I don't know where to look on the web for tracks of very recent Tropical Cyclones.  However, looking at the satellite imagery, it appears  TC Dianne developed in the Southern Indian Ocean at approximately 12S, 97 E on about 0000  UTC 7 April.

I have put up on my web-page a sequence of 850 hPa charts, satellite image and 850-200 shear charts (all taken from the Darwin TLAPS real-time analysis, grabbed at the time). I have put up a sequence of just two days, corresponding to the approximate time of genesis: 00 UTC 6th and 7th.

Looking first at the 850 hPa flow and at the satellite images,  the development occurred in a large scale convective area south of Sumatra and Java, an area that is a climatological convective "hot-spot".  There was a classical monsoon trough in those longitudes stretching along about 10 S, with low-latitude monsoon westerlies to the north and trade easterlies to the south.  I haven't shown the vorticity maps, but clearly there was a maximum of -partial U/partial y cyclonic vorticity along the monsoon trough, there it wasn't particularly sharp or strong.

Turning now to the 850-200 shear maps:  The region of interest is on the western end of they map, remembering the development occurred between 90 and 100 E at about 10S.   Going back to the McBride-Zehr (1981) criterion for genesis, we require a symmetric vortex in the shear pattern in the anticyclonic direction (In our paper we required both large partial/partial-y of  U-shear , AND large partial/partial-x  of V-shear).  By thermal wind considerations, this means the development requires an isolated warm region, rather than a long (monsoon-trough) warm feature.   Thus overall the development of Dianne was a classical monsoon trough  development occurring in/on the persistent large scale cloud cluster south of Sumatra.

A couple of other factors of interest are that over the past month sea surface temperatures in that region have been very high (see synoptic discussion on my web-page for  22 March, (black area on GMS images).

There is another interesting aspect of the vertical shear figures.  If we consider a two-level model of the atmosphere, (say 850 and 200), then our external mode is simply the 850 plus the 200 flow, divided by two; and the first (and only) internal mode is 200 minus 850 divided by two.  Following this philosophy, the shear map is a representation of the first internal mode; and so we can look there for the equatorially trapped waves that would be excited by mid-troposheric heating (following the classic papers of Webster, Matsuno and Gill).  When we do that we see something ve-e-ery interesting.  Look at the shear map in the region immediately north of the developing system on 7 April: an easterly jet over the equator, and an anticyclonic vortex pair:  an n=1 equatorially trapped Rossby-wave, by golly!!

Back soon... I still have to tell you about the development of Bonnie a few days later.
 
 

         Satpic 2300 UTC 6 April                        850hPa wind 06 0000 UTC

Satpic 0000 UTC 7 April                        850hPa wind 07 0000 UTC

                      850 - 200 shear  06 0000                                                                                07 0000
 

Andrew Watkins;

G'day All,

For recent cyclone tracks see;
http://kauai.nrlmry.navy.mil/tc-bin/tc_home (bonnie is currently on the front page)

http://www.solar.ifa.hawaii.edu/Tropical/tropical.html
(bonnie data + map at/via: http://www.solar.ifa.hawaii.edu/Tropical/Data/BONNIE-02.html

and finally http://www.hawaii.edu/News/storm.tracks.html
(bonnie plot at: http://www.hawaii.edu/News/localweather/sin.latest.gif )

Cheers,
Andrew

From: Sheldon Kusselson <Sheldon.Kusselson@noaa.gov>
To: John McBride <jmb@bom.gov.au>
Cc: synoptic_discussion@bom.gov.au, tropical-storms@tstorms.org
Subject: Re: [Tropical-storms] Development (last week) of T.C Dianne

Dr. McBride:    You can check the NRL web site at:
http://kauai.nrlmry.navy.mil:80/sat-bin/tc_home        for past tracks of storms.  Just click
on all   for year 2002 and then click on Dianne and then click on track at the top.    Afterwards, you can click
on previous to get early track gifs of the storms.
Sheldon Kusselson
Satellite Analysis Branch/SSD/NESDIS/NOAA
Camp Springs, MD  USA