Cyclone to hit Eastern Canada....
link http://vortex.plymouth.edu/tropical.html
Hurricane Juan
Moderator: S2k Moderators
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Sciencerocks
- Category 5
- Posts: 8903
- Age: 39
- Joined: Thu Jul 06, 2017 1:51 am
Re: Hurricane Juan
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION FIFTEEN DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT THU SEP 25 2003
AFTER A LONG AND DIFFICULT DEBATE TO DETERMINE THE STRUCTURE OF THE
CYCLONE...TROPICAL OR SUBTROPICAL....THE AREA OF DISTURBED WEATHER
SOUTHEAST OF BERMUDA IS BEING DESIGNATED AS TROPICAL DEPRESSION
FIFTEEN. THERE ARE NO CLEAR CUT SIGNALS AND WE COULD HAVE GONE
TROPICAL OR SUBTROPICAL AT THIS TIME. THE CYCLONE IS STILL
SOMEWHAT ATTACHED TO A FRONTAL ZONE BUT AT THE SAME TIME...IT HAS
ENOUGH CONVECTION NEAR THE CENTER. IN ADDITION...THE LASTEST AMSU
DATA SHOW A WEAK WARM CORE AT THE MID TO UPPER-LEVELS SUGGESTING
THAT THE CYCLONE IS ON ITS WAY TO BECOME MORE TROPICAL. SLOW
STRENGTHENING IS INDICATED BEFORE THE SYSTEM MOVES OVER COOL WATERS
AND BECOMES EXTRATROPICAL IN 4 DAYS.
THE DEPRESSION APPEARS TO BE MOVING SLOWLY TOWARD THE NORTHEAST.
HOWEVER...A DEVELOPING SUBTROPICAL RIDGE TO THE EAST OF THE CYCLONE
WILL FORCE THE SYSTEM TO MOVE ON A GENERAL NORTHWARD TRACK FOR THE
NEXT 3 TO 4 DAYS. THIS IS CONSISTENT WITH THE GFDL AND THE GFS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 25/1500Z 29.5N 61.0W 30 KT
12HR VT 26/0000Z 30.5N 61.0W 35 KT
24HR VT 26/1200Z 32.0N 61.0W 45 KT
36HR VT 27/0000Z 33.5N 61.5W 55 KT
48HR VT 27/1200Z 35.0N 62.0W 55 KT
72HR VT 28/1200Z 40.0N 63.2W 55 KT
96HR VT 29/1200Z 46.0N 62.0W 55 KT...EXTRATROPICAL
120HR VT 30/1200Z...ABSORBED
TTAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU SEP 25 2003
HIGH RESOLUTION SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN
ASSOCIATED WITH THE DEPRESSION HAS CONTINUED TO BECOME BETTER
ORGANIZED. THE LOW-LEVEL CENTER IS NOW EMBEDDED WITHIN THE DEEP
CONVECTION AND THE OUTFLOW IS GRADUALLY IMPROVING. BEST ESTIMATE OF
THE INITIAL INTENSITY IS 45 KNOTS...BASED ON THE LATEST PASS OF THE
ADIOS SCATTEROMETER. IN ADDITION A DRIFTING BUOY NEAR THE CENTER
REPORTED 996.6 MB AT 1800 UTC. THE OCEAN IS STILL WARM AND THE
SHEAR HAS RELAXED A BIT. THEREFORE...THERE IS A CHANCE FOR A MODEST
STRENGTHENING BEFORE THE SYSTEM MOVES OVER COOL WATERS AND BECOMES
EXTRATROPICAL IN 4 DAYS.
THE CENTER WAS MEANDERING DURING THE PAST SEVERAL HOURS. HOWEVER...A
DEVELOPING SUBTROPICAL RIDGE TO THE EAST OF THE CYCLONE WILL FORCE
THE SYSTEM TO MOVE ON A GENERAL NORTH-NORTHWEST TO NORTHWARD TRACK
FOR THE NEXT 3 TO 4 DAYS. THIS IS CONSISTENT WITH MOST OF THE
GLOBAL MODELS WHICH UNANIMOUSLY BRING A LOW PRESSURE SYSTEM ON A
NORTHWARD TRACK FOR NEXT FEW DAYS. HOWEVER...THE MODELS VARY IN
FORWARD SPEED.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 25/2100Z 30.9N 61.8W 45 KT
12HR VT 26/0600Z 32.0N 62.0W 50 KT
24HR VT 26/1800Z 33.5N 62.5W 55 KT
36HR VT 27/0600Z 35.0N 63.0W 60 KT
48HR VT 27/1800Z 37.0N 63.5W 60 KT
72HR VT 28/1800Z 42.0N 63.0W 60 KT
96HR VT 29/1800Z 48.0N 60.8W 50 KT...EXTRATROPICAL
120HR VT 30/1800Z...EXTRATROPICAL
CZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT THU SEP 25 2003
WATER VAPOR IMAGERY SUGGESTS THAT JUAN MAY NOT BE FULLY TROPICAL...
AS THE STORM IS TANGLED WITH AN UPPER-LEVEL LOW TO THE SOUTHEAST.
CONVECTION HAS DECREASED OVER THE PAST 6 HR...WHICH IS NOT UNUSUAL
FOR A QUASI-TROPICAL SYSTEM AT THIS STAGE OF DEVELOPMENT. THE BEST
EVIDENCE OF THE TROPICAL NATURE OF JUAN IS REPORTS FROM DRIFTING
BUOY 41537...WHICH INCLUDED A PRESSURE OF 992.6 MB AT 20Z. THIS
INDICATES THAT JUAN HAS THE TIGHT INNER CORE OF A TROPICAL CYCLONE.
RIGHT NOW...JUAN IS SIMILAR TO KAREN IN 2001...ALTHOUGH IT IS NOT
AS STRONG OR AS BAROCLINIC IN ORIGIN AS KAREN WAS. BASED ON THE
BUOY DATA AND THE PREVIOUS ADVISORY...THE MAXIMUM WINDS ARE
INCREASED TO 50 KT.
THE INITIAL MOTION HAS SLOWED TO 345/5...AND EVEN THAT MAY BE A
LITTLE TOO FAST. WATER VAPOR IMAGERY SHOWS THAT JUAN IS ON THE
SOUTHWEST SIDE OF A BLOCKING MID/UPPER-LEVEL RIDGE OVER THE WEST
CENTRAL ATLANTIC...AND BETWEEN DEEP TROUGHS OVER THE EASTERN UNITED
STATES AND THE EASTERN ATLANTIC. THE TROUGHING OVER THE EASTERN
UNITED STATES IS FORECAST TO ERODE THE RIDGE ENOUGH FOR JUAN TO
MOVE GENERALLY NORTH-NORTHWESTWARD FOR 48-72 HR...FOLLOWED BY
RECURVATURE TO THE NORTH AND NORTHEAST. ALL GUIDANCE EXCEPT THE
UKMET AGREES WITH THIS SCENARIO. THE OFFICIAL FORECAST WILL AS
WELL...WITH THE FORECAST BEING SLIGHTLY SLOWER AND A LITTLE TO THE
LEFT OF THE PREVIOUS TRACK. IT SHOULD BE NOTED THAT THE UKMET IS A
MAJOR OUTLIER...CALLING FOR A SLOW EASTWARD DRIFT FOR THE NEXT
THREE DAYS.
THE INTENSITY FORECAST IS SOMEWHAT PROBLEMATIC. JUAN IS EMBEDDED IN
UPPER-LEVEL WESTERLY TO SOUTHWESTERLY FLOW...AND LARGE-SCALE MODELS
FORECAST THE CYCLONE TO BE AFFECTED BY ONE OR MORE SHORTWAVE
TROUGHS DURING THE NEXT 72 HR. THESE WILL LIKELY CAUSE SHEAR...AS
FORECAST BY THE SHIPS MODEL. HOWEVER...THEY COULD ALSO CAUSE
DYNAMICAL FORCING OR UPPER-LEVEL DIVERGENCE THAT COULD SUSTAIN THE
CYCLONE. THE INTENSITY FORECAST WILL CALL FOR SLOW STRENGTHENING
FOR 24-36 HR. HOWEVER...THE CURRENTLY FORECAST SHEAR SHOULD MAKE
IT DIFFICULT FOR ONE TO STRENGTHEN INTO A HURRICANE...ANMD THE
FORECAST WILL NOT CALL FOR THAT AT THIS TIME. JUAN SHOULD LOSE
TROPICAL CHARACTERISTICS AFTER 72 HR AND BE ABSORBED BY A LARGE LOW
ASSOCIATED WITH THE EASTERN U.S. TROUGH BY 120 HR.
FORECASTER BEVEN
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/0300Z 31.1N 61.9W 50 KT
12HR VT 26/1200Z 32.1N 62.2W 55 KT
24HR VT 27/0000Z 33.7N 62.5W 60 KT
36HR VT 27/1200Z 35.6N 63.1W 60 KT
48HR VT 28/0000Z 37.6N 63.5W 60 KT
72HR VT 29/0000Z 42.5N 64.0W 60 KT
96HR VT 30/0000Z 49.0N 61.0W 50 KT...EXTRATROPICAL
120HR VT 01/0000Z...ABSORBED BY LARGER EXTRATROPICAL LOW
TAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT FRI SEP 26 2003
AFTER COMING OUT OF THE GOES-12 SATELLITE ECLIPSE PERIOD...NEW
IMAGERY INDICATES THAT JUAN HAS BECOME BETTER ORGANIZED AND HAS
ALSO STARTED MOVING NORTHWARD AGAIN. AN EYE-LIKE FEATURE WAS
APPARENT IN THE MID-CLOUDS OF THE PRE-ECLIPSE IMAGERY...BUT NO DEEP
CONVECTION WAS WITHIN 100 NMI OF THE CENTER. HOWEVER...THE EYE
FEATURE IS NOW OBSCURED BY DEEP CONVECTION...TOPS COLDER THAN
-70C...THAT HAVE SURROUNDED MORE THAN 50 PERCENT OF THE INNER CORE
CIRCULATION. ALTHOUGH SATELLITE INTENSITY ESTIMATES ARE A CONSENSUS
T2.5...OR 35 KT...I HAVE OPTED TO INCREASE THE INTENSITY SLIGHTLY
BASED ON THIS NEW INNER-CORE CONVECTIVE BANDING AND RECENT AMSU
INTENSITY ESTIMATES OF 990-992 MB.
THE INITIAL MOTION ESTIMATE IS 350/08. THERE IS NO SIGNIFICANT
CHANGE TO THE PREVIOUS TRACK OR INTENSITY FORECAST. THE NHC MODEL
GUIDANCE SHOWS GOOD CONVERGENCE ABOUT THE PREVIOUS FORECAST TRACK
AND IS ALSO IN GOOD AGREEMENT ON TAKING JUAN NORTH TO
NORTH-NORTHWESTWARD AND GRADUALLY ACCELERATE THE CYCLONE THROUGH 72
HOURS AS A SERIES OF NEGATIVELY TILTED SHORTWAVE TROUGHS UNDERCUT
THE SYSTEM FROM THE WEST AND SOUTH. BY 96 HOURS OR SO...JUAN IS
EXPECTED TO BE OVER THE CANADIAN MARITIMES REGION AND STARTING TO
BECOME EXTRATROPICAL AS THE CYCLONE BEGINS TO INTERACT WITH AND
EVENTUALLY BECOME ABSORBED BY A LARGER EXTRATROPICAL LOW PRESSURE
SYSTEM. THERE IS A LARGE SPREAD IN THE MODEL GUIDANCE BY 96 HOURS
WITH NOGAPS TAKING JUAN THE FARTHEST TO THE NORTHEAST OVER NORTHERN
NEWFOUNDLAND...WHILE THE REST OF THE NHC MODEL GUIDANCE TAKES THE
CYCLONE OVER THE ENTIRE LENGTH OF NOVA SCOTIA. THE OFFICIAL
FORECAST TRACK IS ONLY SLIGHTLY TO THE LEFT OF THE PREVIOUS
TRACK...AND IS CLOSE TO THE GFS AND GFDL MODELS.
