T Storm Helene Advisories=Last Advisory Written by NHC

[WeatherTracker]

Hurricane Helene Discussion Number 18

Statement as of 5:00 PM EDT on September 16, 2006



Dvorak estimates from TAFB and SAB have not changed and a ragged eye
has been observed this afternoon in the visible imagery. CIMSS
experimental advanced Dvorak technique also suggests minimal
hurricane intensity. Thus...a 65 kt initial intensity is retained.
Today...a NOAA salex...Saharan air layer Experiment...mission on
the G-IV aircraft has been taking observations in the periphery of
Helene. While these dropwindsondes are showing substantial dry
air...CIRA precipitable water analyses suggest that sufficient
moisture is found in the system's inner core. Because of 27.5 c
SSTs...light/moderate vertical shear...and a moist environment...
continued slow intensification is anticipated. After two days...
both the shear and SSTs increase. Because of these conflicting
environmental factors...Helene is projected to peak in intensity
near 85 kt at days 2 and 3 with slight weakening thereafter. It is
noted that the GFDL model fields retain weaker shear into longer
lead times than the global models. The official forecast is
slightly above the Standard SHIPS model due to the influence of an
enhancing microwave predictor in the experimental SHIPS-microwave
model and is slightly below the previous prediction.

Current motion is estimated to be 310/11. Helene is moving toward a
break in the west-southwest to east-northeast oriented subtropical
ridge axis. After day 2...there is a large model divergence in the
track of Helene. The GFDL and UK quickly accelerate the system to
the north in advance of a strong short wave moving off of the US
Atlantic Seaboard. In contrast...the GFS...the GFS ensemble and
the ECMWF models turn Helene to the west-northwest and do not have
it picked up by the short wave trough. The NOGAPS and GFDN
models...as well as consensus approaches...split the difference.
As it is difficult to know which group will be correct...the track
forecast depicted here is close to the CONU consensus and is
slightly slower and just to the right of the previous forecast.
Perhaps with the model assimilation of the salex dropwindsondes...
the large model differences will be reduced in the next forecast
cycle.

Forecast positions and Max winds

initial 16/2100z 19.3n 46.3w 65 kt
12hr VT 17/0600z 20.0n 47.4w 70 kt
24hr VT 17/1800z 20.9n 48.7w 80 kt
36hr VT 18/0600z 21.8n 49.8w 85 kt
48hr VT 18/1800z 22.6n 51.0w 85 kt
72hr VT 19/1800z 24.0n 53.5w 85 kt
96hr VT 20/1800z 26.0n 56.0w 80 kt
120hr VT 21/1800z 29.0n 57.5w 75 kt

[WeatherTracker]

Hurricane Helene Forecast/Advisory Number 18

2100 UTC Sat Sep 16 2006


hurricane center located near 19.3n 46.3w at 16/2100z
position accurate within 15 nm

present movement toward the northwest or 310 degrees at 11 kt

estimated minimum central pressure 987 mb
eye diameter 45 nm
Max sustained winds 65 kt with gusts to 80 kt.
64 kt....... 25ne 0se 0sw 0nw.
50 kt....... 40ne 40se 25sw 40nw.
34 kt.......150ne 150se 100sw 125nw.
12 ft seas..200ne 180se 180sw 225nw.
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 19.3n 46.3w at 16/2100z
at 16/1800z center was located near 19.1n 45.9w

forecast valid 17/0600z 20.0n 47.4w
Max wind 70 kt...gusts 85 kt.
64 kt... 30ne 20se 0sw 20nw.
50 kt... 50ne 50se 35sw 50nw.
34 kt...150ne 150se 100sw 125nw.

Forecast valid 17/1800z 20.9n 48.7w
Max wind 80 kt...gusts 100 kt.
64 kt... 30ne 20se 0sw 20nw.
50 kt... 50ne 50se 35sw 50nw.
34 kt...150ne 150se 100sw 125nw.

Forecast valid 18/0600z 21.8n 49.8w
Max wind 85 kt...gusts 105 kt.
64 kt... 35ne 25se 20sw 25nw.
50 kt... 60ne 50se 35sw 50nw.
34 kt...175ne 150se 100sw 150nw.

Forecast valid 18/1800z 22.6n 51.0w
Max wind 85 kt...gusts 105 kt.
50 kt... 60ne 50se 35sw 50nw.
34 kt...175ne 150se 100sw 150nw.

Forecast valid 19/1800z 24.0n 53.5w
Max wind 85 kt...gusts 105 kt.
50 kt... 70ne 60se 35sw 50nw.
34 kt...200ne 175se 125sw 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 20/1800z 26.0n 56.0w
Max wind 80 kt...gusts 100 kt.

Outlook valid 21/1800z 29.0n 57.5w
Max wind 75 kt...gusts 90 kt.

Request for 3 hourly ship reports within 300 miles of 19.3n 46.3w

next advisory at 17/0300z

$$
forecaster Beven/landsea

[WeatherTracker]

Tropical Storm Public Advisory

Statement as of 5:00 PM AST on September 16, 2006



...Helene continues toward the northwest with no change in
intensity...
At 500 PM AST...2100z...the center of Hurricane Helene was located
near latitude 19.3 north...longitude 46.3 west or about 1100 miles
...1775 km...east of the northern Leeward Islands.

