atlantic Major Hurricane Joaquin

[summer blizzard]

TD11 has become a Tropical Storm. Model spread in intensity and track is fairly high but it looks as though the system will be close to the east coast in a few days with a potential impact somewhere between Virginia and Newfoundland. With the moisture plume from 99L also tracking up the coast, rain totals where models show impact are excessive at as much as 10 inches of rain.

Visible satellite imagery this morning shows that the cloud pattern

of the tropical cyclone is somewhat better organized than it was 24

hours ago. The low-level center is situated near the northern side

of the main area of deep convection due to northerly shear. The

upper level outflow is well defined over the southern semicircle of

the system, and restricted over the northern part of the

circulation. The current intensity is conservatively set at 45 kt,

which is a little below the latest Dvorak estimates. An Air Force

plane will be investigating Joaquin in a few hours, and should

provide a better estimate of intensity.

Based on the satellite center fixes, the initial motion continues

to be slowly westward, or 260/04 kt. The forecast track in

this advisory attempts to reconcile large model spread with an

overall shift toward the southwest of the previous track through 72

hours. Joaquin is currently in a relatively weak steering pattern,

but a building shortwave ridge in the northwestern Atlantic should

allow the cyclone to drift west and then west-southwestward. This

pushes the storm in the direction of the Bahamas, but the

deterministic and ensemble model consensus still shows a good

likelihood that Joaquin will stop fairly well short of the Bahamas,

and then begin accelerating to either the north or northeast. The

00Z ECMWF made a closer approach to the Bahamas, but it too turns

the storm sharply and accelerates it back into the Atlantic beyond

72 hours. The official forecast is to the left of the previous

forecast through 72 hours, and significantly slower at 4 and 5

days. It should be repeated that the confidence in the track

forecast is very low.

The vertical shear is predicted by the dynamical models to decrease

in 1 to 2 days. This should allow for additional strengthening,

which is reflected in the official forecast. The NHC wind speed

predictions may be conservative, since some of the guidance suggests

that Joaquin could become a hurricane in a few days.

FORECAST POSITIONS AND MAX WINDS

INIT 29/1500Z 26.5N 70.8W 40 KT 45 MPH

12H 30/0000Z 26.4N 71.5W 45 KT 50 MPH

24H 30/1200Z 26.3N 72.4W 45 KT 50 MPH

36H 01/0000Z 26.2N 73.1W 50 KT 60 MPH

48H 01/1200Z 26.1N 73.7W 55 KT 65 MPH

72H 02/1200Z 26.0N 74.0W 60 KT 70 MPH

96H 03/1200Z 29.0N 73.5W 60 KT 70 MPH

120H 04/1200Z 34.0N 72.0W 60 KT 70 MPH

$

Forecaster Pasch

Recon en route today.

Edited September 30, 2015 by Somerset Squall

[summer blizzard]

Recon in now and has found 994mb, 47KT.

[summer blizzard]

Tropical Storm Joaquin is rapidly intensifying... 990mb, 59KT.

 

All 12z models have pretty much busted already. 

Edited September 29, 2015 by summer blizzard

[summer blizzard]

Southern outflow channel is beautiful. Now drawing moisture from the Caribbean.

 

[summer blizzard]

TROPICAL STORM JOAQUIN DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
ISSUED BY THE NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
500 PM EDT TUE SEP 29 2015

The cloud pattern of the storm has become better organized during
the day, with the low level center now embedded inside the northern
edge of the main area of deep convection. Animation of cirrus
motions suggest that upper-level outflow is becoming a little more
prominent over the northern portion of the circulation, and this is
consistent with decreasing northerly shear. Flight-level,
dropsonde, and SFMR wind observations from an Air Force
reconnaissance aircraft indicate that Joaquin has strengthened and
the intensity is now estimated to be 55 kt. With a more favorable
upper-level wind environment now expected to prevail, the official
forecast calls for more strengthening than the previous advisories.
Joaquin is expected to become a hurricane within 24 hours, with
additional intensification likely thereafter. The NHC intensity
forecast is similar to the latest SHIPS model output.

