Ex Tropical Depression KAREN: Discussions & Images

[gatorcane]

12Z CMC brings Karen just north of the northernmost Leeward islands into the Hebert box heading WNW

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

[CrazyC83]

Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 26 SEP 2007 Time : 024500 UTC
Lat : 11:08:02 N Lon : 40:04:57 W


CI# /Pressure/ Vmax
3.5 / 994.0mb/ 55.0kt


6hr-Avg T# 3hr-Avg T# Adj T# Raw T#
3.5 3.5 3.7 3.7

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -20.6C Cloud Region Temp : -55.1C

Scene Type : CURVED BAND with 0.83 ARC in LT GRAY

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************

[gatorcane]

12Z CMC has Karen just north of the northernmost Leeward island passing through the Hebert box moving WNW.

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

I wouldn't say fish just yet on Karen.

[gatorcane]

I wonder if the models are underestimating the ridge out there. I just don't see how she is going to recurve easily. There is a trough to the north -- but it is WAY north. I see the ridge expanding west with her in tandem.

Oh well, maybe in two days it will be more clear -- or maybe the BAMS and CMC are already sniffing out this more westward moving possibility.

Both models have shifted west today....

No fish here by any means yet.

[jaxfladude]

I wonder if the models are underestimating the ridge out there. I just don't see how she is going to recurve easily. There is a trough to the north -- but it is WAY north. I see the ridge expanding west with her in tandem.

Oh well, maybe in two days it will be more clear -- or maybe the BAMS and CMC are already sniffing out this more westward moving possibility.

Both models have shifted west today....

No fish here by any means yet.

I want Karen to be fish!!!!
Nothing else is acceptable!!!

[Matt-hurricanewatcher]

The ULL has formed a outflow channel form the northern quad. The innercore is becoming organized. I would say 45 knots and a hurricane by tomarrow at 11pm est if the trend keeps up,.

[Matt-hurricanewatcher]

Give me the reasoning that this will be a fish? Personally I think the chances are going down for that. I think a Frances,Floyd like system.

[BigA]

12Z CMC has Karen just north of the northernmost Leeward island passing through the Hebert box moving WNW.

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

I wouldn't say fish just yet on Karen.

Definitely not at this point. Models have been trending somewhat to the west today (although right now it is 12:06) It depends on how much of a weakness there is, and how much the ridge builds back in.

[Matt-hurricanewatcher]

It is just looking at the model trends. We have to watch this system...Yes it could be a fish, but it might not be.

[Matt-hurricanewatcher]

Yeah, that is what is going on. The ULL to it north is now forming a Axis about 5-7 degree's west and 5 degrees north of the system. See the area where it is moving westward then turns around the base to the southwest, that is forming a outflow channel. The convection/CDO is forming over the center of this system. I would say this set up should hold for at least 12-24 hours, unless the ULL gets to close or the system picks up speed, strengthing should occur.

[HURAKAN]

691
WHXX01 KWBC 260625
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0625 UTC WED SEP 26 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) 20070926 0600 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070926 0600 070926 1800 070927 0600 070927 1800

LAT LON LAT LON LAT LON LAT LON
BAMS 11.1N 41.5W 12.2N 44.6W 13.7N 47.5W 15.5N 50.2W
BAMD 11.1N 41.5W 11.8N 43.7W 13.0N 45.5W 14.7N 47.0W
BAMM 11.1N 41.5W 11.8N 44.1W 12.9N 46.3W 14.3N 48.2W
LBAR 11.1N 41.5W 11.7N 43.6W 13.0N 45.8W 14.5N 47.8W
SHIP 45KTS 53KTS 59KTS 63KTS
DSHP 45KTS 53KTS 59KTS 63KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070928 0600 070929 0600 070930 0600 071001 0600

LAT LON LAT LON LAT LON LAT LON
BAMS 16.8N 52.6W 18.8N 56.6W 20.0N 59.6W 20.3N 61.9W
BAMD 16.4N 48.2W 19.1N 50.0W 21.3N 51.1W 24.2N 52.7W
BAMM 15.6N 49.8W 17.6N 52.2W 19.2N 54.0W 20.9N 55.3W
LBAR 16.2N 49.2W 18.6N 51.2W 20.9N 52.3W 23.2N 52.8W
SHIP 64KTS 64KTS 62KTS 61KTS
DSHP 64KTS 64KTS 62KTS 61KTS

