Sandy forms south of Jamaica; TD 19 forms in middle Atlantic

By: Dr. Jeff Masters , 9:48 PM GMT on October 22, 2012

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The Hurricane Hunters found a band of 40 mph winds on the southeast side of Tropical Depression Eighteen this afternoon, prompting NHC to upgrade the system to Tropical Storm Sandy. Sandy is over very warm waters of 29.5°C, is in a moist environment, and has light wind shear of 5 - 10 knots. These conditions are very favorable for intensification, and Sandy's heavy thunderstorms are steadily organizing into curved spiral bands, as seen on satellite loops.


Figure 1. Late afternoon satellite image of Tropical Storm Sandy.

Forecast for Sandy
Wind shear is forecast to be in the low to moderate range, 5 - 20 knots, through Wednesday afternoon. This should allow continued development of Sandy, and rapid development is possible. The latest SHIPS model forecast is calling for a 52% chance that Sandy's winds will increase by 30 mph over a 24-hour period. The 5 pm EDT NHC Wind Probability Forecast gave a 25% chance that Sandy will be a hurricane by 2 pm EDT Wednesday, when the center should be close to Jamaica. Wind shear will rise to a high 25 - 30 knots by Thursday, which should weaken Sandy. By Friday, Sandy should be in the Central or Eastern Bahamas, and wind shear may increase further, making Sandy more of a hybrid subtropical storm. It is unclear at this point whether or not the trough pulling Sandy to the north will be strong enough to pull the storm all the way out to sea to the northeast; a very complicated steering environment will develop late this week, and it is possible that a narrow ridge of high pressure could build in over Sandy, and force the storm to the northwest, with a potential threat to the Northwestern Bahamas and U.S. East Coast by Saturday, as predicted by the ECMWF model. Sandy is not a threat to be a hurricane at that time, due to very high wind shear. Heavy rains are the main threat from Sandy.

Sandy's place in history
Sandy is the eighteenth named storm of the 2012 Atlantic hurricane season, tying this year with 1969 for seventh busiest Atlantic season since record keeping began in 1851. Here are the busiest Atlantic hurricane seasons on record:

2005 (28 named storms)
1933 (20 named storms, according to a new re-analysis)
1887 (19 named storms)
2010 (19 named storms)
2011 (19 named storms)
1995 (19 named storms)
1969 (18 named storms)
2012 (18 named storms)

There are two weak and short-lived storms from 2012 that stayed far out sea, and would likely have gone unnoticed in the pre-satellite era (before 1960): Tropical Storm Joyce and Tropical Storm Oscar. And while this season has been very busy for total number of named storms, we've had a below-average number of major hurricanes (just Hurricane Michael), and the total destructive power of the 2012 hurricane season as measured by the Accumulated Cyclone Energy (ACE) is only about 20% above average. See our newly-launched Accumulated Cyclone Energy (ACE) page for a storm-by-storm breakdown of this years ACE, plus historical ACE stats for each ocean basin. Thanks go to Angela Fritz for putting this together!


Figure 2. MODIS satellite image of TD 19 taken at 12:30 pm EDT October 22, 2012. Image credit: Navy Research Lab, Monterey.

Tropical Depression Nineteen forms in the middle Atlantic
Tropical Depression Nineteen is here, and appears poised to become Tropical Storm Tony by early Tuesday morning. TD 19 has a modest area of heavy thunderstorms, as seen on visible satellite images, and dry air from the upper-level low pressure system that it formed underneath is slowing development. TD 19 is over warm waters of 28°C, and wind shear is a moderate 10 - 20 knots. This shear is forecast to remain in the moderate range until Wednesday morning, which should allow TD 19 to develop into Tropical Storm Tony over the next day. On Wednesday, TD 19 is expected to encounter high wind shear of 20 - 30 knots, which should prevent further strengthening. TD 19 will not threaten any land areas, and is unlikely to reach hurricane strength.

Jeff Masters

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(NON-TROPICAL MODEL)
00Z NAM INIT 23 OCT hr 084 TILL 84


next up 00z GFS in about 40 to 45 mins from now
Member Since: July 15, 2006 Posts: 174 Comments: 54450
It's like watching a car accident in slow motion. I'll see what's up in the morning.
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Quoting trHUrrIXC5MMX:
NO TONY AT 11 PM...
yep no Tony.Maybe tomorrow morning...TROPICAL DEPRESSION MOVING NORTHWARD OVER THE CENTRAL ATLANTIC... ...NO THREAT TO LAND...
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Quoting Tazmanian:



the update is not even out yet


it was...refresh...refresh
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No change for Sandy
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No changes in strength with Sandy or TD19.
The NHC makes Sandy a hurricane in the Caribbean(80mph) and raised the 120hr intensity to 65mph.
Member Since: March 16, 2012 Posts: 127 Comments: 7950
Quoting trHUrrIXC5MMX:
NO TONY AT 11 PM...



the update is not even out yet
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FORECAST VALID 24/1200Z 16.6N 77.5W
MAX WIND 70 KT...GUSTS 85 KT.
64 KT... 20NE 20SE 10SW 15NW.
50 KT... 40NE 40SE 20SW 30NW.
34 KT... 80NE 80SE 50SW 70NW.
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Looking better, not moving much maybe a drift west.
Member Since: August 18, 2008 Posts: 0 Comments: 3113
NO TONY AT 11 PM...
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Quoting TropicalAnalystwx13:

No Taz, it's actually red. Lol.



oh ok
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(NON-TROPICAL MODEL)
00Z NAM INIT 23 OCT hr 075 TILL 84


Member Since: July 15, 2006 Posts: 174 Comments: 54450
Quoting Tazmanian:



my name is yellow nic too meet you red

No Taz, it's actually red. Lol.

