Extratropical Storm Chantal: last CHC advisory issued

[RL3AO]

Some new convection near the center but she is almost extratropical.

[senorpepr]

I'll invite you guys over to the Tropical Analysis section for an interesting bit of climo regarding Chantal.

viewtopic.php?f=29&t=94502

Teaser: we're not as "behind average" as you may think...

[wxman57]

SSTs beneath Chantal are approaching the mid 50s, and I'm not talking Celsius! Looks decidedly frontal now.

[RL3AO]

SSTs beneath Chantal are approaching the mid 50s, and I'm not talking Celsius! Looks decidedly frontal now.

Well I'd hope not.

[Cyclone1]

SSTs beneath Chantal are approaching the mid 50s, and I'm not talking Celsius! Looks decidedly frontal now.

Well I'd hope not.

Yeah, it'd be about a Category 8 by now.

[AnnularCane]

SSTs beneath Chantal are approaching the mid 50s, and I'm not talking Celsius! Looks decidedly frontal now.

Well I'd hope not.

Yeah, it'd be about a Category 8 by now.

Nope, too much shear for that. Probably Cat 6 at best.

[RL3AO]

I guess people are starting to remember that 3 major canes in July is not the norm.

[Chacor]

Don't be surprised if NHC drops Chantal at the next advisory.

Here's the latest from CHC, which says Chantal is already becoming extratropical.

WOCN31 CWHX 010000
TROPICAL STORM CHANTAL INFORMATION STATEMENT ISSUED BY THE
CANADIAN HURRICANE CENTRE OF ENVIRONMENT CANADA AT 9.00 PM ADT
TUESDAY 31 JULY 2007.

THE NEXT STATEMENT WILL BE ISSUED BY 3.00 AM ADT

... CHANTAL IN MARITIME WATERS...

1. CURRENT POSITION, STRENGTH, CENTRAL PRESSURE AND MOTION

AT 9.00 PM ADT... TROPICAL STORM CHANTAL WAS LOCATED NEAR
LATITUDE 42.8 N AND LONGITUDE 59.9 W... ABOUT 65 NAUTICAL MILES
OR 125 KM SOUTH OF SABLE ISLAND . MAXIMUM SUSTAINED WINDS ARE
ESTIMATED AT 45 KNOTS... 83 KM/H... AND CENTRAL PRESSURE AT 998 MB.
CHANTAL IS MOVING NORTHEAST AT 28 KNOTS... 52 KM/H.

2. FORECAST POSITION, CENTRAL PRESSURE AND STRENGTH

DATE TIME LAT LON MSLP MAX WIND
ADT MB KTS KMH
JUL 31 9.00 PM 42.8N 59.9W 998 45 83 BECOMING POST-TROPICAL
AUG 01 3.00 AM 44.7N 57.0W 997 45 83 POST-TROPICAL
AUG 01 9.00 AM 46.7N 53.0W 997 45 83 POST-TROPICAL
AUG 01 3.00 PM 48.9N 49.1W 996 45 83 POST-TROPICAL
AUG 01 9.00 PM 51.0N 45.2W 995 50 93 POST-TROPICAL
AUG 02 3.00 AM 53.6N 40.5W 995 50 93 POST-TROPICAL
AUG 02 9.00 AM 57.1N 34.5W 995 50 93 POST-TROPICAL

3. PUBLIC WEATHER IMPACTS AND WARNINGS SUMMARY MODERATE RAIN MOVED
INTO SABLE ISLAND MID TUESDAY AFTERNOON AHEAD
OF CHANTAL. HALIFAX RADAR INDICATES THAT THE RAIN SHIELD AHEAD OF
CHANTAL IS JUST OFFSHORE OF CAPE BRETON. HEAVY RAINFALL WARNINGS ARE
MAINTAINED FOR THE AVALON AND BURIN PENINSULAS BY THE NEWFOUNDLAND
LABRADOR WEATHER OFFICE.

4. MARINE WEATHER IMPACTS AND WARNINGS SUMMARY GALE FORCE WINDS WERE
REPORTED FROM THE EAST SCOTIAN SLOPE LATE TUESDAY AFTERNOON AS
CHANTAL ENTERED THAT MARINE AREA. MARINE GALE WARNINGS ARE MAINTAINED
BY THE ATLANTIC STORM
PREDICTION CENTRE FOR SOUTHEASTERN MARITIME WATERS AND EASTERN
NEWFOUNDLAND WATERS INCLUDING FUNK ISLAND BANK.

5. TECHNICAL DISCUSSION

A. ANALYSIS WE CONTINUE GETTING A GOOD FIX FROM VISIBLE SATELLITE
IMAGERY. MARGINAL NORTHEAST GALES AT BUOY 44137 TO THE NORTH OF THE
CENTRE CONFIRMS AN INITIAL INTENSITY IN EXCESS OF 40 KNOTS WHICH IS
IN AGREEMENT WITH THE NHC INTENSITY. CHANTAL HAS NOW MOVED OVER WATER
TEMPERATURES COOLER THAN 20 DEGREES AND EXTRATROPICAL TRANSITION IS
IMMINENT.