IT WOULD NOT TAKE MUCH CONVECTION TO WRAP ALL THE AROUND THE
INNER-CORE OF JUAN AND PRODUCE AN EYE. WITH THIS IN MIND...THE
INTENSITY WAS INCREASED SLIGHTLY...BUT NIT AS HIGH AS THE SHIPS AND
GFDL INTENSITY MODELS WHICH BRING JUAN UP TO 75 KT AND 83 KT...
RESPECTIVELY...IN 36 HOURS. UPPER-LEVEL SHEAR WILL GRADUALLY
INCREASE TO MORE THAN 20 KT BY 24 HOURS...AND THIS IS THE PRIMARY
REASON FOR REMAINING BELOW THE MODEL GUIDANCE AT THIS TIME.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/0900Z 31.5N 61.9W 55 KT
12HR VT 26/1800Z 32.5N 62.2W 60 KT
24HR VT 27/0600Z 34.3N 62.6W 65 KT
36HR VT 27/1800Z 36.3N 63.3W 65 KT
48HR VT 28/0600Z 38.4N 63.8W 60 KT
72HR VT 29/0600Z 46.0N 63.0W 55 KT...EXTRATROPICAL INLAND
96HR VT 30/0600Z 50.5N 60.5W 50 KT...EXTRATROPICAL INLAND
120HR VT 01/0600Z...ABSORBED BY LARGER EXTRATROPICAL LOW
TTAA00 KNHC DDHHMM
TROPICAL DEPRESSION FIFTEEN DISCUSSION NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT THU SEP 25 2003
AFTER A LONG AND DIFFICULT DEBATE TO DETERMINE THE STRUCTURE OF THE
CYCLONE...TROPICAL OR SUBTROPICAL....THE AREA OF DISTURBED WEATHER
SOUTHEAST OF BERMUDA IS BEING DESIGNATED AS TROPICAL DEPRESSION
FIFTEEN. THERE ARE NO CLEAR CUT SIGNALS AND WE COULD HAVE GONE
TROPICAL OR SUBTROPICAL AT THIS TIME. THE CYCLONE IS STILL
SOMEWHAT ATTACHED TO A FRONTAL ZONE BUT AT THE SAME TIME...IT HAS
ENOUGH CONVECTION NEAR THE CENTER. IN ADDITION...THE LASTEST AMSU
DATA SHOW A WEAK WARM CORE AT THE MID TO UPPER-LEVELS SUGGESTING
THAT THE CYCLONE IS ON ITS WAY TO BECOME MORE TROPICAL. SLOW
STRENGTHENING IS INDICATED BEFORE THE SYSTEM MOVES OVER COOL WATERS
AND BECOMES EXTRATROPICAL IN 4 DAYS.
THE DEPRESSION APPEARS TO BE MOVING SLOWLY TOWARD THE NORTHEAST.
HOWEVER...A DEVELOPING SUBTROPICAL RIDGE TO THE EAST OF THE CYCLONE
WILL FORCE THE SYSTEM TO MOVE ON A GENERAL NORTHWARD TRACK FOR THE
NEXT 3 TO 4 DAYS. THIS IS CONSISTENT WITH THE GFDL AND THE GFS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 25/1500Z 29.5N 61.0W 30 KT
12HR VT 26/0000Z 30.5N 61.0W 35 KT
24HR VT 26/1200Z 32.0N 61.0W 45 KT
36HR VT 27/0000Z 33.5N 61.5W 55 KT
48HR VT 27/1200Z 35.0N 62.0W 55 KT
72HR VT 28/1200Z 40.0N 63.2W 55 KT
96HR VT 29/1200Z 46.0N 62.0W 55 KT...EXTRATROPICAL
120HR VT 30/1200Z...ABSORBED
TTAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU SEP 25 2003
HIGH RESOLUTION SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN
ASSOCIATED WITH THE DEPRESSION HAS CONTINUED TO BECOME BETTER
ORGANIZED. THE LOW-LEVEL CENTER IS NOW EMBEDDED WITHIN THE DEEP
CONVECTION AND THE OUTFLOW IS GRADUALLY IMPROVING. BEST ESTIMATE OF
THE INITIAL INTENSITY IS 45 KNOTS...BASED ON THE LATEST PASS OF THE
ADIOS SCATTEROMETER. IN ADDITION A DRIFTING BUOY NEAR THE CENTER
REPORTED 996.6 MB AT 1800 UTC. THE OCEAN IS STILL WARM AND THE
SHEAR HAS RELAXED A BIT. THEREFORE...THERE IS A CHANCE FOR A MODEST
STRENGTHENING BEFORE THE SYSTEM MOVES OVER COOL WATERS AND BECOMES
EXTRATROPICAL IN 4 DAYS.
THE CENTER WAS MEANDERING DURING THE PAST SEVERAL HOURS. HOWEVER...A
DEVELOPING SUBTROPICAL RIDGE TO THE EAST OF THE CYCLONE WILL FORCE
THE SYSTEM TO MOVE ON A GENERAL NORTH-NORTHWEST TO NORTHWARD TRACK
FOR THE NEXT 3 TO 4 DAYS. THIS IS CONSISTENT WITH MOST OF THE
GLOBAL MODELS WHICH UNANIMOUSLY BRING A LOW PRESSURE SYSTEM ON A
NORTHWARD TRACK FOR NEXT FEW DAYS. HOWEVER...THE MODELS VARY IN
FORWARD SPEED.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 25/2100Z 30.9N 61.8W 45 KT
12HR VT 26/0600Z 32.0N 62.0W 50 KT
24HR VT 26/1800Z 33.5N 62.5W 55 KT
36HR VT 27/0600Z 35.0N 63.0W 60 KT
48HR VT 27/1800Z 37.0N 63.5W 60 KT
72HR VT 28/1800Z 42.0N 63.0W 60 KT
96HR VT 29/1800Z 48.0N 60.8W 50 KT...EXTRATROPICAL
120HR VT 30/1800Z...EXTRATROPICAL
CZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT THU SEP 25 2003
WATER VAPOR IMAGERY SUGGESTS THAT JUAN MAY NOT BE FULLY TROPICAL...
AS THE STORM IS TANGLED WITH AN UPPER-LEVEL LOW TO THE SOUTHEAST.
CONVECTION HAS DECREASED OVER THE PAST 6 HR...WHICH IS NOT UNUSUAL
FOR A QUASI-TROPICAL SYSTEM AT THIS STAGE OF DEVELOPMENT. THE BEST
EVIDENCE OF THE TROPICAL NATURE OF JUAN IS REPORTS FROM DRIFTING
BUOY 41537...WHICH INCLUDED A PRESSURE OF 992.6 MB AT 20Z. THIS
INDICATES THAT JUAN HAS THE TIGHT INNER CORE OF A TROPICAL CYCLONE.
RIGHT NOW...JUAN IS SIMILAR TO KAREN IN 2001...ALTHOUGH IT IS NOT
AS STRONG OR AS BAROCLINIC IN ORIGIN AS KAREN WAS. BASED ON THE
BUOY DATA AND THE PREVIOUS ADVISORY...THE MAXIMUM WINDS ARE
INCREASED TO 50 KT.
THE INITIAL MOTION HAS SLOWED TO 345/5...AND EVEN THAT MAY BE A
LITTLE TOO FAST. WATER VAPOR IMAGERY SHOWS THAT JUAN IS ON THE
SOUTHWEST SIDE OF A BLOCKING MID/UPPER-LEVEL RIDGE OVER THE WEST
CENTRAL ATLANTIC...AND BETWEEN DEEP TROUGHS OVER THE EASTERN UNITED
STATES AND THE EASTERN ATLANTIC. THE TROUGHING OVER THE EASTERN
UNITED STATES IS FORECAST TO ERODE THE RIDGE ENOUGH FOR JUAN TO
MOVE GENERALLY NORTH-NORTHWESTWARD FOR 48-72 HR...FOLLOWED BY
RECURVATURE TO THE NORTH AND NORTHEAST. ALL GUIDANCE EXCEPT THE
UKMET AGREES WITH THIS SCENARIO. THE OFFICIAL FORECAST WILL AS
WELL...WITH THE FORECAST BEING SLIGHTLY SLOWER AND A LITTLE TO THE
LEFT OF THE PREVIOUS TRACK. IT SHOULD BE NOTED THAT THE UKMET IS A
MAJOR OUTLIER...CALLING FOR A SLOW EASTWARD DRIFT FOR THE NEXT
THREE DAYS.
THE INTENSITY FORECAST IS SOMEWHAT PROBLEMATIC. JUAN IS EMBEDDED IN
UPPER-LEVEL WESTERLY TO SOUTHWESTERLY FLOW...AND LARGE-SCALE MODELS
FORECAST THE CYCLONE TO BE AFFECTED BY ONE OR MORE SHORTWAVE
TROUGHS DURING THE NEXT 72 HR. THESE WILL LIKELY CAUSE SHEAR...AS
FORECAST BY THE SHIPS MODEL. HOWEVER...THEY COULD ALSO CAUSE
DYNAMICAL FORCING OR UPPER-LEVEL DIVERGENCE THAT COULD SUSTAIN THE
CYCLONE. THE INTENSITY FORECAST WILL CALL FOR SLOW STRENGTHENING
FOR 24-36 HR. HOWEVER...THE CURRENTLY FORECAST SHEAR SHOULD MAKE
IT DIFFICULT FOR ONE TO STRENGTHEN INTO A HURRICANE...ANMD THE
FORECAST WILL NOT CALL FOR THAT AT THIS TIME. JUAN SHOULD LOSE
TROPICAL CHARACTERISTICS AFTER 72 HR AND BE ABSORBED BY A LARGE LOW
ASSOCIATED WITH THE EASTERN U.S. TROUGH BY 120 HR.
FORECASTER BEVEN
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/0300Z 31.1N 61.9W 50 KT
12HR VT 26/1200Z 32.1N 62.2W 55 KT
24HR VT 27/0000Z 33.7N 62.5W 60 KT
36HR VT 27/1200Z 35.6N 63.1W 60 KT
48HR VT 28/0000Z 37.6N 63.5W 60 KT
72HR VT 29/0000Z 42.5N 64.0W 60 KT
96HR VT 30/0000Z 49.0N 61.0W 50 KT...EXTRATROPICAL
120HR VT 01/0000Z...ABSORBED BY LARGER EXTRATROPICAL LOW
TAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 4
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT FRI SEP 26 2003
AFTER COMING OUT OF THE GOES-12 SATELLITE ECLIPSE PERIOD...NEW
IMAGERY INDICATES THAT JUAN HAS BECOME BETTER ORGANIZED AND HAS
ALSO STARTED MOVING NORTHWARD AGAIN. AN EYE-LIKE FEATURE WAS
APPARENT IN THE MID-CLOUDS OF THE PRE-ECLIPSE IMAGERY...BUT NO DEEP
CONVECTION WAS WITHIN 100 NMI OF THE CENTER. HOWEVER...THE EYE
FEATURE IS NOW OBSCURED BY DEEP CONVECTION...TOPS COLDER THAN
-70C...THAT HAVE SURROUNDED MORE THAN 50 PERCENT OF THE INNER CORE
CIRCULATION. ALTHOUGH SATELLITE INTENSITY ESTIMATES ARE A CONSENSUS
T2.5...OR 35 KT...I HAVE OPTED TO INCREASE THE INTENSITY SLIGHTLY
BASED ON THIS NEW INNER-CORE CONVECTIVE BANDING AND RECENT AMSU
INTENSITY ESTIMATES OF 990-992 MB.
