Cyclone Monica - Cat. 5

[senorpepr]

It may be 145kt, but I don't think it is any higher than that.

[skysummit]

That storm is absolutely amazing. Has Australia ever seen something so intense before? I hope this is not a precursor to what storms will look like in the Atlantic Basin this year...or at least not the ones that make landfall.

God help those people.

[CrazyC83]

It takes a greater intensity to have stronger winds in that part of the world as opposed to the Atlantic...a Dvorak T8 has an 858 mb pressure attached, for example...

[CrazyC83]

That storm is absolutely amazing. Has Australia ever seen something so intense before? I hope this is not a precursor to what storms will look like in the Atlantic Basin this year...or at least not the ones that make landfall.

God help those people.

That says it all. The 877 mb estimate is just terrifying. As for the winds, the 164 knot flight level wind would translate to about 148 knots at the surface, but I think the actual sustained winds are 145 knots (165 mph) at this time since I'm not too sure about the 90% estimate.

[skysummit]

Check out that eye!!!

[senorpepr]

The real pressure is much higher than 877, though. It's more like 915-925mb.

[benny]

The real pressure is much higher than 877, though. It's more like 915-925mb.

hmm.. and that is based on... ??? I mean, those estimates don't have a low bias.. they don't really have a bias. this sucker is pretty powerful.. anything t 7.0 and above and maintaining it for this long has a chance to be below 900 mb...

[HURAKAN]

Australian Government Bureau of Meteorology
Northern Territory
Darwin Regional Forecasting Centre

TOP PRIORITY

MEDIA: Transmitters serving the Gove area are requested to use the cyclone
emergency warning signal with this message.

TROPICAL CYCLONE WARNING

TROPICAL CYCLONE ADVICE NUMBER 55
Issued by the BUREAU OF METEOROLOGY, DARWIN
at 2:00 pm CST Sunday 23 April 2006

A CYCLONE WARNING continues for coastal and island communities between CAPE
SHIELD and CROKER ISLAND, including NHULUNBUY.

A CYCLONE WATCH extends west for coastal and island communities between CROKER
ISLAND and DALY RIVER MOUTH, including DARWIN, JABIRU and the TIWI ISLANDS.

At 1 pm CST SEVERE TROPICAL CYCLONE Monica CATEGORY 5 was located about 135
kilometres northeast of NHULUNBUY, and 240 kilometres east northeast of ELCHO
ISLAND, moving west at 12 kilometres per hour. The cyclone should remain close
to its current intensity as it moves further west, just north of the north coast
during today. It may cross the north coast of western Arnhem Land later
tomorrow.

The VERY DESTRUCTIVE core of SEVERE TROPICAL CYCLONE Monica with gusts to 320
kilometres per hour is expected to impact islands of northeast Arnhem Land,
including ELCHO ISLAND, later this afternoon and tonight, but is no longer
expected to affect NHULUNBUY. The VERY DESTRUCTIVE core may impact the north
coast of western ARNHEM LAND during Monday.

GALES with gusts to 120 kilometres per hour are being experienced on the far
northeast Arnhem Land coast, and are expected to affect the area between CAPE
SHIELD and ELCHO ISLAND, including NHULUNBUY during the next few hours.
DESTRUCTIVE WINDS with gusts to 160 kilometres per hour are expected along the
far northeast coast, including NHULUNBUY, later this afternoon and continue to
extend westward. GALES near the outer edge of the cyclone may extend west as far
as CROKER ISLAND early tomorrow.

SEVERE TROPICAL CYCLONE Monica is expected to weaken slightly late tomorrow but
GALES will continue to extend westward and may develop over the TIWI ISLANDS
later Monday and DARWIN by Tuesday morning.

DANGEROUSLY HIGH TIDES could cause EXTENSIVE FLOODING at the coast between CAPE
SHIELD and ELCHO ISLAND during today.

HEAVY RAIN is expected to cause significant stream rises and flooding of low
lying areas in northeastern Arnhem land today, extending across the remainder of
the northern Top End on Monday.

Details of SEVERE TROPICAL CYCLONE Monica at 1 pm CST:
. Centre located near...... 11.4 degrees South 137.7 degrees East
. Location accuracy........ within 30 kilometres
. Recent movement.......... towards the west northwest at 12 km/h
. Wind gusts near centre... 320 kilometres per hour
. Intensity................ CATEGORY 5
. Central pressure......... 925 hectoPascals

REPEATING: A CYCLONE WARNING is continues between CAPE SHIELD and CROKER ISLAND.
A CYCLONE WATCH extends west to DALY RIVER MOUTH, including DARWIN, JABIRU and
the TIWI ISLANDS.

