ATL GUSTAV: Tropical Depression - Discussion

[Matt-hurricanewatcher]

http://manati.orbit.nesdis.noaa.gov/sto ... _at_1.html
If the top one is to be believed for 6:08z then those are 40 knot bars. That would make this a tropical storm if that is so, plus it has a well defined LLC.

As I look again you can try the whole northern side with tropical storm force winds. With one bar of 45 knots!!! Likely very upgradable.

[KWT]

Convection weakening again as we leave Dmax.

[Clipper96]

One blow-up does not a TD make.

[KWT]

No clipper but its been having large flare ups for the last few days and the surface data shows its probably had some sort of closed low level circulation as well during that time.

[Matt-hurricanewatcher]

One blow-up does not a TD make.

Did you even see the quickscat??? A depression does not have to have a cdo. Only a closed LLC with some convection.

[KWT]

Yeah I really think the NHC have taken thier eye off the ball with this one, understandable given the difficulties of Fay's track but this will be a good candidate to upgrade post track at this time even if it does develop down the road.

[Hurricane Cheese]

Convection has wanned since the DMax...I don't think this is a cyclone just yet.

[KWT]

Hmm convection has waned but then again thats pretty normal for even some minimal TS so its not a big deal though it probably does make it even less likely the NHC will do anything with it, really should have been code red though this morning.

[Nimbus]

Looks like a TD but the NHC likes consistancy.

12N at 42W would not be too far north to make the Caribbean.

Have to see what the pro mets think about the upper air steering.

[Hyperstorm]

This system is NOT a TD. Quikscat is an important tool, but it DOES NOT, in and of itself, classify a system.

As some mentioned, we (and the NHC) need to see consistent and more organized convection. It doesn't matter at all that it has a circulation. Also, when a system is this far out, the only way to classify it is with either ship/buoy observations or satellite intensity estimates indicating a tropical depression. Neither of those support that idea.

Give it time. The NHC WILL upgrade when/if it reaches that stage. Right now the system is very poorly organized, but it will have a chance if it stays on a southern track with better upper-level conditions.

[abajan]

We need to keep an eye on both 94L and the blob to its ESE. As the convection of one waxes, that of the other wanes! It's also interesting how slowly 94L is presently moving.

http://www.ssd.noaa.gov/goes/east/tatl/loop-wv.html

[cycloneye]

I havent seen a discussion about the tropical atlantic east of the antilles like this one.Its a complete picture of what is going on about potential tropical development.

FXCA62 TJSJ 201016
AFDSJU

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
616 AM AST WED AUG 20 2008

THE TROPICAL ATLC HAS BECOME VERY TROPICAL IN THE PAST WEEK OR
SO...WITH A MID LEVEL 35-40 KT JET EXITING AFRICA ALONG 18-20N AND
STREAKING ALL THE WAY TO THE NE CARIB ATTM...WHILE WLYS UP TO 700
HPA CAN BE NOW FOUND FROM ALMOST 50 WEST TO THE W AFRICAN BULGE
FEEDING INTO THE MONSOON GYRE. THUS THE ATLC MONSOON TROUGH HAS
BECOME WELL ESTABLISHED. 4 PERTURBATIONS CAN BE FOUND ACROSS THE
TROPICAL ATLC BETWEEN THE CARIB AND AFRICA...TWO REFLECTIONS OF
OLD BAROCLINIC LOWS...ALONG ALMOST 60W PROVIDING THE CONVERGENCE
FOR APPROACHING WEATHER LOCALLY...AND ONE ALMOST AT 50W...WHILE
ELONGATED LOW TO MID LEVEL CYCLONIC TURNING CAN BE FOUND WITHIN
THE MONSOON TROF LINGERING ALONG 38/39...AND ANOTHER BROAD
BAROCLINIC LOW MOVING ACROSS THE CAPE VERDE AREA THIS MORNING.
GOOD LOW TO MID LEVEL CYCLONIC TURNING BETWEEN W AFRICA AND
40W...WITHIN THE MONSOON TROF AND THE WRN PERIPHERY OF THE MONSOON
GYRE ARE CAUSING THE GLOBAL MODELS TO BE INCONSISTENT IN DEPICTING
WHICH OF THESES AREAS IS MOST CONDUCIVE FOR POTENTIAL CYLOGENISIS.
NHC HAS BEEN MONITORING THE AREA ALONG 38/39W...BUT IT IS
APPROACHING THE BASE OF A BROAD MID OCEANIC UPPER TROUGH...AND A
SMALL VORT JUST TO ITS WEST HAS PULLED DEEP CONVECTION TEMPORARILY
W AND AWAY FROM THE LLVL CIRCULATION. SO AT THIS TIME...THE
TROPICAL ATLC IS QUITE INTERESTING AND WITH AREAS OF ACTIVE
CONVECTION...AND THE MONSOON TROF WELL ESTABLISHED...BUT AT
PRESENT MY CONFIDENCE IN THE GLOBAL MODELS IS NOT HIGH DUE TO THE
COMPLEX SYNOPTIC PATTERN. GLOBAL MODELS DO SHOW AREAS OF ENHANCED
LOW TO MID LEVEL MOISTURE TRANSITING ACROSS THE LOCAL REGION
DURING THE NEXT SEVERAL DAYS...WITH THE NEXT BROAD AREA OF
MOISTURE FORECAST BY THE GFS FRI NIGHT-SATURDAY...AND THE UKMET
ABOUT 6 HOURS FASTER. BASED ON CURRENT STLT IMAGERY...THE UKMET
SOLUTION LOOKS TO INITIALIZE BETTER. AS WE APPROACH THE PEAK OF
THE ATLANTIC SEASON...ALL INTERESTS ARE URGED TO MONITOR THE
PROGRESS OF THESE AREAS OF POTENTIAL TROPICAL CYCLONE FORMATION.

