ATL: TROPICAL DEPRESSION ANA (02L)

[jasons2k]

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About the only chance Ana has is further downstream, possibly when she arrives in the northern Western Carib....I don't see this one developing into much, mostly because of dry air and land interaction. Should pass well south of Florida as well.

I agree, as others have said, if this makes it to the WCARIB or moves into the GOM, that will be the time something may develop. I think we need to watch Ana carefully as it looks more and more like this could be the system to eventually impact land areas if it redevelops down the road.

[bob rulz]

I'm not sure how they're going to justify keeping this as a TS at the next advisory if they choose to do so. It barely even looks like it's holding onto enough convection to remain a TD.

[storms NC]

I think actually Storms in NC its Ana we have to really watch. Its got a tough long road ahead of it it has to be said I'm not convinced it'll survive but if it does the gulf looks like where its destined to go and conditions in the southern gulf look like they will be decent enough.

I understand what you saying but she is so small and is being torn up by the ULL and I don't think there will be any thing left for it to rebuild in the Gulf. But yes if it did survive the gulf is a boiling pot.

[KWT]

The ULL that tore it up last night is now actually moving away from TS Ana. It should be moving into a window where the shear isn't quite as strong, other factors are likely to hold Ana back, as has been mentioned the dry air could be just one such issue.

Its going to have a hard time though thats certainly true and there probably a good 50% chance it goes poof.

[lonelymike]

As Ana is being beaten to death with clubs and chairs by Big Bubba and Wilma, the fat lady is warming up and Bones is prepping the autopsy table.

[KWT]

Still bursting convection though nearby, its not narly as poorly as it was last time it went poof FWIW. Its probably not a TS but I've thought its been a TD all day to be honest. Recon will show us what state it is in anyway.

[Gustywind]

Hearing the radio, looks like Guadeloupe is under an orange code, alert. As we have our last Cycling Competition of Guadeloupe the last event is at 2PM, the journalist says the the competition will be maintained but the ceremony with the medals etc.. could be earlier than was predicted tonight ( 7PM). That's not official because meteo france Guadeloupe has not requiered any orange alert for the Leewards Guadeloupe, Northern Leewards and even Martinica (Windwards), whereas it could be iminent?. Seems that hopefully we're dealing with a weak TS but we continue to monitor closely the situation...anything can happen as we're in the islands.

[KWT]

Even if this does degenerate yet again I think we have to be very watchful of the long term, remember the long game in these events and keep watching the ULL near the Bahamas.

[cycloneye]

WTNT22 KNHC 161438
TCMAT2
TROPICAL STORM ANA FORECAST/ADVISORY NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1500 UTC SUN AUG 16 2009

AT 11 AM AST...1500 UTC...A TROPICAL STORM WATCH IS IN EFFECT
FOR DOMINICA. A TROPICAL STORM WATCH MEANS THAT TROPICAL
STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY
WITHIN 36 HOURS.

A TROPICAL STORM WATCH ALSO REMAINS IN EFFECT FOR PUERTO RICO...THE
U.S. VIRGIN ISLANDS...THE BRITISH VIRGIN ISLANDS...MONTSERRAT...
ANTIGUA...BARBUDA...ST. KITTS...NEVIS...ANGUILLA...ST.
MAARTEN...SABA...AND ST. EUSTATIUS.

INTERESTS ELSEWHERE IN THE LEEWARD ISLANDS AND THE NORTHEASTERN
CARIBBEAN SEA SHOULD MONITOR THE PROGRESS OF ANA. ADDITIONAL
WATCHES AND WARNINGS MAY BE REQUIRED FOR PORTIONS OF THESE AREAS
LATER TODAY.

TROPICAL STORM CENTER LOCATED NEAR 14.8N 55.8W AT 16/1500Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 20 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB
MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT.
34 KT....... 45NE 0SE 0SW 0NW.
12 FT SEAS.. 90NE 0SE 0SW 0NW.
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 14.8N 55.8W AT 16/1500Z
AT 16/1200Z CENTER WAS LOCATED NEAR 14.6N 54.8W

FORECAST VALID 17/0000Z 15.2N 58.7W
MAX WIND 35 KT...GUSTS 45 KT.
34 KT... 45NE 0SE 0SW 0NW.

FORECAST VALID 17/1200Z 16.1N 62.7W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 50NE 0SE 0SW 50NW.

