Topic: Tropical Cyclone Jasper Coral Sea : from 21 March 2009

[Colin Maitland]

I have been watching a low in the Coral sea, it looks like it could intensify and has been given a high chance to form into a cyclone over the next 3-4 days. All along the coast in QLD, including Brisbane, we have no signs of autumn, we have been getting  high day time temps around 29-30c everyday, and  along with 20c overnight temps. Water temps are still pretty high, so it could add fuel to the system. Worth keeping an eye on this one as well.

[Michael Bath]

You're not wrong Col - I'm a bit over these humid 30/20 type days - especially when there are no storms.

Sea surface temps are still above average over a lot of the Coral and Tasman seas. The track of Hamish shows up as a cooler anomoly

[Colin Maitland]

Just checking BOM latest synop. forecast and it appears that by Friday we may have a cyclone of Townsville/ Mackay region. I have posted the latest charts, by observation it seems the system will move down the coast quickly.

[Colin Maitland]

The low that we have been watching,in the Coral Sea, was at 2.30pm EST, on the 19/03/09;  approximately, 17º South and 154ºEast (or about 480 nautical miles east of Cairns). Its central pressure at this stage is 1001 Hpa. From looking at the various predictions and forecast, the low is expected to deepen further over the next few days while slowly moving. It is presently   moving south West.

If it develops into a cyclone, which looks pretty well on the cards of doing so, it should, going by the names for 2008/09 season, be called Jasper.

Col.

last edit: it has been interesting looking at the developement or formation of the low on the Yoko Sat site from the 3.30- 6.30 UTC time frame (http://realtime2.bsch.au.com/vis_sat2.html?region=coralsea&loop=no&images=&allday=&start=&stop=&pi=200903190633#nav)

Edit: These are only archived for 14 days - can we have something permanent please
(hopefully this is what you are after, it it is using too much web space, delete them, let me know I have the full images saved and can change to what is needed)

[Colin Maitland]

We now officially have a tropical low in the Coral sea, the latest central pressure of this low is 999Hpa. It is interseting to note the two active system now in play. The system is approx. in the same position as the last update of 17deg south and 154 deg east.

[Colin Maitland]

The low in the Coral Sea is said to be stationary, it no longer is classified as a tropical low, it  has a central pressure of 1000Hpa and may move slightly East or south East. It may still intensify over the next 24 hours, will just have to watch what happens.

In QLD we have an Ocean wind warning from Fiji, this is from the remains of Ex Tropical cyclone Ken cat 2. This may have affected the tropical low in the Coral sea, causing it to become disorganized in its structure late Thursday night and yesterday.

From BOM :
(Gale Warning 026 ISSUED FROM RSMC NADI Mar 20/1911 UTC 2009 UTC.

IN AREA BOUNDED BY 20S 160E 20S 163E 25S 165E 25S 160E 20S 160E, EXPECT EAST TO
SOUTHEAST WINDS 30 TO 40 KNOTS.

AREA OF GALES SLOW MOVING.

THIS WARNING CANCELS AND REPLACES WARNING 025.)




Col

[Colin Maitland]

This has a been a persistent complex low over the Coral Sea for the last several days, Bom still have it as a moderate chance to form into a cyclone in the next 48-72 hours. The lows, in the coral sea, at this stage are tending to move in southeasterly direction.

From reading the paper over the week end, some forecasters are predicting an above average rainfall  over the next few weeks for QLD. From what I understood, it is mainly due in the south east corner, probably just in time for the school break. Maybe the lows could form into rain depressions. We cant do anything else but watch and see.

It was off interest that Michael Bath was saying that down through his area, they were experiencing much the same day/ night temps as QLD/ Brisbane.If what the forecaster was predicting is right, for the rain, you may find it travelling right down through northern NSW. I would have thought at this time of year, it would be pleasant night time temps south of the border, but I was wrong.


Col

[Colin Maitland]

It took a while, but the low in the coral sea eventually organised itself into a Cat 1 cyclone called Jasper.
The official report for Jasper from BOM is

TROPICAL CYCLONE INFORMATION BULLETIN
For 6:30am AEST on Tuesday the 24th of March 2009

At 4 am EST Tuesday, Tropical Cyclone Jasper [Category 1] with central pressure
995 hPa was located near latitude 17.6 south longitude 158.0 east, which is
about 1010 km east northeast of Mackay.

The cyclone is moving east southeast at about 32 kilometres per hour.

TROPICAL CYCLONE JASPER, CATEGORY 1, is located in the eastern Coral Sea well
away from the Queensland coast and is expected to maintain its current intensity
as it moves to the southeast. TROPICAL CYCLONE JASPER poses NO IMMEDIATE THREAT
to people in coastal and island communities along the Queensland coast.
 

[Richary]

Interesting looking storm on the forecast track map, all the destructive winds are to one side of the core.

[Colin Maitland]

It is, Jasper now Cat 2, is supposed to head southeast today, but as the above track map from Richary shows, it should swing to the right and head towards southeast coast as a CAT 3 system late Wed or Thursday. Still well out to sea at this stage to pose an immediate threat to us.

[Colin Maitland]

As at 8.21 pm EST, cyclone Jasper is moving in an East southeasterly direction at about 20 km/h. If Jasper continues on his present track he could near the North western tip of New Caledonia's main Island the Grand Terre with in the next 10 hours. As a result of this, New Caledonia have been placed on orange alert. Over the weekend they have received torrential rain resulting in flooding.

On his present track he will leave the Australian Tropical Cyclone area and no further warnings/ reports will be issued by BOM. Of Interest though is that of the Technical information for Jasper from JTWC.

I quote directly from their data where it is stated:

 {THE CYCLONE IS TRACKING EAST-SOUTHEASTWARD ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE. THIS GENERAL MOTION IS EXPECTED TO CONTINUE THROUGH THE NEXT 12 HOURS. THEREAFTER, A SECOND SUBTROPICAL RIDGE TO THE SOUTHWEST WILL INDUCE A COMPETING STEERING INFLUENCE, SLOWING FORWARD TRACK MOTION AND TURNING THE SYSTEM NORTHWESTWARD AFTER TAU 36. THE NUMERICAL MODEL TRACKERS, WITH THE EXCEPTION OF WBAR AND GFDN, ARE IN FAIR AGREEMENT WITH THIS SCENARIO. HOWEVER, DEPICTIONS OF THE EXACT TRACK VARY, AND THE CURRENT FORECAST LIES CLOSE TO THE MODEL CONSENSUS. TC 23P IS EXPECTED TO INTENSIFY THROUGHOUT THE FORECAST PERIOD UNDER THE INFLUENCE OF DUAL-CHANNEL UPPER LEVEL OUTFLOW. INCREASING VERTICAL WIND SHEAR AFTER TAU 24 SHOULD LIMIT THIS INTENSIFICATION TO A SLOWER RATE.}

Another words they are still expecting Jasper to turn. It will be of interest if he ventures back into our waters, that being 160deg East. If he does we may just hear from BOM again.

It has turned out to be the right name for this one. He is like the ghost ( that is Caspers new twin brother), he appeared as a tropical low, disappeared, formed into a cyclone, moved away to disappear from our waters and then may reappear.

The JTWC track map is an intersting one to look at.

Col