An Atlantic tropical wave worth watching

By: Dr. Jeff Masters , 2:46 PM GMT on October 04, 2009

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A large tropical wave near 9N 40W, midway between Africa and the Lesser Antilles Islands, is generating a considerable amount of heavy thunderstorm activity as it moves west to west-northwest at 15 mph. The wave is under about 10 - 15 knots of wind shear, and this morning's QuikSCAT pass showed a large and disorganized region of converging winds in the region, with top winds of 25 mph. There is very little dry air in the vicinity, and conditions appear favorable for some slow development of this wave. None of the computer models develop the wave, but they do show relatively low wind shear along the wave's path for the next five days. The wave should reach the Lesser Antilles Islands by Wednesday.


Figure 1. The large tropical wave in the middle Atlantic.

In the Philippines, Tropical Storm Parma continues to linger offshore the northern tip of the Philippines' Luzon Island, bringing heavy rain. The storm has been blamed for the deaths of 17 people in the Philippines, but has not not had the devastating impact that was earlier feared. Parma's heaviest rains will stay offshore of the Philippines today (Figure 2).


Figure 2. Forecast rain amounts for Parma for the 24-hour period ending at 06 UTC October 5 (2am EDT Monday). This forecast is based on satellite measurements of Parma's current rainfall rate, plus a projection of the storm's path. Four to eight inches of rain (yellow colors) is expected along the extreme northwest tip of Luzon Island. Image credit: NOAA Satellite Services Division.

Super Typhoon Melor hits Cat 5 strength
Super Typhoon Melor has become the second Category 5 tropical cyclone of the year. Melor is expected to recurve to the north pass just south of the coast of Japan later this week.

Jeff Masters

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Quoting sarahjola:

i am a weather idiot. lol! where is that graphic saying its going to go. is it going to the gulf? be gentle please!



From running that animation, I saw Invest 91-L going into the western Caribbean, then getting recurved northeastward into the Gulf of Mexico, taking a trip across Florida, and then deepening into a strong nor'easter after becoming extratropical.
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Quoting KEEPEROFTHEGATE:
and are you visiting this blog


Stop trying to confuse him KOG :)
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Quoting WeatherStudent:


I am.
and are you visiting this blog
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GMZ089-050930-
SYNOPSIS FOR THE GULF OF MEXICO
1030 PM CDT SUN OCT 04 2009

.SYNOPSIS...AN E TO W RIDGE WILL EXTEND ALONG 25N THROUGH WED
THEN SHIFT N TO ALONG 27N WED THROUGH FRI. THE BLOCKING RIDGE
WILL STALL THE NEXT COLD FRONT ACROSS THE NORTHERN COASTAL
PLAINS WED AND THU.


Sigh.
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983. 789
Quoting NCHurricane2009:


Here is a paper to support that theory (I think you can find this paper in Google)

Kwan-yin Kong. Understanding the Genesis of Hurricane Vince Through the Surface Pressure Tendency Equation . City College of New York.

This paper suggests a new paradigm in the thinking of how hurricanes form and develop.

Here is the current way we think: Deep bursts of convection over the center release latent heat, creating a strengthening vertical warm core over the center. A warmed column of air leads to low surface pressure (cyclonic spin at the surface) and high upper air pressure (upper anticyclone with cirrus outflow).

Here is the way this paper alters the thinking: Deep bursts of convection causes the central column of air to have a moist super-adiabatic lapse rate, thus resulting in a statically unstable atmosphere. The statically unstable atmosphere at the core of a hurricane causes air parcels to rise, causing low surface pressure and higher upper air pressure.

Now, this may explain why you can have a hurricane below 26 deg C water. All you need is to have a significantly unstable lapse rate to cause surface pressure falls. Over cooler sea surfaces, a cold core upper low over a deeply-occluded surface cyclone can allow for a super-unstable lapse rate due to the temp difference btn. the sea surface and cold core upper low.

I may have a post on this on my blog later this week (talk about skew-T diagrams, etc., so that this is understandable).
nice !!!
Member Since: July 18, 2009 Posts: 0 Comments: 262
Quoting WeatherStudent:


Orca, my friend, you make it sound as if this blog is only visited by people solely from Florida and not from any other state across the Conus.
are you or are you not from fla
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okay...didn't know. thanks
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Quoting GeoffreyWPB:
What do your graphs show Orca?


Umm in regards to?
They are covering from the Philippines to England, both ways around
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What do your graphs show Orca?
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Quoting 7544:
hi all could this be where 91L ends up after the dip to the south ?
Link

i am a weather idiot. lol! where is that graphic saying its going to go. is it going to the gulf? be gentle please!
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974. xcool





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Quoting AussieStorm:
OMG they named this.... gee must be desperate name things. Remember Danny and Erika, should of they been named???? I don't think so.