...INITIAL CONDITIONS...
LATCUR = 11.1N LONCUR = 41.5W DIRCUR = 280DEG SPDCUR = 12KT
LATM12 = 10.8N LONM12 = 39.2W DIRM12 = 277DEG SPDM12 = 12KT
LATM24 = 10.2N LONM24 = 36.9W
WNDCUR = 45KT RMAXWD = 30NM WNDM12 = 35KT
CENPRS = 1000MB OUTPRS = 1012MB OUTRAD = 175NM SDEPTH = D
RD34NE = 60NM RD34SE = 30NM RD34SW = 0NM RD34NW = 40NM

[vegastar]

45 kts on NRL. It is looking a lot more organized with a well established polar outflow channel, and a consolidated inner core with tops to -70C. If this trend continues I think we can have a hurricane by 2100Z.

[SoonerMaximus]

Wow - the explosion of convection over what appears to be the center in the last few frames as of right now.

link

[deltadog03]

BTW its moving WSW to SW

[marcane_1973]

The center has become alot better organized. Check out what blew up to the southeast of her and just as big if not bigger now.

[tropicsPR]

http://www.wunderground.com/tropical/at ... ublic.html

Statement as of 5:00 am AST on September 26, 2007

...Karen strengthens over the central tropical Atlantic...

at 500 am AST...0900z...the center of Tropical Storm Karen was
located near latitude 11.2 north...longitude 42.1 west or about 1285 miles...2065 km...east of the Windward Islands.

Karen is moving toward the west near 14 mph...22 km/hr...and a turn towards the west-northwest is expected during the next 24 hours.

Maximum sustained winds are near 50 mph...85 km/hr...with higher gusts. Additional strengthening is forecast during the next 24 hours.

Tropical storm force winds extend outward up to 70 miles...110 km from the center.

Estimated minimum central pressure is 1000 mb...29.53 inches.

Repeating the 500 am AST position...11.2 N...42.1 W. Movement toward...west near 14 mph. Maximum sustained winds...50 mph. Minimum central pressure...1000 mb.

The next advisory will be issued by the National Hurricane Center at 1100 am AST.

$$
Forecaster Rhome

[vegastar]

TROPICAL STORM KAREN DISCUSSION NUMBER 6
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL122007
500 AM EDT WED SEP 26 2007

AFTER LOOKING RATHER ANEMIC YESTERDAY...KAREN IS FINALLY STARTING TO
PRODUCE PRODUCE DEEP CONVECTION NEAR THE CENTER AND MICROWAVE DATA
SUGGEST THE EARLY STAGES OF AN INNER CORE. SATELLITE INTENSITY
ESTIMATES HAVE RISEN AND THE INITIAL INTENSITY IS INCREASED TO 45
KT.

KAREN IS MOVING RIGHT ALONG THE PREVIOUS FORECAST TRACK WITH AN
INITIAL MOTION OF 280/11. THE CYCLONE IS EXPECTED TO GRADUALLY
TURN NORTHWESTWARD OVER THE NEXT COUPLE OF DAYS AS A SMALL WEAKNESS
DEVELOPS IN THE DEEP-LAYER SUBTROPICAL RIDGE OVER THE CENTRAL
ATLANTIC. THEREAFTER...THE GLOBAL MODELS DIFFER IN THEIR FORECAST
OF A LARGE MIDDLE-UPPER LEVEL TROUGH EXPECTED TO DEVELOP OVER THE
WESTERN ATLANTIC. THE NOGAPS...GFDN...AND HWRF MODEL SHOW THIS
TROUGH REMAINING IN PLACE LONG ENOUGH TO KEEP THE CYCLONE MOVING
NORTHWESTWARD THROUGHOUT THE ENTIRE FORECAST PERIOD. CONVERSELY...
THE UKMET QUICKLY LIFTS THE SAME TROUGH NORTHWARD BEYOND 72 HOURS
ALLOWING THE CYCLONE TO TURN WESTWARD UNDER THE INFLUENCE OF A
DEVELOPING WEST ATLANTIC RIDGE. THE GFS IS BETWEEN THESE TWO
SOLUTIONS AS IT SHOWS THE TROUGH SIMILARLY LIFTING NORTHWARD BUT
WITH A MUCH WEAKER RIDGE IN ITS WAKE. THIS PATTERN WOULD KEEP THE
CYCLONE MOVING GENERALLY NORTHWESTWARD...ALBEIT VERY SLOWLY. THE
OFFICIAL FORECAST LEANS TOWARD THE GFS SOLUTION BASED ITS PAST
PERFORMANCE AND IS A LITTLE TO THE LEFT OF THE DYNAMICAL MODEL
CONSENSUS. THIS FORECAST IS ALSO CLOSE TO THE FSU SUPERENSEMBLE.

