ATL: PHILIPPE - Post - Tropical - Discussion

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 24
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
1100 PM AST THU SEP 29 2011

THE SATELLITE PRESENTATION OF PHILIPPE HAS BECOME VERY RAGGED THIS
EVENING. THERE ARE NO DISTINCT BANDS OF CONVECTION AND THE CLOUD
TOPS NEAR THE CENTER HAVE BEEN WARMING. A TIMELY 2344 UTC ASCAT
PASS WAS EXTREMELY HELPFUL IN ASSESSING THE INITIAL INTENSITY AND
LOCATION OF THE CYCLONE. THE SCATTEROMETER DATA SHOW AN AREA OF
30-35 KT WINDS. WITH THE KNOWN LOW BIAS OF THAT INSTRUMENT...THE
INITIAL INTENSITY IS KEPT AT 40 KT. THE INTENSITY FORECAST IS QUITE
TRICKY. IN THE SHORT TERM...SHEAR IS FORECAST TO REMAIN LOW AND
PHILIPPE WILL BE MOVING OVER SLIGHTLY WARMER WATER. THIS FAVORS
SOME STRENGTHENING AND THE OFFICIAL FORECAST AGAIN CALLS FOR A
SLIGHT INCREASE IN WIND SPEED. BY 36 HOURS...THE CYCLONE IS
FORECAST TO MOVE INTO AN AREA OF STRONG NORTHERLY UPPER-LEVEL WINDS
ASSOCIATED WITH THE OUTFLOW FROM OPHELIA. ONE WOULD EXPECT THE
CYCLONE TO WEAKEN SIGNIFICANTLY DURING AT TIME...HOWEVER MOST OF
THE INTENSITY GUIDANCE SHOWS LITTLE CHANGE IN STRENGTH. THE
OFFICIAL FORECAST WILL REMAIN BELOW MOST OF THE GUIDANCE.

THE CENTER OF PHILIPPE IS LOCATED A LITTLE TO THE NORTHEAST OF THE
EARLIER ESTIMATES...GIVING A SOMEWHAT UNCERTAIN INITIAL MOTION
ESTIMATE IS 315/11. PHILIPPE IS FORECAST TO CONTINUE NORTHWESTWARD
FOR ANOTHER DAY OR SO...THEN TURN MORE WESTWARD AS A STRONG RIDGE
BUILDS OVER THE NORTH-CENTRAL ATLANTIC. THE CYCLONE SHOULD
CONTINUE ON A GENERAL WESTWARD MOTION ESPECIALLY IF IT BECOMES A
WEAKER SYSTEM. THE NHC FORECAST HAS BEEN SHIFTED A LITTLE TO THE
EAST DURING THE FIRST 24 TO 48 HOURS...PRIMARILY DUE TO THE
REPOSITIONING OF THE CENTER. THE REMAINDER OF THE FORECAST IS
FAIRLY CLOSE TO THE PREVIOUS TRACK AND IS IN GOOD AGREEMENT WITH
THE ECMWF MODEL.


FORECAST POSITIONS AND MAX WINDS

INIT 30/0300Z 21.2N 44.0W 40 KT 45 MPH
12H 30/1200Z 22.3N 45.2W 45 KT 50 MPH
24H 01/0000Z 23.5N 47.1W 45 KT 50 MPH
36H 01/1200Z 24.3N 49.0W 45 KT 50 MPH
48H 02/0000Z 24.8N 50.6W 40 KT 45 MPH
72H 03/0000Z 25.5N 54.5W 35 KT 40 MPH
96H 04/0000Z 25.5N 58.0W 35 KT 40 MPH
120H 05/0000Z 25.0N 61.0W 35 KT 40 MPH

$$
FORECASTER BROWN

[bexar]

A healthy invest looks much more impressive that Philippe's current presentation. Doesn't look like a TS anymore?

