Major Hurricane Bill

[Paranoid]

000

WTNT33 KNHC 151434

TCPAT3

BULLETIN

TROPICAL DEPRESSION THREE ADVISORY NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009

1100 AM AST SAT AUG 15 2009

...TROPICAL DEPRESSION THREE FORMS IN THE EASTERN ATLANTIC...

AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL DEPRESSION THREE

WAS LOCATED NEAR LATITUDE 11.5 NORTH...LONGITUDE 34.0 WEST OR ABOUT

740 MILES...1190 KM...WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS.

THE DEPRESSION IS MOVING TOWARD THE WEST NEAR 17 MPH...27 KM/HR...

AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE

OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER

GUSTS. SLOW STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...

AND THE DEPRESSION IS EXPECTED TO BECOME A TROPICAL STORM LATER

TODAY OR ON SUNDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

...SUMMARY OF 1100 AM AST INFORMATION...

LOCATION...11.5N 34.0W

MAXIMUM SUSTAINED WINDS...35 MPH

PRESENT MOVEMENT...WEST OR 265 DEGREES AT 17 MPH

MINIMUM CENTRAL PRESSURE...1006 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT

500 PM AST.

$$

FORECASTER BEVEN

[Iceberg]

I am currently on Holiday, but am finding the time to have a quick look now and again.

Some very good structure on TD3, Tight circulation, good banding, inflow, outflow, when we get the Dirurnal minimum later we might see a CDO forming, as good solid convection is all it's really missing.

Path is near Puerto Rico at the end of the timeframe as a Major Hurricane, with has some good guidance from the models.

Looking good and a named storm late today probably.

[kold weather]

Models are shifting northwards, CMC 12z run showing a massive recurve...

However I am not buying it in the slightest. The simple reason is the CMC along with the last few ECM runs have been way too slow with regards to TD3's motion. For example todays CMC has this reaching 40W around 36hrs time which given its already around 34.5W and moving about 15kts, thats not going to happen. Also the 0z ECM was even slower, it had TD3 at just 43W by 72hrs, so there can be little surprise that it recurves the system on its morning run. We shall see if the 12z ECM has a better grip on the true nature of TD3 soon enough. The 12z GFS is a much more realisitic run though even that is now just about missing the Leeward islands. We shall see in that respect, tomorrows action should reveal a lot about whether the models tonight have the right idea.

Anyway convection has weakened as a region of low level convergence has once again developed away form the center, which is not going to allow it to strengthen at all. However its structure has improved quite a lot recently. In this case once again all it needs is a big burst of convection and TD3 could be upgraded about 6-9hrs later. Something to moniter.

So in conclusion, models have shifted northwards, but I think they are going to get caught out by the forward speed. Whilst the evolution may be right until they adjust the forward speed issue then thy are going to come acrop...remember Frances, Isabel, Ivan, Dean, Fay and Ike were all forecasted to recurve a LOT sooner then actually ended up doing, if indeed they ever really did...

So I think this is still a huge threat to the Leeward islands, probably the Bahamas if the southern option is right, maybe Florida and the east coast as well but thats very uncertain.

[Iceberg]

Definately a shift northwards. The only model which doesn't is the 12Z Meto. Which forecasts the below.

A shift northwards from GFS, which strongly indicates that Jamaica etc is spared.

General intensity is a CAT3/4.

GFS CAT 3, GFDL CAT 3, SHIPS CAT 3.

HWRF CAT 4, METO CAT 4.

TROPICAL DEPRESSION THREE ANALYSED POSITION : 10.9N 33.7W

ATCF IDENTIFIER : AL032009

VERIFYING TIME POSITION STRENGTH TENDENCY

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

12UTC 15.08.2009 10.9N 33.7W WEAK

00UTC 16.08.2009 11.1N 35.7W MODERATE INTENSIFYING SLIGHTLY

12UTC 16.08.2009 11.3N 39.1W MODERATE INTENSIFYING SLIGHTLY

00UTC 17.08.2009 11.8N 41.8W MODERATE LITTLE CHANGE

12UTC 17.08.2009 12.6N 45.3W MODERATE LITTLE CHANGE

00UTC 18.08.2009 13.5N 49.1W STRONG LITTLE CHANGE

12UTC 18.08.2009 14.0N 52.5W MODERATE WEAKENING SLIGHTLY

00UTC 19.08.2009 14.4N 56.0W MODERATE WEAKENING SLIGHTLY

12UTC 19.08.2009 14.7N 59.3W MODERATE LITTLE CHANGE

00UTC 20.08.2009 14.9N 62.7W MODERATE LITTLE CHANGE

12UTC 20.08.2009 15.9N 66.1W MODERATE INTENSIFYING SLIGHTLY

00UTC 21.08.2009 16.3N 69.0W MODERATE INTENSIFYING SLIGHTLY

12UTC 21.08.2009 16.8N 71.7W INTENSE INTENSIFYING RAPIDLY

[kold weather]

Very true however I'm seeing more data that makes me think at least the right outlier, CMC and the ECM are going to be wrong.

