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Belba Grubb II...
Posted: Sun Sep 12, 2010 7:23 am
Igor is not yet annular, but of the storms thus far this season, it
seems the most likely candidate to reach that status. The NHC
currently has it forecast as a Category 4 starting some time tomorrow
and then for the remainder of the current five-day period (through 8
a.m.), which seems a little unusual. Hurricanes at that intensity
usually weaken and intensify with eyewall replacement cycles. This
amateur did notice that Igor formed an eye visible on satellite
imagery fairly early, and that eye has continued, and Igor has a few
annular characteristics already. Maybe the cyclone will go formally
annular (in the NHC's view), maybe it will go into the more usual
cycle, but it seems worth giving a heads-up as cyclones can change
very quickly and I'm very busy and won't be able to watch this as
closely as I did Earl (unless it threatens the East Coast, which at
this moment doesn't seem too likely; Bermuda, though, will have to
watch this only closely). Here are the best viewing and information
links 24/7:

Of note, Hurricane Fabian, which in 2003 hit Bermuda directly with a
roughly 3-hour passage of the eyewall directly over the island, was a
mid-range Category 3 at that time (max winds 120 mph). Bermuda gets
many gales and have strict building codes, and while there were
casualties and lots of damage, there wasn't the devastation that might
have happened in a less prepared landfall area (Katrina in 2005 was
also a Category 3). A stronger storm with the same path would cause
more problems, but it's way too early to tell for sure whether such a
direct hit will happen.

Hopefully, Igor will present us with another spectacular show and very
little to no human suffering. (Earl, by the way, did cause someone's
death up in Nova Scotia.)

"Florida folks, land of perpetual sunshine. Let's get the auction
started before we have a tornado."
-- Groucho Marx, /The Cocoanuts/ (1929)
Belba Grubb...
Posted: Mon Sep 13, 2010 2:31 am
Igor isn't annular, because it has spiral bands (more easily visible
this morning but last night mostly apparent in microwave imagery), and
also its eye is small, more like "typical" intense hurricanes, rather
than the larger-than-normal eye in annulars (per the 2002 Knaff
paper). Watch how the eye shrank yesterday (compare with the knots
reading upper left):

Igor's main microwave page is:

In their discussions, the NHC is mentioning some concern about the
model evolution of the guiding ridge with Igor but they haven't
changed the forecast track yet. Something to keep an eye on, but
right now it looks like Bermuda and possibly Nova Scotia are most
likely to be threatened by this storm.

"Nothing happens until something moves."
-- Albert Einstein
Belba Grubb...
Posted: Wed Sep 15, 2010 5:14 am
Apparently Julia was feeling neglected:

"The Atlantic hurricane season of 2010 kicked into high gear this
morning, with the landfall of Tropical Storm Karl in Mexico, and the
simultaneous presence of two Category 4 hurricanes in the Atlantic,
Igor and Julia. Tropical Storm Karl's formation yesterday marked the
fifth earliest date that an eleventh named storm of the season has
formed. The only years more active this early in the season were 2005,
1995, 1936 and 1933. This morning's unexpected intensification of
Hurricane Julia into a Category 4 storm with 135 mph winds has set a
new record--Julia is now the strongest hurricane on record so far
east. When one considers that earlier this year, Hurricane Earl became
the fourth strongest hurricane so far north, it appears that this
year's record SSTs have significantly expanded the area over which
major hurricanes can exist over the Atlantic. This morning is just the
second time in recorded history that two simultaneous Category 4 or
stronger storms have occurred in the Atlantic. The only other
occurrence was on 06 UTC September 16, 1926..."
-- Jeff Masters, Wunderground blog post, September 15, 2010 at

If the two hurricanes were close to each other right now, there most
likely would be a Fujiwara effect, as they are the same intensity; the
models do bring Julia in close to Igor in a few days, but in the
meantime Igor's shear plus somewhat cooler water are forecast to
severely weaken Julia, while Igor will have only dropped down to a 3
or maybe a strong 2; a dance is much more unlikely then.

