Tropical Depression 15 : Atlantic : Discussions & Images

[Ptarmigan]

TD 15 came from a upper low which also spawned couple other invests recently. If it becomes more organized, it will become Noel.

[Chacor]

The LLC has moved under the convection. No question now is a tropical storm.

My interpretation of your comment is that any LLC under the convection = tropical storm, which obviously isn't true. There's only one definition of a tropical storm, that is a tropical cyclone with winds of 34-63 knots.

The question is will t numbers go up to get the nhc to upgrade?

NHC doesn't use solely T-numbers to determine an upgrade, as well, although they're often used where there's no other data. Just pointing it out.

[Matt-hurricanewatcher]

The LLC has moved under the convection. No question now is a tropical storm.

My interpretation of your comment is that any LLC under the convection = tropical storm, which obviously isn't true. There's only one definition of a tropical storm, that is a tropical cyclone with winds of 34-63 knots.

True, but normally that does not mean that it is not very close to being a tropical storm. Also look as the LLC strengthens or becomes better defined over the last few hours. The earlier quickscats also shown some 30-35 knot winds. So I would expect it to be very very close.

The question is will t numbers go up to get the nhc to upgrade?

NHC doesn't use solely T-numbers to determine an upgrade, as well, although they're often used where there's no other data. Just pointing it out.

True again, also they use many of other tools to find out how organized the system is. But as said above does not change. Just waiting for more data.


Also this was one of the reasons why I posted the other named systems. To show a point.

[Matt-hurricanewatcher]

I will admit that it is now exposed again. That does not mean that it could not have stronger winds, with the stronger LLC it has developed. I wish we had a clear quickscat.

[Matt-hurricanewatcher]

CI# /Pressure/ Vmax
2.4 /1005.8mb/ 34.0kt

39 mph...

[Chacor]

T2.0 from TAFB and 1.5 from KNES still.

[Matt-hurricanewatcher]

T2.0 from TAFB and 1.5 from KNES still.

can you post link to the sites you got the data form. Thanks...

Yeah, we could go both ways on this being a tropical storm. But there is no soild data to support the upgrade.

[Chacor]

KNES is SAB/SSD.

12/0545 UTC 30.2N 49.5W T1.5/1.5 15L -- Atlantic Ocean

TAFB fix was taken from ATCF, which also says that at 06z TD15 is still a tropical depression.

[Chacor]

WTNT45 KNHC 120831
TCDAT5
TROPICAL DEPRESSION FIFTEEN DISCUSSION NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152007
500 AM EDT FRI OCT 12 2007

SATELLITE IMAGERY THIS MORNING INDICATES THAT TROPICAL DEPRESSION
FIFTEEN HAS CHANGED LITTLE IN ORGANIZATION...WITH THE CENTER A
LITTLE LESS INVOLVED WITH THE CONVECTION THAN 6 HR AGO. SATELLITE
INTENSITY ESTIMATES ARE 30 KT FROM TAFB AND 25 KT FROM SAB...SO THE
INITIAL INTENSITY REMAINS 30 KT. THE CIRRUS OUTFLOW IS FAIR TO THE
EAST AND ALMOST NON-EXISTENT ELSEWHERE.

THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 090/3. THE DEPRESSION IS
EMBEDDED IN THE LOW/MID-LEVEL SUBTROPICAL RIDGE...A CONDITION THAT
IS FORECAST TO CAUSE 24 HR OR SO OF SLOW MOTION. AFTER THAT...A
LOW/MID-LEVEL TROUGH OR FRONTAL SYSTEM APPROACHING FROM THE WEST
WILL WEAKEN THE RIDGE AND STEER THE CYCLONE...OR ITS REMAINS...
NORTHWARD OR NORTH-NORTHEASTWARD. THE NEW FORECAST TRACK IS AGAIN
SHIFTED TO THE WEST OF THE PREVIOUS TRACK BASED ON THE INITIAL
POSITION AND MOTION...AND IT LIES NEAR THE RIGHT EDGE OF THE
GUIDANCE ENVELOPS

THE DEPRESSION IS CURRENTLY UNDER THE AXIS OF AN UPPER-LEVEL
TROUGH...WHICH HAS REDUCED THE VERTICAL WIND SHEAR FOR THE MOMENT.
HOWEVER...ALL DYNAMICAL GUIDANCE FORECASTS THE CYCLONE TO BE
BLASTED BY 40-50 KT OF UPPER-LEVEL NORTHERLY FLOW WITHIN 12-24 HR.
THIS SHOULD CAUSE THE DEPRESSION TO WEAKEN TO A REMNANT LOW IN
24-36 HR...AND THIS COULD OCCUR EARLIER. SOME OF THE DYNAMICAL
MODELS FORECAST A REMNANT CIRCULATION TO SURVIVE 48 HR...SO THE
OFFICIAL FORECAST CONTINUES TO INDICATE A REMNANT LOW TO THAT TIME.

