Gonzalo

Update, October 24, 3:44 p.m. Pacific: NASA just published a couple of interesting satellite views of Bermuda before Gonzalo…
 
bermuda before

…and after Gonzalo:
 
bermuda after
 


 

Update, October 21, 2014, 11:26 a.m. Pacific: Ex-Gonzalo has hit parts of the UK pretty hard, per the BBC. Two fatalities so far, it is reported, and several injured. Much of the UK is still under a yellow warning:
 

Update, October 18, 10:24 a.m., Pacific: Roads are blocked and there is serious damage across Bermuda, the Royal Gazette reports, but the causeway is undamaged. Fabian did damage it back in 2003. Check out the Gazette’s front page for updated news and images. Thankfully, there were no deaths, last I heard.

Gonzalo is down to a high-end Category 1 and getting pretty ragged looking, per the NHC. It will be leaving the Gulf Stream and encountering strong wind shear, and is expected to transition into an extratropical storm in about a day.

The Canadian Hurricane Centre has ex-Gonzalo passing just offshore of St. Johns around 3 a.m. local time on Sunday:
 
track

The UK Met Office has raised gale warnings for Britain on Tuesday from the storm.

Update, 10/17/2014, 11:57 a.m. Pacific:
 

Hurricane Gonzalo's eye on the Bermuda weather radar loop currently.  BMS

Hurricane Gonzalo’s eye on the Bermuda weather radar loop currently. BWS

000
WTNT43 KNHC 171455
TCDAT3

HURRICANE GONZALO DISCUSSION NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082014
1100 AM AST FRI OCT 17 2014

Gonzalo is under surveillance by a NOAA hurricane hunter plane and
its eye is in the scope of the Bermuda radar. Maximum winds
measured so far by the SFMR on board the plane are 104 kt, and on
this basis the initial intensity is lowered to 110 kt. This slight
weakening is in agreement with the fact that the eye on satellite is
not as distinct as it was 12 hours ago, and the Dvorak t-numbers are
decreasing.

Although it appears that a gradual weakening has begun, Gonzalo is
expected to be a dangerous Category 3 hurricane as it
moves near or over Bermuda later today. After that time, increasing
shear and cooler waters along the track of the hurricane should
result in a faster weakening. Gonzalo is likely to transition
into a post-tropical cyclone by 36 to 48 hours as it moves near or
south of Newfoundland, and become fully extratropical thereafter.

Radar and aircraft fixes indicate that the hurricane is moving
toward the north-northeast or 025 degrees at 14 kt. Gonzalo should
accelerate and turn to the northeast once it becomes completely
embedded within the faster southwesterly mid-latitude flow ahead of
a deepening trough along the east coast of the United States. The
guidance remains tightly clustered, and
There is no reason to deviate much from the previous NHC forecast
which shows a powerful hurricane passing near or over Bermuda
later today, and a post-tropical cyclone passing south of
Newfoundland in about 36 to 48 hours.

Significant coastal flooding on Bermuda is likely if Gonzalo
continues on the current NHC forecast track. Although specific
amounts cannot be forecast for Gonzalo, Hurricane Fabian produced an
estimated 10 feet of storm surge when it moved over Bermuda as a
major hurricane in 2003, and similar values could occur with
Gonzalo.

FORECAST POSITIONS AND MAX WINDS

INIT 17/1500Z 30.4N 66.1W 110 KT 125 MPH
12H 18/0000Z 32.6N 64.9W 100 KT 115 MPH
24H 18/1200Z 36.3N 62.5W 90 KT 105 MPH
36H 19/0000Z 41.5N 58.0W 80 KT 90 MPH
48H 19/1200Z 48.0N 49.0W 70 KT 80 MPH…POST-TROP/EXTRATROP
72H 20/1200Z 55.0N 25.0W 45 KT 50 MPH…POST-TROP/EXTRATROP
96H 21/1200Z…POST-TROP/EXTRATROP

$$
Forecaster Avila

The Royal Gazette reports that the storm is about 100 miles away now. This is actually the center of the hurricane, and since hurricane winds extend out 60 miles, conditions on Bermuda have probably already deteriorated. Over 2,000 are already out of power, it’s said.

