the towns are, small circles are made over the dots representing the towns, and the cyclone wind zone image is dragged back to the correct location.
Text fields are added to show the various wind zones and name the obscured towns, the locater lines and the small 'x' are deleted, and the result is saved as 'Vance211600UT' (Steps Steps 16, 17, and 18).
The result can be printed, or, if making an animated GIF of the resulting images from several warnings, they would be saved as PICT (in Mac) or whatever is appropriate for your particular platform, the appropriate suffix added, ie. 'Vance211600UT.pict', and all placed in a singe folder called 'Vance'
A graphics utility is launched, the output mode set to GIF film, the 'Vance' folder is selected, OK is clicked, and it is now just a matter of waiting while the image program makes the GIF animation (exactly how this is achieved depends on the particular image utility and operating system).
Note: The example images linked to through some of the steps below are quite large, so it may be best to download them and use an image viewer to show them on your screen or print them. You could also save this page as a text or html file.
Here is an extract of a typhoon warning downloaded from the Joint Typhoon Warning Centre:-
SUBJ: TROPICAL CYCLONE WARNING
WTPN31 PGTW 052100
1. TYPHOON MAGGIE (06W) WARNING NR 019
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
---
WARNING POSITION:
051800Z4 --- NEAR 21.0N3 121.0E4
MOVEMENT PAST SIX HOURS - 290 DEGREES AT 14 KTS
POSITION ACCURATE TO WITHIN 030 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST SEMICIRCLE
035 NM ELSEWHERE
RADIUS OF 035 KT WINDS - 180 NM NORTHEAST SEMICIRCLE
OVER WATER
140 NM ELSEWHERE
REPEAT POSIT: 21.0N3 121.0E4
---
You will notice that in the PRESENT WIND DISTRIBUTION: section that there are 2 wind speeds zones mentioned, RADIUS OF 050 KT WINDS - 050 NM NORTHEAST SEMICIRCLE 035 NM ELSEWHERE and RADIUS OF 035 KT WINDS - 180 NM NORTHEAST SEMICIRCLE OVER WATER 140 NM ELSEWHERE. These zones are best represented as ellipses positioned with the long axis to the North East.
Note: Whilst a cyclone with minimal influence from other synoptic features may present wind zones of a more or less circular form, other synoptic features, such as the presence of a large High pressure cell or ridge can distort the shape to be of more or less elliptical form, the orientation of which depends on the interaction with the other synoptic features. Interaction with land also modifies the shape of the wind zones, so it is best considered as an idealised representation of a cyclone over water.
We can now draw 2 ellipses using the Wind Zone Scaling Tool to represent these 2 zones (Steps 2 to 6 above - see example m1, example m2).
These 2 ellipses can now be stacked on top of each other and grouped (Step 7 - example m3).
As the warning mentions North East semi-circles, the shape is distorted by other synoptic features (a High pressure ridge in this case), so the stack of ellipses is rotated 45 degrees, so that the long axis is to the North East (Step 8 - see example m4).
The image is rescaled, the vertical axis at 100 percent, and the horizontal at 107 percent according to the table for a Latitude between 20.5 and 21.7 degrees (Step 9).
Note: You may need to experiment with the scaling in your drawing program if you have rotated the image. If scaling the whole grouped and rotated image, the pieces that make up the image may come apart, distorting the result in unwanted ways. My work around is to completely ungroup the image, rescale the ellipses individually, group the centering lines on each cross and rescale individually, and the result recombines quite well.
A direction vector arrow is drawn pointing to the top, rotated 70 degrees to point to 290 degrees, the base of the arrow is placed in the centre of the ellipses and grouped with them, and the result is copied to the clipboard (Steps 10 and 11, example m5).
A fresh sheet is opened from the Hong Kong E tracking map pad and the result is pasted near but not covering the correct location of Typhoon Maggie (Steps 12 and 13, example m6).
As the coordinates both fall on degree lines we do not need locater lines, a small 'x' spanning 0.1 degrees is made and dragged so the bottom left of the 'x' touches the intersection of the 2 intersecting degree lines, and the cyclone wind zone image is dragged so that it's centre aligns with the centre of the 'x' (Steps 14 and 15).
Text fields are added to show the wind zones and any other information desired, the small 'x' is deleted, and the result is saved as 'Maggie051800UT' (Steps Steps 16, 17, and 18).
The result can be printed, or, if wishing to set up a slide show or making an animated GIF from the images resulting from several warnings, they would be saved as PICT (in Mac) or other appropriate format, the appropriate suffix added, ie. 'Maggie051800UT.pict', and all placed in a single folder called 'Maggie'
For a GIF animation, a graphics program is launched, the output mode set to GIF film, the 'Maggie' folder is selected, OK is clicked, and it is now just a matter of waiting while the image program makes the GIF animation (exactly how this is achieved depends on the particular image utility and operating system). For an example of a GIF animation of Typhoon Maggie (211K) that can be downloaded and viewed in your computer with a suitable graphics program, click here.
© C.B.Smith 1999. All users of any map, image, or other information on these Web pages are deemed to have read and accepted the conditions described on the Copyright Information and Disclaimer page.
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