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 25...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
500 AM AST FRI SEP 30 2011

CORRECTED INITIAL MOTION

THE RECENT EVOLUTION OF PHILIPPE IS A BIT OF A MYSTERY. A COUPLE OF
RECENT MICROWAVE OVERPASSES INDICATE THAT PHILIPPE HAS A WELL-
DEFINED EYE FEATURE IN THE LOW LEVELS...SUGGESTING THAT THERE HAS
BEEN A NET INCREASE IN THE STRUCTURAL ORGANIZATION OF THE CYCLONE
DURING THE LAST 24 HOURS. HOWEVER...GEOSTATIONARY SATELLITE IMAGES
INDICATE THAT THE CONVECTIVE PATTERN OF THE STORM IS SOMEWHAT
CHAOTIC...WITH THE MAIN CLUSTER OF DEEP CONVECTION WELL TO THE
NORTHEAST OF THE CENTER UNTIL RECENTLY. GIVEN THAT THERE HAS BEEN
NO APPRECIABLE CHANGE IN THE OVERALL ORGANIZATION SINCE THE LAST
ADVISORY...THE INITIAL WIND SPEED ESTIMATE IS HELD AT 40 KT.

ALTHOUGH THERE HAS BEEN A RELATIVE RELAXATION OF THE SHEAR DURING
THE LAST 12-24 HOURS...PHILIPPE HAS NOT STRENGTHENED YET. HOWEVER...
THE BETTER ORGANIZED LOW-LEVEL STRUCTURE OF THE STORM WOULD SEEM TO
BE CONDUCIVE FOR SOME INCREASE IN STRENGTH WHILE THE SHEAR REMAINS
LOW. WITHIN 24-36 HOURS...WEAKENING SEEMS LIKELY AS PHILIPPE SHOULD
ENTER A REGION DOMINATED BY THE VERY STRONG UPPER-LEVEL
NORTHWESTERLY WINDS ASSOCIATED WITH THE OUTFLOW OF OPHELIA.
ASSUMING THAT PHILIPPE CAN WITHSTAND WIND SHEAR OF THAT
MAGNITUDE...THERE COULD BE AN OPPORTUNITY FOR SOME INTENSIFICATION
TOWARD THE END OF THE FORECAST PERIOD. THE NEW NHC INTENSITY
FORECAST IS UNCHANGED FROM THE PREVIOUS ONE IN THE SHORT TERM BUT A
BIT LOWER AFTER 36 HOURS...JUST BELOW THE STATISTICAL-DYNAMICAL
GUIDANCE.

PHILIPPE APPEARS TO BE MOVING NORTHWESTWARD OR 315 DEGREES AT 11
KT...BUT THE LACK OF CONFIDENCE IN EARLIER CENTER FIXES MAKES THIS
ESTIMATE SOMEWHAT UNCERTAIN. GLOBAL MODELS SHOW PHILIPPE BEING
STEERED WEST-NORTHWESTWARD TO NORTHWESTWARD DURING THE NEXT DAY OR
SO ON THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH OVER THE
EASTERN TROPICAL ATLANTIC. AFTER THAT...AN AMPLIFYING MID- TO
UPPER-LEVEL TROUGH OVER THE EASTERN UNITED STATES SHOULD CAUSE
HEIGHTS TO RISE OVER THE CENTRAL ATLANTIC WHICH...IN TURN...SHOULD
RESULT IN PHILIPPE'S TURNING WESTWARD. THE NEW NHC TRACK IS
BASICALLY AN UPDATE OF THE PREVIOUS FORECAST AND CONTINUES TO
FAVOR THE ECMWF SOLUTION ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE WHICH HAS A WEAKER VERSION OF PHILIPPE. THE OFFICIAL
FORECAST IS WELL TO THE LEFT OF MULTI-MODEL CONSENSUS AT LATER
TIMES SINCE MOST OF THE MODELS ASSUME A STRONGER CYCLONE.


FORECAST POSITIONS AND MAX WINDS

INIT 30/0900Z 21.9N 44.9W 40 KT 45 MPH
12H 30/1800Z 22.9N 46.2W 45 KT 50 MPH
24H 01/0600Z 23.9N 47.9W 45 KT 50 MPH
36H 01/1800Z 24.5N 49.8W 40 KT 45 MPH
48H 02/0600Z 24.9N 51.6W 35 KT 40 MPH
72H 03/0600Z 25.1N 55.4W 30 KT 35 MPH
96H 04/0600Z 25.0N 58.8W 30 KT 35 MPH
120H 05/0600Z 24.5N 62.0W 35 KT 40 MPH

$$
FORECASTER KIMBERLAIN

[Florida1118]

A healthy invest looks much more impressive that Philippe's current presentation. Doesn't look like a TS anymore?

