Severe Tropical Cyclone Monica

Joined
Jan 8, 2006
Messages
444
Location
West Hollywood, CA
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:

sh2306.gif

Note: Satellite image removed, as the link is out of date.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

Radarpriortolandfall.png


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...
 
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]
 
ahhh... almost perfectly symmetrical, clear eye... that classic perfect cat 5 satellite presentation and I agree I would love to be there.
 
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!
 
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.
 
Wow, and I was just guesstimating Monica's track given her previous movements! :blink: How weird is that? Right now Monica is as strong as Hurricane Katrina was at her strongest, with central pressure of 905 mb. With that recent flare of convection around the eyewall I wouldn't be surpised if Monica's sustained winds are in the 150-155 knot range. If Monica continues on her forecast path and maintains her forecast intensity, she should pass directly over or just south of Darwin as a 130 knot strong Cat 4 (US) cyclone with gusts to 160 knots. This could be a very dangerous and devastating situation for Darwin. I wouldn't be suprised to see destruction on a similar level of that caused by infamous Cyclone Tracy which devasted that city on Christmas Eve 1974 if the front right quadrant of Monica's core passes directly over the city (which it very well may do) and Darwin is considerably bigger now that it was in 1974 (only 43,500 in 1974 versus 109,438 today) so there is a lot more real estate for Monica to destroy and a lot more lives at risk. :( Also Monica is a MUCH larger storm than Tracy. Tracy was the smallest tropical cyclone on record with gale force winds only extending out 48 km(30 miles) from the center. Monica absolutely dwarfs Tracy in size. Gale force winds extend out 120 nm from the center! :blink: About the only good news is that after Tracy Darwin revised its building codes significantly, so at least the buildings that have been built since Tracy have been built with cyclone survivability in mind. :)
I think they need to issue an evacuation order for low lying areas and tell residents to either head east out of the path of the storm or move into shelters in substantial structures for those who don't want to or can't evacuate. Monica is a very dangerous storm and I hope the Darwin BoM and the Australian goverment take proper measures to ensure that the residents are either out of harms way or can seek safety in shelters.
 
Mark, you have some kind of magical skill at track prediction. :p

Re: the threat to Darwin... The latest JTWC track (below) shows the center passing close to Darwin in less than 48 hours with winds of 130 kt-- really quite extreme! It's odd, though, that this forecast does not show any weakening during the 12 hours between a fourth landfall near Point Stuart (00Z 04.25) and its closest approach to Darwin (12Z 04.25). Since the center would be over land during this time, I don't quite understand that. I am no pro meteorologist, but I would be surprised to see a system maintain 130-kt winds during a 12-hour trek over land. Odd!

[attachmentid=191]

Re: Cyclone Tracy 1974... What a curious little storm it was! The landfall pressure of 950 mb was hardly record-breaking, but I believe the freakishly small size of the system (that Mark mentioned above) made for an extremely tight pressure gradient that caused the ferocious winds that destroyed 70% of the city. The satellite photo shows how small Tracy was; the other pic illustrates the spectacular wind damage in Darwin.

(Tracy reminds me a bit of Charley 2004 at its Florida landfall. It, too, was a very small system that caused surprisingly high winds (130 kt) for its landfall pressure (941 mb).)

[attachmentid=192] [attachmentid=193]
 
without aircraft recon, there is no way to know what the central pressure is. the sat estimates could be off either way. Regardless, this is a very impressive cat 5.

EDIT: I would also expect signficant weakening as it crosses land before reaching darwin. however assuming the pressure is somewhere below 890mb... it can weaken a lot and still be strong.
 
Interesting, check out the flare in intensity as viewed from CIMMS microwave imaging:
http://cimss.ssec.wisc.edu/tropic/real-tim...fsBy12hr_08.gif
[/b]
Wow, Scott, that loop is a great find. That eyewall almost doesn't look real-- it's so perfect, it looks machine-generated. :D

That flare-up is very interesting. Given the timing of it, I wonder if interaction with the Wessel Islands had anything to do with it-- since the convection deepens just as the center is crossing the island chain.

Those islands must have gotten raked!
 
I've seen some flare-ups before but not many that showed what appeared to be almost a 2x increase in forward motion. The eye shows fast warming and cloud brightness goes signfiicantly up. As for the Dvorak AODT from CIMMS (which isn't as accurate as the two non-public versions) I've seen it under-estimate more often than it has over-estimated, at least in the Atlantic Basin. It doesn't do well in any rapid fluctuations but it usually is within 20mb or 30kts of the offical estimates from Recon (sometimes alot more and sometimes less). For contrast here is Hurricane Wilma during it's peak strength vs. Monica using the AODT Dvorak anaylsis site.


