ATL: TROPICAL STORM BILL (03L)

[Derek Ortt]

for those wanting a US hit, you want a stronger trough, not a weaker trough. A weaker trough is more zonal while a stronger one is more south north

[GeneratorPower]

OK ... so here's the 500mb 126 hour frame of the 12z HWRF:



There is a bit of a trough axis extending down in the vicinity of the Appalachian chain, but frankly this looks like touch and go as far as turning Bill east of north ...

I'd guess that this run would be offshore of the US northeast, but just barely so.

My question is, look at the big indentation Bill is making in the western side of the ridge. Why would that happen? Seems to me that Bill would take the path of least resistance and just scoot around the ridge rather than plow right through it.

[ronjon]

I'm starting to get concerned for the New England coast now. We have a very large, soon to be very strong tropical cyclone that may travel very close to LI, Cape Cod, or eastern Maine. No doubt it will weaken somewhat by the cooler water, but it would also be a major hurricane accelerating in forward speed. If the trough isn't as progressive or takes on a negative tilt, new england could bear the brunt of major storm. This situation really bears watching.

[artist]

hmmmmm

ok deltadog, let me in on what these two models are that are showing a west component at the end. lol What is your hmmmm thinking?!

[TreasureIslandFLGal]

If you look over at the Ana threads, the Melbourne office speaks of the influence of the trough later in the week and how it is expected to lag and then not be as strong as initialy thought. They also expect a more north to south positioning of it, resulting in southerly winds that linger for a few days in front of it.

Such a positioning speaks to a more westerly path for Bill, if the front isn't expected to bypass Melbourne through the weekend, before it then can make the turn north. A north to south front also makes for a more directly north path for Bill, rather than a NNE/NE path.

I think Carolinas to NE should watch for a storm approaching from due south. (see disclaimer...not a pro...just mho..blah blah)

[SEASON_CANCELED]

Its to steep of a curve. Something is amess with the Data. It is south of the Forecast Points. They are readjusting the TFPs with each satelitte refresh making the curve look steeper.


We shall see

[ronjon]

for those wanting a US hit, you want a stronger trough, not a weaker trough. A weaker trough is more zonal while a stronger one is more south north

Great point Derek plus the orientation (neg or pos) but I don't think anyone is wanting a US hit from this major.

[Blown Away]

hmmmmm

ok deltadog, let me in on what these two models are that are showing a west component at the end. lol What is your hmmmm thinking?!

Maybe a stall? Trough not strong enough and leaves Bill behind?

[Blown Away]

for those wanting a US hit, you want a stronger trough, not a weaker trough. A weaker trough is more zonal while a stronger one is more south north

So folks in SFL need to start watching for a strong trough? Come on!!!

[CrazyC83]

AL, 03, 2009081718, , BEST, 0, 144N, 460W, 80, 969, HU, 34, NEQ,

[caneseddy]

AL, 03, 2009081718, , BEST, 0, 144N, 460W, 80, 969, HU, 34, NEQ,

From the 11 am advisory to the best track quoted above it moved .3 north and .8 west

Sorry, couldn't resist the wobble watch

[tolakram]

I'm not seeing any miss of points south or anything else nefarious.

[Brent]

hmmmmm

Hmmmm indeed.

I'm waiting for some more runs before I get too worked up.

[JPmia]

Since nobody posted it. Here is the Euro model 12z.

http://www.ecmwf.int/products/forecasts ... 9081712!!/

[otowntiger]

hmmmmm

Hmmmm indeed.

I'm waiting for some more runs before I get too worked up.

You do know that the straight purple line bringing him right into the FL Straights is just the extrapolated line, right? There's no model suggesting that path.

[CronkPSU]

Since nobody posted it. Here is the Euro model 12z.

http://www.ecmwf.int/products/forecasts ... 9081712!!/

that one looks to give the US less of a scare

[Brent]

BULLETIN
HURRICANE BILL ADVISORY NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST MON AUG 17 2009

...BILL HEADING WEST-NORTHWESTWARD...LITTLE CHANGE IN STRENGTH...

AT 500 PM AST...2100 UTC...THE CENTER OF HURRICANE BILL WAS LOCATED
NEAR LATITUDE 14.6 NORTH...LONGITUDE 46.7 WEST OR ABOUT 975 MILES...
1570 KM...EAST OF THE LESSER ANTILLES.

