Subtropical Depression 17 forms; monsoon rains kill over 100 in Asia

By: Dr. Jeff Masters , 1:04 PM GMT on October 06, 2010

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Subtropical Depression Seventeen formed this morning, approximately 200 miles north of Puerto Rico. The storm is not a threat to bring high winds to any land areas, but will produce heavy rains over Puerto Rico, the Virgin Islands, the northern Lesser Antilles, and perhaps the eastern Dominican Republic. Radar estimated rainfall over Puerto Rico and the Virgin Islands (Figure 1) shows rainfall amounts in excess of eight inches have fallen near St. Thomas in the Virgin Islands, and the St. Thomas Airport officially measured 6.61" yesterday--its 5th wettest day in history. St. Thomas has picked up an additional 1.48" today as of 9am AST. Not surprisingly, Flash Flood Warnings are posted for the island. Weather radar out of Puerto Rico shows that a large area of heavy rain will continue to affect the Virgin Islands and eastern Puerto Rico this morning. Martinique radar shows somewhat less activity over the Lesser Antilles.

Satellite loops show STD 17 has a broad, somewhat ill-defined center of circulation, with the heaviest thunderstorms 50 or so miles from the center. This is characteristic of a subtropical storm, which is a hybrid between a tropical storm and an extratropical storm. An upper level low pressure system to the west of STD 17 has pumped cold, dry air aloft into STD 17, keeping it from being fully tropical. As the trough gradually weakens today and Thursday, STD 17 should become fully tropical and intensify into Tropical Storm Otto. Steering currents favor Otto being lifted northwards and then northeastwards out to sea by Friday.


Figure 1. Radar-estimated rainfall from Subtropical Depression Seventeen over Puerto Rico and the Virgin Islands shows that rains in excess of eight inches (white colors) have fallen near St. Thomas.

Elsewhere in the tropics
Most of the models indicate the possibility that a strong tropical disturbance or tropical depression forming in the Southern Caribbean, off the coast of Nicaragua, 5 - 7 days from now.

Monsoon flooding kills 83 in Indonesia, 28 in Vietnam
Heavy monsoon rains triggered flash flooding in a remote section of Indonesia this week that killed at least 83 people. Another 68 people are missing, and 3,000 homeless. In Vietnam, heavy rains of up to 51" (1300 mm) have fallen since Friday, resulting in river flooding that killed at least 28 people. Over 34,000 people are homeless from the floods, which hit five provinces from Nghe An to Thua Thien-Hue, a swath of territory starting some 300 km (180 miles) south of Hanoi and stretching south. Heavy monsoon rains also hit nearby Hainen Island in China, forcing the evacuation of 64,000 people.

Jeff Masters

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Quoting beell:
Very good conditions for radiational cooling in the GOM.

Dry air- Even when skies are clear, water vapor in the air will absorb and emit longwave radiation. Humid air can act like cloud cover when it comes to longwave energy trying to escape. It is ideal to have low dewpoints throughout the atmosphere...

Link
and yet it still is warm enough to swim and play in......ahhhhh it was a lovely afternoon !
Member Since: February 12, 2007 Posts: 0 Comments: 118
Quoting Orcasystems:
Looks like Pottery opened another bottle.


LOL.
Nop...
and in any case, it is now Petit Careme (small dry season), so it's going to be Bright and Cheerfull for 2 weeks.
(this is written in chalk....)
Member Since: October 24, 2005 Posts: 0 Comments: 24914
Looks like Pottery opened another bottle.

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Quoting Neapolitan:


Well, the Gulf always cools off in October (in fact, it's peak heat content is in August; it's downhill after that), of course. Even if the temp were to reach 100 degrees for several days straight, the fact that nights are hours longer now than they were in summer would mean the GOM would cool. However, though it'll continue to cool, the rate of cooling that takes place with, say, highs of 85 and lows of 65 is substantially slower than when highs are 65 and lows are 45.

IOW: there's still far more than adequate heat in the GOM for cyclogenesis and growth, even at the northern side of things. With the current cold snap snapped, that heat's not going anywhere in a huge hurry.

(Granted, of course, there could be a mighty, record-breaking cold front in a week that blows 40-degree air across the Gulf for a week or more. If that happens, things would be very different. But as it stands, the GOM won't be cooling dramatically for at least the next week and a half.)

Thanks.
Wish I could fast-forward to see how all this pans out.
Great stuff....
Member Since: October 24, 2005 Posts: 0 Comments: 24914
Complete Update


AOI
AOI AOI AOI

AOI AOI AOI

TS BUSTED FORECAST ALIBI
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St. Marteen Radar Link
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Quoting MiamiHurricanes09:
Um, yes. Definitely an omen. It's 77.7F where I'm at.