Helene is moving toward the northwest near 13 mph...20 km/hr...and
this motion is expected to continue during the next 24 hours.

Maximum sustained winds are near 75 mph...120 km/hr...with higher
gusts. Some strengthening is forecast during the next 24 hours.

Hurricane force winds extend outward up to 30 miles...45 km...from
the center...and tropical storm force winds extend outward up to 175
miles...280 km.

Estimated minimum central pressure is 987 mb...29.15 inches.

Repeating the 500 PM AST position...19.3 N...46.3 W. Movement
toward...northwest near 13 mph. Maximum sustained winds...75 mph.
Minimum central pressure...987 mb.

The next advisory will be issued by the National Hurricane Center at
1100 PM AST.

$$
Forecaster Beven/landsea

[Brent]

HURRICANE HELENE FORECAST/ADVISORY NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
0300 UTC SUN SEP 17 2006

HURRICANE CENTER LOCATED NEAR 19.5N 47.5W AT 17/0300Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 984 MB
MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT.
64 KT....... 20NE 20SE 15SW 20NW.
50 KT....... 40NE 40SE 30SW 40NW.
34 KT.......150NE 150SE 100SW 125NW.
12 FT SEAS..200NE 180SE 180SW 225NW.
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 19.5N 47.5W AT 17/0300Z
AT 17/0000Z CENTER WAS LOCATED NEAR 19.3N 47.1W

FORECAST VALID 17/1200Z 20.2N 48.5W
MAX WIND 75 KT...GUSTS 90 KT.
64 KT... 25NE 25SE 15SW 25NW.
50 KT... 50NE 50SE 35SW 50NW.
34 KT...150NE 150SE 100SW 125NW.

FORECAST VALID 18/0000Z 21.2N 49.7W
MAX WIND 80 KT...GUSTS 100 KT.
64 KT... 25NE 25SE 15SW 25NW.
50 KT... 50NE 50SE 35SW 50NW.
34 KT...150NE 150SE 100SW 135NW.

FORECAST VALID 18/1200Z 22.1N 50.8W
MAX WIND 85 KT...GUSTS 105 KT.
64 KT... 30NE 25SE 20SW 25NW.
50 KT... 60NE 50SE 40SW 50NW.
34 KT...160NE 160SE 100SW 150NW.

FORECAST VALID 19/0000Z 22.9N 52.3W
MAX WIND 90 KT...GUSTS 110 KT.
50 KT... 70NE 60SE 40SW 60NW.
34 KT...180NE 180SE 100SW 150NW.

FORECAST VALID 20/0000Z 24.1N 55.0W
MAX WIND 90 KT...GUSTS 110 KT.
50 KT... 70NE 60SE 40SW 60NW.
34 KT...180NE 180SE 100SW 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 21/0000Z 26.0N 57.0W
MAX WIND 85 KT...GUSTS 105 KT.

OUTLOOK VALID 22/0000Z 29.0N 58.5W
MAX WIND 80 KT...GUSTS 100 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.5N 47.5W

NEXT ADVISORY AT 17/0900Z

$$
FORECASTER STEWART

[WeatherTracker]

Tropical Storm Public Advisory

Statement as of 11:00 PM AST on September 16, 2006


...Helene getting a little better organized over the open tropical
Atlantic...

at 1100 PM AST...0300z...the center of Hurricane Helene was located
near latitude 19.5 north...longitude 47.5 west or about 1025 miles
...1645 km...east of the northern Leeward Islands.

Helene is moving toward the west-northwest near 10 mph...17 km/hr.
A motion between west-northwest and northwest is expected during the
next 24 hours

maximum sustained winds are near 80 mph...130 km/hr...with higher
gusts. Slow strengthening is forecast during the next 24 hours.

Hurricane force winds extend outward up to 25 miles...35 km...from
the center...and tropical storm force winds extend outward up to 175
miles...280 km.

The estimated minimum central pressure is 984 mb...29.06 inches.
Repeating the 1100 PM AST position...19.5 N...47.5 W. Movement
toward...west-northwest near 10 mph. Maximum sustained winds...80
mph. Minimum central pressure...984 mb.