Gonzalo is a big hurricane and they are expecting, per the last report I read, some 30 hours of tropical cyclone conditions.

I know from personal experience how incredibly loud these things are. My house was sheltered from the worst of the wind when Katrina went over as a low end Category 1 hurricane/high end tropical storm in 2005, but still the worst thing was all the racket. The wind punches things (meteorologists refer to this as gusts, but in real life it looks and sounds like punches). Thirty hours of that racket will be an endurance trial on top of all the physical stresses and dangers.
 

That little pink thing is Bermuda.  Hey, buddy - pick on something your own size!

That little pink thing is Bermuda. Hey, buddy – pick on something your own size!

 


 

Update, 10/16/2014, 1 p.m. Pacific: Hurricane Gonzalo is a high-end category 4 now, packing winds of 145 mph per the latest NHC discussion. In 24 hours, or about when Gonzalo probably will be rolling right over the island, the NHC has it still at top-end Category 3/low-level Category 4…and it appears likely that Bermuda will be in the most dangerous part of the storm – the northeast quadrant – even if the center of the cyclone misses them.
 

Sigh. This will be just as bad, if not worse, than Fabian. The good news is that Bermuda has very strict building codes, as they also get a lot of powerful winter gales. As in Fabian, most of the buildings will probably do quite well, but the infrastructure and anything that can’t be secured is going to take a terrible beating.

Here’s the Royal Gazette website. They did a superb job of coverage for Fabian and no doubt will for Gonzalo, too. Good luck, Bermuda!

Of note, Jeff Masters notes that intensification has probably halted:

After weakening briefly on Wednesday due to an eyewall replacement cycle, when the eye shrank to a minuscule 5 miles in diameter and the inner eyewall collapsed, Gonzalo successfully consolidated its new 20-mile diameter outer eyewall into an unbroken ring overnight. This allowed the hurricane to intensify from a Category 3 hurricane with 125 mph winds into a Category 4 hurricane with 145 mph winds overnight. That intensification process has now halted, as documented by three passes through the eye between 7 – 10:30 am EDT Thursday morning by a NOAA hurricane hunter aircraft. The plane found that the pressure had stabilized at 940 – 943 mb, a gap had opened in the southern eyewall, and a new concentric eyewall with a diameter of 40 miles had begun to form around an inner 17-mile diameter eyewall–all signs that intensification has halted.

Still, that tiny eye looks mean – Wilma had a tiny eye, too, at its greatest intensity.
 
gonzalo
 
Here is the morphed microwave imagery of Gonzalo over the past 24 hours. There is a bit of what I’m guessing is artifact in the upper right at one point, but overall it shows one beautiful, scary tropical cyclone – note the central symmetry at the end of the run even though the eyewall appears open:
 


 
 


 

Update, 10/15/2014, 10:43 a.m. Pacific: Gonzalo is now a Category 4 hurricane, per the NHC.
 
vis0

2:31 p
Forecast positions and wind speeds listed in the current discussion (I bolded the estimated times of passage near Bermuda and Canada):

INIT 15/1500Z 23.5N 68.0W 115 KT 130 MPH
12H 16/0000Z 24.6N 68.7W 115 KT 130 MPH
24H 16/1200Z 26.3N 68.9W 115 KT 130 MPH
36H 17/0000Z 28.6N 68.0W 110 KT 125 MPH
48H 17/1200Z 31.6N 66.2W 105 KT 120 MPH
72H 18/1200Z 40.6N 60.8W 90 KT 105 MPH
96H 19/1200Z 50.5N 46.0W 65 KT 75 MPH…POST-TROP/EXTRATROP
120H 20/1200Z 54.0N 24.0W 50 KT 60 MPH…POST-TROP/EXTRATROP

$$
Forecaster Cangialosi

Hurricane Gonzalo is currently expected to pass Bermuda 45 nautical miles to the west-northwest around midday Friday. Of note, per the current NHC advisory, the cyclone’s hurricane-force winds only extend 35 miles from the center; tropical-storm-force winds extend out 115 miles.

