Ex Tropical Depression KAREN: Discussions & Images

[RL3AO]

I see the NHC bends Karen slightly west on day 5. Hopefully this stays away from Bermuda.

[JonathanBelles]

I see the NHC bends Karen slightly west on day 5. Hopefully this stays away from Bermuda.

Im not too worried about Bermuda at this point...

[wzrgirl1]

Derek,

What are your thoughts on this one for us in south florida? I guess it's too early to tell at this point, but curious as to your opinion.

[cycloneye]

WHXX01 KWBC 280054
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0054 UTC FRI SEP 28 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE KAREN (AL122007) 20070928 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070928 0000 070928 1200 070929 0000 070929 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 14.6N 49.0W 16.0N 51.7W 17.2N 53.9W 18.2N 55.8W
BAMD 14.6N 49.0W 16.1N 50.1W 17.7N 50.9W 19.2N 51.3W
BAMM 14.6N 49.0W 15.6N 51.1W 16.7N 52.7W 17.5N 54.0W
LBAR 14.6N 49.0W 15.9N 50.5W 17.2N 51.8W 18.2N 53.0W
SHIP 50KTS 45KTS 43KTS 41KTS
DSHP 50KTS 45KTS 43KTS 41KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070930 0000 071001 0000 071002 0000 071003 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 19.0N 56.7W 20.2N 58.4W 21.0N 59.3W 20.9N 59.3W
BAMD 20.7N 51.6W 23.9N 53.1W 27.0N 55.4W 28.1N 56.6W
BAMM 18.5N 54.8W 19.9N 56.2W 21.4N 57.5W 21.8N 58.5W
LBAR 19.1N 54.0W 21.3N 55.2W 23.1N 56.1W 23.7N 56.7W
SHIP 40KTS 43KTS 52KTS 61KTS
DSHP 40KTS 43KTS 52KTS 61KTS

...INITIAL CONDITIONS...
LATCUR = 14.6N LONCUR = 49.0W DIRCUR = 295DEG SPDCUR = 12KT
LATM12 = 13.5N LONM12 = 46.8W DIRM12 = 297DEG SPDM12 = 12KT
LATM24 = 12.7N LONM24 = 44.6W
WNDCUR = 50KT RMAXWD = 20NM WNDM12 = 55KT
CENPRS = 1005MB OUTPRS = 1013MB OUTRAD = 180NM SDEPTH = M
RD34NE = 150NM RD34SE = 140NM RD34SW = 40NM RD34NW = 80NM

Karen mantains at 50kts.

[brunota2003]

Model graphic for those up yet? I dont know where to get them from.

['CaneFreak]

Alright wxman57, I want your full analysis of the setup for Karen early next week and what you think about the chances of this redeveloping and becoming a huge concern late next week please. Thanks. You are the man. Heres my take:

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

We have an amplified trough currently exiting the northeast coast and a ridge building in the central US with a trough out west. The trough from the west over the next several days slowly starts to dig into the Central Plains ridge and eats away at the western side of the dome of high pressure. Eventually, this ridge erodes and gets out of the way. Meanwhile, Tropical Storm Karen maintains its current strength for the next several days and slowly moves to the west or maybe slightly north of west. Once she reaches the western Atlantic she begins to get under that canopy of high pressure and the weakening shear in the western Atlantic and she begins a slow strengthening process. Hurricane Karen, by this point, is still DRIFTING..and I mean drifting...at about 5 knots or less to the west at about 280 or 285 finally gets under the ridge and begins to increase her forward speed a bit due to the increased west/wnw low level steering flow around the southern periphery of the huge 1030 mb surface ridge. At the same time, the trough in the central plains is still digging eastward and finally reaches the east coast; the question is: Is she still over the Atlantic or has she made landfall? My wild guess is that she decides to make a last minute turn to the north and northeast due to the eastern side of the trough forcing its way on the western side of the ridge allowing a weakness to develop. Hurricane Karen is a strong cat 2 at this point and begins to steam north and eventually northeast paralleling (spelling?) the east coast. Its gonna be a close call. Finally, the trough pushes offshore and rolls up Karen and she becomes the third major hurricane of the year but remains harmlessly offshore and steams on out to the northeast towards Nova Scotia and Newfoundland by next weekend. Your thoughts 57?

thanks for adding the disclaimer; I always forget

[cycloneye]

Center is seen exposed.