THE INITIAL MOTION ESTIMATE IS 350/08. THERE IS NO SIGNIFICANT
CHANGE TO THE PREVIOUS TRACK OR INTENSITY FORECAST. THE NHC MODEL
GUIDANCE SHOWS GOOD CONVERGENCE ABOUT THE PREVIOUS FORECAST TRACK
AND IS ALSO IN GOOD AGREEMENT ON TAKING JUAN NORTH TO
NORTH-NORTHWESTWARD AND GRADUALLY ACCELERATE THE CYCLONE THROUGH 72
HOURS AS A SERIES OF NEGATIVELY TILTED SHORTWAVE TROUGHS UNDERCUT
THE SYSTEM FROM THE WEST AND SOUTH. BY 96 HOURS OR SO...JUAN IS
EXPECTED TO BE OVER THE CANADIAN MARITIMES REGION AND STARTING TO
BECOME EXTRATROPICAL AS THE CYCLONE BEGINS TO INTERACT WITH AND
EVENTUALLY BECOME ABSORBED BY A LARGER EXTRATROPICAL LOW PRESSURE
SYSTEM. THERE IS A LARGE SPREAD IN THE MODEL GUIDANCE BY 96 HOURS
WITH NOGAPS TAKING JUAN THE FARTHEST TO THE NORTHEAST OVER NORTHERN
NEWFOUNDLAND...WHILE THE REST OF THE NHC MODEL GUIDANCE TAKES THE
CYCLONE OVER THE ENTIRE LENGTH OF NOVA SCOTIA. THE OFFICIAL
FORECAST TRACK IS ONLY SLIGHTLY TO THE LEFT OF THE PREVIOUS
TRACK...AND IS CLOSE TO THE GFS AND GFDL MODELS.
IT WOULD NOT TAKE MUCH CONVECTION TO WRAP ALL THE AROUND THE
INNER-CORE OF JUAN AND PRODUCE AN EYE. WITH THIS IN MIND...THE
INTENSITY WAS INCREASED SLIGHTLY...BUT NIT AS HIGH AS THE SHIPS AND
GFDL INTENSITY MODELS WHICH BRING JUAN UP TO 75 KT AND 83 KT...
RESPECTIVELY...IN 36 HOURS. UPPER-LEVEL SHEAR WILL GRADUALLY
INCREASE TO MORE THAN 20 KT BY 24 HOURS...AND THIS IS THE PRIMARY
REASON FOR REMAINING BELOW THE MODEL GUIDANCE AT THIS TIME.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/0900Z 31.5N 61.9W 55 KT
12HR VT 26/1800Z 32.5N 62.2W 60 KT
24HR VT 27/0600Z 34.3N 62.6W 65 KT
36HR VT 27/1800Z 36.3N 63.3W 65 KT
48HR VT 28/0600Z 38.4N 63.8W 60 KT
72HR VT 29/0600Z 46.0N 63.0W 55 KT...EXTRATROPICAL INLAND
96HR VT 30/0600Z 50.5N 60.5W 50 KT...EXTRATROPICAL INLAND
120HR VT 01/0600Z...ABSORBED BY LARGER EXTRATROPICAL LOW
Last edited by Sciencerocks on Sat May 20, 2023 7:27 pm, edited 1 time in total.
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Sciencerocks
- Category 5
- Posts: 8903
- Age: 39
- Joined: Thu Jul 06, 2017 1:51 am
Re: Hurricane Juan
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT FRI SEP 26 2003
HIGH RESOLUTION SATELLITE IMAGES REVEAL THAT JUAN HAS DEVELOPED AN
EYE-LIKE FEATURE BUT THE CONVECTION SURROUNDING THIS FEATURE IS NOT
VERY DEEP. IN GENERAL...THIS PATTERN CORRESPONDS TO AN INTENSITY OF
65 KNOTS. LASTEST AMSU ESTIMATES FROM CIRA/NESDIS INDICATE A
MINIMUM PRESSURE OF 985 MB AND 66-KNOT WINDS AND THE
LATEST AMSU CIMSS ESTIMATE IS 986 MB. INITIAL INTENSITY IS THEN
ADJUSTED TO 65 KNOTS MAKING JUAN A HURRICANE. HOWEVER...THIS
INTENSITY IS SOMEWHAT UNCERTAIN. THERE IS SOME OPPORTUNITY FOR
SLIGHT STRENGHTENING BEFORE JUAN REACHES COOL WATERS AND BECOME
EXTRATROPICAL IN 72 HOURS. THIS IS CONSISTENT WITH SHIPS AND GFDL
INTENSITY FORECASTS.
THE HURRICANE IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 7 KNOTS.
THE HURRICANE IS EMBEDDED IN THE FLOW BETWEEN THE ATLANTIC
SUBTROPICAL RIDGE AND A STRONG MID-LATITUDE TROUGH OVER THE UNITED
STATES. THIS STEERING PATTERN WILL MOVE JUAN ON A GENERAL NORTHWARD
TRACK WITH A GRADUAL INCREASE IN FORWARD SPEED.
THIS IS CONSISTENT WITH TRACK GUIDANCE WHICH UNANIMOUSLY BRINGS THE
SYSTEM OVER EASTERN NOVA SCOTIA BETWEEN 48 AND 72 HOURS.
AS USUAL...THE MOST UNCERTAIN PORTION OF THE FORECAST IS TO
DETERMINE IF JUAN WILL CROSS NOVA SCOTIA AS A TROPICAL CYCLONE OR
IN TRANSITION TO EXTRATROPICAL. THE LATTER IS THE MOST LIKELY
SCENARIO. HOWEVER...I WOULD BE PREPARED FOR A TROPICAL CYCLONE.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/1500Z 32.2N 62.0W 65 KT
12HR VT 27/0000Z 33.7N 62.6W 70 KT
24HR VT 27/1200Z 35.5N 63.0W 70 KT
36HR VT 28/0000Z 37.5N 63.5W 70 KT
48HR VT 28/1200Z 40.0N 64.0W 70 KT
72HR VT 29/1200Z 50.0N 61.5W 45 KT...EXTRATROPICAL
96HR VT 30/1200Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT FRI SEP 26 2003
THE OVERALL CLOUD PATTERN CONTINUES TO BECOME BETTER ORGANIZED AND
CONVECTION HAS INCREASED PRIMARILY IN A WELL DEFINED CURVED BAND TO
THE NORTHWEST AND NORTH OF THE CENTER. THE EYE FEATURE HAS BEEN
INTERMETTENT. INITIAL INTENSITY REMAINS AT 65 KNOTS. THERE IS SOME
OPPORTUNITY FOR SLIGHT STRENGTHENING BEFORE JUAN REACHES COOL
WATERS AND BECOME EXTRATROPICAL IN 72 HOURS. IN FACT...THE GFDL
MAKES JUAN A 92-KNOT HURRICANE BY 48 HOURS AND SHIPS SHOWS
ADDITIONAL STRAIGHTENING. AS USUAL...IT IS UNCERTAIN IF JUAN WILL
CROSS NOVA SCOTIA AS A TROPICAL CYCLONE OR IN TRANSITION TO
EXTRATROPICAL. THE LATTER CONTINUES TO BE THE MOST LIKELY SCENARIO.
HOWEVER...I WOULD BE PREPARED FOR A TROPICAL CYCLONE.
THE HURRICANE IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 8
KNOTS...EMBEDDED IN THE FLOW BETWEEN THE ATLANTIC SUBTROPICAL RIDGE
AND A STRONG MID-LATITUDE TROUGH OVER THE UNITED STATES. THIS
PATTERN IS FORECAST TO PERSIST KEEPING JUAN ON A GENERAL NORTHWARD
TRACK WITH A GRADUAL INCREASE IN FORWARD SPEED. THIS IS CONSISTENT
WITH TRACK GUIDANCE WHICH UNANIMOUSLY FORECAST THE SYSTEM CROSSING
NOVA SCOTIA BETWEEN 48 AND 72 HOURS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/2100Z 33.0N 62.2W 65 KT
12HR VT 27/0600Z 34.3N 62.6W 70 KT
24HR VT 27/1800Z 36.5N 63.3W 75 KT
36HR VT 28/0600Z 39.5N 63.5W 75 KT
48HR VT 28/1800Z 42.5N 63.5W 65 KT
72HR VT 29/1800Z 54.0N 60.0W 40 KT...EXTRATROPICAL
96HR VT 30/1800Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 26 2003
JUAN HAS SHOWED AN EYE OR WARM SPOT FOR THE PAST SEVERAL HOURS AND
IS GENERATING CONVECTION AS COLD AS -70C IN THE WESTERN SEMICIRCLE.
THE CIRRUS OUTFLOW IS FAIR TO GOOD OVER THE NORTHEASTERN
SEMICIRCLE...AND POOR OR RESTRICTED TO THE SOUTHWEST AS UPPER-LEVEL
WESTERLIES IMPINGE ON THE HURRICANE. SATELLITE INTENSITY ESTIMATES
ARE 77 KT FROM AFWA AND TAFB...AND 65 KT FROM SAB. THE INITIAL
INTENSITY IS RAISED TO 70 KT.
THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
TRACK...360/7. OTHER THAN THAT...THERE IS LITTLE CHANGE IN THE
SYNOPTIC PATTERN OR FORECAST PHILOSOPHY. A DEEP-LAYER RIDGE OVER
THE NORTH CENTRAL ATLANTIC AND A DEEP-LAYER TROUGH OVER THE EASTERN
UNITED STATES SHOULD STEER JUAN ON A NORTHWARD TO NORTH-
NORTHWESTWARD TRACK WITH GRADUAL ACCELERATION THROUGH 48 HR. THIS
SHOULD BE FOLLOWED BY A NORTH-NORTHEASTWARD MOTION AS JUAN GETS
ABSORBED INTO THE TROUGH. ALL GUIDANCE AGREES WITH THIS
SCENARIO...AND THE OFFICIAL FORECAST BRINGS THE CENTER TO THE SOUTH
COAST OF NOVA SCOTIA IN ABOUT 48 HR.
ALL LARGE-SCALE MODELS FORECAST THE UPPER-LEVEL TROUGH CURRENTLY
AFFECTING JUAN TO WEAKEN...LEAVING THE HURRICANE TO MOVE THROUGH AN
AREA OF LIGHT TO MODERATE SHEAR THROUGH 36 HR. SHOULD THIS
VERIFY...JUAN COULD STRENGTHEN MORE THAN CURRENTLY FORECAST BEFORE
IT REACHES THE COLD WATER NORTH OF THE GULF STREAM. HOWEVER...
WATER VAPOR IMAGERY SUGGESTS THE MODELS MIGHT BE A LITTLE TOO FAST
IN WEAKENING THE SHEAR...AS A STRONG BAND OF UPPER-LEVEL WESTERLY
TO NORTHWESTERLY FLOW IS JUST SOUTHWEST OF JUAN. THE INTENSITY
FORECAST WILL GO WITH THE SCENARIO THAT THE CONDITIONS WILL BE LESS
FAVORABLE THAN SHOWN IN THE MODELS BUT MORE FAVORABLE THAN
CURRENTLY SEEN IN THE IMAGERY...AND THUS CALL FOR A LITTLE MORE
STRENGTHENING. JUAN SHOULD START TO WEAKEN ONCE IT MOVES NORTH OF
THE GULF STREAM...AND IT SHOULD BECOME EXTRATROPICAL BY 72 HR.