The next advisory will be issued by the National Hurricane Center at
500 am AST.

$$
Forecaster Stewart

[WeatherTracker]

Hurricane Helene Discussion Number 19

Statement as of 11:00 PM EDT on September 16, 2006



the initial motion estimate is 300/09 kt...despite a short term
motion of 290/09 between 18z and 00z. The latter motion is believed
to be a short term wobble as the center reorganizes within the deep
convection. The models remain in excellent agreement on Helene
moving west-northwest to northwestward for the next 36-48 hours
toward a weakness in the subtropical ridge...and then make a slight
westward Bend in 48-72 hours. After that...the models diverge quite
significantly with the GFDL...UKMET...Canadian...and NOGAPS model
taking Helene northward...whereas the GFS...GFS ensemble...the
BAMS...and the statistical-dynamical models keep the hurricane on a
more westward course as a mid-level ridge builds to the north and
northwest of Helene off the U.S. Mid-Atlantic coast by day 5. Water
vapor imagery and 00z upper-air data indicate the upper-low that
has recently moved off the U.S. Mid-Atlantic coast has been moving
eastward similar to the GFS solution...rather than digging
southeastward toward Bermuda as forecast by the other models. With
the strongest winds now indicated by water vapor imagery and
upper-air data to be on the south and east side of the upper-low...
the 18z GFS run may be indicating a significant change in the model
forecast tracks could be forthcoming. However...until the other
models make a change similar to the GFS...the official track was
only nudged slightly westward...based mainly on the more southerly
initial position...and is similar to but a little slower than the
NHC model consensus at 96 and 120 hours.

An earlier windsat microwave overpass indicated Helene possessed a
well developed low-level eye feature. Since then...the ragged eye
feature noted previously in conventional satellite imagery has
eroded...although the past couple of images suggest that a banding
eye feature may be forming. The initial intensity was increased to
70 kt based on a blend of satellite estimates from TAFB and SAB.
Only slow intensification is expected as Helene continues to battle
periodic intrusions of dry air. The upper-level flow pattern and
upstream SSTs favors more significant intensification...but it is
too difficult to predict at this time just when and if Helene will
eventually overcome the effects of the mid-level dry air.

Forecast positions and Max winds

initial 17/0300z 19.5n 47.5w 70 kt
12hr VT 17/1200z 20.2n 48.5w 75 kt
24hr VT 18/0000z 21.2n 49.7w 80 kt
36hr VT 18/1200z 22.1n 50.8w 85 kt
48hr VT 19/0000z 22.9n 52.3w 90 kt
72hr VT 20/0000z 24.1n 55.0w 90 kt
96hr VT 21/0000z 26.0n 57.0w 85 kt
120hr VT 22/0000z 29.0n 58.5w 80 kt

$$
forecaster Stewart

[Brent]

HURRICANE HELENE DISCUSSION NUMBER 19
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1100 PM EDT SAT SEP 16 2006

THE INITIAL MOTION ESTIMATE IS 300/09 KT...DESPITE A SHORT TERM
MOTION OF 290/09 BETWEEN 18Z AND 00Z. THE LATTER MOTION IS BELIEVED
TO BE A SHORT TERM WOBBLE AS THE CENTER REORGANIZES WITHIN THE DEEP
CONVECTION. THE MODELS REMAIN IN EXCELLENT AGREEMENT ON HELENE
MOVING WEST-NORTHWEST TO NORTHWESTWARD FOR THE NEXT 36-48 HOURS
TOWARD A WEAKNESS IN THE SUBTROPICAL RIDGE...AND THEN MAKE A SLIGHT
WESTWARD BEND IN 48-72 HOURS. AFTER THAT...THE MODELS DIVERGE QUITE
SIGNIFICANTLY WITH THE GFDL...UKMET...CANADIAN...AND NOGAPS MODEL
TAKING HELENE NORTHWARD...WHEREAS THE GFS...GFS ENSEMBLE...THE
BAMS...AND THE STATISTICAL-DYNAMICAL MODELS KEEP THE HURRICANE ON A
MORE WESTWARD COURSE AS A MID-LEVEL RIDGE BUILDS TO THE NORTH AND
NORTHWEST OF HELENE OFF THE U.S. MID-ATLANTIC COAST BY DAY 5. WATER
VAPOR IMAGERY AND 00Z UPPER-AIR DATA INDICATE THE UPPER-LOW THAT
HAS RECENTLY MOVED OFF THE U.S. MID-ATLANTIC COAST HAS BEEN MOVING
EASTWARD SIMILAR TO THE GFS SOLUTION...RATHER THAN DIGGING
SOUTHEASTWARD TOWARD BERMUDA AS FORECAST BY THE OTHER MODELS. WITH
THE STRONGEST WINDS NOW INDICATED BY WATER VAPOR IMAGERY AND
UPPER-AIR DATA TO BE ON THE SOUTH AND EAST SIDE OF THE UPPER-LOW...
THE 18Z GFS RUN MAY BE INDICATING A SIGNIFICANT CHANGE IN THE MODEL
FORECAST TRACKS COULD BE FORTHCOMING. HOWEVER...UNTIL THE OTHER
MODELS MAKE A CHANGE SIMILAR TO THE GFS...THE OFFICIAL TRACK WAS
ONLY NUDGED SLIGHTLY WESTWARD...BASED MAINLY ON THE MORE SOUTHERLY
INITIAL POSITION...AND IS SIMILAR TO BUT A LITTLE SLOWER THAN THE
NHC MODEL CONSENSUS AT 96 AND 120 HOURS.

