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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Quoting KoritheMan:


Wasn't that cyclonebuster's idea? He called them "tunnels", I believe.


Yes yes! I couldn't remember the details!
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Quoting KoritheMan:


That's what I'm gonna do.

Night all.
KOOL. NIGHT KORI
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Quoting HadesGodWyvern:
India Meteorological Department
Tropical Cyclone Advisory #1
DEPRESSION ARB01-2012
11:30 AM IST October 23 2012
=====================================

SUBJECT: Depression Over Southeast Arabian Sea.

At 6:00 AM UTC. Latest satellite imagery indicates that the low pressure area over southeast Arabian Sea moved west northwestward and concentrated into a depression. Depression ARB01-2012 lays near 11.0N 65.0E or about 800 km west of Amini Divi, India and 1200 km east southeast of Socotra Island, Yemen. The system is likely to intensify further and move west northwestward towards Somalis and Yemen coast during the next 72 hours.

According to satellite imagery, the Dvorak intensity of the system is T1.5. The lowest cloud top temperature is about -70C. Associated broken moderate to intense convection is seen over the Arabian Sea between 9.0N to 16.5N and 60.0E to 70.0E.

3 minute sustained winds near the center is 25 knots with gusts of 35 knots. The central pressure of the system is 1006 hPa. The state of the sea is rough to very rough around the center.

Considering the environmental features, the Madden Julian Oscillation Index currently lies over phase 1 with amplitude >1. As per statistical and numerical weather prediction model predictions, it is expected to move to Phase 2 during next 3 days. Hence it is favorable for further intensification. The sea surface temperature is about 29-30C. Over north Bay of Bengal. The ocean thermal energy is 80-100 kj/cm2 around the system center. It decreases towards Somalia and Yemen coasts. The upper tropospheric ridge lies along 15.0 N and hence lies to the north of the system center. The low level convergence has increased during past 12 hrs as well as upper level divergence and lower level relative vorticity. The vertical wind Shear between 200 and 850 HPA levels is low to moderate (10-20 knots) around system center. There is no change in wind shear during past 24 Hrs.

NOT SURPRISED AT ALL BECAUSE SOME OF THE MJO IS IN THE INDIAN OCEAN
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Quoting KoritheMan:


I left it in the restroom at work. Dad did that once too, back when he worked at Walmart. Runs in the family I guess. >.>

Unfortunately, my plan doesn't expire until March, and I don't have enough money to get on a new one, so I suppose I'll have to settle for a cheap phone in the meantime. Limited texting is better than none at all, ha.
WOW MY MAN I FEEL DA PAIN. I LEFT MY OLD FONE ON TOP OF MY FRIENDS CAR AND FORGOT IT THERE AND NEVER FOUND IT. I MISS DAT FONE T0O. BUT GET U A TRACFONE FROM WALMART
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Quoting bigwes6844:
WOW THATS KRAZY MY MAN. GET U A TRACFONE FROM WALMART KORI


That's what I'm gonna do.

Night all.
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511. HadesGodWyvern (Mod)
Quoting Slamguitar:


Is that this one?



yes, that is the depression marked by Japan Meteorological Agency.
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Quoting KoritheMan:


I left it in the restroom at work. Dad did that once too, back when he worked at Walmart. Runs in the family I guess. >.>

Unfortunately, my plan doesn't expire until March, and I don't have enough money to get on a new one, so I suppose I'll have to settle for a cheap phone in the meantime. Limited texting is better than none at all, ha.
WOW THATS KRAZY MY MAN. GET U A TRACFONE FROM WALMART KORI
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509. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisory #1
DEPRESSION ARB01-2012
11:30 AM IST October 23 2012
=====================================

SUBJECT: Depression Over Southeast Arabian Sea.

At 6:00 AM UTC. Latest satellite imagery indicates that the low pressure area over southeast Arabian Sea moved west northwestward and concentrated into a depression. Depression ARB01-2012 lays near 11.0N 65.0E or about 800 km west of Amini Divi, India and 1200 km east southeast of Socotra Island, Yemen. The system is likely to intensify further and move west northwestward towards Somalis and Yemen coast during the next 72 hours.

According to satellite imagery, the Dvorak intensity of the system is T1.5. The lowest cloud top temperature is about -70C. Associated broken moderate to intense convection is seen over the Arabian Sea between 9.0N to 16.5N and 60.0E to 70.0E.

3 minute sustained winds near the center is 25 knots with gusts of 35 knots. The central pressure of the system is 1006 hPa. The state of the sea is rough to very rough around the center.