FORECASTER BEVEN
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/0300Z 33.7N 61.9W 70 KT
12HR VT 27/1200Z 35.1N 62.1W 75 KT
24HR VT 28/0000Z 37.2N 62.8W 75 KT
36HR VT 28/1200Z 40.1N 63.2W 75 KT
48HR VT 29/0000Z 44.8N 62.8W 65 KT
72HR VT 30/0000Z 57.1N 58.9W 40 KT...EXTRATROPICAL
96HR VT 01/0000Z...ABSORBED BY LARGER EXTRATROPICAL LOW
NNNN
HURRICANE JUAN DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SAT SEP 27 2003
JUAN HAS CONTINUED TO BECOME BETTER ORGANIZED OVERNIGHT WITH A
DISTINCT 15 NMI EYE APPARENT IN INFRARED SATELLITE IMAGERY. THE
INTENSITY HAS BEEN INCREASED TO 75 KT BASED ON A CONSENSUS DVORAK
SATELLITE INTENSITY ESTIMATE OF T4.5...OR 77 KT...FROM ALL THREE
AGENCIES...AND A 3-HOUR OBJECTIVE T-NUMBER OF T4.4...OR 75 KT.
THE INITIAL MOTION ESTIMATE IS 350/11. JUAN APPEARS TO HAVE MADE A
SLIGHT NORTHWESTWARD JOG AS AN UPPER-LEVEL SHORTWAVE TROUGH OR LOW
HAS PASSED JUST TO THE SOUTH. WATER VAPOR IMAGERY INDICATES THAT
THIS FEATURE HAS BECOME LESS DISTINCT DURING THE PAST FEW HOUS...SO
A RETURN TO A BASE NORTH OR NORTH-NORTHWESTWARD COURSE IS EXPECTED
TO RESUME SHORTLY. OTHER THAN THAT...THERE REMAINS NO SIGNIFICANT
CHANGE TO THE PREVIOUS FORECAST TRACK REASONING. THE DEEP-LAYER
RIDGE LOCATED NORTHEAST THROUGH EAST OF JUAN IS CONTINUING TO
AMPLIFY NORTHWARD AS A STRONG DEEP-LAYER TROUGH OVER THE CENTRAL
UNITED STATES CONTINUES TO DIG SOUTHEASTWARD. THE RESULTANT
INCREASING SOUTHERLY FLOW SHOULD GRADUALLY ACCELERATE JUAN
NORTHWARD TOWARD NOVA SCOTIA. ALL OF THE NHC MODEL GUIDANCE AGREES
WITH THIS SCENARIO...AND THE OFFICIAL TRACK IS IN THE MIDDLE OF THE
GUIDANCE ENVELOPE. ON THIS TRACK...JUAN IS EXPECTED TO MAKE
LANDFALL ALONG THE SOUTH COAST OF NOVA SCOTIA BY LATE SUNDAY OR
EARLY MONDAY.
THERE IS LITTLE TIME LEFT FOR JUAN TO STRENGTHEN...ALTHOUGH THE
HURRICANE IS EXPECTED TO REMAIN OVER 26C SSTS FOR ANOTHER 24 HOURS
SO. THEREFORE...ONLY SLIGHT STRENGTHENING IS FORECAST FOR THE NEXT
12 TO 24 HOURS. JUAN SHOULD START TO WEAKEN ONCE IT MOVES NORTH OF
THE GULF STREAM LOCATED ALONG 40N LATITUDE. ALTHOUGH UPPER-LEVELS
ARE FORECAST TO INCREASE TO 40 KT BY 60 HOURS...JUAN SHOULD ALREADY
BE EXTRATROPICAL BY THAT TIME...SO VERTICAL SHEAR MAY NOT PLAY A
SIGNIFICANT ROLE IN THE FORECAST WEAKENING TREND AFTER 24 HOURS.
THEREFORE...IT IS POSSIBLE THAT JUAN COULD MAKE LANDFALL ON NOVA
SCOTIA AS A HURRICANE...AND COASTAL WATCHES OR WARNINGS MAY BE
REQUIRED LATER TODAY. THE CANADIAN WEATHER SERVICE HAS ALREADY
ISSUED HURRICANE FORCE WIND WARNINGS FOR THE NOVA SCOTIA MARINE
AREAS.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/0900Z 34.9N 62.4W 75 KT
12HR VT 27/1800Z 36.4N 62.8W 80 KT
24HR VT 28/0600Z 38.9N 63.4W 80 KT
36HR VT 28/1800Z 43.0N 63.2W 75 KT
48HR VT 29/0600Z 48.7N 62.0W 65 KT...BECOMING EXTRATROPICAL
72HR VT 30/0600Z 61.0N 57.0W 40 KT...EXTRATROPICAL
96HR VT 01/0600Z...ABSORBED BY A LARGER EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SAT SEP 27 2003
VISIBLE SATELLITE IMAGES SHOW THAT THE CLOUD PATTERN ASSOCIATED WITH
JUAN HAS CONTINUED TO BECOME BETTER ORGANIZED...AND IT LOOKS AT ITS
BEST SO FAR. ALTHOUGH THE EYE IS RAGGED...IT IS SURROUNDED BY DEEP
CONVECTION. IN FACT...LATEST SSMI PASS SHOWS A RING OF DEEP
CONVECTION SUGGESTING THE THE EYEWALL IS CLOSED. IN ADDITION...
THERE ARE WELL-DEFINED CURVED BANDS AND THE OUTFLOW IS FAIR. GIVING
THE CURRRENT STRUCTURE AND PATTERN...SOME ADDITIONAL STRENGTHENING
IS POSSIBLE DURING THE NEXT 24 HOURS BEFORE JUAN REACHES COOLER
WATERS. THIS IS CONSISTENT WITH THE GFDL THAT HAS BEEN CORRECTLY
INTENSIFYING THE HURRICANE. JUAN IS EXPECTED TO BE UNDERGOING
EXTRATROPICAL TRANSITION BEYOND 36 HOURS.
JUAN HAS SLOWED DOWN AND IS NOW MOVING TOWARD THE NORTH-NORTHWEST OR
345 DEGREES AT 6 KNOTS OR LESS. HOWEVER...STEERING CURRENTS SHOULD
BECOME STRONGER AS THE MID-LEVEL TROUGH DEEPENS OVER EASTERN NORTH
AMERICA. JUAN SHOULD THEN INCREASE ITS FORWARD SPEED AND TURN MORE
TO THE NORTH. ON THIS TRACK...JUAN SHOULD BE BRINGING HURRICANE
CONDITIONS OVER NOVA SCOTIA IN ABOUT 36 HOURS. THIS TRACK IS
CONSISTENT WITH GUIDANCE AND VERY CLOSE TO THE CONSENSUS GUNA AND
GUNS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/1500Z 35.3N 63.0W 75 KT
12HR VT 28/0000Z 37.5N 63.7W 80 KT
24HR VT 28/1200Z 40.5N 64.5W 80 KT
36HR VT 29/0000Z 44.5N 64.0W 70 KT
48HR VT 29/1200Z 52.0N 61.0W 40 KT...EXTRATROPICAL
72HR VT 30/1200Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SAT SEP 27 2003
THE GFDL MODEL HAD THE CORRECT IDEA ON THE INTENSITY FORECAST.
SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN IS OUTSTANDING AND
STILL IMPROVING. THE EYE IS DISTINCT AND IS EMBEDDED WITHIN A
WELL-DEFINED AND ROUND CENTRAL DENSE OVERCAST. T-NUMBERS HAVE
INCREASED TO 5.0 ON THE DVORAK SCALE CORRESPONDING TO AN INITIAL
INTENSITY OF 90 KNOTS. THIS INTENSIFICATION HAS COINCIDED WITH A
DECREASE IN THE SHEAR AND WITH THE HURRICANE MOVING OVER WARM
WATERS. A DRIFTING BUOY NEAR THE EYE MEASURED A SEA SURFACE
TEMPERATURE OF 81 DEGREES THIS MORNING. HOWEVER...ONLY SMALL
FLUCTUATIONS IN INTENSITY ARE LIKELY TODAY. JUAN SHOULD BEGIN TO
GRADUALLY WEAKEN AS IT REACHES THE COOLER WATERS NEAR NOVA SCOTIA.
JUAN SHOULD BE CROSSING NOVA SCOTIA WHILE UNDERGOING EXTRATROPICAL
TRANSITION.
ANOTHER SURPRISE TODAY WAS THAT JUAN MOVED A LITTLE MORE TO THE
NORTH-NORTHWEST AND SLOWER THAN ANTICIPATED. IN FACT...THE
HURRICANE MOVED TOWARD THE NORTHWEST FOR A WHILE TODAY. HOWEVER...
STEERING CURRENTS SHOULD BECOME STRONGER AS THE MID-LEVEL TROUGH
DEEPENS OVER EASTERN NORTH AMERICA. JUAN SHOULD THEN INCREASE ITS
FORWARD SPEED AND TURN MORE TO THE NORTH. ON THIS TRACK...HURRICANE
CONDITIONS ARE EXPECTED OVER NOVA SCOTIA LATE SUNDAY. TRACK
GUIDANCE CONTINUES TO BE VERY CONSISTENT BRINGING THE CYCLONE
OVER NOVA SCOTIA.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/2100Z 35.9N 63.4W 90 KT
12HR VT 28/0600Z 38.0N 64.3W 85 KT
24HR VT 28/1800Z 42.5N 64.5W 70 KT
36HR VT 29/0600Z 48.0N 63.0W 45 KT...EXTRATROPICAL
48HR VT 29/1800Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SAT SEP 27 2003
CLOUD TOPS AROUND THE EYE HAVE WARMED SOME...BUT THE DVORAK
CLASSIFICATIONS REMAIN 5.0 FROM TAFB AND SAB. THE INITIAL
INTENSITY REMAINS 90 KT FOR THIS ADVISORY. ALTHOUGH THERE WILL NOT
BE AN APPRECIABLE INCREASE IN SHEAR AS JUAN ACCELERATES TOWARD NOVA
SCOTIA...THE SSTS COOL SIGNIFICANTLY AND SO SIGNIFICANT WEAKENING
IS EXPECTED PRIOR TO LANDFALL. THE HURRICANE MAY HAVE CONSIDERABLE
DIFFICULTY BRINGING STRONG WINDS ALOFT DOWNWARD OVER THE COLD WATER
AS WELL. HOWEVER...JUAN SHOULD STILL BE NEAR HURRICANE STRENGTH AT
THAT TIME.
THE INITIAL MOTION IS 340/8. GIVEN THE EXPECTED ACCELERATION...THE
GUIDANCE IS IN REASONABLE AGREEMENT. THERE WAS A LEFTWARD SHIFT IN
THE GUIDANCE SUITE AT 00Z AND THE OFFICIAL FORECAST WAS NUDGED
LEFTWARD AS WELL...AND IS VERY CLOSE TO THE GFDL/UKMET/NOGAPS/GFS
CONSENSUS.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/0300Z 36.8N 63.8W 90 KT
12HR VT 28/1200Z 39.0N 64.4W 80 KT
24HR VT 29/0000Z 44.3N 64.4W 65 KT...INLAND
36HR VT 29/1200Z 50.7N 64.0W 40 KT...EXTRATROPICAL
48HR VT 30/0000Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SUN SEP 28 2003
CLOUD TOPS AROUND THE EYE HAVE COOLED...WITH SOME TOPS COLDER THAN
-75C...AND DVORAK CLASSIFICATIONS REMAIN T5.0...OR 90 KT...FROM
BOTH TAFB AND SAB. THE EYE HAS ALSO DECREASED IN SIZE AND THE 3-HR
AVERAGE DVORAK OBJECTIVE T-NUMBER IS T4.9...OR 88 KT. THEREFORE...
THE INITIAL INTENSITY REMAINS AT 90 KT FOR THIS ADVISORY.