BILL IS MOVING TOWARD THE WEST-NORTHWEST NEAR 16 MPH...26 KM/HR...
AND THIS MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 90 MPH...150 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48
HOURS...AND BILL COULD BECOME A MAJOR HURRICANE BY WEDNESDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 145
MILES...230 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON DATA FROM NOAA BUOY
41041 IS 969 MB...28.61 INCHES.

...SUMMARY OF 500 PM AST INFORMATION...
LOCATION...14.6N 46.7W
MAXIMUM SUSTAINED WINDS...90 MPH
PRESENT MOVEMENT...WEST-NORTHWEST OR 285 DEGREES AT 16 MPH
MINIMUM CENTRAL PRESSURE...969 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.

$$
FORECASTER ROBERTS/BRENNAN

HURRICANE BILL FORECAST/ADVISORY NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
2100 UTC MON AUG 17 2009

HURRICANE CENTER LOCATED NEAR 14.6N 46.7W AT 17/2100Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 14 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 969 MB
MAX SUSTAINED WINDS 80 KT WITH GUSTS TO 100 KT.
64 KT....... 25NE 25SE 25SW 25NW.
50 KT....... 65NE 50SE 30SW 60NW.
34 KT.......125NE 105SE 75SW 125NW.
12 FT SEAS..280NE 225SE 110SW 200NW.
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 14.6N 46.7W AT 17/2100Z
AT 17/1800Z CENTER WAS LOCATED NEAR 14.4N 46.0W

FORECAST VALID 18/0600Z 15.2N 48.7W
MAX WIND 90 KT...GUSTS 110 KT.
64 KT... 30NE 30SE 30SW 30NW.
50 KT... 75NE 55SE 40SW 65NW.
34 KT...145NE 120SE 75SW 130NW.

FORECAST VALID 18/1800Z 16.2N 51.3W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 40NE 35SE 35SW 35NW.
50 KT... 75NE 60SE 45SW 65NW.
34 KT...160NE 120SE 75SW 145NW.

FORECAST VALID 19/0600Z 17.4N 53.8W
MAX WIND 100 KT...GUSTS 120 KT.
64 KT... 40NE 35SE 35SW 40NW.
50 KT... 75NE 60SE 50SW 70NW.
34 KT...160NE 120SE 90SW 145NW.

FORECAST VALID 19/1800Z 18.8N 56.4W
MAX WIND 105 KT...GUSTS 130 KT.
50 KT... 80NE 65SE 55SW 75NW.
34 KT...160NE 120SE 95SW 150NW.

FORECAST VALID 20/1800Z 22.5N 61.0W
MAX WIND 110 KT...GUSTS 135 KT.
50 KT... 90NE 75SE 65SW 75NW.
34 KT...180NE 150SE 105SW 150NW.

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 21/1800Z 27.0N 65.0W
MAX WIND 110 KT...GUSTS 135 KT.

OUTLOOK VALID 22/1800Z 33.1N 67.5W
MAX WIND 105 KT...GUSTS 130 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.6N 46.7W

NEXT ADVISORY AT 18/0300Z

$$
FORECASTER BRENNAN/ROBERTS

HURRICANE BILL DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032009
500 PM AST MON AUG 17 2009

BILL IS BEGINNING TO SHOW SIGNS OF DEVELOPING INNER CORE FEATURES...
WITH HINTS OF AN EYE FORMING IN RECENT SATELLITE IMAGERY AND
EXPANDING COLD CLOUD TOPS AROUND THE CENTER. DVORAK T-NUMBERS WERE
4.5 FROM SAB AND TAFB AT 1800 UTC...AND THE INITIAL INTENSITY IS
HELD AT 80 KT FOR THIS PACKAGE. BILL PASSED JUST TO THE NORTH OF
NOAA BUOY 40141 THIS AFTERNOON...WHICH REPORTED A MINIMUM PRESSURE
OF 972 MB AT 1800 UTC WITH A PEAK 1-MINUTE WIND OF 51 KT. BASED ON
THESE DATA...THE CENTRAL PRESSURE ESTIMATE IS REDUCED TO 969 MB.

