EAST COAST : Tropical Depression ONE

[jinftl]

Interesting excerpt from NHC Discussion....

ALTHOUGH THE SHIPS GUIDANCE DOES NOT
SHOW THE SYSTEM REACHING TROPICAL STORM STRENGTH...THE INITIAL SST
INPUT TO THE MODEL APPEAR TOO COLD. AS A RESULT...THE OFFICIAL
FORECAST WILL CALL FOR THE SYSTEM TO BECOME A TROPICAL STORM OVER
THE NEXT DAY OR SO.

According to the NHC, the system is over 25-26C water right now...most maps do not show the water that warm where the center is....water temp maps, like anything, need to be taken with a grain of salt....there are no absolutes. Water temps in that range (76-78F) could well maintain/support a weak ts.....no rapid ntensification or extreme organization, but clearly those temps can support minimal development....that has already happened. At no point was this system over 80+ deg water.

[cycloneye]

Dr Jeff Masters take on TD one

Posted by: JeffMasters, 3:43 PM GMT on May 28, 2009

Nature is jumping the gun a bit this year, with the season's first tropical depression forming four days before the official start to hurricane season. The area of disturbed weather (91L) that we've been watching, about 250 miles east-northeast of Cape Hatteras, North Carolina, has developed enough heavy thunderstorm activity and spin to be classified as a tropical depression. QuikSCAT imagery from last night revealed a closed surface circulation, but top winds of only 20 - 25 mph. Satellite estimates (using a cloud pattern recognition method called the "Dvorak" technique) were saying this was a tropical depression this morning, though, so the NHC elected to upgrade the system.

The disturbance is over the relatively warm waters of the Gulf Stream (25°C) and has wind shear of 5 - 10 knots over it, and these conditions are marginally favorable for some slow development to occur until Friday, when the system will likely move over waters too cold to support intensification. TD One is not a threat to any land areas. I give the storm a 60% chance of becoming Tropical Storm Ana.

[Aric Dunn]

Interesting excerpt from NHC Discussion....

ALTHOUGH THE SHIPS GUIDANCE DOES NOT
SHOW THE SYSTEM REACHING TROPICAL STORM STRENGTH...THE INITIAL SST
INPUT TO THE MODEL APPEAR TOO COLD. AS A RESULT...THE OFFICIAL
FORECAST WILL CALL FOR THE SYSTEM TO BECOME A TROPICAL STORM OVER
THE NEXT DAY OR SO.

According to the NHC, the system is over 25-26C water right now...most maps do not show the water that warm where the center is....water temp maps, like anything, need to be taken with a grain of salt....there are no absolutes.

very good point...
any thermal imaging from satellites is subject to many possible errors and can only resolve to a certain resolution...
most maps only have a gradient color scheme with no defining lines from one temp to another and if there is, it is likely and average and not the true temp in a specific area.

another thing this system is very small and thermal dynamic processes work at slightly different..

[jinftl]

Good point....things in nature usually happen in degrees, along a spectrum. It would seem very odd that the thermal dynamic processes that are present at 80 or 81 degrees (SST temp) are completely void at 78 or 79 deg. When we are talking about whether or not development can take place....esp the development of a td or weak ts...water temps is important, but only one factor. Water temp (and related issues like depth of warm water) are probably more important in forecasting rapid intensification or development of a strong inner core. What we have been talking about with this system is neither of those....we have been really talking about whether enough organization would take place to meet the minimum thresholds. I think that can happen at 75-78 deg if other factors like shear are favorable. Such a system won't be very pretty or last too long, but it could become a td or weak ts.

Interesting excerpt from NHC Discussion....

ALTHOUGH THE SHIPS GUIDANCE DOES NOT
SHOW THE SYSTEM REACHING TROPICAL STORM STRENGTH...THE INITIAL SST
INPUT TO THE MODEL APPEAR TOO COLD. AS A RESULT...THE OFFICIAL
FORECAST WILL CALL FOR THE SYSTEM TO BECOME A TROPICAL STORM OVER
THE NEXT DAY OR SO.

According to the NHC, the system is over 25-26C water right now...most maps do not show the water that warm where the center is....water temp maps, like anything, need to be taken with a grain of salt....there are no absolutes.

very good point...
any thermal imaging from satellites is subject to many possible errors and can only resolve to a certain resolution...
most maps only have a gradient color scheme with no defining lines from one temp to another and if there is, it is likely and average and not the true temp in a specific area.

another thing this system is very small and thermal dynamic processes work at slightly different..

[Tampa Bay Hurricane]

So TD one on May 28, 2009...3rd year in a row with an early system..
Before advanced technology a lot of storms were probably missed
in previous yrs in early season

[cycloneye]

[jinftl]

True...but advanced technology didn't first surface in 2007....this 3-year-in-a-row occurrence is still remarkable.

So TD one on May 28, 2009...3rd year in a row with an early system..
Before advanced technology a lot of storms were probably missed
in previous yrs in early season

[Tampa Bay Hurricane]

Yes 3 yrs in a row is quite rare especially being recent during the
advanced tech.