AN EARLIER WINDSAT MICROWAVE OVERPASS INDICATED HELENE POSSESSED A
WELL DEVELOPED LOW-LEVEL EYE FEATURE. SINCE THEN...THE RAGGED EYE
FEATURE NOTED PREVIOUSLY IN CONVENTIONAL SATELLITE IMAGERY HAS
ERODED...ALTHOUGH THE PAST COUPLE OF IMAGES SUGGEST THAT A BANDING
EYE FEATURE MAY BE FORMING. THE INITIAL INTENSITY WAS INCREASED TO
70 KT BASED ON A BLEND OF SATELLITE ESTIMATES FROM TAFB AND SAB.
ONLY SLOW INTENSIFICATION IS EXPECTED AS HELENE CONTINUES TO BATTLE
PERIODIC INTRUSIONS OF DRY AIR. THE UPPER-LEVEL FLOW PATTERN AND
UPSTREAM SSTS FAVORS MORE SIGNIFICANT INTENSIFICATION...BUT IT IS
TOO DIFFICULT TO PREDICT AT THIS TIME JUST WHEN AND IF HELENE WILL
EVENTUALLY OVERCOME THE EFFECTS OF THE MID-LEVEL DRY AIR.

FORECAST POSITIONS AND MAX WINDS

INITIAL 17/0300Z 19.5N 47.5W 70 KT
12HR VT 17/1200Z 20.2N 48.5W 75 KT
24HR VT 18/0000Z 21.2N 49.7W 80 KT
36HR VT 18/1200Z 22.1N 50.8W 85 KT
48HR VT 19/0000Z 22.9N 52.3W 90 KT
72HR VT 20/0000Z 24.1N 55.0W 90 KT
96HR VT 21/0000Z 26.0N 57.0W 85 KT
120HR VT 22/0000Z 29.0N 58.5W 80 KT

$$
FORECASTER STEWART

[dixiebreeze]

Hello Helene

[P.K.]

WTNT43 KNHC 170900
TCDAT3
HURRICANE HELENE DISCUSSION NUMBER 20
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
500 AM EDT SUN SEP 17 2006

SHOWER AND THUNDERSTORM ACTIVITY CONTINUES TO ORGANIZE AROUND
THE CENTER OF HELENE...WITH A BROAD BANDING TYPE EYE IS SEEN IN
INFRARED SATELLITE IMAGERY. GIVEN THE SATELLITE APPEARANCE...A
SOMEWHAT SURPRISING...VERY LARGE 45 TO 60 NM WIDE EYE WAS DETECTED
ON A RECENT 0502 UTC AQUA MICROWAVE OVERPASS. BASED ON THE
MICROWAVE DATA AND SATELLITE INTENSITY ESTIMATES OF 77 KT FROM
SAB AND TAFB...THE INITIAL INTENSITY IS INCREASED TO 75 KT.

THE FUTURE TRACK OF HELENE APPEARS TO BE HIGHLY DEPENDENT ON HOW
THE VARIOUS MODELS ARE HANDLING A COUPLE OF KEY FEATURES. THE FIRST
IS THE AMOUNT OF RIDGING THAT BUILDS BETWEEN HELENE AND THE
DEPARTING HURRICANE GORDON TO THE NORTH...AND THE SECOND IS THE
STRENGTH OF THE TROUGH ALONG THE U.S. EAST COAST IN A COUPLE OF
DAYS. IN ANY CASE...THE DYNAMICAL MODELS REMAIN IN GOOD AGREEMENT
ON A GENERAL WEST-NORTHWEST TO NORTHWEST HEADING DURING THE NEXT
COUPLE OF DAYS. THEREAFTER...THE MODEL SPREAD REMAINS EXTREMELY
LARGE. THE GFS REMAINS ON THE LEFT SIDE OF THE GUIDANCE...AS IT
WEAKENS THE TROUGH BETWEEN THE U.S. AND BERMUDA AND BUILDS A NARROW
MID- TO UPPER-LEVEL RIDGE NORTH OF THE HURRICANE...ALLOWING HELENE
TO MOVE MORE WESTWARD. THE REMAINDER OF THE DYNAMICAL MODELS KEEP
ENOUGH OF A TROUGH NEAR BERMUDA TO IMPART A NORTHWESTWARD MOTION AT
DAYS 4 AND 5. IT IS INTERESTING TO NOTE THAT THE GFDL...WHICH USES
THE INITIAL CONDITIONS OF THE GFS MODEL...IS ON THE FAR RIGHT SIDE
OF THE MODEL GUIDANCE. UNTIL IT BECOMES MORE CLEAR AS TO WHICH
MODEL SOLUTION MAY BE CORRECT...THE OFFICIAL TRACK REMAINS NEAR THE
MODEL CONSENSUS...WHICH IS A LITTLE WEST OF THE PREVIOUS FORECAST.

WITH LOW SHEAR AND WARMER SSTS ALONG THE PREDICTED PATH OF
HELENE...THE ENVIRONMENT APPEARS FAVORABLE FOR ADDITIONAL
STRENGTHENING DURING THE NEXT FEW DAYS. THE OFFICIAL INTENSITY
FORECAST FOLLOWS THE SLIGHTLY HIGHER GFDL AND FSU SUPERENSEMBLE
THROUGH 72 HOURS. THEREAFTER...THE GLOBAL MODELS PREDICT THAT
HELENE WILL BE APPROACHING AN AREA OF INCREASING SOUTHWESTERLY
SHEAR...AND THE INTENSITY FORECAST SHOWS SOME WEAKENING AT DAYS 4
AND 5...HOWEVER NOT AS MUCH INDICATED BY THE SHIPS MODEL.

