ATL: HELENE - Post-Tropical

[PTrackerLA]

I think it's a little premature to be calling this a central American storm while it's just now getting upgraded and in the central Atlantic! With that being said the models sure aren't very bullish on development so I wouldn't be surprised to see another Florence situation. I wonder just how hard it's going to be to get a major this season, something seems off.

[drezee]

it looks as though this buoy will take a direct pass over. should give accurate reading of winds and pressure.

http://rammb.cira.colostate.edu/ramsdis ... _floater_2

That's the one I've been talking about since this AM.

If I were the NHC forecaster, I would wait. We have a buoy in place for the 5pm advisory, if needed. No need to upgrade until it gets to the buoy, short of a convective blowup over the exposed center.

Well, the center blew...

[ConvergenceZone]

I think it's a little premature to be calling this a central American storm while it's just now getting upgraded and in the central Atlantic! With that being said the models sure aren't very bullish on development so I wouldn't be surprised to see another Florence situation. I wonder just how hard it's going to be to get a major this season, something seems off.

I agree, unless conditions in the Atlantic/Carib change drastically, a major cane
won't be happening this year....

[Cyclenall]

All models also suggest a continued fast nearly due-west movement, meaning it may have a hard time becoming well-organized.

No. Why?

None of the models suggests a turn toward the central Gulf next week. They all have a building ridge over the central to NE Gulf next Tuesday, keeping anything in the Caribbean on a westerly track toward Central America or the southern Yucatan.

I see you re-clarified that you weren't saying 100% into CA or the Yucatan, but saying all and none for the models doesn't seem realistic. Just my take: I highly doubt this runs into CA or Yucatan, it would be very strange unless 92L remains very weak all the way across.

I saw on one of the models page the low called "SEVEN" and that was 2.5 hours ago. Now they seem to be pulling the trigger.

[Evil Jeremy]

I'm flying to Colombia a wek from today, so I need to kep an eye on this one. Even if it doesn't affect Florida or Colombia, imsure my fliht will be affected somehow by a storm betwwen departure and destination points.

Looks like the latest model set takes this through or just below the carribean islands. To early to call whered this will go, but my guess would be a southern track lik Ernesto. Northern ridging is really strong right now.

[cycloneye]

TROPICAL DEPRESSION SEVEN FORECAST/ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
2100 UTC THU AUG 09 2012

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

INTERESTS IN THE WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM.

TROPICAL DEPRESSION CENTER LOCATED NEAR 13.7N 43.8W AT 09/2100Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 17 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1010 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 13.7N 43.8W AT 09/2100Z
AT 09/1800Z CENTER WAS LOCATED NEAR 13.7N 42.9W

FORECAST VALID 10/0600Z 13.6N 46.3W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 10/1800Z 13.5N 50.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 30NE 0SE 0SW 30NW.

FORECAST VALID 11/0600Z 13.5N 53.7W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 40NE 0SE 0SW 40NW.

FORECAST VALID 11/1800Z 13.8N 57.4W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 50NE 0SE 0SW 50NW.

FORECAST VALID 12/1800Z 14.6N 64.0W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 60NE 20SE 20SW 60NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 175 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 13/1800Z 15.5N 70.5W
MAX WIND 50 KT...GUSTS 60 KT.

OUTLOOK VALID 14/1800Z 16.5N 77.0W
MAX WIND 55 KT...GUSTS 65 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.7N 43.8W

NEXT ADVISORY AT 10/0300Z

$$
FORECASTER PASCH

[southerngale]

000
WTNT32 KNHC 092035
TCPAT2

BULLETIN
TROPICAL DEPRESSION SEVEN ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
500 PM AST THU AUG 09 2012

...TROPICAL DEPRESSION FORMS IN THE TROPICAL ATLANTIC...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...13.7N 43.8W
ABOUT 1155 MI...1860 KM E OF THE WINDWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...1010 MB...29.83 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

INTERESTS IN THE WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL DEPRESSION SEVEN
WAS LOCATED NEAR LATITUDE 13.7 NORTH...LONGITUDE 43.8 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 20 MPH...32 KM/H. THIS
GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. SLOW STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...
AND THE DEPRESSION COULD BECOME A TROPICAL STORM ON FRIDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB...29.83 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...1100 PM AST.

$$
FORECASTER PASCH


--------------------------------------




000
WTNT22 KNHC 092034
TCMAT2

TROPICAL DEPRESSION SEVEN FORECAST/ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
2100 UTC THU AUG 09 2012

THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.