Out of 9 storms that were moving west at this latitude, only 2 recurved, the others all struck land. Secondly take a look at the upper high:

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

You can see the dry air circulation inside the high as its an area of subsidence. Notice now that its extending out to 40W and still pushing westwards. Until it gets past this upper high TD3 won't gain any latitude and may even slightly loose it. The weakness is also quite noticeable in the central Atlantic. Ana is now responding to this feature and now on a 280 track, TD3 should do the same thing however to what extent is something the models have a massive degree of uncertainty about.

The ECM slows TD3 down somewhat and the weakness slowly strengthens which causes TD3 to be lifted out on its 12z run. However the 12z GFS is faster and thus only just clears the islands. The UKMO doesn't make much of the weakness at all. I wouldn't like to make a call right now though given history I'd guess the GFS or the UKMO is probably the best call right now, something between the two.

Something to watch for, the 12z has this at 50W roughly by 12z Tuesday. If this is looking too slow then the ECM run isn't likely to come off. This is the key to me to be honest.

[Paranoid]

The latest HWRF run took this to 920mbar and 117kts. Does HWRF tend to over-estimate things as this seems somewhat intense compared to the GDFL run.

[kold weather]

Firstly looks like TD3 is going to be upgraded to tropical storm Bill this next advisory.

Secondly Paranoid, you need to look at the speed not the pressure, it doesn't seem to have a very good wind speed/pressure relationship usually. Its forecasting a category-4. Whilst thats high if it does get into a good set-up thats quite possible down the line, indeed most systems that became a TS near this area went on to become major hurricanes.

[Paranoid]

Ahh, thanks for clarifing that :lol:

Second advisory here

000

WTNT33 KNHC 152033

TCPAT3

BULLETIN

TROPICAL STORM BILL ADVISORY NUMBER 2

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009

500 PM AST SAT AUG 15 2009

...TROPICAL STORM BILL...THE SECOND TROPICAL STORM OF THE SEASON

FORMS IN THE FAR EASTERN ATLANTIC...

SATELLITE IMAGES INDICATE THAT TROPICAL DEPRESSION TWO HAS

STRENGTHENED AND HAS BECOME TROPICAL STORM BILL..THE SECOND NAME

CYCLONE OF THE SEASON. AT 500 PM AST...2100 UTC...THE CENTER OF

THE TROPICAL STORM WAS LOCATED NEAR LATITUDE 11.3 NORTH...LONGITUDE

35.2 WEST OR ABOUT 820 MILES...1320 KM...WEST-SOUTHWEST OF THE CAPE

VERDE ISLANDS.

BILL IS MOVING TOWARD THE WEST NEAR 16 MPH...26 KM/HR. A GRADUAL

TURN TO THE WEST-NORTHWEST IS EXPECTED DURING THE NEXT FEW DAYS.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 40 MPH...65

KM/HR...WITH HIGHER GUSTS. SOME STRENGTHENING IS FORECAST DURING

THE NEXT 24 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM

FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES.

...SUMMARY OF 500 PM AST INFORMATION...

LOCATION...11.3N 35.2W

MAXIMUM SUSTAINED WINDS...40 MPH

PRESENT MOVEMENT...WEST OR 265 DEGREES AT 16 MPH

MINIMUM CENTRAL PRESSURE...1004 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT

1100 PM AST.

$$

FORECASTER AVILA

[Somerset Squall]

Bill is indeed now a 35kt tropical storm. Convection isn't all that impressive just now actually, especially over the LLC. Most of the convection present is in banding circling the storm. A band is particularly defined in the eastern quadrant of Bill, this may well shield the LLC from the dry air to the north and east. Bill will be able to strengthen more aggressively once the convection builds over the centre, and those outer bands will need to wrap fully around the LLC before this can occur. So, initally, strengthening will probably be quite slow. Once the convection is healthy over Bill's centre then some pretty quick intensifcation could occur especially as the circulation is very strong. Additionally, Bill will probably duck south of most of the dry air in the region, and also Ana may act as a shield against some of it, meaning Bill should get much stronger than Ana, at least initially.

[Cookie]

I like how ana and bill seem connected

models suggest a strong or major hurricane down the line

[ukweathergirl]

I've got a question...what does TD3 mean? I know that is a tropical depression but I don't remember them ever having a number afterwards refering them. Is it just as simple as the strenght it is before it reaches a TS?

[Cookie]

I've got a question...what does TD3 mean? I know that is a tropical depression but I don't remember them ever having a number afterwards refering them. Is it just as simple as the strenght it is before it reaches a TS?

each tropical depression in the atlantic gets a number after it, we had TD1 in may, and TD2 was ana and TD3 bill. the number on corrosponds to the number of tropical depressions in the atlantic this season.

[MAF]

latest update

...BILL MOVING WESTWARD OVER THE FAR EASTERN ATLANTIC...