[Special K]

Can someone post the EURO that everyone is talking about from earlier this afternoon? Just got home from work and can't find it. Thanks.

[chadtm80]

Can someone post the EURO that everyone is talking about from earlier this afternoon? Just got home from work and can't find it. Thanks.

viewtopic.php?f=59&t=98230&p=1645728#p1645728

[americanrebel]

I didn't want to be the first to say it about Andrew path. I have been thinking it since early yesterday.

[cycloneye]

18z GFDL Intensity Animation

Continues to show a hurricane at the end of run.

18z HWRF Intensity Animation

It shows at the end of run hurricane status for Karen.

[Recurve]

I didn't want to be the first to say it about Andrew path. I have been thinking it since early yesterday.

I've been thinking it since she formed and had a NW heading. Anything in that area that gets caught under a ridge is trouble. Good thing it's so much later in the season, much better chance of a front sweeping it away.

[Patrick99]

I don't know, my opinion is neither "out to sea" nor "Florida hit." What about "ripped apart?" Surely that is a possibility, no? Looks sheared right now....that center could be cited for indecent exposure.

[eaglegirl]

Model graphic for those up yet? I dont know where to get them from.

I get them here:

http://moe.met.fsu.edu/tcgengifs/

[brunota2003]

18z GFDL Intensity Animation

Continues to show a hurricane at the end of run.

18z HWRF Intensity Animation

It shows at the end of run hurricane status for Karen.

Interesting. 80 knots for GFDL, 65 for HWRF. Also of note is the fact that the HWRF weakens Karen to a 25 knot TD in a couple days before restrengthening it.

[btangy]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

This 'bursting' convective pattern is very typical of sheared systems. Oftentimes, the convection can be very intense on the downshear side of the storm. It will then weaken as it rotates to the upshear side, and the process will repeat itself.

The upper level pattern consists of a high latitude ridge over the N Atlantic & a high (potential) vorticity tongue extending across 30N over pretty much the entire subtropical Atlantic. This tongue curls up into upper level lows which then get pushed to the W underneath the ridge. As long as this pattern remains, there will be a belt of high shear to the S of 30N, which means Karen will be stuck in this hostile zone for at least 5 days. However given the very large circulation of Karen, it will be hard for the shear to completely destroy it.

[CrazyC83]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.


According to the shear map and adjusting for trends, it appears Karen has to go through high shear for another 220 miles or so. (The area below her has seen dramatic decreases in shear due to the direct impact of Karen - it would be orange or red without Karen over it.) After that it quickly drops off. Once past 20°N, there is minimal shear. That is where the models predict a blossoming system.

The maximum shear has shifted NE of Karen - and that is now over 60 kt of shear!

[CrazyC83]

18z GFDL Intensity Animation

Continues to show a hurricane at the end of run.

18z HWRF Intensity Animation

It shows at the end of run hurricane status for Karen.

Interesting. 80 knots for GFDL, 65 for HWRF. Also of note is the fact that the HWRF weakens Karen to a 25 knot TD in a couple days before restrengthening it.

I'm thinking that is what will happen too...maybe not to 25 kt but weakening then blossoming.

[Evil Jeremy]

Still 60 MPH winds at 11


000
WTNT32 KNHC 280245
TCPAT2
BULLETIN
TROPICAL STORM KAREN ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 PM AST THU SEP 27 2007

...KAREN STRUGGLING OVER THE CENTRAL TROPICAL ATLANTIC...

AT 1100 PM AST...0300Z...THE CENTER OF TROPICAL STORM KAREN WAS
LOCATED NEAR LATITUDE 14.8 NORTH...LONGITUDE 49.5 WEST OR ABOUT 780
MILES...1255 KM...EAST OF THE WINDWARD ISLANDS.