The one to watch Auz will be 91L I think :)
Blog should be nuts in a couple hours when Florida wakes up... went from Zero to a name and invest.
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I knew it was matter of time 91L likely Henri in 24 hrs. Are the other models runing for 91L 00z.
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OMG they named this.... gee must be desperate name things. Remember Danny and Erika, should of they been named???? I don't think so.
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TS Grace, wow A Tropical system at 40N, with 21C SST. How did that happen? I thought TD/TS, Hurricanes required H2O of 80F! Isn't 21C about 70F? A brief explanation anyone?
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Quoting P451:
AH, Thanks for the clarification Storm.

Geoff, 91L is an infant and I don't think anyone can call it. Yet it does have that late season slow-developing, yet, stubborn appearance to it. I would be surprised if it DOESNT develop.

NCHurricane2009, thank you for that, I will check that out in more detail when I get a chance.

To me, if you have the necessary difference in temperature you will have a similar result. I don't necessarily see why not. A little, given how water saturation works with given temperatures, but beyond that....can't think of any other roadblock to the idea of: If you need let's say an 80 degree temperature difference between a lower and upper level to get a certain result - does it matter much at all what actual temperature you are dealing with?

This is of course thinking outside the box but I think to a certain degree it pertains to - if we can get a tropical cyclone at 27C SST why can't we get one at 21C if the upper levels mimic the necessary inversion?

I'm a bit over my head in this but to me it's not without merit as we have seen many late season systems "suprise" us.


...and with that, you all have yourselves a good night.

The next few days seem to look to be interesting.

well at some point water begins to freeze ..
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966. xcool
:0
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Quoting 7544:
hi all could this be where 91L ends up after the dip to the south ?
Link


Would seem to gel with the graphic I posted.
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Joe B. doesn't like GRACE...



SUNDAY 11:30 PM
A SHAM AND/OR A SCAM.



There is no excuse for this out of the National Hurricane center... naming a storm at 41 north, 20 WEST over 21c water... 4 c under the accepted criteria, and in light of the nonsense they have pulled with storms that have done damage to US coastlines without names, the most recent the storm that hit Jersey on Sept 11.

Here read the nonsense for yourself.. The naming of a storm in October, under a cold upper trough , northeast of the Azores:

00 WTNT44 KNHC 050236 TCDAT4 TROPICAL STORM GRACE DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092009 1100 PM AST SUN OCT 04 2009

CONVECTIVE ACTIVITY ASSOCIATED WITH THE LOW PRESSURE AREA NORTHEAST OF THE AZORES ISLANDS HAS BECOME BETTER ORGANIZED THIS EVENING. THE CONVECTION...WHICH HAS SHOWN SOME ORGANIZATION FOR MUCH OF THE DAY...IS RELATIVELY DEEP AND SURROUNDS AN EYE-LIKE FEATURE THAT HAS PERSISTED FOR SEVERAL HOURS. THIS IS THE SAME SURFACE LOW PRESSURE AREA THAT MOVED THROUGH THE AZORES SEVERAL DAYS AGO AND MADE A COUNTER-CLOCKWISE LOOP. THE LOW...PREVIOUSLY ASSOCIATED WITH AN OCCLUDED FRONT AND CO-LOCATED WITH AN UPPER LOW...HAS SINCE LOST ITS FRONTAL STRUCTURE AND IS NOW LOCATED UNDER A FAIRLY UNIFORM SOUTHWESTERLY UPPER FLOW. IN ADDITION...2210Z ASCAT DATA INDICATED A VERY SMALL RADIUS OF MAXIMUM WIND...LESS THAN 20 MILES. WITH THESE STRUCTURAL CHANGES...THE SYSTEM CAN NOW BE CLASSIFIED AS A TROPICAL STORM.

THE ASCAT PASS SHOWED A COUPLE OF 45-50 KT WIND VECTORS TO THE SOUTHEAST OF THE CENTER...AND THESE DATA ARE THE BASIS FOR THE 55 KT INITIAL INTENSITY. GRACE IS CURRENTLY OVER SSTS AROUND 21 DEGREES CELSIUS AND WITHIN AN UPPER-LEVEL ENVIRONMENT CHARACTERIZED BY LIGHT TO MODERATE SOUTHWESTERLY SHEAR. ALTHOUGH THE SHEAR IS NOT FORECAST TO INCREASE DURING THE NEXT DAY OR TWO...THE CYCLONE IS HEADED FOR EVEN COLDER WATER AND WILL LIKELY BEGIN TO WEAKEN VERY SOON. THE GLOBAL MODELS SUGGEST THAT THE SMALL CYCLONE WILL BE ABSORBED BY A LARGER EXTRATROPICAL CYCLONE OVER THE NORTHEASTERN ATLANTIC IN ABOUT 36 HOURS...IF NOT SOONER.

GRACE IS MOVING NORTHEASTWARD IN THE DEEP LAYER SOUTHWESTERLY FLOW OVER THE NORTHEASTERN ATLANTIC. A GENERAL NORTHEASTWARD MOTION IS EXPECTED TO CONTINUE UNTIL DISSIPATION.