Read this from the NHC:

"THE RECENT EVOLUTION OF PHILIPPE IS A BIT OF A MYSTERY. A COUPLE OF
RECENT MICROWAVE OVERPASSES INDICATE THAT PHILIPPE HAS A WELL-
DEFINED EYE FEATURE IN THE LOW LEVELS...SUGGESTING THAT THERE HAS
BEEN A NET INCREASE IN THE STRUCTURAL ORGANIZATION OF THE CYCLONE
DURING THE LAST 24 HOURS. HOWEVER...GEOSTATIONARY SATELLITE IMAGES
INDICATE THAT THE CONVECTIVE PATTERN OF THE STORM IS SOMEWHAT
CHAOTIC...WITH THE MAIN CLUSTER OF DEEP CONVECTION WELL TO THE
NORTHEAST OF THE CENTER UNTIL RECENTLY."

Its still a TS. A few days from now...who knows, hes gone through 30knots so he might make it

[wxman57]

Anything from today causing the pro mets any concern with regard to the US? Please reply as a big trip depends on this. Thanks in advance

Nope, not one tiny bit.

[KUEFC]

Again thank you wxman57 and AJC3, the fact that you dont even have to reply, but still help is brilliant,

[Cranica]

Re: the unusual pair of tracks:

NOT professional opinion! - though I'd sure like it if one could tell me if I've got this right.
As I understand it, the main steering pattern at work here are troughs, which look like a U over the Atlantic (with the steering flowing from the top-left, around the bottom, and to the top-right). When a trough digs down, it breaks down the blocking high pressure that keeps storms flowing west normally, and as it passes, storms get pulled into the vacuum. If a storm is in front of the trough, though, it gets pushed "down" under the trough. Right now, there's a trough passing north of Philippe, which is pulling Ophelia north as it passes, but Philippe is getting pushed along its underside. There's a second trough moving off the east coast in the next few days that, if I understand things right, should either shear Philippe to death, pick him up, or both.

[bg1]

It is now at 50 mph.

A 1212 UTC ASCAT PASS SHOWED A FEW 40-KT WIND VECTORS JUST TO THE
NORTH OF THE CENTER...AND THE INITIAL INTENSITY IS RAISED TO 45 KT.

Looks like new clouds are firing near the center, could strengthen a little more.




Uploaded with ImageShack.us

THE SHEAR COULD RELAX A BIT BY DAY 5 ONCE
THE CYCLONE REACHES AN AREA OF UPPER-LEVEL RIDGING BETWEEN THE
HOSTILE NORTHERLY WINDS OVER THE CENTRAL ATLANTIC AND THE DEEP
TROUGH OVER THE WESTERN ATLANTIC. THE FORECAST THEREFORE ALLOWS
FOR PHILIPPE TO REGAIN TROPICAL-STORM STATUS AT THAT TIME.

The way this season has been going, I wouldn't be surprised if this got downgraded to a wave with no circulation in the next 3 days, regain TS strength after another 2 days, reach Category 4 in 9 days 500 miles northeast of Bermuda, and reach 68 degrees north as it starts to become extratropical, traveling 102.4 mph as it goes between Greenland and Iceland .

This post is obviously NOT an official forecast and should not be used as such. It is just an attempt at humor. For an intelligent and official forecast, refer to the NWS and NHC

[bg1]

Clouds blowing up near the center again.



Uploaded with ImageShack.us

50 mph

Code: Select all

UW - CIMSS                     
              ADVANCED DVORAK TECHNIQUE       
                  ADT-Version 8.1.3               
         Tropical Cyclone Intensity Algorithm       

             ----- Current Analysis -----
     Date :  30 SEP 2011    Time :   181500 UTC
      Lat :   23:14:19 N     Lon :   45:47:10 W

     
                CI# /Pressure/ Vmax
                3.0 /1003.1mb/ [b]45.0kt[/b]

     
             Final T#  Adj T#  Raw T#
                3.0     3.0     3.0

 Center Temp :  -0.9C    Cloud Region Temp : -40.7C

[cycloneye]

Philippe has been a fighter with all the shear it has taken and is still surviving.