THE INTENSITY FORECAST IS UNCHANGED FROM THE PREVIOUS PACKAGE. THE
ENVIRONMENT AROUND THE CYCLONE APPEARS FAVORABLE FOR
INTENSIFICATION. OCEAN TEMPERATURES INCREASE ALONG THE TRACK...AND
THE GFS AND ECMWF BOTH SHOW AN UPPER-LEVEL ANTICYCLONE DEVELOPING
OVER THE SYSTEM. AS WAS THE CASE EARLIER...THE SHIPS AND LGEM SHOW
A BROAD PEAK IN INTENSITY IN 2 OR 3 DAYS...WHILE THE HWRF AND GFDL
SHOW ARE STRONGER LATER IN THE PERIOD. THE OFFICIAL FORECAST REMAINS
UNCHANGED FROM THE PREVIOUS ADVISORY...PEAKING A LITTLE HIGHER THAN
THE SHIPS AND LGEM BEFORE SHOWING SOME WEAKENING AT DAY 5.

THE INITIAL MOTION ESTIMATE IS 285/14. THE TRACK MODEL GUIDANCE IS
IN EXCELLENT AGREEMENT THROUGH 48 HOURS...AND THROUGH THAT TIME THE
OFFICIAL FORECAST IS SIMPLY AN EXTENSION OF THE PREVIOUS PACKAGE.
BEYOND THAT TIME ALMOST ALL OF THE TRACK GUIDANCE HAS SHIFTED TO
THE LEFT....WITH THE EXCEPTION OF THE UKMET...WHICH HAS FINALLY
TRENDED TOWARD A RECURVATURE SCENARIO. ALL OF THE GLOBAL MODELS NOW
SHOW BILL INTERACTING WITH A LARGE MID TO UPPER-LEVEL TROUGH
CENTERED OVER THE EASTERN UNITED STATES BY THE END OF THE
PERIOD...HOWEVER THERE ARE DIFFERENCES IN THE AMPLITUDE AND SPEED OF
THE TROUGH THAT WILL BE CRUCIAL TO WHEN AND WHERE BILL RECURVES.
INTERESTINGLY...THE GFS AND ECMWF ARE IN EXCELLENT AGREEMENT AT 5
DAYS...BUT NOW LIE ON THE EASTERN EDGE OF THE GUIDANCE ENVELOPE...
WITH THE GFS ENSEMBLE MEAN EVEN FARTHER EAST. GIVEN THE SPREAD IN
THE GUIDANCE...THE OFFICIAL FORECAST IS SHIFTED ONLY SLIGHTLY TO
THE LEFT OF THE PREVIOUS PACKAGE AT DAYS 3 THROUGH 5...AND LIES
BETWEEN THE TVCN MULTI-MODEL CONSENSUS AND THE ECMWF/GFS BLEND.

THIS IS A GOOD TIME TO EMPHASIZE THE UNCERTAINTY THAT EXISTS IN
TRACK FORECASTING IN THE 3 TO 5 DAY PERIOD...WHERE AVERAGE NHC
TRACK ERRORS ARE TYPICALLY SEVERAL HUNDRED MILES.

FORECAST POSITIONS AND MAX WINDS

INITIAL 17/2100Z 14.6N 46.7W 80 KT
12HR VT 18/0600Z 15.2N 48.7W 90 KT
24HR VT 18/1800Z 16.2N 51.3W 95 KT
36HR VT 19/0600Z 17.4N 53.8W 100 KT
48HR VT 19/1800Z 18.8N 56.4W 105 KT
72HR VT 20/1800Z 22.5N 61.0W 110 KT
96HR VT 21/1800Z 27.0N 65.0W 110 KT
120HR VT 22/1800Z 33.1N 67.5W 105 KT

$$
FORECASTER BRENNAN/ROBERTS

[storm4u]

i think i may be heading to the cape or eastern maine in a few days we will see.. Im not getting my hopes up yet but im getting there

[Dean4Storms]

Still not completely sold on this trough and the timing with Bill this far out necessarily sending Bill out to sea. The slightest difference in trough orientation (Pos/Neg tilts) or depth of the trough or even the strength of the Atlantic Ridge could bring about some major differences in the track down the road. Keep in mind the degree of miles in error we usually see with forecasted tracks beyond just 3 days then extrapolate that!

[weatherSnoop]

Loosing visible, though shows the inner core development as update mentioned