Considering the environmental features, the Madden Julian Oscillation Index currently lies over phase 1 with amplitude >1. As per statistical and numerical weather prediction model predictions, it is expected to move to Phase 2 during next 3 days. Hence it is favorable for further intensification. The sea surface temperature is about 29-30C. Over north Bay of Bengal. The ocean thermal energy is 80-100 kj/cm2 around the system center. It decreases towards Somalia and Yemen coasts. The upper tropospheric ridge lies along 15.0 N and hence lies to the north of the system center. The low level convergence has increased during past 12 hrs as well as upper level divergence and lower level relative vorticity. The vertical wind Shear between 200 and 850 HPA levels is low to moderate (10-20 knots) around system center. There is no change in wind shear during past 24 Hrs.
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EASTERN SIDE OF SANDY ON THE LAST COUPLE OF FRAMES IS REALLY INSTENSFYING BIG TIME. JAMAICA WATCH THIS STORM CAREFULLY
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Quoting Levi32:
Look at how the upper trough in the eastern GOM takes on a negative tilt in a few days. This may look like a very sheared situation for Sandy, but it is in fact one of the best intensification schemes you can get in October/November, with the ability for the NW quadrant of the storm to become quite ferocious under the divergence aloft. Convection will likely cover the center well in this setup, with dry air wrapping around the southern side. The orientation of the trough also opens the possibility for Sandy to track a bit farther west once north of the Bahamas than the GFS currently shows her doing.

I agree that the environment over the next few days will be quite favorable. However, you appear to be referring to the longer range (the image you posted is for Friday). By this time, I believe conditions will no longer be favorable for intensification. Sure the divergence is there, but I refuse to believe 40 knots of shear is one of the "best intensification schemes", even if this is October. Beyond Friday, though models forecast deepening of the low, they also show it acquiring subtropical characteristics...in other words the shear/divergence will ultimately kill the tropical characteristics of the storm.

Maybe the actual upper level set up will evolve differently, but from that model run, I disagree. The true "best conditions" for Sandy lie in the Caribbean over the next couple days, not over the Bahamas in 3 to 4 days.
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Quoting bigwes6844:
HOW U DID DAT? AND I DID TEXT U LAST WEEK TOO.


I left it in the restroom at work. Dad did that once too, back when he worked at Walmart. Runs in the family I guess. >.>

Unfortunately, my plan doesn't expire until March, and I don't have enough money to get on a new one, so I suppose I'll have to settle for a cheap phone in the meantime. Limited texting is better than none at all, ha.
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TD19 still holding its own.

Member Since: July 2, 2011 Posts: 0 Comments: 1183
Quoting KoritheMan:
Hey Wes, I hope you haven't tried texting me lately. I lost my phone at work. Gonna have to get a new one.
HOW U DID DAT? AND I DID TEXT U LAST WEEK TOO.
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SANDY IS GETTING BETTER ORGANIZED AND SHES SHOWING GREENS IN THE FUNKTOP.
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Hey Wes, I hope you haven't tried texting me lately. I lost my phone at work. Gonna have to get a new one.
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ON TOP OF THAT MR MJO CAME BACK RIGHT ON TIME!">
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SANDY SHOULD BE UP TO 60 MPH AT 5 EDT. RI IS HAPPENING
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Quoting Slamguitar:


Lol, good, take over for me! I have a MET exam tomorrow but I can't seem to take my eyes away from Sandy and 19L.
WELL ILL TRY TO HOLD IT DOWN OVERNIGHT TONIGHT SINCE WERE IN OUR SECOND HURRICANE SEASON PEEK
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Quoting bigwes6844:
good morning blog im finally back on the late night shift


Lol, good, take over for me! I have a MET exam tomorrow but I can't seem to take my eyes away from Sandy and 19L.
Member Since: July 2, 2011 Posts: 0 Comments: 1183
good morning blog im finally back on the late night shift
lets see jet fuel plus lightning fuel equals ROCKET FUEL!
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Quoting HadesGodWyvern:
Japan Meteorological Agency
Tropical Cyclone Advisory #11
TROPICAL DEPRESSION 25
15:00 PM JST October 23 2012
====================================

SUBJECT: Tropical Depression In Sea East Of Mindanao

At 6:00 AM UTC, Tropical Depression (1000 hPa) located at 8.0N 128.9E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving west at 12 knots.

Dvorak Intensity: T2.0

Forecast and Intensity
========================

24 HRS: 9.6N 126.3E - 35 knots (CAT 1/Tropical Storm) Sea East of Mindanao


Is that this one?