FORECAST VALID 18/0000Z 17.1N 66.7W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 60NE 30SE 30SW 60NW.

FORECAST VALID 18/1200Z 18.3N 70.7W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 75NE 30SE 30SW 60NW.

FORECAST VALID 19/1200Z 21.0N 77.5W...INLAND
MAX WIND 30 KT...GUSTS 40 KT.

EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY

OUTLOOK VALID 20/1200Z 23.5N 83.0W
MAX WIND 30 KT...GUSTS 40 KT.

OUTLOOK VALID 21/1200Z 25.5N 85.5W
MAX WIND 30 KT...GUSTS 40 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.8N 55.8W

NEXT ADVISORY AT 16/2100Z

$$
FORECASTER BRENNAN/ROBERTS

WTNT42 KNHC 161443
TCDAT2
TROPICAL STORM ANA DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1100 AM AST SUN AUG 16 2009

ANA CONTINUES TO RACE WESTWARD...WITH LIMITED DEEP CONVECTION OVER
THE LOW-LEVEL CENTER. A 0950 UTC QUIKSCAT PASS SHOWED SOME
BELIEVABLE 30 KT WINDS...AND ASSUMING WINDS ARE HIGHER IN THE
CONVECTION NEAR THE CENTER THE INTENSITY IS HELD GENEROUSLY AT
35 KT FOR THIS PACKAGE. AIRCRAFT RECONNAISSANCE WILL BE
INVESTIGATING THE CYCLONE EARLY THIS AFTERNOON AND SHOULD HELP
DETERMINE IF ANA IS STILL A TROPICAL STORM.

THE ENVIRONMENT NEAR AND AHEAD OF ANA IS RATHER DRY AND DOMINATED BY
SUBSIDENCE...AS INDICATED BY WATER VAPOR IMAGERY AND RADIOSONDE
DATA FROM THE LESSER ANTILLES. THE GFDL...SHIPS...AND LGEM CONTINUE
TO SUGGEST THAT ANA WILL INTENSIFY SOMEWHAT OVER THE NEXT COUPLE OF
DAYS. HOWEVER...GIVEN THE NEGATIVE FACTORS DISCUSSED ABOVE...ONLY
SLIGHT INTENSIFICATION IS SHOWN THROUGH 48 HOURS. BEYOND THAT
TIME...THE INTENSITY OF ANA WILL BE DICTATED PRIMARILY BY ITS
INTERACTION WITH HISPANIOLA AND CUBA...AND THE INTENSITY FORECAST
ACCOUNTS FOR THIS WITH WEAKENING.

THE TRACK FORECAST IS QUITE SIMILAR TO THE PREVIOUS PACKAGE...
SHOWING A QUICK WESTWARD TO WEST-NORTHWESTWARD MOTION THROUGH THE
FIRST 3 OR 4 DAYS OF THE FORECAST PERIOD. BEYOND THAT TIME THERE
IS A SPLIT IN THE TRACK GUIDANCE...WITH THE ECMWF AND HWRF SHOWING
A TURN TOWARD THE NORTHWEST...WHILE THE UKMET AND NOGAPS SHOW A
CONTINUED WEST-NORTHWEST HEADING. THE OFFICIAL FORECAST IS NUDGED
TOWARD THE MULTI-MODEL CONSENSUS AT DAY 5 AND SHOWS A DECREASE IN
FORWARD SPEED.

GIVEN THE UNCERTAINTY IN THE INITIAL INTENSITY OF ANA...TROPICAL
STORM WATCHES CONTINUE FOR MOST OF THE NORTHERN LEEWARD ISLANDS...
THE VIRGIN ISLANDS...AND PUERTO RICO. IF AIRCRAFT RECONNAISSANCE
FINDS ANA IS A TROPICAL STORM...WARNINGS WILL LIKELY BE REQUIRED
LATER TODAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 16/1500Z 14.8N 55.8W 35 KT
12HR VT 17/0000Z 15.2N 58.7W 35 KT
24HR VT 17/1200Z 16.1N 62.7W 40 KT
36HR VT 18/0000Z 17.1N 66.7W 40 KT
48HR VT 18/1200Z 18.3N 70.7W 45 KT
72HR VT 19/1200Z 21.0N 77.5W 30 KT...INLAND
96HR VT 20/1200Z 23.5N 83.0W 30 KT
120HR VT 21/1200Z 25.5N 85.5W 30 KT

$$
FORECASTER BRENNAN/ROBERTS

[KWT]

Ana has lifted up a little, motion now at 275 degrees and thats probably roughly where it'll stay as well for a little while yet.