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Quoting TropicalAnalystwx13:
My name is red.

?? ok...
45-50mph this advisory imo.
Member Since: March 16, 2012 Posts: 127 Comments: 7950
Quoting ProgressivePulse:
KOTG, why do you keep posting the same NAM run over and over?
its not the same the last one was hour 66 of the 00z nam for the 23 of oct the next will be hr 75 then last hr 84
Member Since: July 15, 2006 Posts: 174 Comments: 54450
Quoting CaicosRetiredSailor:


Did you see it first?



he seen nothing 1st
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Quoting TropicalAnalystwx13:
My name is red.


Red Forman?
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Quoting TropicalAnalystwx13:
My name is red.



my name is yellow nic too meet you red
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Quoting Grothar:
See the little wave in the lower right corner.



Did you see it first?
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Quoting Grothar:


Uh huh. I'm like the kid who called blob. (Don't tell Taz, he thinks I'm serious when I say that)



you seen nothing 1st
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My name is red.
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By the way...29 days until the end of the world...

for anyone believing on it... don't take it personal
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Quoting KEEPEROFTHEGATE:
did you see somem first again


Uh huh. I'm like the kid who called blob. (Don't tell Taz, he thinks I'm serious when I say that)
Member Since: July 17, 2009 Posts: 71 Comments: 26522
Quoting ProgressivePulse:
KOTG, why do you keep posting the same NAM run over and over?


maybe because no one says anything about it...
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aparantly someone dosn't understand sarcasm
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290. JLPR2
Quoting Slamguitar:


19 looking better, come on Tony!
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KOTG, why do you keep posting the same NAM run over and over?
Member Since: Posts: Comments:
Quoting Grothar:
See the little wave in the lower right corner.

did you see somem first again
Member Since: July 15, 2006 Posts: 174 Comments: 54450
Quoting Thrawst:


Nassau, The Bahamas. I told you this over WU Mail a whileeee ago! Deutsche mind ;)


Es tut mir leid. I hab' vergessen.

Der Alte.
Member Since: July 17, 2009 Posts: 71 Comments: 26522
(NON-TROPICAL MODEL)
00Z NAM INIT 23 OCT hr 066 TILL 84


Member Since: July 15, 2006 Posts: 174 Comments: 54450
See the little wave in the lower right corner.

Member Since: July 17, 2009 Posts: 71 Comments: 26522
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Whoops.
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282. JRRP
Quoting AztecCe:
6 storms in october for an "el nino" year

we are in neutral mode
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Quoting ProgressivePulse:


A. 24/0000Z,0600Z

Current Date/Time = Oct 22nd 22:37Z


If I'm not mistaken, 0z on the 24th is 8pm EDT on the 23rd.
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280. beell
Quoting ProgressivePulse:


A. 24/0000Z,0600Z

Current Date/Time = Oct 22nd 22:37Z


Item C is departure time
C. 23/1945Z
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Quoting GeoffreyWPB:


Bet you one of Nea's pies that they go :)


My UTC clock switched to Eastern Time for some reason. Blah, lol, you win.

Current Date/Time = Oct 23, 02:42Z
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278. JLPR2
Quoting wxchaser97:

What is with the question marks??
I see a RAW T# of 2.8


2.2 2.4 4.0

RAW T# up to 4.0.
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Quoting Grothar:


Where are you?


Nassau, The Bahamas. I told you this over WU Mail a whileeee ago! Deutsche mind ;)
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Quoting AztecCe:
6 storms in october for an "el nino" year



its not a EL nino year it nevere was
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Quoting Thrawst:


Well isn't that convenient for me?


Where are you?
Member Since: July 17, 2009 Posts: 71 Comments: 26522
274. JLPR2
??

Ah, the confusion. XD
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Quoting GeoffreyWPB:
Gro...possible TS Watches/Warnings for south Fl. under the current model runs?


I think the pressure gradient difference alone would cause extremely windy conditions even if Sandy were to stay well off the coast. She looks like she might be a slow mover which would cause severe beach erosion. Even if there were no I would say the possibility is high that a good portion of the coast would have TS watches at least. Looks like it will go right over Jamaica, eastern Cuba and right through the central Bahamas.
Member Since: July 17, 2009 Posts: 71 Comments: 26522
6 storms in october for an "el nino" year
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

??

What is with the question marks??
I see a RAW T# of 2.8
Member Since: March 16, 2012 Posts: 127 Comments: 7950
Quoting ProgressivePulse:


A. 24/0000Z,0600Z

Current Date/Time = Oct 22nd 22:37Z


Bet you one of Nea's pies they go :)
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:
Raw T# for Sandy is up to hurricane intensity.



???
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Quoting 12george1:

??

??
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Quoting GeoffreyWPB:


Recon is going in tomorrow.

Link


A. 24/0000Z,0600Z

Current Date/Time = Oct 22nd 22:37Z
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:

??


quoting you, qouting doppler 22.... ??
Member Since: September 30, 2008 Posts: 0 Comments: 108

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.