Another one-stop model page:
It is set on the Euro (ECMWF) but GFS and NOGAPS are also available
at links in the upper left corner.


"A single lifetime, even though entirely devoted to the sky, would not
be enough for the study of so vast a subject. A time will come when
our descendants will be amazed that we did not know things that are so
plain to them."
-- Seneca, Book 7, first century AD, quoted at

-- From National Hurricane Center Forecast Discussion 29, Hurricane
Igor, September 15, 2010, at
Belba Grubb...
Posted: Wed Sep 15, 2010 3:19 pm
"The Emergency Measures Organisation (EMO) met today and has this
evening urged the Island’s residents to begin hurricane preparations
by securing their properties and stocking up on hurricane supplies as
Hurricane Igor – a very big and intense storm – is expected to hit
Bermuda over the weekend.

"The Island can expect tropical storm force winds sometime around
midnight Saturday and even worse conditions late Sunday around
midnight when the current forecast is for a direct hit. Residents are
advised to take the warnings seriously as the Island has not
experienced such an intense storm since Hurricane Fabian hit Bermuda
in 2003.

"By 3p.m. on Sunday, 50 knot east to south east winds are expected and
winds will continue to increase and reach sustained hurricane force by
6 p.m. Sunday and continue through the night. If the island sustains a
direct hit as is the current forecast, it also means 90-knot sustained
winds with gusts above 115 knots (132mph); coastline areas can expect
storm surges of 5 – 7 feet above normal tide levels; seas inside the
reef are expected to rise 9 – 12 feet and outside the reef, there will
be waves of 20 – 30 feet. The hurricane is also expected to drop as
much as five inches of rain on the Island. "

"The EMO confirmed that Government Ministries, the Bermuda Regiment,
Bermuda Fire & Rescue Service and the Bermuda Police Service are
-- From Emergency Measures Organization Bermuda announcement,
September 15, 2010, at

The good news: Igor may have dropped down to a Category 2 by then
(Fabian was a strong Category 3). The bad: If the current forecast
track verifies, Bermuda will get the northeast quadrant of the storm,
a hurricane's strongest in terms of winds, surge, and tornado

Bermuda Weather Service's tropicals page:

Tip: Not a household name, but it's the most intense tropical cyclone
ever recorded in modern times:
Belba Grubb...
Posted: Thu Sep 16, 2010 1:14 am
Just a Fujiwhara (note alternative spelling) effect note. There is a
terrific online resource at; registration is
free; it covers many aspects of meteorology, and offerings range from
elementary school level to advanced. From their tropical meteorology,
Fujiwhara section (Chapter 10.6), "Binary interactions (large angular
rotation rates) occurred when the tropical cyclone centers were
separated by distances of less than 1300-1400 km, with this critical
separation distance depending on the sizes of the interacting

Based on the locations given in the 5 a.m. forecast discussions from
the NHC, Igor (Category 4 and intensifying) and Julia (Category 2 and
weakening quickly) are some 2141 km apart. The most likely effect
when they get close enough, given the disparity in intensity will be
for Igor to absorb Julia rather than cyclonic rotation, but Igor is
such a strong, "independent" hurricane, it's hard to say for sure what
is going to happen several days down the road. Yesterday, Igor
started an eyewall cycle, but unlike other hurricanes over recent
seasons, it did not weaken; in fact, convection increased a little.
Igor is teaching the meteorologists stuff.

Of note in the 5 a.m. Igor discussion from the NHC:

"A large-scale environment of light shear and warm water is favorable
for the maintenance of an extremely dangerous hurricane for the
next few days. The exact intensity of Igor will be primarily
dictated by eyewall cycles...which are well beyond our forecast
abilities. The majority of the model guidance indicates that slow
weakening is the most likely solution...and the NHC forecast reflect
this. is more important to recognize that all of the
guidance...and the NHC forecast...keeps Igor as a large and
dangerous hurricane for the next several days."