FORECAST POSITIONS AND MAX WINDS

INITIAL 12/0900Z 30.0N 49.4W 30 KT
12HR VT 12/1800Z 30.1N 49.1W 30 KT
24HR VT 13/0600Z 30.4N 48.9W 25 KT
36HR VT 13/1800Z 30.9N 48.9W 25 KT...REMNANT LOW
48HR VT 14/0600Z 32.3N 48.6W 25 KT...REMNANT LOW
72HR VT 15/0600Z...DISSIPATED

$$
FORECASTER BEVEN

[wxman57]

It's just a highly-sheared TD that is looking less tropical by the minute. Peak intensity was about 24 hours ago.

[HURAKAN]

[Thunder44]

On water vapor imagery, it looks like the ULL to west yesterday, has moved over the top of it this morning. More characteristic of a subtropical cyclone.

[senorpepr]

Karen was history 2 weeks ago... I seriously doubt it.

FWIW, back when I was forecasting in Europe, we'd track former tropical cyclones three or four weeks after it "died" from the NHC. For example, I remember tracking the remnants of Hurricane Kyle as it trekked across central Russia...

[Thunder44]

I believe that somebody suggested that when this system was 93L north of the Carribean, that it had some of Karen's remmants.

[wxman57]

I believe that somebody suggested that when this system was 93L north of the Carribean, that it had some of Karen's remnants.

Yes to both. I have our daily tropical outlook saved (with satellite imagery). Karen's remnants merged with the trof across the Bahamas and became 93L. 93L weakened and began moving northeast and was dropped as an invest. Very easy to track on satellite. It flared up again on Wednesday and became TD 15 yesterday.

[cycloneye]

WHXX01 KWBC 121240
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1240 UTC FRI OCT 12 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 FIFTEEN (AL152007) 20071012 1200 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
071012 1200 071013 0000 071013 1200 071014 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 30.1N 49.2W 30.5N 49.2W 31.5N 49.2W 33.0N 48.5W
BAMD 30.1N 49.2W 29.4N 49.4W 28.7N 50.6W 28.6N 51.5W
BAMM 30.1N 49.2W 30.2N 49.2W 30.6N 49.4W 31.5N 49.1W
LBAR 30.1N 49.2W 30.0N 48.6W 29.7N 48.8W 29.7N 49.5W
SHIP 25KTS 22KTS 19KTS 15KTS
DSHP 25KTS 22KTS 19KTS 15KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
071014 1200 071015 1200 071016 1200 071017 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 34.5N 46.8W 37.3N 41.8W 41.5N 33.1W 45.7N 21.8W
BAMD 28.7N 51.6W 28.3N 48.4W 25.7N 47.4W 22.8N 48.6W
BAMM 32.2N 47.6W 33.1N 43.2W 34.3N 35.9W 34.7N 29.5W
LBAR 29.8N 50.0W 31.0N 50.5W 33.0N 48.2W 37.7N 41.9W
SHIP 0KTS 0KTS 0KTS 0KTS
DSHP 0KTS 0KTS 0KTS 0KTS

...INITIAL CONDITIONS...
LATCUR = 30.1N LONCUR = 49.2W DIRCUR = 85DEG SPDCUR = 5KT
LATM12 = 30.0N LONM12 = 49.9W DIRM12 = 85DEG SPDM12 = 6KT
LATM24 = 29.6N LONM24 = 52.6W
WNDCUR = 25KT RMAXWD = 40NM WNDM12 = 30KT
CENPRS = 1011MB OUTPRS = 1015MB OUTRAD = 125NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM

Looks like is over.

[HURAKAN]

Very sick this morning:

[Sanibel]

Looks like a meandering tight loop.

[cycloneye]

582
WTNT45 KNHC 122030
TCDAT5
TROPICAL DEPRESSION FIFTEEN DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152007
500 PM EDT FRI OCT 12 2007

THE DEPRESSION HAS BECOME A TIGHT SWIRL OF LOW CLOUDS DEVOID OF DEEP
CONVECTION. IN FACT...IT APPEARS THAT IT IS RAPIDLY WEAKENING TO A
REMNANT LOW. THE SHEAR IS FORECAST TO INCREASE SIGNIFICANTLY...
THEREFORE REGENERATION IS NOT ANTICIPATED. THE SYSTEM COULD STILL
PRODUCE INTERMITTENT BURST OF CONVECTION BEFORE DISSIPATION.

THE DEPRESSION HAS BEEN MEANDERING AND ONLY A SMALL NORTHWARD DRIFT
IS ANTICIPATED DURING THE NEXT 12 TO 24 HOURS.

THIS WILL BE THE LAST ADVISORY OF THIS SYSTEM. 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 12/2100Z 30.8N 49.5W 25 KT
12HR VT 13/0600Z 31.5N 49.5W 20 KT...REMNANT LOW
24HR VT 13/1800Z 32.5N 49.5W 20 KT...REMNANT LOW
36HR VT 14/0600Z...DISSIPATED

$$
FORECASTER AVILA

Adios!

[cycloneye]

No more TD 15.