FORECAST POSITIONS AND MAX WINDS

INITIAL 17/0900Z 20.0N 48.2W 75 KT
12HR VT 17/1800Z 20.7N 49.3W 80 KT
24HR VT 18/0600Z 21.7N 50.5W 85 KT
36HR VT 18/1800Z 22.6N 51.7W 90 KT
48HR VT 19/0600Z 23.3N 53.2W 95 KT
72HR VT 20/0600Z 24.0N 56.0W 95 KT
96HR VT 21/0600Z 26.0N 58.0W 85 KT
120HR VT 22/0600Z 29.0N 59.0W 80 KT

$$
FORECASTER BROWN/KNABB

[Brent]

BULLETIN
HURRICANE HELENE ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1100 AM AST SUN SEP 17 2006

...HELENE STRENGTHENS...FORECAST TO REMAIN OVER WATER...

AT 1100 AM AST...1500Z...THE CENTER OF HURRICANE HELENE WAS LOCATED
NEAR LATITUDE 20.5 NORTH...LONGITUDE 49.0 WEST OR ABOUT 935 MILES...
1500 KM...EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.

HELENE IS MOVING TOWARD THE NORTHWEST NEAR 10 MPH...17 KM/HR...AND
THIS MOTION IS EXPECTED TO CONTINUE TODAY WITH A GRADUAL TURN TO THE
WEST-NORTHWEST ON MONDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 105 MPH...165
KM/HR...WITH HIGHER GUSTS. HELENE IS A STRONG CATEGORY TWO
HURRICANE ON THE SAFFIR-SIMPSON HURRICANE SCALE. SOME ADDITIONAL
STRENGTHENING IS POSSIBLE DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175
MILES...280 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 970 MB...28.64 INCHES.

REPEATING THE 1100 AM AST POSITION...20.5 N...49.0 W. MOVEMENT
TOWARD...NORTHWEST NEAR 10 MPH. MAXIMUM SUSTAINED WINDS...105 MPH.
MINIMUM CENTRAL PRESSURE...970 MB.

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

$$
FORECASTER AVILA

HURRICANE HELENE FORECAST/ADVISORY NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1500 UTC SUN SEP 17 2006

HURRICANE CENTER LOCATED NEAR 20.5N 49.0W AT 17/1500Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 970 MB
EYE DIAMETER 25 NM
MAX SUSTAINED WINDS 90 KT WITH GUSTS TO 110 KT.
64 KT....... 35NE 35SE 25SW 30NW.
50 KT....... 60NE 60SE 40SW 60NW.
34 KT.......150NE 125SE 90SW 125NW.
12 FT SEAS..275NE 200SE 200SW 250NW.
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 20.5N 49.0W AT 17/1500Z
AT 17/1200Z CENTER WAS LOCATED NEAR 20.3N 48.6W

FORECAST VALID 18/0000Z 21.3N 50.1W
MAX WIND 95 KT...GUSTS 115 KT.
64 KT... 35NE 35SE 25SW 30NW.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...150NE 125SE 90SW 125NW.

FORECAST VALID 18/1200Z 22.5N 51.5W
MAX WIND 100 KT...GUSTS 120 KT.
64 KT... 35NE 35SE 30SW 30NW.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...150NE 150SE 100SW 125NW.

FORECAST VALID 19/0000Z 23.0N 53.0W
MAX WIND 100 KT...GUSTS 120 KT.
64 KT... 35NE 35SE 30SW 30NW.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...150NE 150SE 100SW 125NW.

FORECAST VALID 19/1200Z 23.5N 54.5W
MAX WIND 95 KT...GUSTS 115 KT.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...175NE 175SE 100SW 150NW.

FORECAST VALID 20/1200Z 24.5N 57.0W
MAX WIND 90 KT...GUSTS 110 KT.
50 KT... 60NE 60SE 40SW 60NW.
34 KT...175NE 175SE 100SW 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 21/1200Z 27.0N 59.0W
MAX WIND 85 KT...GUSTS 105 KT.

OUTLOOK VALID 22/1200Z 30.0N 59.5W
MAX WIND 80 KT...GUSTS 100 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.5N 49.0W

NEXT ADVISORY AT 17/2100Z

$$
FORECASTER AVILA

HURRICANE HELENE DISCUSSION NUMBER 21
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1100 AM EDT SUN SEP 17 2006

VISIBLE SATELLITE IMAGES SHOW THAT HELENE HAS DEVELOPED A LARGE
RAGGED EYE SURROUNDED BY A RING OF DEEP CONVECTION. SATELLITE
INTENSITY ESTIMATES FROM ALL AGENCIES HAVE INCREASED TO 5.0 ON THE
DVORAK SCALE. THE 3-HOUR AVERAGE ADVANCED OBJECTIVE TECHNIQUE FROM
THE UNIVERSITY OF WISCONSIN IS 5.6. ON THIS BASIS...THE INITIAL
INTENSITY HAS BEEN INCREASED TO 90 KNOTS. THERE IS A CHANCE FOR AN
ADDITIONAL STRENGTHENING DURING THE NEXT DAY OR TWO BEFORE THE
SHEAR INCREASES AS SUGGESTED BY SHIPS MODEL. THE OCEAN IS EXPECTED
TO REMAIN WARM ALONG THE FORECAST TRACK.