Member Since: July 2, 2011 Posts: 0 Comments: 1183
495. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #11
TROPICAL DEPRESSION 25
15:00 PM JST October 23 2012
====================================

SUBJECT: Tropical Depression In Sea East Of Mindanao

At 6:00 AM UTC, Tropical Depression (1000 hPa) located at 8.0N 128.9E has 10 minute sustained winds of 30 knots with gusts of 45 knots. The depression is reported as moving west at 12 knots.

Dvorak Intensity: T2.0

Forecast and Intensity
========================

24 HRS: 9.6N 126.3E - 35 knots (CAT 1/Tropical Storm) Sea East of Mindanao
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Sandy is really consolidating in these early morning hours.

Member Since: July 2, 2011 Posts: 0 Comments: 1183
Quoting evilpenguinshan:
huh. I was in the right place, but somehow couldnt find my way here. thx.




2.5? really?

and this is 2.3? i'm no expert, but...pshaw.






Maybe I'm just stupid, but that site always seemed difficult to navigate to me. That or I'm just too lazy to actually look around. >.>
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Quoting Levi32:


Extremely.


I know the feeling. In MET school myself. O_o
Member Since: July 2, 2011 Posts: 0 Comments: 1183
Quoting KoritheMan:


School keeping you busy?


Extremely.
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Quoting Levi32:


I'm still forming my opinion. I don't have as much time in the day as I used to to analyze everything, so I've been a bit slow coming up with an idea. Tomorrow morning I should have a post/video out with an actual forecast.


School keeping you busy?
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Quoting psuweathernewbie1:
Whats up Levi, great to have you here at the blog. So what are your thoughts with this whole scenario shown on the 00z EURO, of a storm tracking up the East Coast of the US?


I'm still forming my opinion. I don't have as much time in the day as I used to to analyze everything, so I've been a bit slow coming up with an idea. Tomorrow morning I should have a post/video out with an actual forecast.
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Quoting psuweathernewbie1:
Whats up Levi, great to have you here at the blog. So what are your thoughts with this whole scenario shown on the 00z EURO, of a storm tracking up the East Coast of the US?


A.K.A. Nor'Sandy.
Member Since: July 2, 2011 Posts: 0 Comments: 1183
Whats up Levi, great to have you here at the blog. So what are your thoughts with this whole scenario shown on the 00z EURO, of a storm tracking up the East Coast of the US?
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Levi, we all miss you. =D
Member Since: July 2, 2011 Posts: 0 Comments: 1183
Quoting Levi32:
Look at how the upper trough in the eastern GOM takes on a negative tilt in a few days. This may look like a very sheared situation for Sandy, but it is in fact one of the best intensification schemes you can get in October/November, with the ability for the NW quadrant of the storm to become quite ferocious under the divergence aloft. Convection will likely cover the center well in this setup, with dry air wrapping around the southern side. The orientation of the trough also opens the possibility for Sandy to track a bit farther west once north of the Bahamas than the GFS currently shows her doing.



Agreed.
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The NWrn part of Sandy is still suffering from drier air, as convection overnight collapsed, but now is trying to fill in again, perhaps why the process is slow at this current time.
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Another late night blog update.
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Look at how the upper trough in the eastern GOM takes on a negative tilt in a few days. This may look like a very sheared situation for Sandy, but it is in fact one of the best intensification schemes you can get in October/November, with the ability for the NW quadrant of the storm to become quite ferocious under the divergence aloft. Convection will likely cover the center well in this setup, with dry air wrapping around the southern side. The orientation of the trough also opens the possibility for Sandy to track a bit farther west once north of the Bahamas than the GFS currently shows her doing.

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In a year with one major Atlantic tropical cyclone...

One storm stands out as the challenger.

Her name is...

SANDY!!!

(To be read in that movie preview voice or something like that)

I should just go to sleep...
Member Since: July 2, 2011 Posts: 0 Comments: 1183
huh. I was in the right place, but somehow couldnt find my way here. thx.




2.5? really?

and this is 2.3? i'm no expert, but...pshaw.



Quoting KoritheMan:




Link

Link

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Quoting psuweathernewbie1:
Sandy has a chance to become the strongest tropical cyclone of the season.


Not really saying much, lol.
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Sandy has a chance to become the strongest tropical cyclone of the season.
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Quoting evilpenguinshan:
any idea where to find recent dvorak estimates? the most recent one i can find from UW is about 3 hours old, showing T2.5 - she is clearly past that.