THE INITIAL MOTION ESTIMATE IS 355/10...EVEN THOUGH THE PAST 6-HR
MOTION HAS BEEN 340/09. THE LAST FEW SATELLITE POSITIONS...ALONG
WITH WATER VAPOR MOTIONS...SUGGEST THAT JUAN MAY BE FINALLY MAKING
THE TURN MORE TOWARD THE NORTH THAT THE GLOBAL MODELS HAVE BEEN
FORECASTING THE PAST 24 HOURS. THERE IS A SLIGHT CONFLICT BETWEEN
THE VARIOUS MODELS WITH THE GFS AND CANADIAN MODELS BRINGING A
SURFACE LOW CENTER WEST OF NOVA SCOTIA AND INTO EXTREME EASTERN
MAINE...WHILE THE UKMET...GFDL...AND NOGAPS MODELS TAKE JUAN OVER
OR JUST WEST OF HALIFAX NOVA SCOTIA. HOWEVER...THE CANADIAN AND GFS
850-500 MB VORTICITY CENTERS ARE FORECAST TO REMAIN VERTICALLY
STACKED AND PASS JUST WEST OF HALIFAX IN ABOUT 18-21 HOURS...SO THE
OFFICIAL FORECAST TRACK WAS ONLY NUDGED SLIGHTLY TO THE EAST OF THE
PREVIOUS FORECAST TRACK. THIS IS CONSISTENT WITH ALL OF THE MODELS
FORECASTING THE 500-200 MB MEAN WIND FLOW TO BE FROM A SOUTH TO
SOUTH-SOUTHWESTERLY DIRECTION AFTER 12 HOURS...WHICH SHOULD KEEP
JUAN MOVING IN A GENERAL NORTHERLY DIRECTION. NOTE...AN 18-HR/00Z
FORECAST POSITION WOULD PLACE JUAN NEAR 43.3N 64.2W AND 70-KT.
SINCE JUAN IS FORECAST TO BEGIN ACCELERATING LATER THIS MORNING AND
UNTIL LANDFALL...THERE WILL LIKELY NOT BE ANY SIGNIFICANT INCREASE
IN THE VERTICAL SHEAR. THEREFORE...THE WEAKENING TREND THAT IS
FORECAST IS MAINLY DUE TO THE CYCLONE PASSING OVER MUCH COOLER SSTS
NORTH OF 40N LATITUDE. ALSO...THE COOLER WATER MAY CAUSE THE
BOUNDARY LAYER TO BECOME MORE STABLE...WHICH MAY NOT ALLOW ALL OF
THE STRONGER WINDS ALOFT TO COME DOWN TO THE SURFACE. HOWEVER...
JUAN IS STILL EXPECTED TO BE NEAR HURRICANE STRENGTH AT LANDFALL.
SINCE JUAN IS EXPECTED TO MAKE LANDFALL IN THE VICINITY OF HALIFAX
BETWEEN 00-03Z THIS EVENING AT ASTRONOMICAL HIGH TIDE...SOME STORM
SURGE FLOODING MAY OCCUR ALONG THE SOUTH COAST OF NOVA SCOTIA
...ESPECIALLY IN HARBORS AND INLETS IN AND AROUND HALIFAX.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/0900Z 37.6N 64.1W 90 KT
12HR VT 28/1800Z 40.7N 64.3W 80 KT
24HR VT 29/0600Z 46.0N 63.9W 60 KT...INLAND BECOMING E.T.
36HR VT 29/1800Z 53.8N 62.9W 40 KT...EXTRATROPICAL
48HR VT 30/0600Z...ABSORBED BY LARGER EXTRATROPICAL LOW
[img]ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SUN SEP 28 2003
THE EYE HAS BECOME LESS DISTINCT AND DVORAK T-NUMBERS ARE DOWN TO
4.5...SO THE CURRENT INTENSITY IS LOWERED SLIGHTLY TO 85 KT. THE
SEA SURFACE UNDER JUAN WILL COOL SIGNIFICANTLY WHEN IT MOVES NORTH
OF 40N LATITUDE...AND THIS SHOULD CAUSE JUAN TO WEAKEN.
HOWEVER...SINCE THE CYCLONE IS EXPECTED TO ACCELERATE TO 20 TO 25
KT AS IT APPROACHES THE COAST...IT WILL NOT HAVE MUCH TIME TO
WEAKEN PRIOR TO LANDFALL. THEREFORE JUAN IS EXPECTED TO CROSS THE
SOUTH COAST OF NOVA SCOTIA AS A HURRICANE. ALSO...SINCE THE SYSTEM
IS EXPECTED TO MAKE LANDFALL NEAR THE TIME OF ASTRONOMICAL HIGH
TIDE...THERE IS THE POTENTIAL FOR A SIGNIFICANT STORM SURGE IN NOVA
SCOTIA.
JUAN HAS ACCELERATED NORTHWARD AND IS NOW MOVING AT LEAST 17 KT.
THERE IS NO SIGNIFICANT CHANGE TO THE TRACK FORECAST OR REASONING
FROM THE PREVIOUS ADVISORY. THE CYCLONE SHOULD CONTINUE TO
ACCELERATE NORTHWARD AHEAD OF A LARGE MID-LATITUDE TROUGH OVER THE
EASTERN UNITED STATES.
JUAN SHOULD BEGIN TO MAKE THE EXTRATRAPICAL TRANSITION SOON AFTER
LANDFALL. THE OFFICIAL FORECAST SHOWS A POINT AT 36 H BUT GLOBAL
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY GET ABSORBED BY A
LARGER EXTRATROPICAL CYCLONE EVEN SOONER THAN THAT TIME.
FORECASTER PASCH
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/1500Z 39.4N 64.1W 85 KT
12HR VT 29/0000Z 43.1N 64.1W 80 KT
24HR VT 29/1200Z 49.7N 63.2W 50 KT...EXTRATROPICAL
36HR VT 30/0000Z 57.0N 61.0W 30 KT...EXTRATROPICAL
48HR VT 30/1200Z...ABSORBED BY EXTRATROPICAL LOW
NNNN
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT FRI SEP 26 2003
HIGH RESOLUTION SATELLITE IMAGES REVEAL THAT JUAN HAS DEVELOPED AN
EYE-LIKE FEATURE BUT THE CONVECTION SURROUNDING THIS FEATURE IS NOT
VERY DEEP. IN GENERAL...THIS PATTERN CORRESPONDS TO AN INTENSITY OF
65 KNOTS. LASTEST AMSU ESTIMATES FROM CIRA/NESDIS INDICATE A
MINIMUM PRESSURE OF 985 MB AND 66-KNOT WINDS AND THE
LATEST AMSU CIMSS ESTIMATE IS 986 MB. INITIAL INTENSITY IS THEN
ADJUSTED TO 65 KNOTS MAKING JUAN A HURRICANE. HOWEVER...THIS
INTENSITY IS SOMEWHAT UNCERTAIN. THERE IS SOME OPPORTUNITY FOR
SLIGHT STRENGHTENING BEFORE JUAN REACHES COOL WATERS AND BECOME
EXTRATROPICAL IN 72 HOURS. THIS IS CONSISTENT WITH SHIPS AND GFDL
INTENSITY FORECASTS.
THE HURRICANE IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 7 KNOTS.
THE HURRICANE IS EMBEDDED IN THE FLOW BETWEEN THE ATLANTIC
SUBTROPICAL RIDGE AND A STRONG MID-LATITUDE TROUGH OVER THE UNITED
STATES. THIS STEERING PATTERN WILL MOVE JUAN ON A GENERAL NORTHWARD
TRACK WITH A GRADUAL INCREASE IN FORWARD SPEED.
THIS IS CONSISTENT WITH TRACK GUIDANCE WHICH UNANIMOUSLY BRINGS THE
SYSTEM OVER EASTERN NOVA SCOTIA BETWEEN 48 AND 72 HOURS.
AS USUAL...THE MOST UNCERTAIN PORTION OF THE FORECAST IS TO
DETERMINE IF JUAN WILL CROSS NOVA SCOTIA AS A TROPICAL CYCLONE OR
IN TRANSITION TO EXTRATROPICAL. THE LATTER IS THE MOST LIKELY
SCENARIO. HOWEVER...I WOULD BE PREPARED FOR A TROPICAL CYCLONE.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/1500Z 32.2N 62.0W 65 KT
12HR VT 27/0000Z 33.7N 62.6W 70 KT
24HR VT 27/1200Z 35.5N 63.0W 70 KT
36HR VT 28/0000Z 37.5N 63.5W 70 KT
48HR VT 28/1200Z 40.0N 64.0W 70 KT
72HR VT 29/1200Z 50.0N 61.5W 45 KT...EXTRATROPICAL
96HR VT 30/1200Z...ABSORBED BY A LARGE EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT FRI SEP 26 2003
THE OVERALL CLOUD PATTERN CONTINUES TO BECOME BETTER ORGANIZED AND
CONVECTION HAS INCREASED PRIMARILY IN A WELL DEFINED CURVED BAND TO
THE NORTHWEST AND NORTH OF THE CENTER. THE EYE FEATURE HAS BEEN
INTERMETTENT. INITIAL INTENSITY REMAINS AT 65 KNOTS. THERE IS SOME
OPPORTUNITY FOR SLIGHT STRENGTHENING BEFORE JUAN REACHES COOL
WATERS AND BECOME EXTRATROPICAL IN 72 HOURS. IN FACT...THE GFDL
MAKES JUAN A 92-KNOT HURRICANE BY 48 HOURS AND SHIPS SHOWS
ADDITIONAL STRAIGHTENING. AS USUAL...IT IS UNCERTAIN IF JUAN WILL
CROSS NOVA SCOTIA AS A TROPICAL CYCLONE OR IN TRANSITION TO
EXTRATROPICAL. THE LATTER CONTINUES TO BE THE MOST LIKELY SCENARIO.
HOWEVER...I WOULD BE PREPARED FOR A TROPICAL CYCLONE.
THE HURRICANE IS MOVING TOWARD THE NORTH OR 350 DEGREES AT 8
KNOTS...EMBEDDED IN THE FLOW BETWEEN THE ATLANTIC SUBTROPICAL RIDGE
AND A STRONG MID-LATITUDE TROUGH OVER THE UNITED STATES. THIS
PATTERN IS FORECAST TO PERSIST KEEPING JUAN ON A GENERAL NORTHWARD
TRACK WITH A GRADUAL INCREASE IN FORWARD SPEED. THIS IS CONSISTENT
WITH TRACK GUIDANCE WHICH UNANIMOUSLY FORECAST THE SYSTEM CROSSING
NOVA SCOTIA BETWEEN 48 AND 72 HOURS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 26/2100Z 33.0N 62.2W 65 KT
12HR VT 27/0600Z 34.3N 62.6W 70 KT
24HR VT 27/1800Z 36.5N 63.3W 75 KT
36HR VT 28/0600Z 39.5N 63.5W 75 KT
48HR VT 28/1800Z 42.5N 63.5W 65 KT
72HR VT 29/1800Z 54.0N 60.0W 40 KT...EXTRATROPICAL
96HR VT 30/1800Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 26 2003
JUAN HAS SHOWED AN EYE OR WARM SPOT FOR THE PAST SEVERAL HOURS AND
IS GENERATING CONVECTION AS COLD AS -70C IN THE WESTERN SEMICIRCLE.
THE CIRRUS OUTFLOW IS FAIR TO GOOD OVER THE NORTHEASTERN
SEMICIRCLE...AND POOR OR RESTRICTED TO THE SOUTHWEST AS UPPER-LEVEL
WESTERLIES IMPINGE ON THE HURRICANE. SATELLITE INTENSITY ESTIMATES
ARE 77 KT FROM AFWA AND TAFB...AND 65 KT FROM SAB. THE INITIAL
INTENSITY IS RAISED TO 70 KT.