HELENE IS MOVING TOWARD THE NORTHWEST OR 305 DEGREES AT 9 KNOTS. THE
FORECAST SCENARIO COULD BE DESCRIBED AS SUCH...HELENE CURRENTLY
LOCATED ON THE SOUTHWESTERN EDGE A SUBTROPICAL RIDGE AND MOVING
TOWARD A WEAKNESS CAUSED BY A SHARP MID-LEVEL SHORT WAVE JUST EAST
OF THE UNITED STATES CAST. THEN...AS THE SHORT WAVE MOVES OUT THE
AREA...THE RIDGE WILL LIKELY BUILD WESTWARD FORCING HELENE TO
TEMPORARILY TURN MORE TO THE WEST-NORTHWEST. AFTER 3 DAYS...A
LARGER TROUGH IS EXPECTED TO MOVE EASTWARD AND FINALLY PICK UP
HELENE. THE DILEMMA IS HOW FAR WEST WILL HELENE GO SINCE TWO GOOD
MODELS DIVERGE...PUTTING ME BETWEEN A ROCK AND HARD PLACE. THE GOOD
GFS AND THE GFS ENSEMBLE MEAN HAVE THE WESTERNMOST SOLUTIONS WHILE
THE OUTSTANDING AND HARD TO BEAT GFDL HAS HELENE TURNING NORTHWARD
FARTHER EAST. SINCE THE REST OF THE GUIDANCE IS IN BETWEEN THESE
TWO EXTREME OPTIONS...THE OFFICIAL FORECAST DOES IT AS WELL.


FORECAST POSITIONS AND MAX WINDS

INITIAL 17/1500Z 20.5N 49.0W 90 KT
12HR VT 18/0000Z 21.3N 50.1W 95 KT
24HR VT 18/1200Z 22.5N 51.5W 100 KT
36HR VT 19/0000Z 23.0N 53.0W 100 KT
48HR VT 19/1200Z 23.5N 54.5W 95 KT
72HR VT 20/1200Z 24.5N 57.0W 90 KT
96HR VT 21/1200Z 27.0N 59.0W 85 KT
120HR VT 22/1200Z 30.0N 59.5W 80 KT

$$
FORECASTER AVILA

[cycloneye]

870
WTNT33 KNHC 172030
TCPAT3
BULLETIN
HURRICANE HELENE ADVISORY NUMBER 22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
500 PM AST SUN SEP 17 2006

...NOAA PLANE CONFIRMS THAT HELENE IS A STRONG CATEGORY TWO
HURRICANE...

AT 500 PM AST...2100Z...THE CENTER OF HURRICANE HELENE WAS LOCATED
NEAR LATITUDE 21.2 NORTH...LONGITUDE 49.3 WEST OR ABOUT 920 MILES...
1480 KM...EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.

HELENE IS MOVING TOWARD THE NORTHWEST NEAR 9 MPH...15 KM/HR. A
GRADUAL TURN TO THE WEST-NORTHWEST IS EXPECTED ON MONDAY.

DATA FROM A NOAA PLANE INDICATE THAT MAXIMUM SUSTAINED WINDS ARE
NEAR 105 MPH...165 KM/HR...WITH HIGHER GUSTS. SOME STRENGTHENING
IS POSSIBLE DURING THE NEXT 24 HOURS.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 40 MILES...65 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175
MILES...280 KM.

MINIMUM CENTRAL PRESSURE RECENTLY MEASURED BY A NOAA RECONNAISSANCE
PLANE WAS 970 MB...28.64 INCHES.

REPEATING THE 500 PM AST POSITION...21.2 N...49.3 W. MOVEMENT
TOWARD...NORTHWEST NEAR 9 MPH. MAXIMUM SUSTAINED WINDS...105 MPH.
MINIMUM CENTRAL PRESSURE...970 MB.