[wxman57]

No need to waste recon resources on this system.

[jinftl]

Perhaps the Atlantic Season needs to start the same date at the EPAC on May 15. Talk about a controversial proposal though...fighting words if people try to link it to global warming and not better technology or simple observed realities.

Yes 3 yrs in a row is quite rare especially being recent during the
advanced tech.

[fci]

I think Aric's comment is a generalized statement that need not be taken in a sarcastic way but is truly reality. Even the NHC didn't think this would develop because all the odds were against it but it still did anyways. Pretty humbling to all of us I think.

I've got to pile on here too.
In my opinion; an extra large font, dire looking statement about a non-issue, inconsequential TD is out of line.

Who really cares about the fact that the Pro Mets did not get worked up at all about this unimportant system?

JMO

[CrazyC83]

I agree, there have probably been a lot more early (and late) storms missed. I definitely agree in proposing an extension of hurricane season for 2010.

Personally I would eliminate the term and make it year-round, but at least start it on May 1 or May 15 and end it December 15.

[WeatherLovingDoc]

Went to bed last night with 91L being suspect, come here today and voila'. For a new watcher like me, a good lesson on the power of the warm gulf stream and a reminder to never take your eyes off the ball.

[jinftl]

It goes to our understanding of what is needed for a system to develop...if there is a flaw or bias towards underestimating development given certain conditions (SST,shear, time of year), that is significant. Can't understand the Katrinas of the world if we can't quite figure out what causes (or is necessary) for even a td to develop. Just my 2 cents. We can either approach the tropics as waiting for model runs to guide our forecasts and beliefs (even if they have bad data...like some models did for SSTs for this system, per the NHC) or getting to the science of it all.

I think Aric's comment is a generalized statement that need not be taken in a sarcastic way but is truly reality. Even the NHC didn't think this would develop because all the odds were against it but it still did anyways. Pretty humbling to all of us I think.

I've got to pile on here too.
In my opinion; an extra large font, dire looking statement about a non-issue, incosequential TD is out of line.

Who really cares about the fact that the Pro Mets did not get worked up at all about this unimportant system?

JMO

[Lurker]

Exactly! If this forum had a post of the day I would nominate this!!

Went to bed last night with 91L being suspect, come here today and voila'. For a new watcher like me, a good lesson on the power of the warm gulf stream and a reminder to never take your eyes off the ball.

[xironman]

I thought the GFS started picking up on this about five days out as opposed to its normal 10 day ghost systems, but I could have missed something.

[fci]

It goes to our understanding of what is needed for a system to develop...if there is a flaw or bias towards underestimating development given certain conditions (SST,shear, time of year), that is significant. Can't understand the Katrinas of the world if we can't quite figure out what causes (or is necessary) for even a td to develop. Just my 2 cents. We can either approach the tropics as waiting for model runs to guide our forecasts and beliefs (even if they have bad data...like some models did for SSTs for this system, per the NHC) or getting to the science of it all.

I think Aric's comment is a generalized statement that need not be taken in a sarcastic way but is truly reality. Even the NHC didn't think this would develop because all the odds were against it but it still did anyways. Pretty humbling to all of us I think.

I've got to pile on here too.
In my opinion; an extra large font, dire looking statement about a non-issue, incosequential TD is out of line.

Who really cares about the fact that the Pro Mets did not get worked up at all about this unimportant system?

JMO

What you saying is fundamentally true.
I was critical of the form in which the statement was made.
Extra large font, overtly critical of Pro Mets........
Message sent was sound, delivery was flawed; in my opinion.

[jasons2k]

Let's get back on topic please. Thanks

[Aric Dunn]

I think Aric's comment is a generalized statement that need not be taken in a sarcastic way but is truly reality. Even the NHC didn't think this would develop because all the odds were against it but it still did anyways. Pretty humbling to all of us I think.

I've got to pile on here too.
In my opinion; an extra large font, dire looking statement about a non-issue, inconsequential TD is out of line.

Who really cares about the fact that the Pro Mets did not get worked up at all about this unimportant system?

JMO

this will be the last i say about that... non-issue? how do you come to that conclusion?
and it has nothing to do with getting worked up.. it was a simple statement. was not meant to bash or cause confrontation .. was simply meant to reassure people that anything can happen and calling things dead ( i did as well) is not the right thing to do.. watching and analyzing till its completely out of the picture is more prudent... i see it all year around everywhere.. people calling it dead , its not coming or any number of other statements .... that kind of talk can lead to very dangerous consequences..... some people on here listen to what other say and take it too heart.. so a non-issue i beg to differ!! so what if you think its a small inconsequential TD-1, there may be a sail boat out there right now taking on water ... you dont know ... thats the point... so stop with the bashing and turning something into more than it was..

[Aric Dunn]

Exactly! If this forum had a post of the day I would nominate this!!

Went to bed last night with 91L being suspect, come here today and voila'. For a new watcher like me, a good lesson on the power of the warm gulf stream and a reminder to never take your eyes off the ball.

hehe... great
Aric likes this !!!