http://www.srh.noaa.gov/fwd/productview ... &version=0

[fasterdisaster]

This system is NOT a TD. Quikscat is an important tool, but it DOES NOT, in and of itself, classify a system.

As some mentioned, we (and the NHC) need to see consistent and more organized convection. It doesn't matter at all that it has a circulation. Also, when a system is this far out, the only way to classify it is with either ship/buoy observations or satellite intensity estimates indicating a tropical depression. Neither of those support that idea.

Give it time. The NHC WILL upgrade when/if it reaches that stage. Right now the system is very poorly organized, but it will have a chance if it stays on a southern track with better upper-level conditions.

What does consistency have to do with anything? If it's a TD for 5 minutes we should know. Oh and yes it does matter very much that it has a circulation. And more organization? I don't see how you could ask for any more organization...are you expecting a buzzsaw with a round eye because that's not what constitutes a TD.

And I can tell you for sure, the NHC does not care about a 35-45 mph system when it's a thousand miles away, they often (certainly not always though) wait until either a system is forming an eyewall or is a few hundred miles away from civilization.

[cycloneye]

Down to code Yellow:

085
ABNT20 KNHC 201144
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED AUG 20 2008

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM FAY...CENTERED ALONG THE EAST COAST OF FLORIDA NEAR CAPE
CANAVERAL.

AN AREA OF LOW PRESSURE LOCATED ABOUT MIDWAY BETWEEN AFRICA AND THE
LESSER ANTILLES HAS BECOME LESS ORGANIZED. ANY DEVELOPMENT OF THIS
SYSTEM IS EXPECTED TO BE SLOW TO OCCUR AS IT MOVES WESTWARD AT
ABOUT 10 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BLAKE

[Hyperstorm]

This system is NOT a TD. Quikscat is an important tool, but it DOES NOT, in and of itself, classify a system.

As some mentioned, we (and the NHC) need to see consistent and more organized convection. It doesn't matter at all that it has a circulation. Also, when a system is this far out, the only way to classify it is with either ship/buoy observations or satellite intensity estimates indicating a tropical depression. Neither of those support that idea.

Give it time. The NHC WILL upgrade when/if it reaches that stage. Right now the system is very poorly organized, but it will have a chance if it stays on a southern track with better upper-level conditions.

What does consistency have to do with anything? If it's a TD for 5 minutes we should know. Oh and yes it does matter very much that it has a circulation. And more organization? I don't see how you could ask for any more organization...are you expecting a buzzsaw with a round eye because that's not what constitutes a TD.

And I can tell you for sure, the NHC does not care about a 35-45 mph system when it's a thousand miles away, they often (certainly not always though) wait until either a system is forming an eyewall or is a few hundred miles away from civilization.

Consistency has MUCH more to do than what you think. If the NHC upgrades every system that show some signs of being a tropical depression or tropical storm for "5 minutes", we would run out of numbers and names. More importantly, there would be SO much confusion among the public about systems that develop for "5 minutes" and weaken the next 5. The NHC cannot afford to make a 5-day forecast for a system that would weaken to no more than a tropical wave/low in 6-12 hours. We see MANY tropical waves/lows come off Africa each year that you could argue that they would be tropical cyclones. However, the systems don't persist long enough to be classified.

If a system shows signs of developing, we NEED consistency. It's very logical.

[Category 5]

Last night the circulation looked elongated, I wonder if that's whats stopping it.