FORECAST POSITIONS AND MAX WINDS

INITIAL 05/0300Z 41.2N 20.3W 55 KT 12HR VT 05/1200Z 44.0N 18.0W 50 KT 24HR VT 06/0000Z 48.0N 16.0W 45 KT 36HR VT 06/1200Z...DISSIPATED



41 north. 41 north!!!! 21 c water. moving northeast at 22kts and dissipated within 36 hours. So let me get this straight. They let eyelike features with verified hurricane force winds by recons in the Carolina coastal waters in late September last year. ( water temp Look at the sat shot. This is a joke.. Think about what was racking Jersey or even Danny after it was downgraded and look at this and find the storm

http://www.ssd.noaa.gov/eumet/neatl/avn-l.jpg


28C) go but you name this. Look at the upper air map http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/18/images/gfs_500_000 l.gif The surface map:

http://www.nco.ncep.noaa.gov/pmb/nwprod/analysis/carib/gfs/18/images/gfs_slp_00 0l.gif


The lat, the lon, the wqter temp. Storms with eyes develop in the winter, the least you can do is name something that is causing 60 mph winds, flooding and knocking out power on Sep 11 to the US that was over water greater than 26C and SOUTH OF 40 NORTH. in the heart of the hurricane season.

Your taxes as work What a joke. The only positive to this... it was forecasted in by me in the hurricane preseason forecast.. the late season naming of storms in the middle of nowhere that had to be factored into a total number forecast. That is what "science" is coming down to with this bunch... Figuring out how many storms need to be named and who is working at the time. Dont laugh, I know people with masters and PHD's in this field that have off the record said that to me. I will say it for the record, that is what this looks like.

Is there any conceivable defense of this? again 21C water 41 north 20 west. They ought to be ashamed of themselves, given the great people who have forecasted before them. Seriously.

This would have never never never never been named until the recent agenda driven forecasting, as outlined in a Miami Herald expose over a year ago, started. I can not believe the director of the hurricane center is allowing this. DO you think Neil Frank would agree with this.


What a nutso world weather is turning out to be. The chief science advisor the president was screaming Ice ages 35 years ago , now he is yelling about global warming and how we have to "de-develop" the United States..which sounds to me like lifting weights in an effort to get out of shape. so I guess Storms getting named over water that is plainly non tropical, and then forecasted to dissipate within 2 days isnt so looney in comparison. Of course maybe why this can get named over such gool water... global warming, or whatever it is we call it these days. Afterall we are calling storms like this tropical cyclones but we dont call the ones that hit the US in the middle of hurricane season anything.. or we downgrade them

Or should I say de-develop?

You gotta laugh at this stuff, though I am not sure this age will pass.

By the way, there have been storms even more fierce looking than this out there.. in the middle of winter. With this crew working, the d-day storm of 44 would have been named.. Actually probably not since it was early in the year and they would not have been desperate to jack up numbers, given the 9-14 season and normal "ace" forecasted, of which we are at less than 50%.

Hopefully other folks besides me will make noise about this, and other travesties.

Again.. closed rotary circulation over water warmer than 25C gales in one quad, name it and leave the name on. This is not in water over 25c It cant be that people are naming storms over water 8 F below the accepted thresh hold, In places where recon cant get to them. They have said themselves that sat pics and wind profile is not reliable as reasons for not naming storms before.




ciao for now. ****
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Only 38 posts away from 1000!
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Quoting Orcasystems:

AOI

AOI

AOI

AOI

Special Notice (AussieStorm/Caritas)

Daily Chuckles in Comments section


Orca,

When I tried to read your chuckles, a post came up that I couldn't. I have always enjoyed how funny they are and cannot imagine why I can't read them.
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960. 7544
hi all could this be where 91L ends up after the dip to the south ?
Link
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Well...at least early models show no threat to the CONUS. The islands should watch out as they are only about three days away.
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956. JRRP

out
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Quoting WeatherStudent:
Indeed all, a controversial night in here, alright. Although, I don't blame Storm for being upset and frustrated.


Sorry you are upset StormW. As I stated just a few posts ago...you are a very valuable and reliable asset in the blog. Have a good night.
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ok guys, im out, I have a few papers to review, have a goodnight all
Member Since: June 28, 2006 Posts: 25 Comments: 8360
Quoting WeatherStudent:


Really?
wait watch see
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Hmmmm? Big change in pattern. Looks like after the next front no more troughs. They show a low in the gulf and look at Cuba. Could that be where they think 91L will be? Things may get interesting lets just hope not too interesting. Especially if the mjo shows up at the same time.
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Quoting ElConando:
Whats the H storm name?


Henri
Member Since: June 28, 2006 Posts: 25 Comments: 8360
Excellent show on the Discovery Channel, called "Drain the Ocean".
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Thanks 451. Will keep a look out for your posts on 91.
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Whats the H storm name?
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944. JLPR
dont forget about Melor xD

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night
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Quoting Stormchaser2007:
What an interesting night.

A controversial TS declared and an invest declared.
yep 1000 post night been awhile
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939. xcool



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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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