Ex Tropical Depression KAREN: Discussions & Images

[MCWX]

Interesting to note the last 3 runs of the European operational model.

Position of Karen valid 8pm Friday October 5th per the last 3 ECMWF operational runs (the positions are approximates):

0z Wed run: 24N/63W
12z Tue run: 24N/59W
0z Tue run: 38N/38W

The value of dprog/dt is somewhat in question per literature, but it is interesting to note the trend of consecutive runs of this model. As expected, there is considerable spread in the ensembles from various forecast centers. Nonetheless, it appears a stall and then an eventual move west is possible later next week.

This time of year with the projected latitude per numerical weather guidance would seem to suggest that an eventual US mainland impact is not the most probable solution. Nonetheless, the simple "out to sea" ideas from just 2 days ago, while ultimately could be correct, the path getting to that final outcome may not be so simple.

I am also impressed with the guidance suggestion of a retrograding positive height anomaly over Scandanavia (moving west to Greenland) over the next 2 weeks and what implication that could mean for the tropics.

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.

[gatorcane]

CMC has Karen just north of Puerto Rico moving towards SE Bahamas:

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... hour=144hr

We now have the Euro and CMC showing a big bend to the West.

NHC must take note of this at some point

Karen may not be a fish storm.

[gatorcane]

Indeed the Euro -- a model that has nailed all CV storms this season -- is showing a big bend to the west and WSW.

So why is the NHC ignoring this solution now? I think the NHC will have to start bending their cone more W with time.

Climatology says fish but this season is not following climatology. It almost seems like the peak has shifted by about 2 weeks later this season.

A long-tracker cape verde storm making it to the U.S is not out of the question given the synoptics.

[CrazyC83]

With the eye trying to clear, I would say 60 kt right now.

[cycloneye]

What will recon find later this evening is the question.

[CrazyC83]

What will recon find later this evening is the question.

At the current pace, quite likely Hurricane Karen by then...

[Derek Ortt]

the decision likely will not be made regarding cancellation until this afternoon

[cycloneye]

Derek,you think that they will go the extra mile (meaning more east than 46w) to find out if it is a hurricane?

[Derek Ortt]

absolutely not... this flight is for HWRF development, not a standard recon mission

if they cannot get the pattern they need... no flight

[MCWX]

Indeed the Euro -- a model that has nailed all CV storms this season -- is showing a big bend to the west and WSW.

So why is the NHC ignoring this solution now? I think the NHC will have to start bending their cone more W with time.

Climatology says fish but this season is not following climatology. It almost seems like the peak has shifted by about 2 weeks later this season.

A long-tracker cape verde storm making it to the U.S is not out of the question given the synoptics.

Actually, the current NHC 120hr forecast position is 22.5/55.0W valid 2am Oct 1st. This position is actually west of where the ECMWF op has the system at the same time. NHCs forecast goes out to 120hrs and in their discussion they mention their forecast is to the west/left of the dynamical guidance consensus.

I am not sure there is too much to disagree with.

[cycloneye]

Lets wait until this afternoon to see by 4 PM if the plane departs or not.Or if they write remarks before that time about a no go.

[Derek Ortt]

I may know around 1 p.m. after the HRD briefing

[CrazyC83]

http://www.nrlmry.navy.mil/tc_pages/tc0 ... atest.html

Looks like half of an eyewall formed?

[gatorcane]

still no indication of turning yet...chugging along W to WNW....

[cycloneye]

WTNT32 KNHC 261453
TCPAT2
BULLETIN
TROPICAL STORM KAREN ADVISORY NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 AM AST WED SEP 26 2007

...KAREN NEAR HURRICANE INTENSITY OVER THE EASTERN NORTH ATLANTIC...

AT 1100 AM AST...1500Z...THE CENTER OF TROPICAL STORM KAREN WAS
LOCATED NEAR LATITUDE 11.9 NORTH...LONGITUDE 42.9 WEST OR ABOUT 1225
MILES...1970 KM...EAST OF THE WINDWARD ISLANDS.