Will be interesting to see just how much latitude Ana can gain, its going to be very important indeed for the system's future I feel...

[Sanibel]

Pffzzzz...


A technical feature that managed to develop but didn't have the strength to overcome the negative conditions ahead of it.

[KWT]

Not yet anyway Sanibel, I am reminded of Frederic and how it had David's outflow shear to handle for days on end, then its trip over PR which it survived. However I doubt the general atmosphere was that unfavorable but we shall see.

[Gustywind]

Not yet anyway Sanibel, I am reminded of Frederic and how it had David's outflow shear to handle for days on end, then its trip over PR which it survived. However I doubt the general atmosphere was that unfavorable but we shall see.

Oh yeah, I hate weakning system approaching the islands, always suspicious, people don't pay attention and bang a strong TS regenerated under the islands. Remember Iris too...That's not the moment to let out guard in the Leewards...even the Windwards(Dominica/Martinica) given the possible path.

[KWT]

Yep Ana is taking a good jog to the WNW, motion seems to be about 285, heading back towards the NHC track now it seems, looks like its going to kill itself overland then!

Then again I also seem to remember a certain annoying storm called Fay....

[Gustywind]

Anna as it debuts... a fighter in spite of its poor sat apparence...

[Gustywind]

Yep Ana is taking a good jog to the WNW, motion seems to be about 285, heading back towards the NHC track now it seems, looks like its going to kill itself overland then!

Then again I also seem to remember a certain annoying storm called Fay....

NHC continue on west drift...


000
WTNT42 KNHC 161443
TCDAT2
TROPICAL STORM ANA DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1100 AM AST SUN AUG 16 2009

ANA CONTINUES TO RACE WESTWARD...WITH LIMITED DEEP CONVECTION OVER
THE LOW-LEVEL CENTER.
000
WTNT42 KNHC 161443
TCDAT2
TROPICAL STORM ANA DISCUSSION NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1100 AM AST SUN AUG 16 2009

ANA CONTINUES TO RACE WESTWARD...WITH LIMITED DEEP CONVECTION OVER
THE LOW-LEVEL CENTER.
000
WTNT22 KNHC 161438
TCMAT2
TROPICAL STORM ANA FORECAST/ADVISORY NUMBER 18
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1500 UTC SUN AUG 16 2009
TROPICAL STORM CENTER LOCATED NEAR 14.8N 55.8W AT 16/1500Z
POSITION ACCURATE WITHIN 25 NM

PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT 20 KT

[KWT]

Looks to me ove the last few hours Ana has lifted up onto a 285 type heading, that would be right along the NHC track path and would cause it to probably degenerate over Cuba I'd guess.

[Gustywind]

Looks to me ove the last few hours Ana has lifted up onto a 285 type heading, that would be right along the NHC track path and would cause it to probably degenerate over Cuba I'd guess.

Let's wait and see as usual

[jinftl]

One graphic that most folks don't take a look at is the Wind Probability Distribution the NHC puts out with each advisory. The latest one for Ana is shown below.

What it shows is important for folks to keep in mind...forecast intensity is based on 'what has the highest probability' of taking place. Given the larger than usual unknowns with Ana....those include imminent dissipation (and possible reformation down the road in the Gulf?) and interaction with land or slipping south of Hispanola & Cuba....it's just good to keep in mind that very few solutions have been completely ruled out.

What is interesting...and this may be because of the chance Ana may have dissipated...is that on Wed morning, there is a 50% chance Ana will be a ts (even though official forecast is for a 35mph td). Ana has a higher probability (16%) of being a hurricane at that time than having dissipated (13%). Upon reaching the se GoM of florida on thursday morning, Ana being a ts is still the highest single probability outcome (40%).

Once in the Gulf of Friday, there is 42% chance we will be looking at a ts or hurricane (35% ts + 7% hurricane), 26% chance of being a depression, and a 32% of being dissipated. Out of all that, comes the current forecast for a 35 mph td.

[Javlin]

Good info jinftl now that it has been stated I would maybe assume the forcast intensity's are man made by the NHC while the chart is computer generated?If so while most models throw out Ana to dissipation were do they get the numbers?