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
500 PM AST FRI SEP 30 2011

THE STRUCTURE OF PHILIPPE HAS CHANGED LITTLE THROUGH THE DAY EXCEPT
THAT THE LOW-LEVEL CENTER HAS BEEN RE-COVERED BY DEEP CONVECTION
SINCE THE LAST ADVISORY. THE INITIAL INTENSITY IS BEING HELD AT 45
KT BASED ON THE EARLIER ASCAT PASS...AND THIS IS SUPPORTED BY
DVORAK ESTIMATES OF T3.0 FROM TAFB AND T2.9 FROM THE UW-CIMSS ADT.
HILARY IS CURRENTLY LOCATED WITHIN A COL REGION BETWEEN AN
UPPER-LEVEL LOW TO ITS SOUTH AND A LARGE DEEP-LAYER TROUGH COVERING
THE EASTERN ATLANTIC. HOWEVER...THE CYCLONE WILL BE EXITING THE
COL REGION WITHIN THE NEXT 12 HOURS OR SO AND IS FORECAST TO BE
CONTINUOUSLY BLASTED BY STRONG NORTHERLY SHEAR FOR THE NEXT SEVERAL
DAYS. IN FACT...THE SHIPS MODEL DIAGNOSTICS ARE INDICATING UP TO
40 KT OF SHEAR WITHIN ABOUT 24 HOURS. IT IS PARADOXICAL...
HOWEVER...THAT NEARLY EVERY INTENSITY MODEL IS EITHER SHOWING
PHILIPPE MAINTAINING ITS INTENSITY OR STRENGTHENING DURING THE
FORECAST PERIOD. THIS IS HARD TO BELIEVE GIVEN THE HOSTILE
CONDITIONS EXPECTED...AND THE OFFICIAL INTENSITY FORECAST IS
CLOSEST TO THE LGEM MODEL...WHICH IS ALONG THE LOWER BOUND OF THE
GUIDANCE ENVELOPE.

PHILIPPE IS MOVING AT 320 DEGREES AT 11 KT AND IS FORECAST TO
GRADUALLY TURN WESTWARD OVER THE NEXT COUPLE OF DAYS AS IT COMES
UNDER THE INFLUENCE OF A BUILDING LOW- TO MID-LEVEL HIGH TO ITS
NORTH. THE SPREAD IN THE TRACK GUIDANCE DOES NOT BECOME
SIGNIFICANT UNTIL AFTER 72 HOURS. MOST OF THE GUIDANCE IS
INDICATING THAT PHILIPPE WILL RECURVE BY DAY 4 OR 5 AS IT
APPROACHES A DEEP-LAYER LONGWAVE TROUGH OVER THE WESTERN ATLANTIC.
THE GFS IS A SOUTHERN OUTLIER AND KEEPS PHILIPPE ON A WESTWARD
COURSE...MOST LIKELY BECAUSE IT APPEARS TO DE-AMPLIFY THE WESTERN
ATLANTIC TROUGH SOONER THAN THE OTHER MODELS. THE OFFICIAL TRACK
FORECAST SHOWS THE BEGINNING OF A SLOW RECURVATURE BY DAY 5 BUT IS
TO THE SOUTHWEST OF THE TVCA CONSENSUS AND NOT AS FAST AS THE 12Z
ECMWF AND UKMET MODELS AT THAT TIME.

FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 23.5N 46.2W 45 KT 50 MPH
12H 01/0600Z 24.2N 47.6W 45 KT 50 MPH
24H 01/1800Z 25.0N 49.4W 40 KT 45 MPH
36H 02/0600Z 25.7N 51.2W 40 KT 45 MPH
48H 02/1800Z 26.1N 53.0W 40 KT 45 MPH
72H 03/1800Z 26.0N 57.0W 30 KT 35 MPH
96H 04/1800Z 26.5N 61.0W 30 KT 35 MPH
120H 05/1800Z 28.5N 61.5W 35 KT 40 MPH

$$
FORECASTER BERG

[somethingfunny]

lol

[HurricaneRobert]

I guess when this storm reaches Ophelia's location the ocean might be out of Jesus juice.

[LarryWx]

FWIW....not much at all.....the 18Z Fri gfs hits New England on 10/12 with Philippe. This the 1st run showing a CONUS hit. OMG, JB is going to go crazy lol.