This morning, the Canadian Hurricane Centre is now predicting ex-Gonzalo may miss Nova Scotia and pass the island to the southeast on Sunday night, but there is almost a 400-mile cone of uncertainty this far in advance of the actual event.
 
track

The CHC says they will start issuing daily bulletins this afternoon.

Morphed microwave imagery of the last 12 hours, though jumpy, shows, to this amateur’s eyes, something like an eyewall replacement cycle. These do decrease a hurricane’s intensity a bit, but it may be over (the red and orange are reappearing at the end of this run):
 

I’m really not sure what’s going on there with Gonzalo’s eye, but it may have to do with what the NHC mentioned in the current forecast discussion:

Given the evidence of concentric eyewalls [these are not seen in the above MIMIC animation], and with the inner eyewall already about as small as it can get, the current period of intensification could be about over. The hurricane will likely fluctuate in strength while the environmental conditions remain favorable during the next day or two.

Meanwhile, in Bermuda, they’re reportedly telling people to prepare for another Fabian. Hopefully Gonzalo’s eyewall won’t pass over the island as Category 3 Fabian’s did in 2003.

Hopefully not…

 


 

Update, 10/14/2014, 1:44 p.m. Pacific: Gonzalo is rapidly intensifying, per the NHC’s latest discussion – the pressure dropped 2 mB while the Hurricane Hunter craft was in the storm!

000
WTNT43 KNHC 142041
TCDAT3

HURRICANE GONZALO DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082014
500 PM AST TUE OCT 14 2014

Data from an Air Force Reserve Hurricane Hunter aircraft earlier
today indicated flight-level and SFMR wind data that were just below
the threshold of a major hurricane. On the last flight leg, the
aircraft measured a central pressure of 971 mb, which was down 2 mb
from what was measured at the start of the mission. The eye had also
contracted from a 20 nmi diameter down to about 16 nmi on the last
report. Recent data from the NOAA Doppler radar in San Juan indicate
that the eye has contracted to about 15 nmi at an altitude of about
36,000 ft since the aircraft departed a few hours ago, signifying
that the eye diameter is likely smaller at lower altitudes. In
addition, satellite imagery indicates that the eye has cleared out
and warmed while cloud tops have cooled significantly in the
surrounding eyewall. Based on the trends noted in the radar and
satellite data, the intensity has been increased to 100 kt, which is
supported by a UW-CIMSS ADT value of T5.4/100 kt.

Gonzalo continues to move steadily northwestward with a motion of
320/11 kt. The NHC model guidance is tightly packed and remains is
in excellent agreement on Gonzalo moving steadily northwestward
around the periphery of a deep-layer ridge located to its north
during the next 36 hours or so. By 48 hours, a deep mid-tropospheric
trough and cold front are expected to move eastward across the
Bahamas and weaken the western portion of the ridge. This should
allow the cyclone to turn slowly northward, and then accelerate
northeastward by 72 hours ahead of the aforementioned trough and
front, with the hurricane potentially threatening Bermuda on Day 3.
Gonzalo is expected to merge with the cold front or become
extratropical by 120 hours. The new track forecast is just an update
of the previous advisory track, and lies close to a blend of the
GFEX and TVCA consensus models.