THE INITIAL MOTION IS A LITTLE TO THE RIGHT OF THE PREVIOUS
TRACK...360/7. OTHER THAN THAT...THERE IS LITTLE CHANGE IN THE
SYNOPTIC PATTERN OR FORECAST PHILOSOPHY. A DEEP-LAYER RIDGE OVER
THE NORTH CENTRAL ATLANTIC AND A DEEP-LAYER TROUGH OVER THE EASTERN
UNITED STATES SHOULD STEER JUAN ON A NORTHWARD TO NORTH-
NORTHWESTWARD TRACK WITH GRADUAL ACCELERATION THROUGH 48 HR. THIS
SHOULD BE FOLLOWED BY A NORTH-NORTHEASTWARD MOTION AS JUAN GETS
ABSORBED INTO THE TROUGH. ALL GUIDANCE AGREES WITH THIS
SCENARIO...AND THE OFFICIAL FORECAST BRINGS THE CENTER TO THE SOUTH
COAST OF NOVA SCOTIA IN ABOUT 48 HR.
ALL LARGE-SCALE MODELS FORECAST THE UPPER-LEVEL TROUGH CURRENTLY
AFFECTING JUAN TO WEAKEN...LEAVING THE HURRICANE TO MOVE THROUGH AN
AREA OF LIGHT TO MODERATE SHEAR THROUGH 36 HR. SHOULD THIS
VERIFY...JUAN COULD STRENGTHEN MORE THAN CURRENTLY FORECAST BEFORE
IT REACHES THE COLD WATER NORTH OF THE GULF STREAM. HOWEVER...
WATER VAPOR IMAGERY SUGGESTS THE MODELS MIGHT BE A LITTLE TOO FAST
IN WEAKENING THE SHEAR...AS A STRONG BAND OF UPPER-LEVEL WESTERLY
TO NORTHWESTERLY FLOW IS JUST SOUTHWEST OF JUAN. THE INTENSITY
FORECAST WILL GO WITH THE SCENARIO THAT THE CONDITIONS WILL BE LESS
FAVORABLE THAN SHOWN IN THE MODELS BUT MORE FAVORABLE THAN
CURRENTLY SEEN IN THE IMAGERY...AND THUS CALL FOR A LITTLE MORE
STRENGTHENING. JUAN SHOULD START TO WEAKEN ONCE IT MOVES NORTH OF
THE GULF STREAM...AND IT SHOULD BECOME EXTRATROPICAL BY 72 HR.
FORECASTER BEVEN
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/0300Z 33.7N 61.9W 70 KT
12HR VT 27/1200Z 35.1N 62.1W 75 KT
24HR VT 28/0000Z 37.2N 62.8W 75 KT
36HR VT 28/1200Z 40.1N 63.2W 75 KT
48HR VT 29/0000Z 44.8N 62.8W 65 KT
72HR VT 30/0000Z 57.1N 58.9W 40 KT...EXTRATROPICAL
96HR VT 01/0000Z...ABSORBED BY LARGER EXTRATROPICAL LOW
NNNN
HURRICANE JUAN DISCUSSION NUMBER 8
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SAT SEP 27 2003
JUAN HAS CONTINUED TO BECOME BETTER ORGANIZED OVERNIGHT WITH A
DISTINCT 15 NMI EYE APPARENT IN INFRARED SATELLITE IMAGERY. THE
INTENSITY HAS BEEN INCREASED TO 75 KT BASED ON A CONSENSUS DVORAK
SATELLITE INTENSITY ESTIMATE OF T4.5...OR 77 KT...FROM ALL THREE
AGENCIES...AND A 3-HOUR OBJECTIVE T-NUMBER OF T4.4...OR 75 KT.
THE INITIAL MOTION ESTIMATE IS 350/11. JUAN APPEARS TO HAVE MADE A
SLIGHT NORTHWESTWARD JOG AS AN UPPER-LEVEL SHORTWAVE TROUGH OR LOW
HAS PASSED JUST TO THE SOUTH. WATER VAPOR IMAGERY INDICATES THAT
THIS FEATURE HAS BECOME LESS DISTINCT DURING THE PAST FEW HOUS...SO
A RETURN TO A BASE NORTH OR NORTH-NORTHWESTWARD COURSE IS EXPECTED
TO RESUME SHORTLY. OTHER THAN THAT...THERE REMAINS NO SIGNIFICANT
CHANGE TO THE PREVIOUS FORECAST TRACK REASONING. THE DEEP-LAYER
RIDGE LOCATED NORTHEAST THROUGH EAST OF JUAN IS CONTINUING TO
AMPLIFY NORTHWARD AS A STRONG DEEP-LAYER TROUGH OVER THE CENTRAL
UNITED STATES CONTINUES TO DIG SOUTHEASTWARD. THE RESULTANT
INCREASING SOUTHERLY FLOW SHOULD GRADUALLY ACCELERATE JUAN
NORTHWARD TOWARD NOVA SCOTIA. ALL OF THE NHC MODEL GUIDANCE AGREES
WITH THIS SCENARIO...AND THE OFFICIAL TRACK IS IN THE MIDDLE OF THE
GUIDANCE ENVELOPE. ON THIS TRACK...JUAN IS EXPECTED TO MAKE
LANDFALL ALONG THE SOUTH COAST OF NOVA SCOTIA BY LATE SUNDAY OR
EARLY MONDAY.
THERE IS LITTLE TIME LEFT FOR JUAN TO STRENGTHEN...ALTHOUGH THE
HURRICANE IS EXPECTED TO REMAIN OVER 26C SSTS FOR ANOTHER 24 HOURS
SO. THEREFORE...ONLY SLIGHT STRENGTHENING IS FORECAST FOR THE NEXT
12 TO 24 HOURS. JUAN SHOULD START TO WEAKEN ONCE IT MOVES NORTH OF
THE GULF STREAM LOCATED ALONG 40N LATITUDE. ALTHOUGH UPPER-LEVELS
ARE FORECAST TO INCREASE TO 40 KT BY 60 HOURS...JUAN SHOULD ALREADY
BE EXTRATROPICAL BY THAT TIME...SO VERTICAL SHEAR MAY NOT PLAY A
SIGNIFICANT ROLE IN THE FORECAST WEAKENING TREND AFTER 24 HOURS.
THEREFORE...IT IS POSSIBLE THAT JUAN COULD MAKE LANDFALL ON NOVA
SCOTIA AS A HURRICANE...AND COASTAL WATCHES OR WARNINGS MAY BE
REQUIRED LATER TODAY. THE CANADIAN WEATHER SERVICE HAS ALREADY
ISSUED HURRICANE FORCE WIND WARNINGS FOR THE NOVA SCOTIA MARINE
AREAS.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/0900Z 34.9N 62.4W 75 KT
12HR VT 27/1800Z 36.4N 62.8W 80 KT
24HR VT 28/0600Z 38.9N 63.4W 80 KT
36HR VT 28/1800Z 43.0N 63.2W 75 KT
48HR VT 29/0600Z 48.7N 62.0W 65 KT...BECOMING EXTRATROPICAL
72HR VT 30/0600Z 61.0N 57.0W 40 KT...EXTRATROPICAL
96HR VT 01/0600Z...ABSORBED BY A LARGER EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SAT SEP 27 2003
VISIBLE SATELLITE IMAGES SHOW THAT THE CLOUD PATTERN ASSOCIATED WITH
JUAN HAS CONTINUED TO BECOME BETTER ORGANIZED...AND IT LOOKS AT ITS
BEST SO FAR. ALTHOUGH THE EYE IS RAGGED...IT IS SURROUNDED BY DEEP
CONVECTION. IN FACT...LATEST SSMI PASS SHOWS A RING OF DEEP
CONVECTION SUGGESTING THE THE EYEWALL IS CLOSED. IN ADDITION...
THERE ARE WELL-DEFINED CURVED BANDS AND THE OUTFLOW IS FAIR. GIVING
THE CURRRENT STRUCTURE AND PATTERN...SOME ADDITIONAL STRENGTHENING
IS POSSIBLE DURING THE NEXT 24 HOURS BEFORE JUAN REACHES COOLER
WATERS. THIS IS CONSISTENT WITH THE GFDL THAT HAS BEEN CORRECTLY
INTENSIFYING THE HURRICANE. JUAN IS EXPECTED TO BE UNDERGOING
EXTRATROPICAL TRANSITION BEYOND 36 HOURS.
JUAN HAS SLOWED DOWN AND IS NOW MOVING TOWARD THE NORTH-NORTHWEST OR
345 DEGREES AT 6 KNOTS OR LESS. HOWEVER...STEERING CURRENTS SHOULD
BECOME STRONGER AS THE MID-LEVEL TROUGH DEEPENS OVER EASTERN NORTH
AMERICA. JUAN SHOULD THEN INCREASE ITS FORWARD SPEED AND TURN MORE
TO THE NORTH. ON THIS TRACK...JUAN SHOULD BE BRINGING HURRICANE
CONDITIONS OVER NOVA SCOTIA IN ABOUT 36 HOURS. THIS TRACK IS
CONSISTENT WITH GUIDANCE AND VERY CLOSE TO THE CONSENSUS GUNA AND
GUNS.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/1500Z 35.3N 63.0W 75 KT
12HR VT 28/0000Z 37.5N 63.7W 80 KT
24HR VT 28/1200Z 40.5N 64.5W 80 KT
36HR VT 29/0000Z 44.5N 64.0W 70 KT
48HR VT 29/1200Z 52.0N 61.0W 40 KT...EXTRATROPICAL
72HR VT 30/1200Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SAT SEP 27 2003
THE GFDL MODEL HAD THE CORRECT IDEA ON THE INTENSITY FORECAST.
SATELLITE IMAGES INDICATE THAT THE CLOUD PATTERN IS OUTSTANDING AND
STILL IMPROVING. THE EYE IS DISTINCT AND IS EMBEDDED WITHIN A
WELL-DEFINED AND ROUND CENTRAL DENSE OVERCAST. T-NUMBERS HAVE
INCREASED TO 5.0 ON THE DVORAK SCALE CORRESPONDING TO AN INITIAL
INTENSITY OF 90 KNOTS. THIS INTENSIFICATION HAS COINCIDED WITH A
DECREASE IN THE SHEAR AND WITH THE HURRICANE MOVING OVER WARM
WATERS. A DRIFTING BUOY NEAR THE EYE MEASURED A SEA SURFACE
TEMPERATURE OF 81 DEGREES THIS MORNING. HOWEVER...ONLY SMALL
FLUCTUATIONS IN INTENSITY ARE LIKELY TODAY. JUAN SHOULD BEGIN TO
GRADUALLY WEAKEN AS IT REACHES THE COOLER WATERS NEAR NOVA SCOTIA.
JUAN SHOULD BE CROSSING NOVA SCOTIA WHILE UNDERGOING EXTRATROPICAL
TRANSITION.
ANOTHER SURPRISE TODAY WAS THAT JUAN MOVED A LITTLE MORE TO THE
NORTH-NORTHWEST AND SLOWER THAN ANTICIPATED. IN FACT...THE
HURRICANE MOVED TOWARD THE NORTHWEST FOR A WHILE TODAY. HOWEVER...
STEERING CURRENTS SHOULD BECOME STRONGER AS THE MID-LEVEL TROUGH
DEEPENS OVER EASTERN NORTH AMERICA. JUAN SHOULD THEN INCREASE ITS
FORWARD SPEED AND TURN MORE TO THE NORTH. ON THIS TRACK...HURRICANE
CONDITIONS ARE EXPECTED OVER NOVA SCOTIA LATE SUNDAY. TRACK
GUIDANCE CONTINUES TO BE VERY CONSISTENT BRINGING THE CYCLONE
OVER NOVA SCOTIA.