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 28
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
1100 PM AST FRI SEP 30 2011

A PAIR OF MICROWAVE PASSES FROM LATE THIS AFTERNOON WERE VERY
HELPFUL IN FIXING THE CENTER OF PHILIPPE AFTER THE CENTER BECAME
OBSCURED...AND INDICATED THE CYCLONE WAS A LITTLE TO THE RIGHT OF
THE PREVIOUS TRACK. THE INITIAL MOTION IS 320/8. THE MICROWAVE
DATA ALSO SHOWED A VERY WELL-DEFINED LOW-LEVEL CONVECTIVE
RING...BUT THE CURRENT INFRARED DEPICTION SUGGESTS THAT UPPER-LEVEL
NORTHWESTERLY FLOW FROM OPHELIA IS BEGINNING TO TAKE A TOLL.
DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB WERE 45 AND 35
KT...RESPECTIVELY...AND THE ADVISORY INTENSITY IS HELD AT 45 KT.

WATER VAPOR IMAGERY AND GLOBAL MODEL FORECASTS SUGGEST THAT THE
NORTHWESTERLY SHEAR WILL LIKELY EXCEED 40 KT OVER THE NEXT COUPLE
OF DAYS...SUCH THAT PHILIPPE COULD WELL SUFFER A BEHEADING AT THE
HANDS OF OPHELIA. THE LGEM...TRADITIONALLY THE BEST INTENSITY
GUIDANCE...SHOWS A SLOW DECREASE IN STRENGTH AND THE OFFICIAL
FORECAST IS IN GOOD AGREEMENT WITH THIS MODEL. THE REMAINING
GUIDANCE IS INEXPLICABLY INDIFFERENT TO THE SHEAR AND SHOWS LITTLE
NET CHANGE IN STRENGTH. NEAR THE END OF THE FORECAST PERIOD...
SHOULD PHILIPPE SURVIVE...THE SHEAR IS EXPECTED TO LESSEN
AND SO THE OFFICIAL FORECAST SHOWS A LITTLE STRENGTHENING AT THAT
TIME.

A MID-LEVEL RIDGE IN BETWEEN THE TWO TROPICAL CYCLONES IS EXPECTED
TO TURN PHILIPPE TO THE WEST-NORTHWEST AND PERHAPS WEST OVER THE
NEXT COUPLE OF DAYS. HOWEVER...THE STRENGTH OF THIS TURN WILL
DEPEND ON HOW MUCH CONVECTION PHILIPPE CAN MAINTAIN AS THE
NORTHWESTERLY SHEAR INCREASES...WITH A WEAKER OR SHALLOWER SYSTEM
MAINTAINING A NORTHWARD COMPONENT OF MOTION LONGER. BY DAY
FOUR...PHILIPPE SHOULD BE APPROACHING A LARGE TROUGH OFF THE U.S.
EAST COAST AND TURN NORTHWARD. MODEL GUIDANCE DIVERGES
SIGNIFICANTLY AT THAT POINT...WITH THE ECMWF AND UKMET SHOWING
PHILIPPE TURNING NORTHEASTWARD AND THE GFS MUCH FARTHER SOUTHWEST.
THE OFFICIAL FORECAST HAS BEEN ADJUSTED TO THE RIGHT OF THE
PREVIOUS FORECAST TOWARDS THE ECMWF AND SHALLOW BAM...UNDER THE
ASSUMPTION THAT PHILIPPE WILL NOT BE ABLE TO MAINTAIN MUCH VERTICAL
COHERENCE OVER THE NEXT TWO TO THREE DAYS.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 24.0N 46.4W 45 KT 50 MPH
12H 01/1200Z 24.7N 47.5W 45 KT 50 MPH
24H 02/0000Z 25.5N 49.4W 40 KT 45 MPH
36H 02/1200Z 26.1N 51.5W 40 KT 45 MPH
48H 03/0000Z 26.5N 53.4W 35 KT 40 MPH
72H 04/0000Z 27.0N 57.5W 30 KT 35 MPH
96H 05/0000Z 28.0N 60.0W 30 KT 35 MPH
120H 06/0000Z 31.0N 60.0W 35 KT 40 MPH

$$
FORECASTER FRANKLIN

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 30
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
1100 AM AST SAT OCT 01 2011

PHILIPPE IS LOOKING MORE AND MORE LIKE A SHEARED TROPICAL CYCLONE
DUE TO STRONG NORTHWESTERLY UPPER-LEVEL WINDS. DEEP CONVECTION IS
PRIMARILY LIMITED NEAR AND TO THE EAST OF THE CENTER...BUT THE
INITIAL INTENSITY WILL REMAIN 45 KT BASED ON SIMILAR DVORAK
ESTIMATES FROM TAFB...SAB...AND THE UW-CIMSS ADT.