Belba Grubb...
Posted: Thu Sep 16, 2010 3:31 am
Just a note on Karl - it is ramping up pretty quickly now that it's
out in the Bay of Campeche and here's the most recent statement on
It's still a tropical storm but will soon become a Category 1
hurricane and NHC says warnings will likely be needed along portions
of mainland Mexico later today. Here is Mexico's met service page

All this water sloshing around in the tropical Atlantic basin might be
useful on those fires on the West Coast, if we could somehow transport
it there!


PS: It looks to this layman like Igor has completely blown Julia
away ( time
sensitive), but will see what NHC says later this morning.
Belba Grubb...
Posted: Thu Sep 16, 2010 7:03 am
The first Hurricane Hunter flight went into Igor today: Dropsonde
recorded a minimum pressure of 940 mb (estimated pressure had been 934
mb), maximum surface wind found by flight was 110 mph, and the maximum
wind they encountered on the flight out, through the NE quadrant, was
almost 150 mph (130 knots). Meteorologists can derive much
information from all the readings they take, and I do not understand
how they do it, but NHC did upgrade the storm's 11 a.m. intensity from
115 to 120 knots, still a strong Category 4, and those winds in the NE
quadrant are approaching the 156 mph Category 5 range. NASA has been
running a variety of experimental missions into the storm, too; that
information doesn't get displayed publicly, AFAIK.

Julia's still alive and kicking, but drastically weakening. Karl, on
the other hand, may make up to Category 3 status by the time it makes

Belba Grubb...
Posted: Thu Sep 16, 2010 11:25 am
Sorry - Igor is currently forecast to pass Bermuda as a 3, not a 4; it
might even be a strong 2. Fabian was the 4.

Posted: Thu Sep 16, 2010 10:37 pm
I gather the NW sheer will keep him from Florida. I understand this is
subject to change; I'm working on reading and understanding the
forecast dicussons.

On Sep 16, 5:25 pm, Belba Grubb <trungsister... at (no spam)> wrote:
[quote]Sorry - Igor is currently forecast to pass Bermuda as a 3, not a 4; it
might even be a strong 2.  Fabian was the 4.

Belba Grubb...
Posted: Fri Sep 17, 2010 2:16 am
Just a Fujiwhara effect note: Per the locations given for Igor and
Julia at 5 a.m. by the NHC, the two cyclones are 1506 km apart --
about 100 km shy of the "magic zone" of 1300-1400 km, where
interactions happen. One thing I've learned in all this is that
cyclonic rotation is only one possible Fujiwhara interaction. This is
such a complicated situation, though, whatever happens likely isn't
going to be too obvious. Julia likely isn't going to be absorbed, and
while I'd like to see Igor orbit a bit to the east, sparing Bermuda
that northeast quadrant, it's hard to imagine that happening.

Igor is weakening a bit, but still Category 3. Julia is hanging in
there. Karl has bombed, is a 3 now and expected to be a **4** at
landfall (pobre Mexico).

"Have a nice day and Good Morning to you from a nervous Bermuda on
this Friday September 17Th. 2010."
-- A Bermuda correspondent at Storm Carib,
Belba Grubb...
Posted: Fri Sep 17, 2010 5:29 am
As of 11 a.m. Eastern, per the locations given in that NHC discussion,
Igor and Julia were 1370 km apart, or within the Fujiwhara "magic
distance" where an effect can happen ("magic distance" is just my own
term for convenience, BTW, not something in regular use).

NHC also said Julia had moved unexpectedly far to the west but
probably because of the effects of an upper level cyclone to the
south. Gee, I can't figure out why they don't think these two
hurricanes would affect each other:


Just a wee bit of a size discrepancy on that GOES East infrared image
there. (This also shows where nerves are just a tad ragged in Bermuda
right now...if nothing else, it's going to be very noisy there for a
very long time as Igor slowly rolls over the island.)

