Severe Tropical Cyclone Monica

[Josh Morgerman]

Tropical Cyclone Monica, off the Queensland coast, is currently a 55-kt tropical storm (USA scale) and Cat-1 cyclone (Australian scale).

Monica is expected to track generally W and strengthen up until landfall between 36 and 48 hours on the Cape York Peninsula of N Queensland. The Joint Typhoon Warning Center brings it ashore at 80 kt-- i.e., Cat 1 (USA)/Cat 3 (AUS). Earlier advisories did not have it strengthening very much, so this recent forecast bringing it to hurricane strength represents a shift in thinking.

Australia has had a couple of newsworthy landfalls this year, including:

* Larry: Cat 5* (AUS) at landfall near Innisfail, Queensland (20 Mar)
* Glenda: Cat 3* (AUS) at landfall near Onslow, Western Australia (30 Mar)

(*Note: Both landfall intensity estimates are still being investigated and are not final.)

The track map and satellite image of TC Monica (below) are dynamic images and will automatically update:

Note: Satellite image removed, as the link is out of date.

 

[Michael Thompson]

The Bureau is expecting Monica to be Cat 3 by landfall, Current track will see no damage of note. The only town in the landfall area is the aboriginal mission of Lockhart river.

Monica should cross into the Gulf of Carpentaria where she should gain cyclone statis again. Most models have Monica persisting all week.

What I find interesting is the complete contrast in the Australia weather map at present. While Monica will be in the gulf later this week, the south east of Australia will be under a significant cold front that should bring 5400 thickness over the mainland. This may mean some brief snow above 5000-6000ft on the mountains in the extreme SE and Tasmania.

 

[Josh Morgerman]

Hey Michael, thanks for your comments! I notice a couple of things this morning:

* The Australian Bureau of Meterology has upgraded Monica to a Severe Tropical Cyclone (Cat 3 AUS), with max wind gusts up to 180 km/hr (97 kt) and a central pressure of 970 mb. The system is still deepening and gusts as high as 220 km/hr (119 kt) are expected at landfall.
* Monica is now a Cat-1 hurricane by the USA scale (70-kt winds according to the JTWC).
* The system looks much, much better organized on the latest satellite image (above). There's a dramatic difference from last night. The outflow is looking very healthy and way more symmetrical. Wow.

One thing: I find the JTWC's forecast positions and intensity predictions (see above) a bit puzzling. They have the system just offshore at 00Z 19 Apr with 75-kt winds. The next forecast position (12Z 19 Apr) has the center still over land but stronger (80 kt) than at landfall. That seems a bit counterintuitive to me. Is this a computer-generated prediction that does not factor in land interaction? Very odd!

 

[Josh Morgerman]

Monica just made landfall a little to the S of Lockhart River.

The 3 pm (local time) advice has the center 35 km SSE of Lockhart River with a pressure of 960 mb. The max gusts of 200 km/hr (108 kt) make Monica a mid-range Cat 3 AUS and I think a solid Cat 2 USA (the JTWC has the max 1-min wind at 85 kt).

Here's a landfall shot of Monica. There's a nice circulation and a distinct inner core, but no distinct eye-- so I'd say it looks like a classic Cat 2 USA:

[attachmentid=165]

Even more interesting are potential developments in 48 hours: the JTWC's projected track (above) has Monica strengthening significantly over the Gulf of Carpentaria and approaching the town of Nhulunbuy as a 95-kt system.

 

[Josh Morgerman]

Monica emerged into the Gulf of Carpentaria yesterday and, after some weakening over land, is now re-intensifiying. It looks much better organized this morning and is now a Cat 4 AUS/Cat 3 USA, with gusts near the center as high as 235 km/hr (127 kt) and a central pressure of 950 mb. That's a pretty big drop-- ~35 mb-- over the last 24 hours.

The system is expected to approach the Arnhem Land coast Saturday night or Sunday morning (local time) with gusts as high as 250 km/hr (135 kt). The Australian Bureau of Meterology (BoM) has Monica reaching Cat 5 AUS intensity over the Gulf of Carpentaria, although the JTWC indicates some weakening as the system approaches land.

The forecast track seems to be up for some debate. Note (below) that the BoM has Monica approaching the Arnhem Land coast pretty squarely, whereas the JTWC has it skirting just to the NE.

Nhulunbuy-- a town of several thousand-- is at the NE corner of this land mass. Even if Monica misses a direct hit, the town could experience the stronger left side of the storm's inner core.

Monica Track - BoM
[attachmentid=180]

Monica Track - JTWC
[attachmentid=181]

 

[Josh Morgerman]

Over the last 24 hours, Monica has intensified to a Cat 5 AUS/Cat 4 USA over the Gulf of Carpentaria.

The 11pm (local time) Australian Bureau of Meteorology (BoM) advice says the storm has gusts as high as 320 km/hr (173 kt/~200 mph!) and a pressure of 925 mb, and that it should "maintain its current intensity" as it nears the Arnhem Lands of the Northern Territory. The JTWC, on the other hand, calls for some significant weakening in the next 12-24 hours-- so the bottom line is that the BoM and JTWC do not seem to be in agreement Re: Monica's future intensity.