INTERESTS IN THE WINDWARD ISLANDS SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM.

TROPICAL DEPRESSION CENTER LOCATED NEAR 13.7N 43.8W AT 09/2100Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 17 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1010 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 13.7N 43.8W AT 09/2100Z
AT 09/1800Z CENTER WAS LOCATED NEAR 13.7N 42.9W

FORECAST VALID 10/0600Z 13.6N 46.3W
MAX WIND 30 KT...GUSTS 40 KT.

FORECAST VALID 10/1800Z 13.5N 50.0W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 30NE 0SE 0SW 30NW.

FORECAST VALID 11/0600Z 13.5N 53.7W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 40NE 0SE 0SW 40NW.

FORECAST VALID 11/1800Z 13.8N 57.4W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 50NE 0SE 0SW 50NW.

FORECAST VALID 12/1800Z 14.6N 64.0W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 60NE 20SE 20SW 60NW.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 175 NM
ON DAY 4 AND 225 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 13/1800Z 15.5N 70.5W
MAX WIND 50 KT...GUSTS 60 KT.

OUTLOOK VALID 14/1800Z 16.5N 77.0W
MAX WIND 55 KT...GUSTS 65 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.7N 43.8W

NEXT ADVISORY AT 10/0300Z

$$
FORECASTER PASCH

[USTropics]

5 Day Cone:



INIT 09/2100Z 13.7N 43.8W 30 KT 35 MPH
12H 10/0600Z 13.6N 46.3W 30 KT 35 MPH
24H 10/1800Z 13.5N 50.0W 35 KT 40 MPH
36H 11/0600Z 13.5N 53.7W 40 KT 45 MPH
48H 11/1800Z 13.8N 57.4W 40 KT 45 MPH
72H 12/1800Z 14.6N 64.0W 45 KT 50 MPH
96H 13/1800Z 15.5N 70.5W 50 KT 60 MPH
120H 14/1800Z 16.5N 77.0W 55 KT 65 MPH

[cycloneye]

TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072012
500 PM AST THU AUG 09 2012

LOW CLOUD MOTIONS FROM ANIMATION OF SATELLITE IMAGERY INDICATE THAT
THE AREA OF LOW PRESSURE ACCOMPANYING A TROPICAL WAVE OVER THE
CENTRAL TROPICAL ATLANTIC HAS DEVELOPED A WELL-DEFINED LOW-LEVEL
CIRCULATION. THERE IS SUFFICIENT ORGANIZED DEEP CONVECTION TO
WARRANT THE DESIGNATION OF THE SYSTEM AS A TROPICAL CYCLONE AT THIS
TIME. THE CURRENT INTENSITY ESTIMATE IS 30 KT PENDING OBSERVATIONS
FROM NOAA DATA BUOY 41041...WHICH THE CYCLONE SHOULD PASS NEAR OR
OVER A FEW HOURS FROM NOW. THE SYSTEM IS EXPECTED TO MOVE THROUGH
AN ATMOSPHERIC ENVIRONMENT THAT IS MARGINALLY FAVORABLE FOR
STRENGTHENING...AS THE LGEM GUIDANCE INDICATES SHEAR IN THE 15 TO 20
KT RANGE LATER IN THE FORECAST PERIOD. MOREOVER...THE ECMWF AND GFS
MODELS SUGGEST THAT THE SYSTEM COULD OPEN UP INTO A WAVE IN A FEW
DAYS. THE OFFICIAL INTENSITY FORECAST CALLS FOR ONLY SLOW
STRENGTHENING...AND MORE OR LESS FOLLOWS THE LATEST LGEM GUIDANCE.

A STRONG MID-LEVEL RIDGE IS SITUATED TO THE NORTH OF THE DEPRESSION
AND THE CYCLONE IS MOVING RAPIDLY WESTWARD AT AROUND 17 KT. AN
EVEN FASTER FORWARD MOTION OVER THE NEXT SEVERAL DAYS IS INDICATED
BY THE GLOBAL MODELS...AND BY THE OFFICIAL FORECAST. THE GFDL AND
HWRF MODELS SUGGEST A MORE NORTHWESTWARD TRACK IN THE LATTER PART
OF THE FORECAST PERIOD. THAT SCENARIO SEEMS LESS LIKELY GIVEN THE
STRENGTH OF THE RIDGE FORECAST BY THE GFS AND ECMWF AT THIS TIME.