KAREN IS MOVING TOWARD THE WEST-NORTHWEST NEAR 13 MPH...20 KM/HR...
AND THIS MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS AND
KAREN COULD BECOME A HURRICANE TODAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.

REPEATING THE 1100 AM AST POSITION...11.9 N...42.9 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 13 MPH. MAXIMUM SUSTAINED WINDS...70
MPH. MINIMUM CENTRAL PRESSURE...990 MB.

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

$$
FORECASTER LANDSEA/PASCH

137
WTNT22 KNHC 261453
TCMAT2
TROPICAL STORM KAREN FORECAST/ADVISORY NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1500 UTC WED SEP 26 2007

TROPICAL STORM CENTER LOCATED NEAR 11.9N 42.9W AT 26/1500Z
POSITION ACCURATE WITHIN 20 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 11 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 990 MB
MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT.
50 KT....... 45NE 0SE 0SW 0NW.
34 KT....... 75NE 45SE 0SW 45NW.
12 FT SEAS..150NE 60SE 30SW 120NW.
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 11.9N 42.9W AT 26/1500Z
AT 26/1200Z CENTER WAS LOCATED NEAR 11.7N 42.4W

FORECAST VALID 27/0000Z 12.6N 44.5W
MAX WIND 65 KT...GUSTS 80 KT.
64 KT... 30NE 0SE 0SW 0NW.
50 KT... 60NE 45SE 0SW 45NW.
34 KT... 90NE 60SE 30SW 60NW.

FORECAST VALID 27/1200Z 14.0N 46.8W
MAX WIND 75 KT...GUSTS 90 KT.
64 KT... 30NE 20SE 0SW 0NW.
50 KT... 60NE 45SE 0SW 45NW.
34 KT... 90NE 60SE 30SW 60NW.

FORECAST VALID 28/0000Z 15.5N 48.5W
MAX WIND 75 KT...GUSTS 90 KT.
64 KT... 30NE 30SE 0SW 0NW.
50 KT... 60NE 60SE 0SW 45NW.
34 KT...120NE 90SE 45SW 75NW.

FORECAST VALID 28/1200Z 16.8N 50.0W
MAX WIND 70 KT...GUSTS 85 KT.
50 KT... 60NE 60SE 0SW 45NW.
34 KT...120NE 90SE 45SW 75NW.

FORECAST VALID 29/1200Z 19.0N 52.0W
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 60NE 60SE 0SW 45NW.
34 KT...120NE 90SE 45SW 75NW.

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 30/1200Z 21.0N 54.0W
MAX WIND 60 KT...GUSTS 75 KT.

OUTLOOK VALID 01/1200Z 23.0N 55.5W
MAX WIND 55 KT...GUSTS 65 KT.

REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 11.9N 42.9W

NEXT ADVISORY AT 26/2100Z

$$
FORECASTER LANDSEA/PASCH

[gatorcane]

Tropical Storm KAREN Public Advisory
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000
WTNT32 KNHC 261453
TCPAT2
BULLETIN
TROPICAL STORM KAREN ADVISORY NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 AM AST WED SEP 26 2007

...KAREN NEAR HURRICANE INTENSITY OVER THE EASTERN NORTH ATLANTIC...

AT 1100 AM AST...1500Z...THE CENTER OF TROPICAL STORM KAREN WAS
LOCATED NEAR LATITUDE 11.9 NORTH...LONGITUDE 42.9 WEST OR ABOUT 1225
MILES...1970 KM...EAST OF THE WINDWARD ISLANDS.

KAREN IS MOVING TOWARD THE WEST-NORTHWEST NEAR 13 MPH...20 KM/HR...
AND THIS MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 24 HOURS.

MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 24 HOURS AND
KAREN COULD BECOME A HURRICANE TODAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 85 MILES...140 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 990 MB...29.23 INCHES.

REPEATING THE 1100 AM AST POSITION...11.9 N...42.9 W. MOVEMENT
TOWARD...WEST-NORTHWEST NEAR 13 MPH. MAXIMUM SUSTAINED WINDS...70
MPH. MINIMUM CENTRAL PRESSURE...990 MB.