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

$$

FORECASTER AVILA

[Brent]

HURRICANE HELENE DISCUSSION NUMBER 22
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
500 PM EDT SUN SEP 17 2006

THERE HAS BEEN A DATA BONUS TODAY. A NOAA P-3 PLANE ON A RESEARCH
MISSION HAS MADE TWO FIXES ON HELENE AND JUST REPORTED A MINIMUM
PRESSURE OF 970 MB AND FLIGHT LEVEL WINDS OF 111 KNOTS AT 850 MB. A
DROPSONDE MEASURED A SURFACE WIND OF 90 KNOTS BUT THIS MIGHT NOT
REPRESENT A SUSTAINED VALUE. ALL OF THE ABOVE OBSERVATIONS
COINCIDES WITH T-NUMBERS OF 5.0 ON THE DVORAK SCALE ESTIMATED BY
ALL AGENCIES. I WAS TEMPTED TO LOWER THE INTENSITY A LITTLE BIT
SINCE THE SFMR ON BOARD OF NOAA PLANE HAS ONLY REPORTED PEAK WINDS
OF 80 KNOTS SO FAR. HOWEVER...GIVEN THE CURRENT SATELLITE
PRESENTATION...THE 3-H AVERAGE OBJECTIVE NUMBERS AODT= 5.6 FROM
UW-CIMSS...AND THE DROP IN PRESSURE FROM THE 976 MB VALUE IN THE
PREVIOUS FIX...THE INITIAL INTENSITY IS KEPT AT 90 KNOTS AT THIS
TIME. SOME ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE NEXT
DAY OR TWO BEFORE THE SHEAR INCREASES AS SUGGESTED BY SHIPS MODEL.
THE OCEAN IS EXPECTED TO REMAIN WARM ALONG THE FORECAST TRACK.

HELENE IS NOW MOVING TOWARD THE NORTHWEST OR 315 DEGREES AT 8 KNOTS
BETWEEN THE SUBTROPICAL RIDGE AND WEAKNESS LEFT BY HURRICANE
GORDON. HOWEVER...AS GORDON MOVES OUT THE RIDGE IS EXPECTED TO
BUILD WESTWARD AND THIS PATTERN COULD STEER HELENE TEMPORARILY ON A
MORE WESTWARD TRACK UNTIL A LARGE TROUGH BECOMES IN PLACE OVER THE
WESTERN ATLANTIC AND FORCES HELENE NORTHWARD. THE WESTWARD TURN FOR
THE NEXT 2 TO 3 DAYS IS SHOWN BY EVERY MODEL. THERE IS HIGH
UNCERTAINTY THEREAFTER SINCE GLOBAL MODELS HAVE BEEN SHIFTING THE
TRACK FROM ONE RUN TO THE NEXT. THE GFS HAS HAD THE LEFTMOST TRACK
SO FAR...BUT NOW THE UKMET MODEL HAS SHIFTED TO NEAR THE GFS
SOLUTION. THE GFDL HAS BEEN VERY CONSISTENT IN TURNING HELENE
NORTHWARD AND ITS SOLUTION IS HEAVILY WEIGHTED IN THE OFFICIAL
FORECAST.


FORECAST POSITIONS AND MAX WINDS

INITIAL 17/2100Z 21.2N 49.3W 90 KT
12HR VT 18/0600Z 22.0N 50.3W 95 KT
24HR VT 18/1800Z 22.8N 51.5W 100 KT
36HR VT 19/0600Z 23.1N 53.0W 100 KT
48HR VT 19/1800Z 23.5N 55.0W 95 KT
72HR VT 20/1800Z 24.5N 57.5W 90 KT
96HR VT 21/1800Z 27.1N 59.5W 85 KT
120HR VT 22/1800Z 30.5N 61.0W 80 KT

$$

FORECASTER AVILA

[cycloneye]

674
WTNT33 KNHC 180236
TCPAT3
BULLETIN
HURRICANE HELENE ADVISORY NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1100 PM AST SUN SEP 17 2006

...HELENE BECOMES THE SECOND MAJOR HURRICANE OF THE 2006 SEASON...

AT 1100 PM AST...0300Z...THE EYE OF HURRICANE HELENE WAS LOCATED
NEAR LATITUDE 21.6 NORTH...LONGITUDE 49.4 WEST OR ABOUT 920 MILES...
1480 KM...EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.

HELENE IS MOVING TOWARD THE NORTHWEST NEAR 8 MPH...13 KM/HR...AND
THIS MOTION IS EXPECTED TO CONTINUE OVERNIGHT WITH A GRADUAL TURN
TOWARD THE WEST-NORTHWEST ON MONDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 115 MPH...185
KM/HR...WITH HIGHER GUSTS. HELENE IS A CATEGORY THREE HURRICANE ON
THE SAFFIR-SIMPSON HURRICANE SCALE. SOME FURTHER STRENGTHENING IS
FORECAST DURING THE NEXT 24 HOURS.

HELENE IS BECOMING A LARGE TROPICAL CYCLONE. HURRICANE FORCE WINDS
EXTEND OUTWARD UP TO 50 MILES...85 KM...FROM THE CENTER...AND
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 200 MILES...325 KM.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 962 MB...28.41 INCHES.

REPEATING THE 1100 PM AST POSITION...21.6 N...49.4 W. MOVEMENT
TOWARD...NORTHWEST NEAR 8 MPH. MAXIMUM SUSTAINED WINDS...115 MPH.
MINIMUM CENTRAL PRESSURE...962 MB.