FORECAST POSITIONS AND MAX WINDS

INIT 09/2100Z 13.7N 43.8W 30 KT 35 MPH
12H 10/0600Z 13.6N 46.3W 30 KT 35 MPH
24H 10/1800Z 13.5N 50.0W 35 KT 40 MPH
36H 11/0600Z 13.5N 53.7W 40 KT 45 MPH
48H 11/1800Z 13.8N 57.4W 40 KT 45 MPH
72H 12/1800Z 14.6N 64.0W 45 KT 50 MPH
96H 13/1800Z 15.5N 70.5W 50 KT 60 MPH
120H 14/1800Z 16.5N 77.0W 55 KT 65 MPH

$$
FORECASTER PASCH

[Weatherboy1]

I think we're just going to have to see how strong Seven can get. That will probably have a lot to do with eventual track, in terms of whether it heads more NW than Ernesto or just plows into Central America. Plenty of time to watch and wait, and revisit the issue on Saturday, when we'll have a better idea from another couple days of modeling!

[tolakram]

latest

[psyclone]

From a renumber to a denumber and back to a renumber...or is it a re-renumber? looks very ernesto-ish. in fact, the 5 day end point on advisory 1 is almost identical to ernesto's first advisory 5 day end point. of course, ernesto ultimately tracked south of initial projections.

[meriland23]

So about this disturbance, I have watched the current runs of GFS and others, looks as thought it favors going into the Carribean, but dissipates dramatically around Haiti or so. I am wondering if this is due to non favorable conditions or because of the fact it is hard to predict 200+ hours out.

[Ivanhater]

Models did not see this one develop just like Florence...looks like they are playing catch up now

[Kingarabian]

So about this disturbance, I have watched the current runs of GFS and others, looks as thought it favors going into the Carribean, but dissipates dramatically around Haiti or so. I am wondering if this is due to non favorable conditions or because of the fact it is hard to predict 200+ hours out.

You should always take forecasts 200+ hours out with a grain of salt, but the reason the GFS and Euro have this weakening is because of the predicted shear. Pretty similar to Ernesto's situation.

[KWT]

Well NHC keep all options open, making note that both the ECM and the GFS open this up to a wave in the Caribbean, the two best models...

Anyway looks to me like its moving due west right now or maybe a hair north of that.

If it does survive the hellhole of the E.Caribbean (for TC's a hellhole!) then it'll probably come across better conditions in the W.Caribbean like Ernesto did.

[gatorcane]

12Z FIM experimental global model is slower than and to the right of the NHC forecast track through the 5 day position and the 12Z GFS prediction and ends up killing the system near Hispaniola:

[meriland23]

So about this disturbance, I have watched the current runs of GFS and others, looks as thought it favors going into the Carribean, but dissipates dramatically around Haiti or so. I am wondering if this is due to non favorable conditions or because of the fact it is hard to predict 200+ hours out.

You should always take forecasts 200+ hours out with a grain of salt, but the reason the GFS and Euro have this weakening is because of the predicted shear. Pretty similar to Ernesto's situation.

True, it has been a while since I have caught up with the Atlantic/Pacific.. little rusty. It is true that these models should be taken with a grain of salt, you never know till it gets closer. I wonder though if, in the past, predicted shear has been accurate this far out or if that too should not be focused on this far out cause that is also just as unpredictable.

[JPmia]

yes that model predicts it to move over hispainola so we know why it would dissipate it, but it is telling that the GFS and the EURO aren't too bullish on this system... we'll just have to wait and see what happens over the next few days on modeling to see if the trend changes.

[Kingarabian]

So about this disturbance, I have watched the current runs of GFS and others, looks as thought it favors going into the Carribean, but dissipates dramatically around Haiti or so. I am wondering if this is due to non favorable conditions or because of the fact it is hard to predict 200+ hours out.

You should always take forecasts 200+ hours out with a grain of salt, but the reason the GFS and Euro have this weakening is because of the predicted shear. Pretty similar to Ernesto's situation.

True, it has been a while since I have caught up with the Atlantic/Pacific.. little rusty. It is true that these models should be taken with a grain of salt, you never know till it gets closer. I wonder though if, in the past, predicted shear has been accurate this far out or if that too should not be focused on this far out cause that is also just as unpredictable.

Shear predictions that far out should be taken with a grain of salt as well but, with Ernesto the GFS and Euro successful predicted shear that no one saw coming despite the SHIPS shear index model forecasting minimal shear.