FORECASTER AVILA
FORECAST POSITIONS AND MAX WINDS
INITIAL 27/2100Z 35.9N 63.4W 90 KT
12HR VT 28/0600Z 38.0N 64.3W 85 KT
24HR VT 28/1800Z 42.5N 64.5W 70 KT
36HR VT 29/0600Z 48.0N 63.0W 45 KT...EXTRATROPICAL
48HR VT 29/1800Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SAT SEP 27 2003
CLOUD TOPS AROUND THE EYE HAVE WARMED SOME...BUT THE DVORAK
CLASSIFICATIONS REMAIN 5.0 FROM TAFB AND SAB. THE INITIAL
INTENSITY REMAINS 90 KT FOR THIS ADVISORY. ALTHOUGH THERE WILL NOT
BE AN APPRECIABLE INCREASE IN SHEAR AS JUAN ACCELERATES TOWARD NOVA
SCOTIA...THE SSTS COOL SIGNIFICANTLY AND SO SIGNIFICANT WEAKENING
IS EXPECTED PRIOR TO LANDFALL. THE HURRICANE MAY HAVE CONSIDERABLE
DIFFICULTY BRINGING STRONG WINDS ALOFT DOWNWARD OVER THE COLD WATER
AS WELL. HOWEVER...JUAN SHOULD STILL BE NEAR HURRICANE STRENGTH AT
THAT TIME.
THE INITIAL MOTION IS 340/8. GIVEN THE EXPECTED ACCELERATION...THE
GUIDANCE IS IN REASONABLE AGREEMENT. THERE WAS A LEFTWARD SHIFT IN
THE GUIDANCE SUITE AT 00Z AND THE OFFICIAL FORECAST WAS NUDGED
LEFTWARD AS WELL...AND IS VERY CLOSE TO THE GFDL/UKMET/NOGAPS/GFS
CONSENSUS.
FORECASTER FRANKLIN
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/0300Z 36.8N 63.8W 90 KT
12HR VT 28/1200Z 39.0N 64.4W 80 KT
24HR VT 29/0000Z 44.3N 64.4W 65 KT...INLAND
36HR VT 29/1200Z 50.7N 64.0W 40 KT...EXTRATROPICAL
48HR VT 30/0000Z...ABSORBED BY EXTRATROPICAL LOW
HURRICANE JUAN DISCUSSION NUMBER 12
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT SUN SEP 28 2003
CLOUD TOPS AROUND THE EYE HAVE COOLED...WITH SOME TOPS COLDER THAN
-75C...AND DVORAK CLASSIFICATIONS REMAIN T5.0...OR 90 KT...FROM
BOTH TAFB AND SAB. THE EYE HAS ALSO DECREASED IN SIZE AND THE 3-HR
AVERAGE DVORAK OBJECTIVE T-NUMBER IS T4.9...OR 88 KT. THEREFORE...
THE INITIAL INTENSITY REMAINS AT 90 KT FOR THIS ADVISORY.
THE INITIAL MOTION ESTIMATE IS 355/10...EVEN THOUGH THE PAST 6-HR
MOTION HAS BEEN 340/09. THE LAST FEW SATELLITE POSITIONS...ALONG
WITH WATER VAPOR MOTIONS...SUGGEST THAT JUAN MAY BE FINALLY MAKING
THE TURN MORE TOWARD THE NORTH THAT THE GLOBAL MODELS HAVE BEEN
FORECASTING THE PAST 24 HOURS. THERE IS A SLIGHT CONFLICT BETWEEN
THE VARIOUS MODELS WITH THE GFS AND CANADIAN MODELS BRINGING A
SURFACE LOW CENTER WEST OF NOVA SCOTIA AND INTO EXTREME EASTERN
MAINE...WHILE THE UKMET...GFDL...AND NOGAPS MODELS TAKE JUAN OVER
OR JUST WEST OF HALIFAX NOVA SCOTIA. HOWEVER...THE CANADIAN AND GFS
850-500 MB VORTICITY CENTERS ARE FORECAST TO REMAIN VERTICALLY
STACKED AND PASS JUST WEST OF HALIFAX IN ABOUT 18-21 HOURS...SO THE
OFFICIAL FORECAST TRACK WAS ONLY NUDGED SLIGHTLY TO THE EAST OF THE
PREVIOUS FORECAST TRACK. THIS IS CONSISTENT WITH ALL OF THE MODELS
FORECASTING THE 500-200 MB MEAN WIND FLOW TO BE FROM A SOUTH TO
SOUTH-SOUTHWESTERLY DIRECTION AFTER 12 HOURS...WHICH SHOULD KEEP
JUAN MOVING IN A GENERAL NORTHERLY DIRECTION. NOTE...AN 18-HR/00Z
FORECAST POSITION WOULD PLACE JUAN NEAR 43.3N 64.2W AND 70-KT.
SINCE JUAN IS FORECAST TO BEGIN ACCELERATING LATER THIS MORNING AND
UNTIL LANDFALL...THERE WILL LIKELY NOT BE ANY SIGNIFICANT INCREASE
IN THE VERTICAL SHEAR. THEREFORE...THE WEAKENING TREND THAT IS
FORECAST IS MAINLY DUE TO THE CYCLONE PASSING OVER MUCH COOLER SSTS
NORTH OF 40N LATITUDE. ALSO...THE COOLER WATER MAY CAUSE THE
BOUNDARY LAYER TO BECOME MORE STABLE...WHICH MAY NOT ALLOW ALL OF
THE STRONGER WINDS ALOFT TO COME DOWN TO THE SURFACE. HOWEVER...
JUAN IS STILL EXPECTED TO BE NEAR HURRICANE STRENGTH AT LANDFALL.
SINCE JUAN IS EXPECTED TO MAKE LANDFALL IN THE VICINITY OF HALIFAX
BETWEEN 00-03Z THIS EVENING AT ASTRONOMICAL HIGH TIDE...SOME STORM
SURGE FLOODING MAY OCCUR ALONG THE SOUTH COAST OF NOVA SCOTIA
...ESPECIALLY IN HARBORS AND INLETS IN AND AROUND HALIFAX.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/0900Z 37.6N 64.1W 90 KT
12HR VT 28/1800Z 40.7N 64.3W 80 KT
24HR VT 29/0600Z 46.0N 63.9W 60 KT...INLAND BECOMING E.T.
36HR VT 29/1800Z 53.8N 62.9W 40 KT...EXTRATROPICAL
48HR VT 30/0600Z...ABSORBED BY LARGER EXTRATROPICAL LOW
[img]ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT SUN SEP 28 2003
THE EYE HAS BECOME LESS DISTINCT AND DVORAK T-NUMBERS ARE DOWN TO
4.5...SO THE CURRENT INTENSITY IS LOWERED SLIGHTLY TO 85 KT. THE
SEA SURFACE UNDER JUAN WILL COOL SIGNIFICANTLY WHEN IT MOVES NORTH
OF 40N LATITUDE...AND THIS SHOULD CAUSE JUAN TO WEAKEN.
HOWEVER...SINCE THE CYCLONE IS EXPECTED TO ACCELERATE TO 20 TO 25
KT AS IT APPROACHES THE COAST...IT WILL NOT HAVE MUCH TIME TO
WEAKEN PRIOR TO LANDFALL. THEREFORE JUAN IS EXPECTED TO CROSS THE
SOUTH COAST OF NOVA SCOTIA AS A HURRICANE. ALSO...SINCE THE SYSTEM
IS EXPECTED TO MAKE LANDFALL NEAR THE TIME OF ASTRONOMICAL HIGH
TIDE...THERE IS THE POTENTIAL FOR A SIGNIFICANT STORM SURGE IN NOVA
SCOTIA.
JUAN HAS ACCELERATED NORTHWARD AND IS NOW MOVING AT LEAST 17 KT.
THERE IS NO SIGNIFICANT CHANGE TO THE TRACK FORECAST OR REASONING
FROM THE PREVIOUS ADVISORY. THE CYCLONE SHOULD CONTINUE TO
ACCELERATE NORTHWARD AHEAD OF A LARGE MID-LATITUDE TROUGH OVER THE
EASTERN UNITED STATES.
JUAN SHOULD BEGIN TO MAKE THE EXTRATRAPICAL TRANSITION SOON AFTER
LANDFALL. THE OFFICIAL FORECAST SHOWS A POINT AT 36 H BUT GLOBAL
MODEL GUIDANCE SUGGESTS THAT THE SYSTEM MAY GET ABSORBED BY A
LARGER EXTRATROPICAL CYCLONE EVEN SOONER THAN THAT TIME.
FORECASTER PASCH
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/1500Z 39.4N 64.1W 85 KT
12HR VT 29/0000Z 43.1N 64.1W 80 KT
24HR VT 29/1200Z 49.7N 63.2W 50 KT...EXTRATROPICAL
36HR VT 30/0000Z 57.0N 61.0W 30 KT...EXTRATROPICAL
48HR VT 30/1200Z...ABSORBED BY EXTRATROPICAL LOW
NNNN
Last edited by Sciencerocks on Sat May 20, 2023 7:40 pm, edited 5 times in total.
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Sciencerocks
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Re: Hurricane Juan
CZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SUN SEP 28 2003
THE SYSTEM'S APPEARANCE ON SATELLITE IMAGES IS ABOUT THE SAME AS IT
WAS EARLIER TODAY...WITH A CLOUD-FILLED EYE STILL APPARENT. LATEST
DVORAK CLASSIFICATIONS SUGGEST NO CHANGE IN STRENGTH. JUAN IS
LIKELY TO BEGIN FEELING THE EFFECT OF SIGNIFICANTLY COLDER WATERS
VERY SOON. HOWEVER...BECAUSE OF THE RAPID FORWARD MOTION...THERE
WILL WILL BE LITTLE TIME FOR WEAKENING PRIOR TO LANDFALL. THUS THE
CYCLONE IS EXPECTED TO STILL BE OF HURRICANE STRENGTH WHEN IT
REACHES NOVA SCOTIA. THE FAST FORWARD SPEED WILL SHOULD LIMIT
RAINFALL AMOUNTS TO AROUND 4 INCHES...100 MM. SINCE LANDFALL IS
EXPECTED TO BE AROUND THE TIME OF ASTRONOMICAL HIGH TIDE...STORM
SURGE FLOODING COULD BE SIGNIFICANT ALONG PORTIONS OF THE SOUTH
COAST OF NOVA SCOTIA.
WIND AND RAIN WARNINGS HAVE BEEN ISSUED FOR MOST OF NOVA SCOTIA BY
THE CANADIAN HURRICANE CENTER. ADDITIONAL DETAILS CAN BE FOUND AT
THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
JUAN CONTINUES TO ACCELERATE TO THE NORTH WITH CURRENT MOTION AROUND
360/20. THE FORWARD SPEED SHOULD CONTINUE TO INCREASE OVER THE
NEXT 12 TO 24 HOURS. THE NHC TRACK FORECAST AND REASONING REMAIN
BASICALLY UNCHANGED. JUAN IS EXPECTED TO CONTINUE TO BE SWEPT
NORTHWARD BY THE FLOW AHEAD OF A LARGE MID-LATITUDE 500 MB TROUGH
OVER THE EASTERN UNITED STATES...AND IN ABOUT 36 HOURS OR LESS
BECOME ABSORBED BY THE EXTRATROPICAL CYCLONE ASSOCIATED WITH THIS
TROUGH.
FORECASTER PASCH
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/2100Z 41.2N 64.1W 85 KT
12HR VT 29/0600Z 46.0N 64.1W 70 KT
24HR VT 29/1800Z 53.0N 62.5W 45 KT...EXTRATROPICAL
36HR VT 30/0600Z...ABSORBED BY EXTRATROPICAL CYCLONE
NNNN
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SUN SEP 28 2003
THE INITIAL MOTION ESTIMATE IS 360/28 AND THE MOTION FOR THE PAST
FEW HOURS IS PROBABLY CLOSER TO 30 KNOTS. THE TRACK FORECAST
SCENARIO REMAINS THE SAME...WITH AN APPROACHING TROUGH IN THE
WESTERLIES ACCELERATING JUAN NORTHWARD. JUAN IS EXPECTED TO BE
QUICKLY ABSORBED BY THIS APPROACHING EXTRATROPICAL SYSTEM.