Fixes from the aircraft show a southward component of motion and
the initial motion estimate is now 240/4 kt. Joaquin is currently
south of the southwestern periphery of a weak mid-level ridge. The
ECMWF model shows this ridging to the north of the tropical cyclone
to be more prominent over the next few days than the other dynamical
models. Consequently, the ECMWF takes Joaquin more to the
west and southwest through 72 hours than any of the other available
guidance. Later in the forecast period, there is a significant
divergence in the track guidance. The HWRF and U.K. Met Office
models forecast Joaquin to move over the east coast of the United
States later in the period whereas the ECMWF and GFS keep the system
well offshore. The official forecast lies between these
possibilities and is similar to the latest Florida State University
Superensemble solution.

Interests in the Bahamas should monitor the progress of this storm.
Watches or warnings may be issued for portions of these islands
later this evening.

FORECAST POSITIONS AND MAX WINDS

INIT 29/2100Z 26.0N 71.0W 55 KT 65 MPH
12H 30/0600Z 25.8N 71.6W 60 KT 70 MPH
24H 30/1800Z 25.5N 72.5W 65 KT 75 MPH
36H 01/0600Z 25.1N 73.3W 70 KT 80 MPH
48H 01/1800Z 24.8N 73.9W 75 KT 85 MPH
72H 02/1800Z 25.0N 74.0W 80 KT 90 MPH
96H 03/1800Z 29.0N 73.0W 80 KT 90 MPH
120H 04/1800Z 34.0N 71.0W 75 KT 85 MPH

[Thunder Snow]

Wow she is gaining strength fast

[Sainsbo]

HWRF and GFDL still giving quite extreme solutions, 80+kts slamming into the NY area. Still plenty of time to change, but definitely one to keep an eye on. It looks as if the rapid intensification may have already started.

 

18z predicted intensities:

 

 

The NHC still have the warning cone way out to sea, let's hope that they are right on this one!

[radiohead]

Latest GFS, UKMO, GEM, HWRF, NAVGEM, JMA, GFDL all showing a US east coast landfall. ECM is the only major model showing a very different track out to sea. But since it's the ECM, it certainly cannot be dismissed. Hopefully we get better agreement soon.

[summer blizzard]

Euro is a category 4 fish. GFS and UKMO are category 2 into Virginia/New Jersey.

The other problem with a landfall between the Carolina's and New York is that anything headed west will force easterlies and a storm surge directly into the coast.

[Nouska]

Latest GFS, UKMO, GEM, HWRF, NAVGEM, JMA, GFDL all showing a US east coast landfall. ECM is the only major model showing a very different track out to sea. But since it's the ECM, it certainly cannot be dismissed. Hopefully we get better agreement soon.

 

According to a pro-met, the reasons for the difference ...

 

The biggest differences I continue to see in the Euro vs the other globals are twofold:

1) It nudges Joaquin farther SW during the first couple of days, resulting in a later initial northward motion, and

2) It shows the remnants of Ida (plus whatever junk it's interacting with out there) leaving a larger weakness in the Atlantic ridge near Bermuda, allowing for just enough distance between Joaquin and the cutoff low/neg tilt trough to avoid "capture".

The only bias I have noticed in the ECMWF this year is that it has consistently shown too much retrogression of troughs which have morphed into cutoff lows over the SE US/western Atlantic. Otherwise, I haven't seen anything that sticks out at me.

 

We'll soon see if this is what actually occurs.

 

http://www.storm2k.org/phpbb2/viewtopic.php?p=2481199#p2481199

 

Edit to add the UKMO.

 

Edited September 30, 2015 by Nouska

[radiohead]

Euro is a category 4 fish. GFS and UKMO are category 2 into Virginia/New Jersey.

The other problem with a landfall between the Carolina's and New York is that anything headed west will force easterlies and a storm surge directly into the coast.

 

Full res GFS has it down to 939mb at the surface prior to landfall. HWRF and GFDL are similar in the low to mid 940's.

 

[radiohead]

Recon has found Joaquin to be a 971mb hurricane. That's deeper than even the bullish 06Z GFS which had it around 985mb at this time and eventually bottomed out at 926mb at 84 hours before making landfall in North Carolina ~935mb around 104 hours.