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 AM AST.

$$
FORECASTER BLAKE/PASCH

[Brent]

HURRICANE HELENE DISCUSSION NUMBER 23
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082006
1100 PM EDT SUN SEP 17 2006

THE HURRICANE IS LOOKING STRONGER THIS EVENING WITH THE RING OF
EYEWALL CONVECTION COOLING AROUND THE WARM EYE. IN ADDITION... THE
INNER CORE IS MORE SYMMETRIC THAN A FEW HOURS AGO WITH CIRRUS
OUTFLOW EXPANDING IN ALL DIRECTIONS... ESPECIALLY TO THE EAST.
SUBJECTIVE AND OBJECTIVE DVORAK ESTIMATES SUGGEST THAT HELENE IS A
MAJOR HURRICANE AND THE INITIAL INTENSITY HAS BEEN CONSERVATIVELY
INCREASED TO 100 KT... MAKING HELENE THE SECOND MAJOR HURRICANE OF
THE SEASON. THERE ARE NO OBVIOUS HINDRANCES TO FUTURE
INTENSIFICATION OVER THE NEXT COUPLE OF DAYS AS HELENE MOVES OVER
PROGRESSIVELY WARMER WATERS AND STAYS IN A RELATIVELY LIGHT SHEAR
ENVIRONMENT. CURIOUSLY... THE SHIPS/GFDL DO NOT SHOW MUCH FURTHER
STRENGTHENING IN AN ENVIRONMENT THAT IS SEEMINGLY FAVORABLE FOR
MORE INTENSIFICATION. THE OFFICIAL WIND SPEED FORECAST IS A LITTLE
HIGHER THAN SHIPS/GFDL AND CLOSE TO THE FSU SUPERENSEMBLE. A SLOW
WEAKENING COULD COMMENCE IN A COUPLE OF DAYS AS SOME MODELS HINT AT
AN INCREASE IN SHEAR. HOWEVER THE LARGE SPREAD OF THE TRACK MODELS
IN THE EXTENDED PERIOD MAKES FOR A MORE UNCERTAIN INTENSITY
FORECAST THAN USUAL AT 3-5 DAYS.

THE INITIAL MOTION IS A LITTLE SLOWER THAN PREVIOUSLY ESTIMATED...
ABOUT 315/7. GLOBAL MODELS ARE IN GOOD AGREEMENT ON THIS GENERAL
MOTION CONTINUING FOR ABOUT 24 HOURS FOLLOWED BY A TURN TOWARD THE
WEST OR WEST-NORTHWEST AS RIDGING REBUILDS IN BETWEEN GORDON AND
HELENE. THEREAFTER... THE BIG PROBLEM IS IF A TROUGH... NOW
CURRENTLY JUST OFFSHORE OF THE UNITED STATES... WEAKENS THE RIDGE
ENOUGH TO ALLOW THE HURRICANE TO BE PICKED UP BY A SECOND TROUGH IN
A FEW DAYS. MODEL GUIDANCE IS GENERALLY SPLIT INTO TWO CLUSTERS.
THE GFS/UKMET/NOGAPS SUGGEST THAT THE TROUGH WILL LEAVE THE
HURRICANE BEHIND WHILE THE ECMWF/GFDL BELIEVE THE TROUGH WILL
ACCELERATE THE HURRICANE OUT TO SEA. MODEL GUIDANCE HAS BEEN
TRENDING WESTWARD WITH TIME... AND THE OFFICIAL FORECAST LEANS
TOWARD THE WESTWARD CLUSTER OF GFS/UKMET/NOGAPS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 18/0300Z 21.6N 49.4W 100 KT
12HR VT 18/1200Z 22.3N 50.2W 105 KT
24HR VT 19/0000Z 23.0N 51.5W 110 KT
36HR VT 19/1200Z 23.3N 53.1W 110 KT
48HR VT 20/0000Z 23.6N 54.8W 110 KT
72HR VT 21/0000Z 25.0N 58.0W 100 KT
96HR VT 22/0000Z 27.5N 59.5W 95 KT
120HR VT 23/0000Z 29.5N 61.5W 90 KT

$$
FORECASTER BLAKE/PASCH

[HurricaneHunter914]

I'm sorry, but I think 115 mph winds with a SAT Presentation that looks like a strong 3/ low 4 is Bull Crap.

[Josephine96]

If they don't have recon.. They probably have to be conservative with intensity..

[cycloneye]

[HurricaneHunter914]

If they don't have recon.. They probably have to be conservative with intensity..

But aren't they kinda hiding the real winds behind the storm? If they know that 115 is being conservative, then why can't they just show the real intensity?

[SouthFloridawx]

If they don't have recon.. They probably have to be conservative with intensity..

But aren't they kinda hiding the real winds behind the storm? If they know that 115 is being conservative, then why can't they just show the real intensity?

Perhaps because there is no recon out there taking actual data, there is no way to know except satelite intesities and blend them with data from previous storms in the past. You don't know the real intensity and I don't know the real intesity. What is the problem with the current intensity?

EDIT: One more thing... they are not hiding anything, why would they?

[abajan]

Ouch!
Bermudians waking up tomorrow aren't going to like the looks of that track at all. Let's hope and pray it weakens by the time it gets there (assuming that's where it's going, of course).

And to think that just a couple days ago I swore this would be a fish.