The system looks very symmetrical on the latest satellite image:

[attachmentid=183]

It is moving WNW and the latest BoM track has the center skirting the N coast of the Northern Territory-- so it looks like it will be a very close call for Nhulunbuy. The town may get off lucky and miss the storm's intense inner core, but it looks to be a very close call-- and, either way, Nhulunbuy will probably be on the left/stronger side of the circulation.

[attachmentid=184]

 

[Mark Farnik]

After looking at Monica's track from birth to present time, it appears she is roughly paralleling the northern coast of Australia. If this trend were to continue, she would eventually curve west towards Melville Island and then southwest towards Darwin. :blink: However it seems more likely that Monica's core will pass over the northern half of Cape Don and the town of Snake Bay on Melville Island and out into the Indian Ocean. But it certainly bears watching. Darwinians need to keep a close eye on this one. Monica is an intense storm and I wouldn't be suprised to see her maintain this intensity for the next day or two.

 

[Josh Morgerman]

After looking at Monica's track from birth to present time, it appears she is roughly paralleling the northern coast of Australia. If this trend were to continue, she would eventually curve west towards Melville Island and then southwest towards Darwin. :blink: However it seems more likely that Monica's core will pass over the northern half of Cape Don and the town of Snake Bay on Melville Island and out into the Indian Ocean. But it certainly bears watching. Darwinians need to keep a close eye on this one. Monica is an intense storm and I wouldn't be suprised to see her maintain this intensity for the next day or two.
[/b]

Mark, interestingly, it looks like your forecast may verify, as the Darwin BoM is now warning of some serious impact in the Darwin area in the next couple of days (see next entry).

 

[Josh Morgerman]

Monica intensified more and is a very deep Cat 5 cyclone (on the AUS and USA scales), with winds of at least 145 kt and a central pressure of 905 mb. The intense inner core is closing in on Cape Wessel, which recently reported a sustained 10-min wind of 56 kt (64 kt when converted to 1-min).

The storm presents a spectacular picture on satellite:

[attachmentid=185]

On radar, the cyclone's eyewall presents very well:

The Darwin BoM's latest advice suggests that the cyclone may impact the Darwin area as a slightly weakened but still intense cyclone on Tuesday. It will be an interesting couple of days for sure...

 

[Josh Morgerman]

Monica is moving directly over the Wessel Islands now-- making this an official Cat 5 landfall (according to both AUS and USA scales).

The last report out of the Cape Wessel was 67 kt (10-min average, I believe-- so that would convert to 77 kt 1-min sustained) and 982 mb before the station stopped reporting.

The latest satellite picture shows the eye perfectly centered over Marchinbar Island. Unfortunately, it's not a high-res visible image-- but still an amazing sight. (What I'd give to be on Marchinbar Island right now... <sigh> )

[attachmentid=186]

 

[MClarkson]

ahhh... almost perfectly symmetrical, clear eye... that classic perfect cat 5 satellite presentation and I agree I would love to be there.

 

[Marko Korosec]

Hi guys,

I was checking this site and it says currently 868.6hPa pressure??

http://cimss.ssec.wisc.edu/tropic/adt/odt26.html

Is this measured with satelite if I understand that site right...'cause that's one of the deepest pressure ever observed! :blink: How true is that value?

Otherwise indeed really an impresive storm structure!

 

[Jeff Snyder]

Hi guys,

I was checking this site and it says currently 868.6hPa pressure??

http://cimss.ssec.wisc.edu/tropic/adt/odt26.html

Is this measured with satelite if I understand that site right...'cause that's one of the deepest pressure ever observed! :blink: How true is that value?

Otherwise indeed really an impresive storm structure!
[/b]

Satellite estimates (it's a remote measurement) can sometimes be very erroneous. Even if it's off by 25-30mb, that's still a VERY impressive storm!

 

[Josh Morgerman]

I think the Dvorak numbers exaggerated the intensity a bit, although it is clearly an extremely severe storm. The official maximum intensity of Monica is unclear to me, but the Asutralian Bureau of Meteorology was indicating 905 mb and maximum gusts of 350 km/hr (189 kt/218 mph!) as the center passed through the Wessel Island chain. The Joint Typhoon Warning Center has been indicating max 1-min winds of 145 kt-- so Monica is a solid Cat 5 on both the Australian and American (Saffir-Simpson) scales.

P.S. Between 1) having two different agency estimates (BoM and JTWC), 2) the lag time with the JTWC statements (only once every 12 hours), and 3) the peculiar P) way that the Australians indicate system intensity (max gusts), it's not very easy to get a handle on the exact intensity of cyclones in this region, is it?? Ggrrr.

 

[Scott Olson]

Interesting, check out the flare in intensity as viewed from CIMMS microwave imaging:
http://cimss.ssec.wisc.edu/tropic/real-tim...fsBy12hr_08.gif