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

$$
FORECASTER LANDSEA/PASCH

[Evil Jeremy]

70 MPH winds

[Lowpressure]

absolutely not... this flight is for HWRF development, not a standard recon mission

if they cannot get the pattern they need... no flight

Am I correct in thinking that takes about 4 hours?

[gatorcane]

000
WTNT42 KNHC 261454
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 AM EDT WED SEP 26 2007

KAREN CONTINUES TO SPIN UP AS A RAGGED EYE HAS BEEN SEEN
INTERMEDITENTLY THIS MORNING IN VISIBLE AND INFRARED IMAGERY.
SUBJECTIVE DVORAK CLASSIFICATIONS AT 12Z ARE AT 4.0 AND 3.5 FROM
TAFB AND SAB...RESPECTIVELY. AN AMSU PASS AT 08Z SUGGESTED AROUND
60 KT FROM THE CIMSS TECHNIQUE. THE ADT...HOWEVER...ANALYSES KAREN
A BIT WEAKER AT ABOUT 50 KT. GIVEN THE IMPROVED PRESENTATION SINCE
SYNOPTIC TIME...THE INITIAL INTENSITY OF KAREN IS SET AT 60 KT.

THE TROPICAL STORM IS MOVING AT 285/11 SOUTH OF A WEAK DEEP LEVEL
RIDGE. AN UPPER TROUGH NORTHWEST OF KAREN IS FORECAST BY ALL
MODELS TO SLOWLY RETROGRADE AND PRODUCE ENOUGH OF A WEAKNESS IN THE
RIDGE TO ALLOW THE CYCLONE TO TURN TO THE NORTHWEST. THE MODEL
GUIDANCE IS TIGHTLY CLUSTERED FOR THE FIRST 48 HOURS. AT DAYS 3 TO
5...MOST MODELS SLOW KAREN'S PROGRESSION AS THE STEERING FLOW
SLACKENS. THE MODELS DIFFER AT THE LONG RANGE ON BOTH THE STRENGTH
OF THE CYCLONE'S VORTEX AS WELL AS THE AMPLITUDE OF A SHORTWAVE
TROUGH NEAR BERMUDA. THE TRACK FORECAST IS CLOSE TO THE CONSENSUS
OF DYNAMICAL MODELS WITH LESS WEIGHT BEING PLACED ON THE NORTHERN
OUTLYING NOGAPS MODEL.

GIVEN THAT THE CYCLONE IS INTENSIFYING...IT APPEARS THAT IT MAY
REACH HURRICANE INTENSITY SOON. ENVIRONMENTAL CONDITIONS ARE
MIXED. SSTS ARE A WARM 28C THOUGH THE SHEAR IS ANALYZED TO BE
ABOUT 15 KT OUT OF THE WEST. THIS SHEAR DOES APPEAR TO BE
RESTRICTING THE WESTERN OUTFLOW OF KAREN. THE SHEAR IS PREDICTED
BY ALL MODELS TO BE MAINTAINED OR EVEN GET STRONGER AT DAYS 3 TO 5
DUE TO THE INFLUENCE OF THE EARLIER MENTIONED UPPER LEVEL TROUGH.
THE INTENSITY FORECAST BRINGS KAREN TO A HURRICANE SHORTLY...
LEVELING OFF IN A DAY OR TWO...AND THEN WEAKENING AT DAYS 4 AND 5.
THIS IS IN AGREEMENT WITH SHIPS AND LGEM BUT STRONGER THAN HWRF AND
GFDL WHICH DO NOT BRING KAREN TO HURRICANE INTENSITY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/1500Z 11.9N 42.9W 60 KT
12HR VT 27/0000Z 12.6N 44.5W 65 KT
24HR VT 27/1200Z 14.0N 46.8W 75 KT
36HR VT 28/0000Z 15.5N 48.5W 75 KT
48HR VT 28/1200Z 16.8N 50.0W 70 KT
72HR VT 29/1200Z 19.0N 52.0W 65 KT
96HR VT 30/1200Z 21.0N 54.0W 60 KT
120HR VT 01/1200Z 23.0N 55.5W 55 KT

$$
FORECASTER LANDSEA/PASCH

[gatorcane]