Edited September 30, 2015 by radiohead

[mountain shadow]

Landfall bang on NYC, will change though.

 

http://www.nhc.noaa.gov/refresh/graphics_at1+shtml/084150.shtml?5-daynl

[summer blizzard]

Recon found 969mb, 80mph earlier. Its size and structure are probably limiting the winds from catching up to pressure right now.

[Gray-Wolf]

I just hope it doesn't get to 'feed' on those warmer waters for very long or we will see it bomb over the next 48hrs? From reading the forecast advisories there appears to be multiple forcings on the 'Cane and so figuring whether or not it'll land on the coast is still pretty 'up in the air'?

 

With all the talk of the bad weather already hammering the east coast ,as the 'cane forms and moves up the coast, how 'prepared ' can folk make themselves???

[Nouska]

I just hope it doesn't get to 'feed' on those warmer waters for very long or we will see it bomb over the next 48hrs? From reading the forecast advisories there appears to be multiple forcings on the 'Cane and so figuring whether or not it'll land on the coast is still pretty 'up in the air'?

 

With all the talk of the bad weather already hammering the east coast ,as the 'cane forms and moves up the coast, how 'prepared ' can folk make themselves???

 

A point the NHC address with the very unusual appendix of 'key messages'.

 

KEY MESSAGES:

1. Confidence in the details of the track forecast late in the

period remains low, since the environmental steering currents are

complex and the model guidance is inconsistent. A wide range of

outcomes is possible, from a direct impact of a major hurricane

along the U.S. east coast to a track of Joaquin out to sea away from

the coast. It is therefore way too soon to talk about specific

wind, rain, or surge impacts from Joaquin in the U.S.

2. Should the threat to the U.S. increase, any further adjustments

of the forecast to the west would likely be accompanied by an

increase in the forecast forward speed, with impacts along the coast

occurring sooner than currently forecast. A hurricane watch could

be required for portions of the U.S. coast as early as Thursday

evening.

3. Many areas of the eastern U.S. are currently experiencing heavy

rains and gusty winds associated with a frontal system. This

inclement weather is expected to continue over the next few days,

which could complicate preparations for Joaquin should it head

toward the coast.

 

                                                      * * * * * *

 

Getting the nautilus look and eye just popping now.

 

Edited September 30, 2015 by Nouska

[matty40s]

If the remnants of Ida continue to reform into a tropical storm (likely in 48 hours), will this return as Ida or the K name next on the list??

[summer blizzard]

It's lost the gap between the moisture and the core in its northern half as convection has expanded and it now has a nearly solid ring of extreme convection. I expect the winds will probably respond and NHC make this a category 3 in 72 hours.

[summer blizzard]

[summer blizzard]

[summer blizzard]

Still the Euro to go but if we do get a hit around North Carolina/Virginia then the UKMO will have nailed this at day 6. Tonight's UKMO is identical in pressure and location, 976mb, North Carolina.

[Lauren]

I really hope it doesn't disrupt my flight to Mexico on Monday. They normally fly down the East Coast. #firstworldproblems

[summer blizzard]

I really hope it doesn't disrupt my flight to Mexico on Monday. They normally fly down the East Coast. #firstworldproblems

 

It'll be making landfall on Monday. 

 

They'd probably just head into Canada and then more south west to avoid any bad weather though. I can't imagine it's unusual or would effect flight time that much.

[Sainsbo]

Euro still doesn't want to play nice with the other models. Still showing Joaquim recurving back out to sea..

[Singularity]

An aside I know, but is anyone keeping an eye on that low to the west of Sicily in the Mediterranean? It's taking on the appearance of a 'medicane'.

 

Meanwhile, Joaquin has started to display a neater, clearer eye:

 

 

While we wait to see what it gets up to over the coming day or two, I find myself struggling to comprehend some of the most extreme 7 day totals appearing for the eastern U.S. coasts that may be affected by both this 'cane and a stalled frontal boundary before it; I just read that projected totals are as high as 20 inches which is about 500 mm or two thirds of the average annual rainfall in some parts of southern England, for example. Surely that would be disastrous in itself?