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A tropical low has formed just inland from the southern Gulf Of Carpentaria, about 150 miles west of Mornington Island. The low is showing some rotation, and some limited convection forming as it feeds of warm waters to the north. The system is expected to drift eastwards over land over the next 12 hours or so and then emerge over warm waters, where it is expected to strengthen and become a tropical cyclone. As 08U becomes a tropical cyclone and a more vertically deep system, it is forecast to track back west under the influence of ridging to the south. Heavy rains are a primary concern from this system.

 

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08U has become much better organised as it has moved over the warm waters of the far south of the Gulf Of Carpentaria (GOC), and has become Tropical Cyclone Fletcher, with winds of of 35kts. Convection is persistant over the LLCC, and there are good banding features in the northern quadrant of the cyclone. Fletcher is approaching landfall on the eastern shore of the GOC, and BOM expect Fletcher to weaken to a remnant low this afternoon. Once the westward heading materalises, Fletcher should move back over the warm water of the southern GOC and become a tropical cyclone once more, before eventually making landfall where it emerged from! GOC systems always seem to have bizarre tracks!

 

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Fletcher moved east and made landfall on the southeast coast of the Gulf Of Carpentria yesterday afternoon and has remained over land since. The system was downgraded to a remnant low last night. The westward turn looks to be materialising now, and the remnant low appears to be moving back over water. This should allow the low to become a minimal tropical cyclone again before it makes another landfall, south of Sweers Island. As the system is not expected to be over water for long, significant intensification appears unlikely before the second landfall.

 

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Fletcher moved east and made landfall on the southeast coast of the Gulf Of Carpentria yesterday afternoon and has remained over land since. The system was downgraded to a remnant low last night. The westward turn looks to be materialising now, and the remnant low appears to be moving back over water. This should allow the low to become a minimal tropical cyclone again before it makes another landfall, south of Sweers Island. 

 

Fletcher reminds me of Alessia at the start of this season. Alessia also meandered for quite a long time in the Gulf of Carpentria with a very erratic track as well. In the end, Alessia dissipated in the Gulf itself. The odd track of Alessia can be seen below:

 

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Moreover, both Fletcher and Alessia were/are very difficult systems to forecast, with BOM having to make a considerable amount of shifts in track and intensity of Alessia during the forecast period. (this was mainly caused by the fact that Alessia was always very close to land during its lifetime).

 

Interaction between two tropical lows

 

And yet Fletcher has an even more exciting part during its existence. The cyclone (or tropical low) is interacting with another tropical low currently located to the southwest of Fletcher, causing a high level of uncertanity in the forecast tracks and intensities of both cyclones. It has some resemblance to the Fujiwara effect Posted Image.

 

Quoted from the Bureau of Metorology (this is about the tropical cyclone to the southwest of Fletcher):

 

 

Although the low is expected to remain over land, there is a possibility the low will move over the southwest Gulf of Carpentaria on Thursday or Friday as it interacts with Ex-Tropical Cyclone Fletcher, prior to recurving back to the west. For this reason, there is a moderate risk that the low may develop into a tropical cyclone.

 

Because of this possible interaction, the track of both systems seems to be far from set in stone. For now, it seems to me that Fletcher will be adsorbed by the low currently to the southwest of the cyclone in a few days, but it is no more than a wild guess. Such interactions are always very difficult to predict, and the JTWC, regarding Fletcher, states that:

 

 

NUMERIC MODELS ARE SPREAD OUT IN PROJECTING WHERE THE SYSTEM WILL TRACK; HOWEVER, MOST OF THEM DRIVE THE VORTEX BACK OVER LAND WITHIN 24 HOURS AND NONE OF THEM PREDICT ANY SIGNIFICANT INTENSIFICATION

 

Of note is that despite the complex nature of the steering environment around Fletcher, both BOM and JTWC agree with the system not strengthening much.

 

Current state of Fletcher

 

Currently, Fletcher doesn't seem to be very well organized. It consists of some linear areas of deep convection to the north and a small blob to the south of the system. Moreover, there is some cyclonic turning evident in the southern half of Fletcher. A visible imagery loop of the system can be seen below:

 

Posted Image

 

The center of Fletcher appears to be over water once again (as analyzed by Bureau of Meteorology, see the track forecasts shown by Sommerset Squall above). However, because of the apparent loose organization of the cyclone, significant intensification appears unlikely.

 

EDIT: To show the disorganzed state from another perspective, check the 850 mb vorticity chart from CIMSS below:

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Vorticity is, in laymans terms, a measure of the amount of spinning motion of an air parcel.

 

Note that the vorticity maximum at 850 hPa associated with Fletcher is located over land to the south of the analyzed position of the LLCC by the Bureau of Meteorology. This indicates that Fletcher is most likely elongated north-south. Such elongations usually impede development, as the vortices have to be on top of each other to ensure intensification.

 

On the contrary, wind analysis from earth.nullschool.net shows that the LLCC is also located over the southeastern tip of the Gulf of Carpentria. Moreover, it shows the 500 hPa center is located to the north of the apparent LLCC position (analyzed from the site itself). Hence, though both sources do indicate an elongation, the direction of the elongation (bottom-up) seems to be uncertain.

 

Concluding, Fletcher has been a tenacious cyclone thus far, developing without many signals pointing in that direction like Edna. Moreover, its future still seems to be very uncertain. it will be interesting to see how the interaction between the two systems unfolds. 

 

Sources:

http://en.wikipedia.org/wiki/2013%E2%80%9314_Australian_region_cyclone_season

http://www.usno.navy.mil/JTWC/

http://en.wikipedia.org/wiki/Fujiwhara_effect

http://www.bom.gov.au/nt/forecasts/tcoutlook.shtml

http://www.ssd.noaa.gov/PS/TROP/floaters/94P/94P_floater.html

http://tropic.ssec.wisc.edu/real-time/windmain.php?&basin=austeast&sat=wgms∏=vor&zoom=&time=

http://earth.nullschool.net/#current/wind/isobaric/500hPa/overlay=total_precipitable_water/orthographic=-226.74,-21.20,1620

Edited by Vorticity0123

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The remnant low of Fletcher remains overland and has not moved westward back over the GOC. Regeneration is increasingly unlikely as the remnants have become even less organised over land.

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