Yet...if there is *no* effect, then the Fujiwhara theory is
disproved. It seems pretty well established, though, so anybody who's
interested should be able to identify it.

Just looking at that GOES East IR image above, capture is definitely
possible. Then there are two possible results: merging or escape.
It's all about centroids and vortices, and so forth, and too
complicated for me to really get into. But it's worth mentioning, and
this is a good question to bring up, too: did Earl and Fiona get
within 1300-1400 km of each other, and if so, what was the Fujiwhara

Some interesting papers are going to come out of this season,

Oh, and there's a lovely series of new waves coming off Africa, one of
which is already marked by the NHC as an area of interest. There is
still some 40% of the hurricane season left.

Belba Grubb...
Posted: Sun Sep 19, 2010 4:54 am
The good news is that Igor's eyewall has collapsed, and it isn't going
to intensify before the core hits Bermuda; actually, Igor has weakened
tremendously, and is a mid-range Category 1 storm now. Those are
still not fun, and the bad news, at least from this keyboard, is that
Igor seems to have still had a northwestward component in its motion
in microwave imagery, although that's difficult to tell in the latter
images with the eye gone:

This puts Bermuda in the northeast quadrant. However, per reports at
StormCarib, things are not really bad on the island yet, and the power
company there is restoring what power outages there are but telling
everybody that for safety they are going to have to turn it off
tonight: usually, that isn't optional in a hurricane. It will be
interesting to see who flicks the switch, man or nature.

Julia is still a tropical storm and in fact intensified a bit last
night. If I were in meteorology, I would find the changes in both
storms fascinating, but I'm not, and nobody is mentioning them, so I
won't delve into it further. Of note, Igor and Julia are now moving
apart, being 1316 km about 24 hours ago and 1352 km this morning,
using the NHC location data given in the 8 a.m. advisory.

Meanwhile, in an unusually quiet Pacific basin, Typhoon Fanapi made
landfall in Taiwan as a Category 3 and killed 3 people, per Jeff

"Go quietly, Igor, and remember what peace there may be in silence… "
-- Astronaut Doug Wheelock, from space, September 14, 2010, at
Belba Grubb...
Posted: Sun Sep 19, 2010 7:28 am
Bermuda's /Royal Gazette/ put a couple of its reporters in a hotel and
they are doing a live chat online at Lots of
updates from Bermuda, encouragement from the outside world, and my
favorite so far, from Ian: "For those asking earlier in the day, Man
Utd beat Liverpool 3-2. Stay safe."

I love the British.

Anyway, it sounds like the strong winds are coming in now. Smart
money is on the hurricane shutting down the island's power switch,
although just now, 97% of the responders said that they still had
power (some credibility in that, given the expansion of mobile phones
and batteries).

BWS reports the NW jog in Igor's track. They are getting the NE
quadrant, and so are very fortunate that the cyclone weakened so
much. The BWS Web cam is in the East End and the weather director has
been predicting "tornadic winds" there though no tornadoes have been
reported yet, per this article:
The rain bands look like fog on the cam but perhaps a tornado sighting
might be possible there, with persistent viewing

Storm surge up to 5 feet is predicted by BWS.

Belba Grubb...
Posted: Tue Sep 21, 2010 6:16 am
Igor, yes, Category 1 Hurricane Igor, is causing a lot of flooding in
Canada, so just wanted to post again the CHC URL:

Please note also the current special statements:

The current tracking map is interesting. Igor is expected to lose its
warm core and so become a post-tropical storm later today, but not to
weaken much as it passes through the Davis Straits, per the NHC, until
it nears Greenland! The NHC is still tracking it, too:

Otherwise, there are a couple of probable "fish" out in the eastern
Atlantic (one of them TS Lisa), but the current Invest 95L in the
Caribbean is the one worth keeping an eye on:

Per Jeff Masters (and the models), it could become a West Caribbean
hurricane endangering Central America with flooding, or it could
possibly get into the Gulf. There is still a lot of heat potential to
be tapped in the Caribbean; what became Karl didn't touch it.