Link

Link
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fresh (ish) ASCAT
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any idea where to find recent dvorak estimates? the most recent one i can find from UW is about 3 hours old, showing T2.5 - she is clearly past that.

Quoting KoritheMan:

I think she's already doing it.
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Quoting evilpenguinshan:
BULLETIN
TROPICAL STORM SANDY INTERMEDIATE ADVISORY NUMBER 3A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012
200 AM EDT TUE OCT 23 2012

...SANDY EXPECTED TO STRENGTHEN AS IT BEGINS MOVING NORTHWARD
TODAY...


SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...12.9N 78.7W
ABOUT 375 MI...605 KM SSW OF KINGSTON JAMAICA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES





Sandy looking really good...can she build a core tonight?
I think she's already doing it.
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BULLETIN
TROPICAL STORM SANDY INTERMEDIATE ADVISORY NUMBER 3A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182012
200 AM EDT TUE OCT 23 2012

...SANDY EXPECTED TO STRENGTHEN AS IT BEGINS MOVING NORTHWARD
TODAY...


SUMMARY OF 200 AM EDT...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...12.9N 78.7W
ABOUT 375 MI...605 KM SSW OF KINGSTON JAMAICA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...STATIONARY
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES





Sandy looking really good...can she build a core tonight?
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Quoting 7544:


agree but would a stronger sandy pull more northward before turning ne ? tia
As long as it doesn't get too strong (sub 950 mb), then yes, it's very possible. But there is an amplifying weakness over the western Atlantic above 400 mb.
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471. 7544
Quoting KoritheMan:

The environment is highly conducive, and if Wilma can do it in 24 hours, so can Sandy.


agree but would a stronger sandy pull more northward before turning ne ? tia
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Quoting TomTaylor:
Certainly possible, for now I'm thinking it will peak as a strong cat 1, though I won't be surprised to see a cat 2 peak. Just not feeling cat 3, but maybe Sandy will teach me a lesson.
The environment is highly conducive, and if Wilma can do it in 24 hours, so can Sandy.
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Quoting KoritheMan:

I think she could become a major hurricane. Right now I have her at 80 kt by the time she reaches Jamaica, but I anticipate that she could get a little stronger.
Certainly possible, for now I'm thinking it will peak as a strong cat 1, though I won't be surprised to see a cat 2 peak. Just not feeling cat 3, but maybe Sandy will teach me a lesson.
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Quoting KoritheMan:
Water vapor loops show a newly-developed upper low located between south Florida and the north coast of Cuba. The GFS suggests this feature will gradually weaken and move eastward, but it looks like it's moving west for now. It could play a major role in rapid intensification with Sandy, even if it retrogrades as forecast.
That's an upper level trough and it will be retrograding westward, at first weakening, and then strongly amplifying on Wednesday as a jet max heads down toward the base of the trough. As it amplifies it will begin to shear Sandy. It won't move east for another few days, but when it does it will bring significantly more shear to Sandy (on the order of 40-50knots by Friday and Saturday).
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There is tw just exiting Africa at about 8n-13w showing rotation on satelite images and ascat.I guess the wave train still has some surprises this year.
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Quoting TomTaylor:
Really like Stewart's forecast.

INIT 23/0300Z 12.7N 78.6W 40 KT 45 MPH
12H 23/1200Z 13.6N 78.4W 50 KT 60 MPH
24H 24/0000Z 14.8N 77.9W 60 KT 70 MPH
36H 24/1200Z 16.6N 77.5W 70 KT 80 MPH
48H 25/0000Z 18.5N 77.1W 60 KT 70 MPH...INLAND OVER JAMAICA
72H 26/0000Z 22.7N 75.8W 55 KT 65 MPH...OVER WATER
96H 27/0000Z 25.7N 75.4W 55 KT 65 MPH
120H 28/0000Z 28.2N 73.6W 55 KT 65 MPH...SUBTROPICAL

Sandy looks like she will be a hurricane by Wednesday. Could become a cat2 hurricane if she can build up her core enough tomorrow. Likely peak on Wednesday night or before it crosses Cuba. After that, land interaction coupled with building shear will prevent the storm from intensifying. There may be a slight chance for the storm to peak beyond Cuba, but it looks as though shear will be too strong for this too occur. By Friday, although the storm may continue to deepen, it will be from baroclinic processes (i.e. the strong jet aloft providing divergence, lowering surface pressures). Thus we can expect the storm to begin to expand its wind field and begin to look less purely tropical by Friday.
I think she could become a major hurricane. Right now I have her at 80 kt by the time she reaches Jamaica, but I anticipate that she could get a little stronger.
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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.