B. PROGNOSTIC MODEL GUIDANCE TIGHTLY CLUSTERED REGARDING TRACK
DIRECTION ALTHOUGH SPEED VARIES SOMEWHAT FROM MODEL TO MODEL. WITH
NOTHING NEW TO
CHANGE OUR MINDS WE MAINTAIN A CONSISTENT MESSAGE WITH PREVIOUS
FORECAST AND ALSO NHC BY KEEPING NEAR THE MIDDLE OF THE CONSENSUS...
WITH CHANTAL PASSING NEAR OR OVER THE SOUTHERN EDGE OF THE AVALON
PENINSULA TOMORROW MORNING. ALL MODELS DEEPEN THE SYSTEM
SIGNIFICANTLY AFTER IT PASSES
NEWFOUNDLAND...WITH THE GEM STILL LEADING THE PACK FOR THE ONSET AND
RATE OF INTENSIFICATION.

C. PUBLIC WEATHER
AS MENTIONED IN THE PREVIOUS FORECAST...THE HIGH GEM QPF OVER
SOUTHEASTERN NEWFOUNDLAND PROVIDE A CAUTIONARY NOTE THAT HIGH AMOUNTS
ARE POSSIBLE...ALTHOUGH IT APPEARS RATHER HIGH.THE BOTTOM LINE IS
THAT THE RAINFALL WARNINGS ARE JUSTIFIED. WE ALSO REMAIN ON ALERT
REGARDING THE POSSIBILITY OF COASTAL GALES
IN SOUTHEASTERN NEWFOUNDLAND...WHICH WOULD REQUIRE TROPICAL STORM
WATCHES OR WARNINGS. AS MENTIONED EARLIER THE EXPECTATION THAT
CHANTAL WILL BE EXTRATROPICAL ALONG WITH ITS LIKELIHOOD TO REMAIN
ON THE SOUTHERN EXTENT OF THE AVALON DIRECTS US TO NOT ISSUE THESE
WARNINGS AT THIS TIME.

D. MARINE WEATHER
THE GALE RADII WILL BECOME LESS MEANINGFUL AS CHANTAL UNDERGOES AND
THEN COMPLETES EXTRATROPICAL TRANSITION AND THE STORM BECOMES
ENTRAINED IN THE ENVIRONMENT.

PREDICTED WIND RADII (NM)
TIME GALES STORMS HURRICANE
NE SE SW NW NE SE SW NW NE SE SW NW
01/00Z 120 180 30 60 0 0 0 0 0 0 0 0
01/06Z 140 210 60 60 0 0 0 0 0 0 0 0
01/12Z 160 210 100 60 0 0 0 0 0 0 0 0
01/18Z 180 230 150 60 0 0 0 0 0 0 0 0
02/00Z 200 250 150 100 0 100 0 0 0 0 0 0
02/06Z 220 250 150 120 0 100 0 0 0 0 0 0
02/12Z 220 250 150 120 0 100 0 0 0 0 0 0

END PJB/MC

[RL3AO]

I think thats what the forecasts have said since advisory 1.

[wxman57]

00Z model guidance is titled "Tropical Cyclone Chantal". Could be the final advisory at 10pm declaring it extratropical.

[Chacor]

00Z model guidance is titled "Tropical Cyclone Chantal". Could be the final advisory at 10pm declaring it extratropical.

They do that sometimes. TD8E's also says "Tropical Cyclone Eight".

[AnnularCane]

00Z model guidance is titled "Tropical Cyclone Chantal". Could be the final advisory at 10pm declaring it extratropical.

I wouldn't be surprised. I can't see how much longer she can stay tropical in those water temperatures.

[Thunder44]

00Z model guidance is titled "Tropical Cyclone Chantal". Could be the final advisory at 10pm declaring it extratropical.

Well it was nice to watch while it lasted. It doesn't look like 99L will be developing very soon.

[brunota2003]

00Z model guidance is titled "Tropical Cyclone Chantal". Could be the final advisory at 10pm declaring it extratropical.

Bingo!
Tropical Weather Outlook:
1030 PM EDT TUE JUL 31 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER HAS ISSUED THE LAST ADVISORY ON
TROPICAL STORM CHANTAL...RAPIDLY BECOMING EXTRATROPICAL ABOUT 260
MILES EAST-SOUTHEAST OF HALIFAX NOVA SCOTIA.

Well Chantal, nice to see you around, have a good after life!

[CrazyC83]

Goodbye Chantal! Don't let the crash on you! Better luck in 2013!