PHILIPPE IS LOCATED TO THE SOUTH OF A LOW- TO MID-LEVEL ANTICYCLONE
AND HAS TURNED WEST-NORTHWESTWARD WITH A MOTION OF 300 DEGREES AT 8
KT. GLOBAL MODEL FIELDS ARE INDICATING THAT A RIDGE AXIS WILL
BUILD SOUTHWESTWARD AS HURRICANE OPHELIA MOVES OUT OF THE AREA...AND
THIS FEATURE SHOULD FORCE PHILIPPE ON A GENERAL WESTWARD MOTION
BETWEEN 24 AND 72 HOURS. THE STORM IS THEN EXPECTED TO REACH A
WEAKNESS IN THE RIDGE CREATED BY A MID- TO UPPER-LEVEL CUT-OFF LOW
OVER THE WESTERN ATLANTIC...AND CONSEQUENTLY MAKE A SLOW TURN
TOWARD THE NORTH AND NORTHEAST ON DAYS 4 AND 5. ALL OF THE TRACK
MODELS AGREE ON THIS SCENARIO...BUT THE GFS SHOWS A SMALLER CUT-OFF
LOW AND LEAVES PHILIPPE IN A WEAKER STEERING FLOW. THIS MAKES THE
GFS A SLOWER...SOUTHERN OUTLIER RELATIVE TO THE OTHER MODELS. OUT
OF RESPECT FOR THAT MODEL...THE OFFICIAL FORECAST IS A LITTLE
SLOWER THAN THE TVCA CONSENSUS AND THE PREVIOUS FORECAST ON DAYS 4
AND 5.

THIRTY TO FORTY KNOTS OF NORTHERLY VERTICAL SHEAR IS FORECAST TO
AFFECT PHILIPPE DURING THE NEXT COUPLE OF DAYS...BUT IT IS BECOMING
MORE APPARENT THAT THE CYCLONE MAY BE RESILIENT ENOUGH TO WITHSTAND
THIS ENVIRONMENT. PHILIPPE WILL BY NO MEANS BE A HEALTHY-LOOKING
CYCLONE...BUT IT SHOULD NOT BE TOO DIFFICULT FOR IT TO MAINTAIN
CONVECTION AND REMAIN AS A TROPICAL CYCLONE WHILE IT MOVES OVER
WARMER WATERS. THE OFFICIAL FORECAST IS CLOSE TO THE INTENSITY
CONSENSUS AND INDICATES WEAKENING DURING THE FIRST 72 HOURS. SOME
RE-STRENGTHENING IS INDICATED ON DAYS 4 AND 5 WHEN PHILIPPE ENTERS
A LOWER-SHEAR ENVIRONMENT...BUT THE OFFICIAL FORECAST...WHICH IS OF
LOW CONFIDENCE...IS NOT AS HIGH AS THE INTENSITY MODELS DURING THAT
PERIOD.

FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 24.8N 48.0W 45 KT 50 MPH
12H 02/0000Z 25.4N 49.4W 45 KT 50 MPH
24H 02/1200Z 25.9N 51.3W 40 KT 45 MPH
36H 03/0000Z 26.1N 53.2W 35 KT 40 MPH
48H 03/1200Z 25.9N 55.3W 35 KT 40 MPH
72H 04/1200Z 26.0N 59.5W 30 KT 35 MPH
96H 05/1200Z 28.0N 61.0W 35 KT 40 MPH
120H 06/1200Z 30.5N 58.5W 40 KT 45 MPH

$$
FORECASTER BERG

[dwsqos2]

http://i55.tinypic.com/3467sbk.jpg

Philippe is a poorly organized storm, but a 1330Z ASCAT pass had several unflagged 50 knot vectors. And, ASCAT has a low bias.