KAREN IS MOVING TOWARD THE WEST-NORTHWEST NEAR 14 MPH...22 KM/HR...
AND A MOTION BETWEEN WEST-NORTHWEST AND NORTHWEST IS EXPECTED FOR
THE NEXT DAY OR SO.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/HR...WITH HIGHER
GUSTS. SOME WEAKENING IS FORECAST DURING THE NEXT 24 HOURS DUE TO
UNFAVORABLE UPPER-LEVEL WINDS.

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

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB...29.68 INCHES.

REPEATING THE 1100 PM AST POSITION...14.8 N...49.5 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 14 MPH. MAXIMUM SUSTAINED WINDS...60
MPH. MINIMUM CENTRAL PRESSURE...1005 MB.

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

$$
FORECASTER BLAKE

[cycloneye]

221
WTNT32 KNHC 280245
TCPAT2
BULLETIN
TROPICAL STORM KAREN ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 PM AST THU SEP 27 2007

...KAREN STRUGGLING OVER THE CENTRAL TROPICAL ATLANTIC...

AT 1100 PM AST...0300Z...THE CENTER OF TROPICAL STORM KAREN WAS
LOCATED NEAR LATITUDE 14.8 NORTH...LONGITUDE 49.5 WEST OR ABOUT 780
MILES...1255 KM...EAST OF THE WINDWARD ISLANDS.

KAREN IS MOVING TOWARD THE WEST-NORTHWEST NEAR 14 MPH...22 KM/HR...
AND A MOTION BETWEEN WEST-NORTHWEST AND NORTHWEST IS EXPECTED FOR
THE NEXT DAY OR SO.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/HR...WITH HIGHER
GUSTS. SOME WEAKENING IS FORECAST DURING THE NEXT 24 HOURS DUE TO
UNFAVORABLE UPPER-LEVEL WINDS.

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

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB...29.68 INCHES.

REPEATING THE 1100 PM AST POSITION...14.8 N...49.5 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 14 MPH. MAXIMUM SUSTAINED WINDS...60
MPH. MINIMUM CENTRAL PRESSURE...1005 MB.

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

$$
FORECASTER BLAKE



180
WTNT22 KNHC 280245
TCMAT2
TROPICAL STORM KAREN FORECAST/ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
0300 UTC FRI SEP 28 2007

TROPICAL STORM CENTER LOCATED NEAR 14.8N 49.5W AT 28/0300Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 295 DEGREES AT 12 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB
MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT.
50 KT....... 60NE 60SE 20SW 30NW.
34 KT.......150NE 140SE 40SW 80NW.
12 FT SEAS..210NE 150SE 120SW 180NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.

REPEAT...CENTER LOCATED NEAR 14.8N 49.5W AT 28/0300Z
AT 28/0000Z CENTER WAS LOCATED NEAR 14.6N 49.0W

FORECAST VALID 28/1200Z 15.7N 50.9W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT...130NE 120SE 40SW 70NW.

FORECAST VALID 29/0000Z 16.9N 52.5W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT...100NE 70SE 30SW 50NW.

FORECAST VALID 29/1200Z 18.0N 53.8W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT...100NE 70SE 30SW 50NW.

FORECAST VALID 30/0000Z 19.2N 54.8W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT...100NE 70SE 30SW 50NW.

FORECAST VALID 01/0000Z 21.0N 56.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT...100NE 70SE 30SW 50NW.

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 02/0000Z 22.5N 57.5W
MAX WIND 45 KT...GUSTS 55 KT.

OUTLOOK VALID 03/0000Z 23.5N 59.5W
MAX WIND 50 KT...GUSTS 60 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.8N 49.5W

NEXT ADVISORY AT 28/0900Z

$$
FORECASTER BLAKE


002
WTNT42 KNHC 280249
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 PM EDT THU SEP 27 2007

A LARGE BURST OF DEEP CONVECTION FORMED NEAR THE CENTER OF KAREN
TONIGHT. HOWEVER...THUNDERSTORMS ARE ALREADY DIMINISHING AND
SOUTHWESTERLY WIND SHEAR CONTINUES TO HINDER ANY DEVELOPMENT.
DVORAK SATELLITE ESTIMATES ARE A LITTLE HIGHER THAN EARLIER...BUT
ARE STILL BELOW THE PREVIOUS INITIAL INTENSITY. WINDS WILL BE KEPT
AT 50 KT FOR THIS ADVISORY.