WILMA: 6CI 927mb 115kts Eye temp: 15.88C Cloud Temp: -64C
MONICA: 8CI 868mb 170kts Eye Temp: 19.8C Cloud Temp: -81.2C

Obviously it did pretty bad with Wilma, which is not suprising because of the incredible rate that Wilma deepend. Even with all that said the Dvorak IR/ VIS appearance is exactly what you would expect from a violent Hurricane. I can't remember seeing the CI max out for so long.

Here is a picture of Monica taken sometime today that I have enhanced a bit:

 
Geez, I thought it was just the U.S. Gulf Coast that Nature had it out for. What’d you Aussies do to get on her bad side? :blink:
 
INTENSITY
As usual, there are slightly conflicting signals between JTWC and BoM, probably due simply to the fact that JTWC only updates every 12 hours. The JTWC intensity has edged up, but the BoM intensity (based on central pressure) has simply held steady after filling a little since yesterday. JTWC currently indicates a spectacular 155 kt 1-min sustained wind! BoM indicates 915 mb and 350 km/hr (189 kt/218 mph) max gusts. Both agencies indicate a solid Cat 5 (AUS/USA) storm.

Both forecast tracks bring the center generally WSW to near Darwin as a weakened-- but still substantial-- cyclone in about 24 hours. The JTWC has the storm at 100 kt at its closest approach to Darwin; the Australian BoM has the storm as a Cat 3 AUS (high-end Cat 1/Cat 2 USA).

The precise intensity as the inner core approaches Darwin will depend largely on land interaction-- which in turn depends on the track.

TRACK
The JTWC track (below) has the cyclone making landfall around Maningrida as a 140-kt system and staying inland all the way to Darwin-- about 18 hours later. The BoM has the track curving poleward more gradually, and therefore reemerging over the Van Diemen Gulf before approaching the Darwin area. I think this track would be more threatening, as the reemergence over water will help the cyclone maintain its intensity as the inner core approaches the city.

CONCLUSION
Given that there will be significant land interaction before the system reaches Darwin, my gut feeling is that the BoM's more conservative forecast for the Darwin-area intensity seems more realistic.

Note: This image will dynamically update and will no longer reflect the above commentary when the next warning graphic is issued.
 
Judging from the latest satellite imagery, Monica seems to be making its third landfall somewhere between Junction Bay and Maningrida. Maningrida is just left of the center-- on the stronger side-- and is most certainly experiencing extremely severe conditions right now. This landfall point is a little sooner and a little further E than previously forecast-- cetainly some good news for Darwin.

The very latest JTWC warning still estimates intensity at an amazing 155 kt, with the center just offshore the Arnhem Land.

The new projected track curves even more abruptly poleward, meaning 1) the system does not come as near to Darwin and 2) it has more time over land before its point of closest approach to the city. Additionally, this track keeps Darwin outside of the intense inner core and on the weaker side of the system, which-- according to this-- should have winds somewhere between 115 kt and 90 kt at its point of closest approach. Inland towns such as Adelaide River and Pine Creek are more directly threatened.

Note: This image will dynamically update and will no longer reflect the above commentary when the next warning graphic is issued.
 
You should be able to read some first hand accounts in about 12 hours on this board

http://www.weatherzone.com.au/cgi-bin/ulti...?ubb=forum;f=12

Just a warning there is a lot of noise and chatter, but some good stuff in between the junk.

We have a few enthusiasts in Darwin so there should be pictures with luck.

Michael
[/b]
Hey, thanks, Michael! I did find some interesting stuff in there, including a link to the observations from Maningrida Airport, which appeared-- based on visible satellite imagery-- to be extremely close to the center as it came ashore.

http://www.bom.gov.au/products/IDD60701/IDD60701.95142.shtml

Monica's wind field must have been very tight, because the highest 10-min wind on this table is only 51 kt and the highest gust 80 kt-- at about the time of the lowest pressure (986 mb)! Data such as these suggest Maningrida was clearly outside of the eyewall-- although I was so sure it was getting mega-raked when I looked on the visible satellite shots. Puzzling!

THE LATEST
Monica made landfall several hours ago and is moving WSW over the Arnhem Land toward the general Darwin area.

As of 10 pm (local time), the central pressure is 935 mb and max gusts are way down to 260 km/hr (140 kt/162 mph)-- now a Cat 4 AUS. The system has filled a bit and will continue to do do-- however, the BoM indicates it could be a Cat 3 AUS (high-end Cat 1/Cat 2 USA) when it reaches the Darwin area, where max gusts of 175 km/hr (95 kt/109 mph) are expected.

Darwin will not experience another Tracy-- but it may experience some significant effects.
 
Back
Top