MH09, you dog. Did you just crack a joke? You're a tropical student, without question. I sense some humor there, as well.
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Quoting Neapolitan:


Of course, which was partially my point; the decreasing hours of sunlight as the northern hemisphere moves toward the winter solstice means less light energy entering the Gulf, and that alone will drive SSTs downward in the fall and upward in the spring. But all other things being equal, a body of a liquid (especially an easily evaporated one, such as seawater) at a given temperature will lose--that is, transfer--more of its heat to a cool airmass above it than it will to a warmer airmass, just as a cold beer will warm up more quickly when poured into a warm stein than into a chilled one.

IOW, those claiming the hurricane season over this morning because of the cooler air over the northern Gulf region must, out of scientific honesty, admit that perhaps it's not over after all.
I don't think you're giving a dry wind enough credit, still...(vs 1 foot waves, no wind, and humid as can be)
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805. beell
Very good conditions for radiational cooling in the GOM.

Dry air- Even when skies are clear, water vapor in the air will absorb and emit longwave radiation. Humid air can act like cloud cover when it comes to longwave energy trying to escape. It is ideal to have low dewpoints throughout the atmosphere...

Link
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Quoting atmoaggie:
Air temperature isn't really all that needs to be considered with gulf temps. Otherwise we'd never have 88 degree water temps when the daily average air temp is less than that all summer. Wouldn't happen. (air temps over 90 F are rare over water)

The effect of wind and, in my thinking, a lower dew point, as well as less direct sunlight for a shorter time period has more to do with lower gulf temps than air temps.


Of course, which was partially my point; the decreasing hours of sunlight as the northern hemisphere moves toward the winter solstice means less light energy entering the Gulf, and that alone will drive SSTs downward in the fall and upward in the spring. But all other things being equal, a body of a liquid (especially an easily evaporated one, such as seawater) at a given temperature will lose--that is, transfer--more of its heat to a cool airmass above it than it will to a warmer airmass, just as a cold beer will warm up more quickly when poured into a warm stein than into a chilled one.

IOW, those claiming the hurricane season over this morning because of the cooler air over the northern Gulf region must, out of scientific honesty, admit that perhaps it's not over after all.
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Just wrote a blog on Otto. Check it out!
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801. beell
Sorry 'bout that, folks.
Thanks.

GFS 700mb/Relative Humidity (or lack of)
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Quoting beell:
GFS 200mb 40-70 knot Southern Stream Jet over the GOM
GFS 700mb/Relative Humidity (or lack of)

It would seem that "The tropics" are confined to the Caribbean in the mid-range.
Geez, 3 diving troughs in 384 hours? Like HPC said. Nov or early Dec looks like this...
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Quoting beell:
GFS 700mb/Relative Humidity (or lack of)


Bad link
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Quoting beell:
GFS 200mb 40-70 knot Southern Stream Jet over the GOM
GFS 700mb/Relative Humidity (or lack of)

It would seem that "The tropics" are confined to the Caribbean in the mid-range.
Bad second link (2 "http://" s ... happens to me when posting using Linux.)
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794. beell
GFS 200mb 40-70 knot Southern Stream Jet over the GOM
GFS 700mb/Relative Humidity (or lack of)



It would seem that "The tropics" are confined to the Caribbean in the mid-range.
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Good evening. Well we are still experiencing heavy weather from what is left behind OTTO. Here in the northern leewards, rainfall amounts above 8 to 10 inches are now common. If the rain continues like this, there could be some major problems. Tomorrow, schools will be closed in St Martin.
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792. Relix
Otto has made for a lackbuster show here in PR =P
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Quoting Neapolitan:


Well, the Gulf always cools off in October (in fact, it's peak heat content is in August; it's downhill after that), of course. Even if the temp were to reach 100 degrees for several days straight, the fact that nights are hours longer now than they were in summer would mean the GOM would cool. However, though it'll continue to cool, the rate of cooling that takes place with, say, highs of 85 and lows of 65 is substantially slower than when highs are 65 and lows are 45.

IOW: there's still far more than adequate heat in the GOM for cyclogenesis and growth, even at the northern side of things. With the current cold snap snapped, that heat's not going anywhere in a huge hurry.

(Granted, of course, there could be a mighty, record-breaking cold front in a week that blows 40-degree air across the Gulf for a week or more. If that happens, things would be very different. But as it stands, the GOM won't be cooling dramatically for at least the next week and a half.)
Air temperature isn't really all that needs to be considered with gulf temps. Otherwise we'd never have 88 degree water temps when the daily average air temp is less than that all summer. Wouldn't happen. (air temps over 90 F are rare over water)

The effect of wind and, in my thinking, a lower dew point, as well as less direct sunlight for a shorter time period has more to do with lower gulf temps than air temps.