With the eye of Gonzalo having contracted and become more distinct
in satellite, radar, and recon wind data, the system appears primed
for intensification into a category 4 hurricane later tonight or
on Wednesday. Sea-surface temperatures ahead of the cyclone are
sufficiently warm enough at 28C-28.5C to support a category 4
hurricane through at least the next 36 hours. The global models
continue to indicate that the best vertical shear conditions and 200
mb upper-level outflow pattern are expected to occur on Wednesday
and continue into Thursday morning. Afterwards, eyewall cycles and
possible cold upwelling beneath the hurricane are likely to cause
some fluctuations in the intensity. By 72 hours, increasing vertical
wind shear ahead of the aforementioned deep trough is expected to
induce weakening. By 120 hours, Gonzalo will be over sub-20C SSTs in
the North Atlantic and experiencing vertical shear of 50-60 kt,
which should result in the cyclone becoming an extratropical low.
The NHC intensity forecast is similar to the previous advisory and
remains above all of the available intensity guidance.

FORECAST POSITIONS AND MAX WINDS

INIT 14/2100Z 21.2N 66.0W 100 KT 115 MPH
12H 15/0600Z 22.5N 67.1W 110 KT 125 MPH
24H 15/1800Z 24.0N 68.2W 115 KT 130 MPH
36H 16/0600Z 25.4N 68.7W 120 KT 140 MPH
48H 16/1800Z 27.2N 68.3W 110 KT 125 MPH
72H 17/1800Z 32.0N 65.6W 100 KT 115 MPH
96H 18/1800Z 39.9N 60.4W 85 KT 100 MPH
120H 19/1800Z 49.0N 50.0W 65 KT 75 MPH…POST-TROP/EXTRATROP

$$
Forecaster Stewart

Bermuda’s Royal Gazette reports that conditions there are expected to deteriorate Thursday night, with seas reaching 30 feet in addition to hurricane winds.

A look at the North Atlantic satellite imagery shows that the northern air circulation mentioned in the previous update here has indeed improved. No wonder it’s bombing!
 

Gonzalo is big, beautiful, deadly...and probably a major hurricane right now.

Gonzalo is big, beautiful, deadly…and probably a major hurricane right now.

 


 

Update, 10/14/2014, 10:27 a.m. Pacific: Hurricane Gonzalo’s eye was affected by shear, which is never good for a tropical cyclone. However, the NHC says that:

Recent radar and satellite data indicate that the eye of Gonzalo has been clearing out and gradually becoming better defined with a diameter of about 20 nmi. Once the eyewall stabilizes again, intensification will likely resume, and in fact the reconnaissance aircraft a few moments ago observed an SFMR wind of 99 kt that suggests this intensification is beginning.

You can just see the eye poking out on the current satellite view, and on the North Atlantic view it’s clear that Gonzalo’s southern air circulation is drawing on the entire Caribbean:
 

Gonzalo:  Current visible satellite view (left) and North Atlantic visible satellite view (right)

Gonzalo: Current visible satellite view (left) and North Atlantic visible satellite view (right)

If shear wasn’t interfering with the hurricane’s northern air circulation, and if Fay hadn’t recently come through here and cooled off the surface waters a bit, this amateur thinks that Gonzalo would immediately bomb out into a Category 5. For some reason, I keep thinking “Ivan” this morning – don’t know why. As it is, the shear is predicted to relax enough on Wednesday and early Thursday for the storm to max out, the NHC believes, at a Category 4.

That will be about a day before it reaches Bermuda, but it’s still predicted to be a Category 3 when it reaches the island’s vicinity. The Bermuda Weather Service is currently predicting Gonzalo to pass by 87 nautical miles to the southwest of Bermuda around noon, local time, on Friday.

Besides Bermuda, the only other landfall expected for this dangerous cyclone will be in Canada after it has undergone extratropical transition. The Canadian Hurricane Centre expects it to hit St. John’s on Sunday evening evening, packing 80-mph winds:
 
track

 


 

Update, 10/13/2014, 3:14 p.m. Pacific: Gonzalo is now a hurricane. Per the NHC, the latest model runs show it reaching Bermuda as a high-end category 2 or possibly a low-end category 3, per forecast wind speeds, late Friday or early Saturday:

000
WTNT43 KNHC 132056
TCDAT3

HURRICANE GONZALO DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082014
500 PM AST MON OCT 13 2014

Another Air Force Reserve reconnaissance aircraft investigating
Gonzalo this afternoon recently found 700-mb maximum flight-level
winds of 77 kt along with believable SFMR surface winds of 62-67 kt
in the northeastern quadrant, plus a central pressure of 984 mb.
Based on these data, the intensity has been increased to 65 kt,
making Gonzalo the sixth hurricane of the 2014 Atlantic hurricane
season. Note that some higher SFMR winds were observed, but these
were believed to be contaminated by shallow-water shoaling.