[Ptarmigan]

Tropical Chantal is like that unnamed tropical storm last year. It's interesting to point out that Hurricane Chantal formed around this time in 1989. I remember Hurricane Chantal well because it was rainy and very windy for the whole day. Lots of rain fell. Interestingly, the southwest side was the dirty side and made landfall on High Island.

Wikipedia-Hurricane Chantal

Rainfall Totals

[Brent]

BULLETIN
TROPICAL STORM CHANTAL ADVISORY NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032007
1100 PM EDT TUE JUL 31 2007

...CHANTAL RAPIDLY BECOMING EXTRATROPICAL...

AT 1100 PM EDT...0300Z...THE CENTER OF TROPICAL STORM CHANTAL WAS
LOCATED NEAR LATITUDE 43.6 NORTH...LONGITUDE 58.5 WEST OR ABOUT 260
MILES...420 KM...EAST-SOUTHEAST OF HALIFAX NOVA SCOTIA AND ABOUT 340
MILES...545 KM...SOUTHWEST OF CAPE RACE NEWFOUNDLAND.

CHANTAL IS MOVING TOWARD THE NORTHEAST NEAR 32 MPH...52 KM/HR...AND
THIS MOTION IS EXPECTED TO CONTINUE WITH SOME INCREASE IN FORWARD
SPEED DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 50 MPH...85 KM/HR...WITH HIGHER
GUSTS. CHANTAL IS EXPECTED TO BECOME A STRONG EXTRATROPICAL STORM.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 200 MILES...325 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB...29.35 INCHES.

REPEATING THE 1100 PM EDT POSITION...43.6 N...58.5 W. MOVEMENT
TOWARD...NORTHEAST NEAR 32 MPH. MAXIMUM SUSTAINED WINDS...50 MPH.
MINIMUM CENTRAL PRESSURE...994 MB.

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON CHANTAL. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE
FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

TROPICAL STORM CHANTAL DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032007
1100 PM EDT TUE JUL 31 2007

SATELLITE IMAGERY SUGGESTS THAT CHANTAL IS RAPIDLY BECOMING
EXTRATROPICAL. THE CONVECTIVE BAND THAT WAS WRAPPING AROUND THE
CENTER DURING THE AFTERNOON HAS WEAKENED THIS EVENING. SATELLITE
INTENSITY ESTIMATES CONTINUE TO SUPPORT AN INITIAL INTENSITY OF 45
KT. AS CHANTAL PASSED VERY NEAR BUOY 44912 AROUND 2300 UTC...THE
BUOY REPORTED A MINIMUM PRESSURE OF 995.1 MB. THE GLOBAL MODELS
SUGGEST THAT THE SYSTEM WILL INTENSIFY INTO A POWERFUL
EXTRATROPICAL LOW OVER THE NORTH ATLANTIC DURING THE NEXT 2-3
DAYS.

THE INITIAL MOTION ESTIMATE IS 045/28. THE TRACK GUIDANCE IS
TIGHTLY CLUSTERED ON A NORTHEASTWARD MOTION DURING THE DAY OR SO.
ON THIS TRACK...EXTRATROPICAL CHANTAL IS EXPECTED TO PASS OVER OR
VERY NEAR THE AVALON PENINSULA OF NEWFOUNDLAND IN ABOUT 12 HOURS.
BEYOND 72 HOURS...THE MODEL SPREAD IS MUCH GREATER...WITH THE ECMWF
SHOWING A SLOWER MOTION THAN EITHER THE GFS OR NOGAPS. THE
OFFICIAL FORECAST IS CLOSE TO THE PREVIOUS ADVISORY AND IS NEAR THE
GFS GLOBAL MEAN ENSEMBLE.

THIS IS THE LAST ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON
CHANTAL. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...UNDER
AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

FORECAST POSITIONS AND MAX WINDS

INITIAL 01/0300Z 43.6N 58.5W 45 KT
12HR VT 01/1200Z 46.6N 53.6W 45 KT...EXTRATROPICAL
24HR VT 02/0000Z 51.7N 45.1W 45 KT...EXTRATROPICAL
36HR VT 02/1200Z 56.0N 37.0W 50 KT...EXTRATROPICAL
48HR VT 03/0000Z 57.9N 32.3W 60 KT...EXTRATROPICAL
72HR VT 04/0000Z 60.0N 25.0W 50 KT...EXTRATROPICAL
96HR VT 05/0000Z 62.0N 16.5W 40 KT...EXTRATROPICAL
120HR VT 06/0000Z 65.5N 8.0W 35 KT...EXTRATROPICAL

[CrazyC83]

That 994 pressure makes Chantal the strongest storm so far in 2007 (Barry was 997).

[Chacor]

That 994 pressure makes Chantal the strongest storm so far in 2007 (Barry was 997).

994 is not while fully tropical however.

[CrazyC83]

That 994 pressure makes Chantal the strongest storm so far in 2007 (Barry was 997).

994 is not while fully tropical however.

Well, it says in the discussion it is not extratropical yet (but about to be).