The next advice will be issued at 5 pm CST.

This advice is available on telephone NT-1300 659 211

DARWIN Tropical Cyclone Warning Centre

NOTHING NEW!!!

[Matt-hurricanewatcher]

senorpepr, Monica looks very much like Katrina and Rita do you agree. What is the difference between the cyclones?

[senorpepr]

The real pressure is much higher than 877, though. It's more like 915-925mb.

hmm.. and that is based on... ??? I mean, those estimates don't have a low bias.. they don't really have a bias. this sucker is pretty powerful.. anything t 7.0 and above and maintaining it for this long has a chance to be below 900 mb...

Actual observations and studies for storms in all basins have shown that those estimates tend to be too high on wind speed and too low in pressure, espically in the Pacific Ocean.

Furthermore, the 916mb that the Navy is saying is more realistic. There are numerous papers written by several authors regarding Dvorak estimates to storms, based on the days when recon covered much of the world.

[senorpepr]

senorpepr, Monica looks very much like Katrina and Rita do you agree. What is the difference between the cyclones?

The biggest difference is background pressure.

The background pressure is lower here than it was for Katrina and Rita, yielding low wind speeds.

[benny]

UW - CIMSS
ADVANCED OBJECTIVE DVORAK TECHNIQUE
AODT - Version 6.4.2
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 23 APR 2006 Time : 033300 UTC
Lat : 11:27:02 S Lon : 137:31:47 E


CI# /Pressure/ Vmax
7.8 / 876.9mb/164.0kt


Latitude bias adjustment to MSLP : +10.5mb

Estimated radius of max. wind based on IR : 22.1km

6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
7.8 7.8 7.9 7.9

We can argue all we want on the intensity.. but it is much stronger based on satellite alone than anything the atlantic had last year.. i think rita had a picture or two of 7.3

[CrazyC83]

The Navy 125 knot estimate (2 1/2 hours old) is a 10-minute sustained or 1-minute sustained?

[wxmann_91]

Furthermore, the 916mb that the Navy is saying is more realistic. There are numerous papers written by several authors regarding Dvorak estimates to storms, based on the days when recon covered much of the world.

Although I would agree with you usually Senor, I would have to disagree with the above statement. This was an estimate at 18Z (the first timestamp in the image). However I do concur it is not 877 mb, although I would estimate it around 900 mb.

Question: what does "hectoPascals" mean? Is it the same or different than millibars?

[CrazyC83]

Question: what does "hectoPascals" mean? Is it the same or different than millibars?

Exactly the same.

[senorpepr]

We can argue all we want on the intensity.. but it is much stronger based on satellite alone than anything the atlantic had last year.. i think rita had a picture or two of 7.3

However, due to normal differences in background pressures, if two systems looked the same on satellite, but one was in the Atlantic and one was in the Pacific... the Atlantic storm would be stronger.

[benny]

Furthermore, the 916mb that the Navy is saying is more realistic. There are numerous papers written by several authors regarding Dvorak estimates to storms, based on the days when recon covered much of the world.

Although I would agree with you usually Senor, I would have to disagree with the above statement. This was an estimate at 18Z (the first timestamp in the image). However I do concur it is not 877 mb, although I would estimate it around 900 mb.

Question: what does "hectoPascals" mean? Is it the same or different than millibars?

hPA is just the metric unit, same thing

[senorpepr]

The Navy 125 knot estimate (2 1/2 hours old) is a 10-minute sustained or 1-minute sustained?

1-minute. It should be updated to 140kt.

[HURAKAN]

LOOKING MORE AND MORE IMPRESSIVE BY THE SECOND!!!!!

[benny]

We can argue all we want on the intensity.. but it is much stronger based on satellite alone than anything the atlantic had last year.. i think rita had a picture or two of 7.3

However, due to normal differences in background pressures, if two systems looked the same on satellite, but one was in the Atlantic and one was in the Pacific... the Atlantic storm would be stronger.

Yeah that could be right. But.. the background pressures around Wilma were extremely low (embedded in a reverse oriented monsoonish trough almost). It is all in the pressure gradient... how much gradient can tighten in the eyewall. This one is pretty tight... there doesn't seem to be that large of an outer wind field. But really.. recon is what is needed to settle all of this.. any takers w/ a plane?