AT 1100 PM AST...0300 UTC...THE CENTER OF TROPICAL STORM BILL WAS

LOCATED NEAR LATITUDE 11.3 NORTH...LONGITUDE 36.6 WEST OR ABOUT 905

MILES...1460 KM...WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS.

BILL IS MOVING TOWARD THE WEST NEAR 16 MPH...26 KM/HR...AND THIS

MOTION WITH A GRADUAL TURN TO THE WEST-NORTHWEST IS EXPECTED DURING

THE NEXT 24 TO 48 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/HR...WITH HIGHER

GUSTS. SOME STRENGTHENING IS FORECAST AND BILL IS FORECAST TO

BECOME A HURRICANE DURING THE NEXT FEW DAYS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM

FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES.

[Iceberg]

I thought it was time to show a quick picture will all three storms on it (didn't think I would be saying that this year ! ).

I've put it in here, as you can see quite how big Bill is. His outer bands would stretch from Florida to Texas.

Due to his size he's probably going to take a few days to wind up, He's also sucking up alot of moisture, which he needs to digest and spit out again, in order to get his core working probably.

The Convection he's been firing up over his core shows that he's trying and he's certaintly improving and won't suffer from the same problems as Ana.

The path is looking more and more land free, but to do this is needs to start the NW turn in the next 24 hours, if he does the first land he might hit would be Greenland as he recurves all the way around the Atlantic High.

Current intensity looks to still be around 35-40Kts as he continues to re-organise from a well banded TS to a true warm core storm.

[Iceberg]

This is where ECM puts Bill 10 days down the line.......

Edited August 16, 2009 by Iceberg

[Rob]

looks like bill will be a CAT 1 hurricane by tomorrow evening according the the latest forecasts.

[kold weather]

Yeah models are now showing Carol 1953 as the best match to Bill, indeed the track is exceptionally close. Bil is starting to take on a more classic look with the convection now also wrapping around the eastern side and over the northern part of the circulation itself which suggest this is strengthening.

Still looking highly likely this will be a major hurricane a category-4 also seems more then possible IMO if it doesn't speed up too much.

[Rob]

completely agree with you kold, this is a rapidly developing system and a strong cat 4 is looking very likely.

[Somerset Squall]

Track continues to shift northwards for Bill; the stronger it gets initally, the more likely it will get picked up and re-curved to the northeast. As Ana has remained weak, she is more likely to track through the Caribbean. Looks very likely Bill will become a major hurricane, so let's hope he continues to shift to the north and stays away from land.

Bill, unlike last night, is building some more concentrated convection over the centre. This should be the precursor to some significant strengthening now.

[Typhoon John]

It looks like a potential East Coast (Carolinas? Long Island?) hurricane to me with that high in the Atlantic just forcing it close enough to land.

Also convection really starting to pick up now so some rapid intensification to hurricane status.

[geoffw]

does anyone know the websitte for the eastern usa that follows the hurricane? it is a forum discussion. steve murr mentioned it last year.

[Cookie]

5 day forecast from weather underground

and sat image

[Paranoid]

Strengthening at a fair rate now , up to 60mph

000

WTNT33 KNHC 161441

TCPAT3

BULLETIN

TROPICAL STORM BILL ADVISORY NUMBER 5

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009

1100 AM AST SUN AUG 16 2009

...BILL STRENGTHENING OVER THE CENTRAL TROPICAL ATLANTIC OCEAN...

AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL STORM BILL WAS

LOCATED NEAR LATITUDE 12.1 NORTH...LONGITUDE 38.4 WEST OR ABOUT 1555

MILES...2500 KM...EAST OF THE LESSER ANTILLES.

BILL IS MOVING TOWARD THE WEST-NORTHWEST NEAR 16 MPH...26 KM/HR...

AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE

OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/HR...WITH HIGHER

GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS AND BILL

COULD BECOME A HURRICANE ON MONDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 140 MILES...220 KM

FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB...29.44 INCHES.

...SUMMARY OF 1100 AM AST INFORMATION...

LOCATION...12.1N 38.4W

MAXIMUM SUSTAINED WINDS...60 MPH

PRESENT MOVEMENT...WEST-NORTHWEST OR 285 DEGREES AT 16 MPH

MINIMUM CENTRAL PRESSURE...997 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT

500 PM AST.

$$

FORECASTER BLAKE

[Iceberg]

Bill is looking very good atm, improving nicely and probably 55Kt to 60Kts now.

Convection steady in the centre, outflow and inflow good.

[weatherobsuk]

If Bill continues on a southerly track being taken by the trade winds towards Puerto Rico whilst maintaining strength to (what some are speculating) could be a CAT4 storm, then by tomorrow or Tuesday morning i'd seriously be considering booking the next avaliable plane to the Island for a Intercept.

If that fails and Bill keeps a Northerly track then Bermuda would be my next best bet.

Edited August 16, 2009 by SNOW_JOKE