[cycloneye]

TROPICAL STORM PHILIPPE DISCUSSION NUMBER 31
NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011
500 PM AST SAT OCT 01 2011

AN ASCAT SWATH PARTIALLY CAUGHT PHILIPPE AT 1331 UTC...AND SOMEWHAT
SURPRISINGLY...IT SHOWED A COUPLE OF 55-KT WIND BARBS LOCATED TO
THE NORTH OF THE CENTER. THIS IS BEING SET AS THE INITIAL
INTENSITY...AND IT COULD BE CONSERVATIVE DUE TO A POTENTIAL LOW
BIAS IN THE DATA...AND BECAUSE THE ENTIRE WIND FIELD WAS NOT
MEASURED BY THE INSTRUMENT. GIVEN THE HIGHER INITIAL INTENSITY...
THE NEW OFFICIAL FORECAST HAS BEEN INCREASED THROUGHOUT THE
FORECAST PERIOD BUT INDICATES THE SAME GENERAL PATTERN OF WEAKENING
AND RE-STRENGTHENING AS BEFORE. THE REASONING FOR THIS INTENSITY
FORECAST HAS NOT CHANGED. STRONG NORTHERLY SHEAR IS EXPECTED TO
IMPACT PHILIPPE FOR THE NEXT 3 DAYS OR SO AND SHOULD INDUCE SOME
GRADUAL WEAKENING. THE SHEAR COULD RELAX BY DAY 4 WHEN PHILIPPE
REACHES A NARROW UPPER-LEVEL RIDGE AXIS...AND THE STATISTICAL
MODELS...AS WELL AS THE GFDL...ARE SUGGESTING THAT SOME
STRENGTHENING COULD OCCUR.

THE INITIAL MOTION REMAINS 300 DEGREES AT 8 KT. A LOW- TO MID-LEVEL
AREA OF HIGH PRESSURE OVER THE SUBTROPICAL CENTRAL ATLANTIC IS
FORECAST TO BUILD SOUTHWESTWARD IN THE WAKE OF HURRICANE OPHELIA...
AND THAT SHOULD TURN PHILIPPE WESTWARD OVER THE NEXT 24 TO 48
HOURS. THE GLOBAL MODELS AGREE THAT A WEAKNESS WILL DEVELOP IN THE
RIDGE BY DAY 3 WITH PHILIPPE RESPONDING BY SLOWING DOWN AND TURNING
TOWARD THE NORTH. THERE CONTINUES TO BE DISAGREEMENT AMONG THE
MODELS ABOUT WHETHER OR NOT PHILIPPE WILL BE PICKED UP BY THE FLOW
AHEAD OF A LARGE CUT-OFF LOW NEAR THE NEW ENGLAND COAST. THE GFS
IS STILL A SLOWER AND SOUTHERN OUTLIER...HAVING PHILIPPE MISS THE
TROUGH AND GETTING STUCK TO THE SOUTH OF A POST-FRONTAL HIGH
PRESSURE SYSTEM. DUE TO THE LARGE SPREAD IN THE GUIDANCE...THE
OFFICIAL FORECAST IS STILL SLOWER THAN THE MODEL CONSENSUS ON DAYS
4 AND 5.

BASED ON THE ASCAT DATA...ADJUSTMENTS TO THE WIND RADII AND THE
12-FT SEAS RADII WERE REQUIRED ON THIS FORECAST ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 25.2N 49.1W 55 KT 65 MPH
12H 02/0600Z 25.6N 50.6W 55 KT 65 MPH
24H 02/1800Z 25.9N 52.6W 50 KT 60 MPH
36H 03/0600Z 25.8N 54.9W 45 KT 50 MPH
48H 03/1800Z 25.7N 57.1W 40 KT 45 MPH
72H 04/1800Z 26.5N 61.0W 40 KT 45 MPH
96H 05/1800Z 28.5N 61.0W 45 KT 50 MPH
120H 06/1800Z 32.0N 57.0W 50 KT 60 MPH

$$
FORECASTER BERG

[cycloneye]

Surprise,surprise!!!

...PHILIPPE STRONGER THAN PREVIOUSLY ESTIMATED...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...25.2N 49.1W
ABOUT 1070 MI...1720 KM ESE OF BERMUDA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.41 INCHES

[brunota2003]

Is it possible Philippe peaked out at 70 or 75 mph? Hmmm...