Hud: "Ocean is big, dude. All I'm saying is a couple of years ago,
they found a fish in Madagascar that they thought been extinct for
Rob: "So what? It's been down there this whole time, and nobody
Hud: "Sure. Maybe it erupted from an ocean trench, you know? Or a
crevasse...I mean, crevice. It's just a theory. I mean, for all we
know, it's from another planet and it flew here."
Marlena: "Like Superman?"
Hud: "Yeah, exactly like... Wait. You know who Superman is?"
Marlena: "Oh, my God. You know who Superman is?"
Hud: "Okay, I'm not..."
Marlena: "I'm, like, feeling something. Are you aware of Garfield?"
-- A little tunnel talk from /Cloverfield/
Belba Grubb...
Posted: Thu Sep 23, 2010 12:10 pm
Tropical Storm Matthew has been declared. There's nothing really
remarkable about this cyclone just yet (although the potential for
flooding from high rainfall amounts and storm surge along the Yucatan,
Honduran, Nicaraguan Caribbeean coast lines over the next several days
may eventually make it infamous), but I was reading Jeff Masters'
update with a summary of Matthew's predicted course and got thinking
of how geologists complain that they can't forecast earthquakes well
because so much of their data source is hidden from them.
Meteorologists do not necessarily have it better just because
everything what they study is out in the open:

"Forecast for TD 15" [he probably posted this just before the NHC
declared it Matthew.]


"The future track and intensity of TD 15 depends critically upon the
storm's interaction with land over the coming days. If TD 15 misses
making landfall in Nicaragua and Honduras, and instead skirts the
north coast of Honduras, the storm is likely to intensify into a
hurricane by Sunday, as indicated in the official NHC forecast.
However, if TD 15 spends significant time over or barely offshore of
Honduras, the storm will likely stay below hurricane strength. TD 15
is being forced just north of due west by a strong ridge of high
pressure. This ridge will keep the storm moving at 15 mph through
Saturday. On Sunday, a trough of low pressure diving southwards over
the Eastern U.S. will weaken the steering currents over the Western
Caribbean and cause TD 15 to slow and turn more to the north. TD 15
will begin a period of slow and erratic movement on Sunday that may
last many days, as the storm wanders in the Western Caribbean and over
Belize, Honduras, and Mexico's Yucatan Peninsula. If the center of TD
15 spends significant time over water, the storm could easily develop
into powerful and dangerous Hurricane Matthew. If the center remains
mostly over land, TD 15 will still generate extremely heavy rains over
Central America, but remain below hurricane strength. By late next
week, the trough of low pressure over the Eastern U.S. may lift out,
allowing a ridge of high pressure to build in and force TD 15
westwards across the Yucatan Peninsula and into the Gulf of Mexico's
Bay of Campeche. Alternatively, the trough of low pressure over the
Eastern U.S. may amplify, drawing TD 15 northwards across Western Cuba
and into Florida. A complicating factor may be the development of a
new tropical depression in the Central Caribbean 6 - 8 days from now,
as predicted by both the GFS and NOGAPS models with their latest 12Z
(8am EDT) runs. The uncertainties in the long-range fate of TD 15 are
high, and depend strongly on slight variations in its track that
determine how much time the storm spends over land...."

-- From Jeff Masters Wunderground blog post at 7:32 p.m. GMT on
September 23, 2010, at

"IF you can keep your head when all about you
Are losing theirs and blaming it on you,
If you can trust yourself when all men doubt you,
But make allowance for their doubting too;
If you can wait and not be tired by waiting...."
-- Kipling, "If" at
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