000
WTNT42 KNHC 261454
TCDAT2
TROPICAL STORM KAREN DISCUSSION NUMBER 7
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
1100 AM EDT WED SEP 26 2007

KAREN CONTINUES TO SPIN UP AS A RAGGED EYE HAS BEEN SEEN
INTERMEDITENTLY THIS MORNING IN VISIBLE AND INFRARED IMAGERY.
SUBJECTIVE DVORAK CLASSIFICATIONS AT 12Z ARE AT 4.0 AND 3.5 FROM
TAFB AND SAB...RESPECTIVELY. AN AMSU PASS AT 08Z SUGGESTED AROUND
60 KT FROM THE CIMSS TECHNIQUE. THE ADT...HOWEVER...ANALYSES KAREN
A BIT WEAKER AT ABOUT 50 KT. GIVEN THE IMPROVED PRESENTATION SINCE
SYNOPTIC TIME...THE INITIAL INTENSITY OF KAREN IS SET AT 60 KT.

THE TROPICAL STORM IS MOVING AT 285/11 SOUTH OF A WEAK DEEP LEVEL
RIDGE. AN UPPER TROUGH NORTHWEST OF KAREN IS FORECAST BY ALL
MODELS TO SLOWLY RETROGRADE AND PRODUCE ENOUGH OF A WEAKNESS IN THE
RIDGE TO ALLOW THE CYCLONE TO TURN TO THE NORTHWEST. THE MODEL
GUIDANCE IS TIGHTLY CLUSTERED FOR THE FIRST 48 HOURS. AT DAYS 3 TO
5...MOST MODELS SLOW KAREN'S PROGRESSION AS THE STEERING FLOW
SLACKENS. THE MODELS DIFFER AT THE LONG RANGE ON BOTH THE STRENGTH
OF THE CYCLONE'S VORTEX AS WELL AS THE AMPLITUDE OF A SHORTWAVE
TROUGH NEAR BERMUDA. THE TRACK FORECAST IS CLOSE TO THE CONSENSUS
OF DYNAMICAL MODELS WITH LESS WEIGHT BEING PLACED ON THE NORTHERN
OUTLYING NOGAPS MODEL.

GIVEN THAT THE CYCLONE IS INTENSIFYING...IT APPEARS THAT IT MAY
REACH HURRICANE INTENSITY SOON. ENVIRONMENTAL CONDITIONS ARE
MIXED. SSTS ARE A WARM 28C THOUGH THE SHEAR IS ANALYZED TO BE
ABOUT 15 KT OUT OF THE WEST. THIS SHEAR DOES APPEAR TO BE
RESTRICTING THE WESTERN OUTFLOW OF KAREN. THE SHEAR IS PREDICTED
BY ALL MODELS TO BE MAINTAINED OR EVEN GET STRONGER AT DAYS 3 TO 5
DUE TO THE INFLUENCE OF THE EARLIER MENTIONED UPPER LEVEL TROUGH.
THE INTENSITY FORECAST BRINGS KAREN TO A HURRICANE SHORTLY...
LEVELING OFF IN A DAY OR TWO...AND THEN WEAKENING AT DAYS 4 AND 5.
THIS IS IN AGREEMENT WITH SHIPS AND LGEM BUT STRONGER THAN HWRF AND
GFDL WHICH DO NOT BRING KAREN TO HURRICANE INTENSITY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/1500Z 11.9N 42.9W 60 KT
12HR VT 27/0000Z 12.6N 44.5W 65 KT
24HR VT 27/1200Z 14.0N 46.8W 75 KT
36HR VT 28/0000Z 15.5N 48.5W 75 KT
48HR VT 28/1200Z 16.8N 50.0W 70 KT
72HR VT 29/1200Z 19.0N 52.0W 65 KT
96HR VT 30/1200Z 21.0N 54.0W 60 KT
120HR VT 01/1200Z 23.0N 55.5W 55 KT

$$
FORECASTER LANDSEA/PASCH