[cycloneye]

12:00 UTC Best Track has it as a Tropical low.

AL, 94, 2008082012, , BEST, 0, 122N, 420W, 25, 1008, LO, 34, NEQ, 0, 0, 0,

[Gustywind]

000
AXNT20 KNHC 201155
TWDAT

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT WED AUG 20 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...
A 1010 MB LOW IS IN THE CENTRAL ATLC NEAR 13N38W DRIFTING W NEAR
5 KT. BROAD AREA OF DEEP LAYERED MOISTURE IS INDICATED BY
MIMIC-TPW ANIMATION S OF 15N WITH A WELL DEFINED MID LEVEL LOW
OBSERVED ON SATELLITE IMAGERY OVER THE LOW CENTER. CONVECTION
HAS DECREASED OVER THE PAST 6 HOURS WITH CLUSTERS OF SCATTERED
MODERATE CONVECTION FROM 10N-14N BETWEEN 39W-43W. ALTHOUGH
ENVIRONMENTAL CONDITIONS ARE ONLY MARGINALLY FAVORABLE...SOME
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT COUPLE OF
DAYS AS IT MOVES SLOWLY WESTWARD.

[gerrit]

And the NHC continues to be really conservative on this. Maybe they are too busy eating crow as a result of Fay?

Is this a joke? That's NOT a Tropical Depression? Or at least Red on the TWO?


NHC is really fooling around...if that convection expands this may intensify to a TS before they even give it notice.

This is stupid.

I mean the fact that the NHC doesn't upgrade this let alone give it red on the TWD. It's not going away, it's been stable for 2 days, quikscat says closed, so it is pretty dumb.

But yeah it does look very good. It should have a red by now though. I know why they didnt though.

Yeah I really think the NHC have taken thier eye off the ball with this one

The above comments - and similar comments (including those of S2K moderators who were talking about Fay when it was still an invest!) in the thread about 92L before it was upgraded to a TS are the reason that I read this forum mainly for entertainment. I don't pay attention to any predictions other than those from Pro Mets.

NHC has a big responsibility and it's their job to inform the general public. Whenever a system is upgraded to a TD or named, this has an enormous impact.
I've been following the tropics for 7 years - that's how long I've been living in Puerto Rico. The NHC has been doing a great job as far as I'm concerned - their info was as accurate as it could be.

If I would have listened to all the yelling about upgrading 92L when it was approaching Puerto Rico last week, I would have put the hurricane shutters on the windows. Instead I was sitting on the porch, enjoying the rain and the light breeze.

Apart from the fact that whining that a system should be upgraded doesn't help - I'm sure the NHC forecasters don't take the opinion of S2K posters in account when doing their job - I seem to remember that it's against the S2K policy to bash the NHC and other pro mets...

Oh uhm.. did you all notice that 94L has been 'downgraded' to yellow?

[Category 5]

And the NHC continues to be really conservative on this. Maybe they are too busy eating crow as a result of Fay?

Is this a joke? That's NOT a Tropical Depression? Or at least Red on the TWO?


NHC is really fooling around...if that convection expands this may intensify to a TS before they even give it notice.

This is stupid.

I mean the fact that the NHC doesn't upgrade this let alone give it red on the TWD. It's not going away, it's been stable for 2 days, quikscat says closed, so it is pretty dumb.

But yeah it does look very good. It should have a red by now though. I know why they didnt though.

Yeah I really think the NHC have taken thier eye off the ball with this one

The above comments - and similar comments (including those of S2K moderators who were talking about Fay when it was still an invest!) in the thread about 92L before it was upgraded to a TS are the reason that I read this forum mainly for entertainment. I don't pay attention to any predictions other than those from Pro Mets.

NHC has a big responsibility and it's their job to inform the general public. Whenever a system is upgraded to a TD or named, this has an enormous impact.
I've been following the tropics for 7 years - that's how long I've been living in Puerto Rico. The NHC has been doing a great job as far as I'm concerned - their info was as accurate as it could be.

If I would have listened to all the yelling about upgrading 92L when it was approaching Puerto Rico last week, I would have put the hurricane shutters on the windows. Instead I was sitting on the porch, enjoying the rain and the light breeze.

Apart from the fact that whining that a system should be upgraded doesn't help - I'm sure the NHC forecasters don't take the opinion of S2K posters in account when doing their job - I seem to remember that it's against the S2K policy to bash the NHC and other pro mets...

Oh uhm.. did you all notice that 94L has been 'downgraded' to yellow?

I agree with this post.

Besides, this doesn't impress me, I don't know about you, but it looks quite elongated, more so then last night.