The initial motion estimate is 305/10 kt. The center of Gonzalo has
been developing northward on the Guadeloupe radar while the entire
circulation has been moving west-northwestward. The result is now
a northwestward motion, which is expected to continue for the next
36 hours or so. After that time, Gonzalo is forecast to gradually
turn northward as a break in the subtropical to its north develops
by 48-72 hours. On days 4 and 5, the hurricane is forecast to
accelerate to the northeast as the southwesterly flow ahead of
fast-moving deep-layer trough and associated cold front that is
currently located over the south-central United States. The models
are in better agreement on this track scenario with only a minor
eastward shift noted through 36 hours. After that, however, the
models have made a significant westward shift and now bring Gonzalo
very close to Bermuda in the 96-120 hour time period. The official
forecast track lies close to a blend of the GFEX and TVCN consensus
models through 48 hours, and is a little to the right of the
consensus models at 72-120 hours.

Both the radar and satellite presentations of Gonzalo continue to
improve, with a 20 n mi diameter eye noted in the radar data since
about 1400-1500 UTC. Gonzalo has been strengthening at a rate of
20-25 kt since this time yesterday. Given that current environmental
and oceanic conditions are expected to remain essentially unchanged
for the next 48 hours, a similar rate of strengthening is forecast
during that time, with Gonzalo forecast to become a major hurricane
by 48 hours. After that, gradually increasing southwesterly vertical
wind shear ahead of the aforementioned deep-layer trough is expected
to induce gradual weakening. The NHC intensity forecast remains
above the intensity consensus models, and closely follows the SHIPS
intensity model.

Although hurricane conditions are not currently expected in the U.S.
Virgin Islands, only a slight deviation to the left of the forecast
track, or a more rapid strengthening of the storm, would result in
the need to extend the hurricane warning into those areas. Interests
in the hurricane watch area are reminded that the watch means that
hurricane conditions are possible, and in this case within the
next 12-18 hours.

FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 17.9N 62.9W 65 KT 75 MPH
12H 14/0600Z 18.8N 64.1W 70 KT 80 MPH
24H 14/1800Z 20.5N 65.7W 80 KT 90 MPH
36H 15/0600Z 22.2N 67.1W 90 KT 105 MPH
48H 15/1800Z 23.8N 68.2W 100 KT 115 MPH
72H 16/1800Z 26.3N 68.5W 100 KT 115 MPH
96H 17/1800Z 30.0N 66.4W 95 KT 110 MPH
120H 18/1800Z 35.0N 62.8W 90 KT 105 MPH

$$
Forecaster Stewart

 


 
Original post:
 

Miss one day, and the Atlantic springs a tropical cyclone on you!

Yesterday afternoon, a Hurricane Hunter plane found tropical-storm-strength winds in that former tropical wave we had been following: Tropical Storm Gonzalo was documented.

five day cone

This morning, the National Hurricane Center says it expects slow strengthening of Gonzalo into a hurricane over the next 96 hours. Hurricane warnings are flying in the British Virgin Islands.

The GFS shows an intense hurricane rolling over Bermuda this coming weekend, but the current NHC forecast discussion says that after 96 hours Gonzalo will be affected by strong wind shear and begin to weaken. Bermuda has just gotten a nasty knock from Tropical Storm Fay, so I hope Gonzalo does weaken by Saturday.
 
Gonzalo appears to be wrapping up nicely on the current satellite view. Despite its appearance, reports at Storm Carib from the Lesser Antilles are reassuring thus far.
 
gonzalo



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