THE INITIAL MOTION ESTIMATE OF 295/12 IS A BLEND OF THE EXTRAPOLATED
MOVEMENT FROM THE LAST AVAILABLE VISIBLE IMAGES AND A RECENT SSMIS
MICROWAVE PASS. A SMALL RIGHTWARD BEND TO THE TRACK IS EXPECTED
OVER THE NEXT COUPLE OF DAYS AS LOW TO MID-LEVEL RIDGING TO THE
NORTH OF THE SYSTEM SLOWLY WEAKENS. THE RIDGE IS EXPECTED TO BE
THE WEAKEST IN ABOUT 48-72 HOURS DUE TO A MIDDLE-LATITUDE TROUGH IN
THE CENTRAL ATLANTIC AND COULD STEER THE STORM MORE TO THE
NORTH-NORTHWEST AT THAT TIME. HOWEVER...THIS TROUGH IS NOT EXPECTED
TO BE STRONG ENOUGH TO TURN THE STORM OUT TO SEA AND ALL MODELS
BUILD RIDGING TO THE NORTH OF THE STORM...FORCING A WEST-NORTHWEST
TURN AT THE END OF THE FORECAST PERIOD. THE OFFICIAL FORECAST IS
SHIFTED WESTWARD WITH THIS PACKAGE IN BEST AGREEMENT WITH THE
GFS/ECMWF MODELS AND IS ON THE LEFT SIDE OF THE GUIDANCE ENVELOPE.
IF THE STORM WEAKENS MORE THAN EXPECTED...THIS FORECAST MAY HAVE TO
BE ADJUSTED FARTHER TO THE WEST..ESPECIALLY IN THE SHORT-TERM.

KAREN SHOULD BE IN AN ENVIRONMENT OF STRONG WESTERLY SHEAR CAUSED BY
THE MID-OCEANIC TROUGH FOR AT LEAST THE NEXT 48-72 HOURS. THIS
PATTERN FAVORS AT LEAST SLOW WEAKENING DURING THAT TIME. HOWEVER...
IF THE STORM SURVIVES THE SHEAR...GLOBAL MODELS SUGGEST THAT AN
OPPORTUNITY FOR RESTRENGTHENING COULD OCCUR IN THE LONG-RANGE AS
THE TROUGH WEAKENS AND IS REPLACED BY RIDGING. RELIABLE INTENSITY
GUIDANCE RESPONDS TO THIS CHANGE IN SHEAR AND SHOWS AN INCREASE IN
STRENGTH BEYOND 3 DAYS. IN FACT...THE GFDL/HWRF MODELS ACTUALLY
MAKE KAREN A HURRICANE IN 5 DAYS. DUE TO LARGE UNCERTAINTY AT THE
LONGER-RANGES...THE OFFICIAL FORECAST WILL ONLY BE SLIGHTLY
INCREASED...AND COULD BE CONSERVATIVE IF THE STORM ENDURES THE NEXT
48 HOURS OR SO.

FORECAST POSITIONS AND MAX WINDS

INITIAL 28/0300Z 14.8N 49.5W 50 KT
12HR VT 28/1200Z 15.7N 50.9W 45 KT
24HR VT 29/0000Z 16.9N 52.5W 45 KT
36HR VT 29/1200Z 18.0N 53.8W 40 KT
48HR VT 30/0000Z 19.2N 54.8W 40 KT
72HR VT 01/0000Z 21.0N 56.0W 40 KT
96HR VT 02/0000Z 22.5N 57.5W 45 KT
120HR VT 03/0000Z 23.5N 59.5W 50 KT

$$
FORECASTER BLAKE