THE 03Z INTENSITY ESTIMATE IS 70 KT. THE CENTER PASSED OVER
CANADIAN DATA BUOY 44142 BETWEEN 23Z AND 00Z. THE BUOY WIND WENT
FROM 090/54 KT AT 23Z TO 210/37 KT AT 00Z AND THE PRESSURE WENT
FROM 981 TO 975 MB. THE BOUY WIND SPEED BETWEEN THE TWO HOURS
COULD HAVE BEEN AS HIGH AS 60 TO 70 KNOTS. THE BUOY ALSO REPORTED
40 FT WAVES. OVER VERY COLD WATER...JUAN SHOULD CONTINUE TO
QUICKLY WEAKEN...BUT WINDS MAY STILL BE NEAR HURRICANE FORCE AS THE
CENTER REACHES THE SOUTH COAST OF NOVA SCOTIA BY AROUND 03Z.
WIND AND HEAVY RAIN WARNINGS HAVE BEEN ISSUED FOR PORTIONS OF NOVA
SCOTIA AND PRINCE EDWARD ISLAND BY THE CANADIAN HURRICANE CENTER.
INFORMATION FROM THE CANADIAN HURRICANE CENTER CAN BE FOUND AT
THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
FORECASTER LAWRENCE
FORECAST POSITIONS AND MAX WINDS
INITIAL 29/0300Z 44.5N 63.8W 70 KT
12HR VT 29/1200Z 49.0N 63.0W 55 KT...EXTRATROPICAL
24HR VT 30/0000Z 58.0N 60.0W 35 KT...EXTRATROPICAL
36HR VT 30/1200Z 65.0N 55.0W 25 KT...EXTRATROPICAL
48HR VT 01/0000Z...ABSORBED BY EXTRATROPICAL LOW
NNNN
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM JUAN DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT MON SEP 29 2003
JUAN HAS REMAINED ON TRACK AND THE INITIAL MOTION ESTIMATE IS NOW
010/35 AS THE CYCLONE CONTINUES TO ACCELERATE AHEAD OF A NEGATIVELY
TILTED MID/UPPER-LEVEL TROUGH. JUAN SHOULD CONTINUE MOVING NORTH OR
NORTH-NORTHEASTWARD UNTIL IT IS ABSORBED IN 24-36 HOURS BY AN
EXTRATROPICAL LOW PRESSURE SYSTEM APPROACHING FROM THE WEST.
THE 09Z INTENSITY ESTIMATE IS IS DECREASED TO 60 KT BASED ON SURFACE
OBS AND THE OCCLUDED APPEARANCE NOTED IN HALIFAX RADAR ANIMATIONS.
THE CENTER PASSED OVER THE SOUTH COAST OF NOVA SCOTIA JUST WEST OF
HALIFAX AT 29/03Z. THE HIGHEST WIND REPORT RECEIVED SO FAR WAS A
SUSTAINED WIND OF 62 MPH AT 1204 AM AST...WITH A GUST TO 89 MPH AT
1214 AM AST THIS MORNING...AT HALIFAX INTERNATIONAL AIRPORT.
WIND AND HEAVY RAIN WARNINGS REMAIN IN EFFECT FOR PORTIONS OF NOVA
SCOTIA AND PRINCE EDWARD ISLAND BY THE CANADIAN HURRICANE CENTER.
ADDITIONAL INFORMATION FROM THE CANADIAN WEATHER SERVICE CAN BE
FOUND AT THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
THIS WILL BE THE LAST ADVISORY AND FORECAST DISCUSSION ISSUED ON
JUAN SINCE THE CYCLONE IS RAPIDLY LOSING ITS TROPICAL
CHARACTERISTICS.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 29/0900Z 47.8N 63.4W 60 KT...BECOMING EXTRATROPICAL
12HR VT 29/1800Z 53.5N 61.2W 50 KT...EXTRATROPICAL
24HR VT 30/0600Z 61.1N 56.3W 35 KT...EXTRATROPICAL
36HR VT 30/1800Z...ABSORBED BY LARGER EXTRATROPICAL LOW
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT SUN SEP 28 2003
THE SYSTEM'S APPEARANCE ON SATELLITE IMAGES IS ABOUT THE SAME AS IT
WAS EARLIER TODAY...WITH A CLOUD-FILLED EYE STILL APPARENT. LATEST
DVORAK CLASSIFICATIONS SUGGEST NO CHANGE IN STRENGTH. JUAN IS
LIKELY TO BEGIN FEELING THE EFFECT OF SIGNIFICANTLY COLDER WATERS
VERY SOON. HOWEVER...BECAUSE OF THE RAPID FORWARD MOTION...THERE
WILL WILL BE LITTLE TIME FOR WEAKENING PRIOR TO LANDFALL. THUS THE
CYCLONE IS EXPECTED TO STILL BE OF HURRICANE STRENGTH WHEN IT
REACHES NOVA SCOTIA. THE FAST FORWARD SPEED WILL SHOULD LIMIT
RAINFALL AMOUNTS TO AROUND 4 INCHES...100 MM. SINCE LANDFALL IS
EXPECTED TO BE AROUND THE TIME OF ASTRONOMICAL HIGH TIDE...STORM
SURGE FLOODING COULD BE SIGNIFICANT ALONG PORTIONS OF THE SOUTH
COAST OF NOVA SCOTIA.
WIND AND RAIN WARNINGS HAVE BEEN ISSUED FOR MOST OF NOVA SCOTIA BY
THE CANADIAN HURRICANE CENTER. ADDITIONAL DETAILS CAN BE FOUND AT
THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
JUAN CONTINUES TO ACCELERATE TO THE NORTH WITH CURRENT MOTION AROUND
360/20. THE FORWARD SPEED SHOULD CONTINUE TO INCREASE OVER THE
NEXT 12 TO 24 HOURS. THE NHC TRACK FORECAST AND REASONING REMAIN
BASICALLY UNCHANGED. JUAN IS EXPECTED TO CONTINUE TO BE SWEPT
NORTHWARD BY THE FLOW AHEAD OF A LARGE MID-LATITUDE 500 MB TROUGH
OVER THE EASTERN UNITED STATES...AND IN ABOUT 36 HOURS OR LESS
BECOME ABSORBED BY THE EXTRATROPICAL CYCLONE ASSOCIATED WITH THIS
TROUGH.
FORECASTER PASCH
FORECAST POSITIONS AND MAX WINDS
INITIAL 28/2100Z 41.2N 64.1W 85 KT
12HR VT 29/0600Z 46.0N 64.1W 70 KT
24HR VT 29/1800Z 53.0N 62.5W 45 KT...EXTRATROPICAL
36HR VT 30/0600Z...ABSORBED BY EXTRATROPICAL CYCLONE
NNNN
ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM
HURRICANE JUAN DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SUN SEP 28 2003
THE INITIAL MOTION ESTIMATE IS 360/28 AND THE MOTION FOR THE PAST
FEW HOURS IS PROBABLY CLOSER TO 30 KNOTS. THE TRACK FORECAST
SCENARIO REMAINS THE SAME...WITH AN APPROACHING TROUGH IN THE
WESTERLIES ACCELERATING JUAN NORTHWARD. JUAN IS EXPECTED TO BE
QUICKLY ABSORBED BY THIS APPROACHING EXTRATROPICAL SYSTEM.
THE 03Z INTENSITY ESTIMATE IS 70 KT. THE CENTER PASSED OVER
CANADIAN DATA BUOY 44142 BETWEEN 23Z AND 00Z. THE BUOY WIND WENT
FROM 090/54 KT AT 23Z TO 210/37 KT AT 00Z AND THE PRESSURE WENT
FROM 981 TO 975 MB. THE BOUY WIND SPEED BETWEEN THE TWO HOURS
COULD HAVE BEEN AS HIGH AS 60 TO 70 KNOTS. THE BUOY ALSO REPORTED
40 FT WAVES. OVER VERY COLD WATER...JUAN SHOULD CONTINUE TO
QUICKLY WEAKEN...BUT WINDS MAY STILL BE NEAR HURRICANE FORCE AS THE
CENTER REACHES THE SOUTH COAST OF NOVA SCOTIA BY AROUND 03Z.
WIND AND HEAVY RAIN WARNINGS HAVE BEEN ISSUED FOR PORTIONS OF NOVA
SCOTIA AND PRINCE EDWARD ISLAND BY THE CANADIAN HURRICANE CENTER.
INFORMATION FROM THE CANADIAN HURRICANE CENTER CAN BE FOUND AT
THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
FORECASTER LAWRENCE
FORECAST POSITIONS AND MAX WINDS
INITIAL 29/0300Z 44.5N 63.8W 70 KT
12HR VT 29/1200Z 49.0N 63.0W 55 KT...EXTRATROPICAL
24HR VT 30/0000Z 58.0N 60.0W 35 KT...EXTRATROPICAL
36HR VT 30/1200Z 65.0N 55.0W 25 KT...EXTRATROPICAL
48HR VT 01/0000Z...ABSORBED BY EXTRATROPICAL LOW
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TROPICAL STORM JUAN DISCUSSION NUMBER 16
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 AM EDT MON SEP 29 2003
JUAN HAS REMAINED ON TRACK AND THE INITIAL MOTION ESTIMATE IS NOW
010/35 AS THE CYCLONE CONTINUES TO ACCELERATE AHEAD OF A NEGATIVELY
TILTED MID/UPPER-LEVEL TROUGH. JUAN SHOULD CONTINUE MOVING NORTH OR
NORTH-NORTHEASTWARD UNTIL IT IS ABSORBED IN 24-36 HOURS BY AN
EXTRATROPICAL LOW PRESSURE SYSTEM APPROACHING FROM THE WEST.
THE 09Z INTENSITY ESTIMATE IS IS DECREASED TO 60 KT BASED ON SURFACE
OBS AND THE OCCLUDED APPEARANCE NOTED IN HALIFAX RADAR ANIMATIONS.
THE CENTER PASSED OVER THE SOUTH COAST OF NOVA SCOTIA JUST WEST OF
HALIFAX AT 29/03Z. THE HIGHEST WIND REPORT RECEIVED SO FAR WAS A
SUSTAINED WIND OF 62 MPH AT 1204 AM AST...WITH A GUST TO 89 MPH AT
1214 AM AST THIS MORNING...AT HALIFAX INTERNATIONAL AIRPORT.
WIND AND HEAVY RAIN WARNINGS REMAIN IN EFFECT FOR PORTIONS OF NOVA
SCOTIA AND PRINCE EDWARD ISLAND BY THE CANADIAN HURRICANE CENTER.
ADDITIONAL INFORMATION FROM THE CANADIAN WEATHER SERVICE CAN BE
FOUND AT THE FOLLOWING INTERNET ADDRESS:
WWW.ATL.EC.GC.CA/WEATHER/HURRICANE/INDEX_E.HTML
THIS WILL BE THE LAST ADVISORY AND FORECAST DISCUSSION ISSUED ON
JUAN SINCE THE CYCLONE IS RAPIDLY LOSING ITS TROPICAL
CHARACTERISTICS.
FORECASTER STEWART
FORECAST POSITIONS AND MAX WINDS
INITIAL 29/0900Z 47.8N 63.4W 60 KT...BECOMING EXTRATROPICAL
12HR VT 29/1800Z 53.5N 61.2W 50 KT...EXTRATROPICAL
24HR VT 30/0600Z 61.1N 56.3W 35 KT...EXTRATROPICAL
36HR VT 30/1800Z...ABSORBED BY LARGER EXTRATROPICAL LOW
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