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

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

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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friend on Tortola, BVI just posted pic of landslide across the valley from her - on FB - says it's larger than any she has seen in recent times...
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Quoting Jeff9641:

GFS and Euro actually want to pull something toward FL at the end of there runs.

Again there you go, the models dont want to pull anything towards florida at all, the euro has it coming towards east cuba and passing east of florida and the GFS has it actually crossing into the GOM before dissipitation, i am basing this on the most recent model runs as per the GFS from the NHC website, and the Euro from the ECMWF site.
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Quoting Jeff9641:

GFS and Euro actually want to pull something toward FL at the end of there runs.

Hopefully it will curve out to sea.
Member Since: June 16, 2005 Posts: 0 Comments: 1884
Thanks Dr. Masters.Great update.
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Quoting cat5hurricane:
Try this.

....thaaaats the one!!!,thanks abunch cat!!!
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Quoting stillwaiting:
from last blog:....we wer fed poppy-cock..*snip*.."all the built up heat in the carib,has to go some where(arrows pointed towards fl and se)",remember. that line well.guess what all that built up heat in the carib is going somewhere: a large diffused conveyer belt of energy heading ne out over the open atlantic,no threat same way the carib heat gets distributed most years....im learning w/most tc forecasts,its better to be conservative imo....

Not to mention the strong N/NE breeze, low dewpoints and cloudless skies north of the front, in the trough...perfect for evaporational and radiational cooling. The tropical season isn't over yet though.
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Wow, I'm not sure if I am upset that i missed those posts or not. Doc rarely mentions a strong disturbance 5-7 days away...he must have an inclination of something going on somewhere down there. I bet there is at lest one conus hit of a TS or cane... only because it would make the most sense at this point in this weird season.
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Asia Floods: Indonesia, China Among Hardest-Hit

LAODE MURSIDIN | 10/ 6/10 08:23 AM |

TELUK WONDAMA, Indonesia — Helicopters dropped food to isolated villages and security forces helped clear debris and search for survivors as the number of people killed by floods and landslides across Asia climbed Wednesday to nearly 110.

Three-quarters of the deaths were in eastern Indonesia, where days of torrential downpours caused mud and debris to crash into hillside villages, damaging thousands of homes. Twenty-six fatalities were reported in Vietnam.

On the nearby Chinese island of Hainan, 64,000 people had to be evacuated.
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Quoting stillwaiting:
anyone have the link to a website that has the model runs and lists the time they start running,it was a awsome link but i lost it:(

Here is one with a few of them on it... not as comprehensive as the other one.. but easier to use.

Member Since: October 1, 2007 Posts: 81 Comments: 26525
Thanks,Dr. Masters,for now US is safe.Wonder if the pattern will change last half of October.
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anyone have the link to a website that has the model runs and lists the time they start running,it was a awsome link but i lost it:(
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Good Morning.

Met Service predicting more rain for Jamaica.

Today's forecast...

October 6, 2010 at 5:00 a.m.


SIGNIFICANT FEATURE… Broad Trough across the central Caribbean, including Jamaica.

Comment… The Trough is expected to linger across the central Caribbean and Jamaica.
Increased showers expected across the island on Friday as a Low forms west of Jamaica.

This Morning… Morning showers over sections of northern parishes.
This Afternoon… Scattered showers and isolated thunderstorms mainly over central and western parishes.
Tonight…Partly cloudy

3-DAYS FORECAST (after tomorrow)
Thu…Mainly sunny morning. Scattered showers and isolated thunderstorms mainly over hilly areas inland areas.
Fri… Mainly sunny morning. Scattered showers and isolarted thunderstorms over southern parishes.
Sat… Mostly cloudy morning. Periods of showers and thunderstorms mainly over western parishes.

Regionally…Tropical Depression Seventeen formed north of Puerto Rico is moving northwest but a turn toward the
north-northwest is expected tonight.

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Invest 97L
4Oct 12pmGMT - - 17.6n63.8w - - 25knots - - 1007mb -- NHC-ATCF *17.7n65.4w*17.6n64.5w
4Oct 06pmGMT - - 17.8n64.2w - - 25knots - - 1007mb -- NHC-ATCF *17.7n65.8w*17.6n64.8w
5Oct 12amGMT - - 18.1n64.6w - - 25knots - - 1007mb -- NHC-ATCF *17.5n64.5w
5Oct 06amGMT - - 18.6n65.0w - - 25knots - - 1006mb -- NHC-ATCF *18.5n65.0w
5Oct 12pmGMT - - 19.5n65.3w - - 30knots - - 1006mb -- NHC-ATCF *19.0n65.3w
5Oct 06pmGMT - - 20.6n65.7w - - 30knots - - 1004mb -- NHC-ATCF
6Oct 12amGMT - - 21.4n66.2w - - 30knots - - 1002mb -- NHC-ATCF *21.5n66.1w
6Oct 06amGMT - - 21.9n66.7w - - 30knots - - 1001mb -- NHC-ATCF
6Oct 12pmGMT - - 22.2n67.0w - - 35mph - - - 1001mb -- NHC.Adv.#1
* Before NHC reevaluated&altered the ATCF numbers.
25knots=~28.8mph=46.3km/h __ 30knots=~34.5mph=~55.6km/h __ 35mph=~56.3km/h

Copy&paste 17.6n63.8w, 17.8n64.2w, 18.1n64.6w, 18.6n65.0w, 19.5n65.3w-20.6n65.7w, 20.6n65.7w-21.4n66.2w, 21.4n66.2w-21.9n66.7w, 21.9n66.7w-22.2n67.0w, myg, mni into the GreatCircleMapper for a look at the last 24hours.
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Ha HA...on the last blog I had just posted that based on bailing the dingy twice last night and what was left this morning measurements I thought we had gotten about 8"-12" in of rain..
So my new rain guage is my 10' inflatable..measure depth divide by two
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That's all from me for now. See you all later.
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Quoting StormChaser81:

Thanx for the Obvious

Obvious or not, I like it when people post info like that.
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Quoting stormwatcherCI:
John Foster's cold front ?

Yes, the tail end sagging to the SW over our area
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Quoting kmanislander:

It was earlier but bright susshine now. Coming from the NE

John Foster's cold front ?
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Quoting stormwatcherCI:
I think I was typing my post when you posted but I see it. Is it raining down there ? Up hear is pouring.

It was earlier but bright sunshine now. Coming from the NE

Member Since: August 19, 2006 Posts: 0 Comments: 16311
Quoting Jax82 (#6):
Hmmm, comparing Oct 4th, 2010 with Oct 4th, 2009. Anyone see a difference? I do!

Oct 4, 2009

Oct 4, 2010

For this year as compared to last, I see:

1) Far cooler temps in the EPac, as sure a sign of a strong La Nina as anything;

2) Pockets of cool water in the Bermuda region, vestiges of the passage of Earl, Igor, etc.;

3) Cooler temps in the GOM due to the past week's cooling breezes;

4) A cool pocket in the BOC from Karl's passage;

5) Warmer temps overall in the Caribbean

It pays to remember, of course, that any water inside the red line is capable of generating and sustaining a tropical cyclone (2009, which ended with just nine storms, nevertheless managed to squeeze out two October storms and one November storm as well).
Member Since: November 8, 2009 Posts: 4 Comments: 14845
GFS @ 108 hrs

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Tropical Update Oct. 6th. 2010
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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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