South of Mobile

Air temps 10 meters up:


Wind speed 10 meters up:


Dew point 10 meters up:


Water temps 1 meter down:
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Quoting KoritheMan:


Burden of proof.
The way this blog comment section has been going the last month or so....it's more like the "Burden Of Poof".
.
.
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Quoting CybrTeddy:
At my house its 66.6F.. should I be concerned?


No, but I should be. It's only 53 here in central NC. Nice warmup on the way though.
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Quoting CybrTeddy:
At my house its 66.6F.. should I be concerned?
Um, yes. Definitely an omen. It's 77.7F where I'm at.
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Quoting CybrTeddy:
At my house its 66.6F.. should I be concerned?


About? thats a sunny day at this time of year here.
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At my house its 66.6F.. should I be concerned?
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Quoting pottery:

That's an interesting forecast.
How far south will it affect, do you think? The GOM?


Well, the Gulf always cools off in October (in fact, it's peak heat content is in August; it's downhill after that), of course. Even if the temp were to reach 100 degrees for several days straight, the fact that nights are hours longer now than they were in summer would mean the GOM would cool. However, though it'll continue to cool, the rate of cooling that takes place with, say, highs of 85 and lows of 65 is substantially slower than when highs are 65 and lows are 45.

IOW: there's still far more than adequate heat in the GOM for cyclogenesis and growth, even at the northern side of things. With the current cold snap snapped, that heat's not going anywhere in a huge hurry.

(Granted, of course, there could be a mighty, record-breaking cold front in a week that blows 40-degree air across the Gulf for a week or more. If that happens, things would be very different. But as it stands, the GOM won't be cooling dramatically for at least the next week and a half.)
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http://www.weatherincayman.com/buoy.php776. pottery 1:18 AM GMT on October 07, 2010
Thanks, Petrol.
No problem, here the link if you're interested.
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781. beell
Quoting Neapolitan:
From the looks of things, the eastern low comprising the right-hand leg of the omega block that's been parked over the country for the past week--bringing unseasonably cool temps to the southeast and hundreds of record highs to the west and central US--will be finally be pushed out into the Atlantic tomorrow. Warm and humid weather will set back in, with highs along the northern GOM--New Orleans, Houston, Mobile, Pensacola---over the next week expected in the mid- to upper 80s, with lows mostly at 60 and above. (And here in southern Florida, lows will all be at 70 and above for at least the next ten days.)

It looks like the oft-touted end of the 2010 Hurricane Season will have to wait at least a few more weeks, no?


Not related to to the end of the 2010 season but...

Not much humidity expected here in Houston or most of the Gulf Coast for a while. Forecast soundings show PWAT'S pooling along a couple of dry fronts to get us briefly up around 1.5" next week then back to below 1". Current PWAT's are around .2-.4"'s

It is gonna take a while to get moisture back into the gulf.
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780. JLPR2
Quoting CybrTeddy:


If 15 named storms on October 6th is a bust I'll eat my hat with a side of Medium-rare crow w/ some A1 sauce.

Only 2005 and 1995 can claim they saw their 'O' storm at an earlier date, 1995 barely.


Agreed.
I'll join ya, but I want my crow well done. XD
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To Cybertedy:I personally think Igor should be retyird due to the damaged cuased in canada.Goodnight.
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Quoting CybrTeddy:


If 15 named storms on October 6th is a bust I'll eat my hat with a side of Medium-rare crow w/ some A1 sauce.

Only 2005 and 1995 can claim they saw their 'O' storm at an earlier date, 1995 barely.
LMAO!! +10
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Quoting JLPR2:


It's still October I don't get why people say they were a bust when there are still two months to go of the Hurricane Season. :\


If 15 named storms on October 6th is a bust I'll eat my hat with a side of Medium-rare crow w/ some A1 sauce.

Only 2005 and 1995 can claim they saw their 'O' storm at an earlier date, 1995 barely.
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Thanks, Petrol.
Member Since: October 24, 2005 Posts: 0 Comments: 24914
Quoting OEG:
I was wondering if we are late enough in the season ("sub" tropical, etc.) to say that the hurricane forecast of 2010 were complete busts. Do the errent forecasters ever confess?


Dunno. Lets use some common sense.

We're at 15.. CSU and TSR twice predicted 18 storms. I predicted 17. Pretty good likelihood that we'll see 2 more, or 17.

The UKMO came out with 20 once, and NOAA came out with 14-24 and 14-20 later on in August. It was pretty obvious to me 20 wasn't going to happen, but 18 is still very reasonable.

No, if anything the forecasters got it right.. again.