WITH THE RECENT DEVELOPMENT OF CONVECTION NEAR THE CENTER AND
GENERALLY FAVORABLE ENVIRONMENTAL CONDITIONS...KAREN SHOULD
STRENGTHEN DURING THE NEXT DAY OR TWO. THEREAFTER...THE INTENSITY
FORECAST BECOMES HIGHLY PROBLEMATIC DUE TO THE POSSIBLE DEVELOPMENT
OF UNFAVORABLE UPPER-LEVEL WINDS. THE GLOBAL MODELS SHOW STRONG
WESTERLY FLOW IMPINGING UPON THE CYCLONE IN A DAY OR TWO.
HOWEVER...NEITHER THE GFDL NOR THE HWRF MODELS RESPOND TO THE SHEAR
AND CONTINUE TO STRENGTHEN KAREN THROUGHOUT THE FORECAST. IN
FACT...THE HWRF MODEL MAKES KAREN A CATEGORY 2 HURRICANE BY DAY 5.
SINCE SUCH ROBUST DEVELOPMENT SEEMS QUESTIONABLE GIVEN THE EXPECTED
INCREASE IN VERTICAL SHEAR...THE OFFICIAL FORECAST IS BASED MORE ON
THE SHIPS AND LGEM MODELS WHICH SHOW KAREN REACHING MINIMAL
HURRICANE STRENGTH IN A DAY OR TWO FOLLOWED BY SLIGHT WEAKENING.

FORECAST POSITIONS AND MAX WINDS

INITIAL 26/0900Z 11.2N 42.1W 45 KT
12HR VT 26/1800Z 11.9N 43.9W 55 KT
24HR VT 27/0600Z 13.0N 46.1W 60 KT
36HR VT 27/1800Z 14.3N 48.0W 65 KT
48HR VT 28/0600Z 15.6N 49.4W 65 KT
72HR VT 29/0600Z 18.0N 51.5W 60 KT
96HR VT 30/0600Z 20.0N 53.0W 55 KT
120HR VT 01/0600Z 22.5N 55.0W 55 KT

$$
FORECASTER RHOME

[HURAKAN]

KAREN? Did you do something with your face?

LOOKING GORGEOUS!!!

[Nimbus]

You can see the axis of the high near Texas starting to move east. Chances are good that there will be a coastal trough to greet Karen at this time. I wonder what would happen to the models if Karen became a major hurricane north of the islands? In the past we have seen large storms pump up the ridge and not recurve. hopefully she will start gaining some latitude today and put out the gone fishing sign.

[ronjon]

Well, the 00Z Euro synoptic setup is looking quite ominous. It lifts Karen northward like most models between 55W and 60W to about 25N. The trough lifts out and she gets trapped under a strong 500 mb ridge where the storm slowly moves west. Eventually, the 500 mb ridge migrates north of Karen and causes a W-SW motion to develop bringing a major hurricane just to the east of the Bahamas in 10 days. It's a long way out, but the Euro has been stellar with upper air patterns - the Euro basically builds in strong ridging over the US east coast and western Atlantic over the next 5-10 days and I don't see any signs of it breaking down at 10 days. If this verifies, it may put the SE US and Bermuda at risk. I certainly wouldn't say fish storm at this time - too early. Climatology says yes but synoptics say no.

http://www.ecmwf.int/products/forecasts/d/charts/medium/deterministic/msl_uv850_z500!Wind%20850%20and%20mslp!240!North%20America!pop!od!oper!public_plots!2007092600!!/