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Quoting Neapolitan:
From the looks of things, the eastern low comprising the right-hand leg of the omega block that's been parked over the country for the past week--bringing unseasonably cool temps to the southeast and hundreds of record highs to the west and central US--will be finally be pushed out into the Atlantic tomorrow. Warm and humid weather will set back in, with highs along the northern GOM--New Orleans, Houston, Mobile, Pensacola---over the next week expected in the mid- to upper 80s, with lows mostly at 60 and above. (And here in southern Florida, lows will all be at 70 and above for at least the next ten days.)

It looks like the oft-touted end of the 2010 Hurricane Season will have to wait at least a few more weeks, no?

That's an interesting forecast.
How far south will it affect, do you think? The GOM?
Member Since: October 24, 2005 Posts: 0 Comments: 24914


Owned and maintained by National Data Buoy Center
10-meter discus buoy
ARES payload
16.834 N 81.501 W (1650'2" N 8130'2" W)

Quoting pottery:

Where is that Buoy?
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Quoting stormpetrol:
Conditions at 42057 as of
(7:50 pm EDT)
2350 GMT on 10/06/2010: Unit of Measure: English Metric Time Zone: Station Local

Wind Direction (WDIR): NNW ( 340 deg true )
Wind Speed (WSPD): 17.5 kts
Wind Gust (GST): 21.4 kts
Wave Height (WVHT): 8.5 ft
Dominant Wave Period (DPD): 7 sec
Average Period (APD): 6.0 sec
Atmospheric Pressure (PRES): 29.76 in
Pressure Tendency (PTDY): +0.00 in ( Steady )
Air Temperature (ATMP): 81.1 °F
Water Temperature (WTMP): 84.2 °F
Dew Point (DEWP): 79.5 °F
Heat Index (HEAT): 90.0 °F

Where is that Buoy?
Member Since: October 24, 2005 Posts: 0 Comments: 24914
770. stormpetrol
Got some friends fishing in that area in a 32ft,boat for snappers, 8.5feet seas can't be fun!
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Conditions at 42057 as of
(7:50 pm EDT)
2350 GMT on 10/06/2010: Unit of Measure: English Metric Time Zone: Station Local

Wind Direction (WDIR): NNW ( 340 deg true )
Wind Speed (WSPD): 17.5 kts
Wind Gust (GST): 21.4 kts
Wave Height (WVHT): 8.5 ft
Dominant Wave Period (DPD): 7 sec
Average Period (APD): 6.0 sec
Atmospheric Pressure (PRES): 29.76 in
Pressure Tendency (PTDY): +0.00 in ( Steady )
Air Temperature (ATMP): 81.1 °F
Water Temperature (WTMP): 84.2 °F
Dew Point (DEWP): 79.5 °F
Heat Index (HEAT): 90.0 °F
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From the looks of things, the eastern low comprising the right-hand leg of the omega block that's been parked over the country for the past week--bringing unseasonably cool temps to the southeast and hundreds of record highs to the west and central US--will be finally be pushed out into the Atlantic tomorrow. Warm and humid weather will set back in, with highs along the northern GOM--New Orleans, Houston, Mobile, Pensacola---over the next week expected in the mid- to upper 80s, with lows mostly at 60 and above. (And here in southern Florida, lows will all be at 70 and above for at least the next ten days.)

It looks like the oft-touted end of the 2010 Hurricane Season will have to wait at least a few more weeks, no?
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Quoting KoritheMan:


Confess to their conspiracy to keep the numbers in line with the preseason prognostications, of course. Didn't you know?


But of course, how silly of me to even ask.
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Quoting OEG:
I was wondering if we are late enough in the season ("sub" tropical, etc.) to say that the hurricane forecast of 2010 were complete busts. Do the errent forecasters ever confess?


No, they never will. It's like the other gov agencies. They are already clamoring for everyone to get flu shots. Wait for the headlines: "Worst flu season ever predicted!"
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766. JLPR2
Quoting OEG:
I was wondering if we are late enough in the season ("sub" tropical, etc.) to say that the hurricane forecast of 2010 were complete busts. Do the errent forecasters ever confess?


It's still October I don't get why people say they were a bust when there are still two months to go of the Hurricane Season. :\
Member Since: September 4, 2007 Posts: 7 Comments: 8747
765. JLPR2
Quoting KoritheMan:


I think it's partially contingent upon the upper low responsible for Otto's subtropical characteristics. That low should gradually weaken and deamplify, and I'd imagine this convection will dissipate after that.


It is becoming it's own feature with 850mb vort developing, probably the reason why it is exploding even though it is so far from Otto, though the ULL to the NE might be helping it too.
Member Since: September 4, 2007 Posts: 7 Comments: 8747

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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.

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