Invest 99L in Eastern Caribbean Thread #5

[tolakram]

So is there any guidance on how quickly a LLC can form underneath a vigorous wave? I was under the impression it took a while and wasn't something that can pop in 3 or 4 hours.

I would expect to see some wind curvature on QuikScat, an open low I believe is the term, and then observe this open low slowly closing off.

[bvigal]

What I'm looking at on satellite is within 1hr flight time from St. Croix, isn't that where the plane is? Maybe the speed of the system moving west was greater than they anticipated 24hrs ago when they wrote the flight plan?

[melhow]

000
NOUS42 KNHC 011500
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1100 AM EDT WED 01 AUGUST 2007
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 02/1100Z TO 03/1100Z AUGUST 2007
TCPOD NUMBER.....07-070

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (CARIBBEAN)
FLIGHT ONE
A. 02/1600Z
B. AFXXX 02DDA INVEST
C. 02/1400Z
D. 14.0N 65.5W
E. 02/1500Z TO 02/2000Z
F. SFC TO 10,000 FT
2. SUCCEEDING DAY DAY OUTLOOK: BEGIN 12-HRLY FIXES
AT 03/1200Z IF SYSTEM DEVELOPS.
3. REMARKS: THIS MISSION ORIGINALLY SCHEDULED FOR 02/1200Z
HAS BEEN SLIPPED TO 02/1600Z.

4. SUSPECT AREA (GULF OF MEXICO)
FLIGHT ONE
A. 02/1800Z
B. AFXXX 01EEA INVEST
C. 02/1730Z
D. 29.0N 88.0W
E. 02/1745Z TO 02/2200Z
F. SFC TO 10,000 FT

FLIGHT TWO
A. 03/1200,1800Z
B. AFXXX 02EEA CYCLONE
C. 03/1030Z
D. 30.0N 88.0W
E. 03/1045Z TO 03/1730Z
F. SFC TO 10,000 FT
5. OUTLOOK FOR SUCCEEDING DAY: CONTINUE 6-HRLY FIXES
IF SYSTEM REMAINS A THREAT.

II.PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
JWP

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

[x-y-no]

So is there any guidance on how quickly a LLC can form underneath a vigorous wave? I was under the impression it took a while and wasn't something that can pop in 3 or 4 hours.

I would expect to see some wind curvature on QuikScat, an open low I believe is the term, and then observe this open low slowly closing off.

The first thing needed is some strong convergence at the surface. Given that, something can spin up pretty quick (as in less than half a day).

[Chacor]

That is yesterday's flight plan for today. Note line C: 02/1400Z was scheduled takeoff time.

[skysummit]

Still very little convergence, but at least there's some.

http://cimss.ssec.wisc.edu/tropic2/real ... g8conv.GIF

[windstorm99]

[Chacor]

883
NOUS42 KNHC 021415
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1015 AM EDT THU 02 AUGUST 2007
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 03/1100Z TO 04/1100Z AUGUST 2007
TCPOD NUMBER.....07-071

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (CARIBBEAN)
FLIGHT ONE
A. 03/1600Z
B. AFXXX 03DDA INVEST
C. 02/1330Z
D. 14.5N 74.0W
E. 03/1500Z TO 03/2000Z
F. SFC TO 10,000 FT
2. SUCCEEDING DAY DAY OUTLOOK.....NEGATIVE.

3. SUSPECT AREA (GULF OF MEXICO)
FLIGHT ONE
A. 03/1800Z
B. AFXXX 01EEA INVEST
C. 03/1730Z
D. 30.0N 86.0W
E. 03/1730Z TO 03/2200Z
F. SFC TO 10,000 FT
4. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
5. REMARKS: TASKING ON THIS SYSTEM FOR 02/1800Z
AND 03/1200Z AND 1800Z CANCELED BY NHC AT 02/1330Z.

II.PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY.....NEGATIVE.
JWP

Still doing flights on 99L, GOM flights cancelled.

[x-y-no]

As far as I'm concerned, recon ought to be cancelled today for both this and the mess in the Gulf.

[rockyman]

What I'm looking at on satellite is within 1hr flight time from St. Croix, isn't that where the plane is? Maybe the speed of the system moving west was greater than they anticipated 24hrs ago when they wrote the flight plan?

The flight plan anticipated a center near 65.5...the Navy site has the "center" at 65W...so it's about right on track (though it's further SOUTH than was anticipated...at 12.6 instead of 14)

[Weatherfreak14]

What I'm looking at on satellite is within 1hr flight time from St. Croix, isn't that where the plane is? Maybe the speed of the system moving west was greater than they anticipated 24hrs ago when they wrote the flight plan?

The flight plan anticipated a center near 65.5...the Navy site has the "center" at 65W...so it's about right on track (though it's further SOUTH than was anticipated...at 12.6 instead of 14)

i think that they will investigate both areas if needed.

[RL3AO]

So 1330 takeoff?

[drezee]

The low level clouds to the S of the convection are travelling W now. Travelling at 20+ mph...I would suspect that the recon will find a Tropical Storm and a deepening one at that.

I see no reason to change my thinking above. This is a classic fast moving Tropical Cyclone in the Eastern Caribbean. I mean classic. If recon does not find a tropical storm, then the equipment is faulty. I would gladly eat crow on this one. I could care less about the IR, the visible tells the story!

You must be joking.

What do you mean? The flauty equipment part yes, the TC part no.

[Ivanhater]

hmm..they have NEGATIVE for tomorrow

[drezee]

As far as I'm concerned, recon ought to be cancelled today for both this and the mess in the Gulf.

Well, let me be the first to be happy that it is not up to you...

[Chacor]

So 1330 takeoff?

That's the plan for tomorrow, there's probably a typo in there, but yes tomorrow's flight is scheduled to leave at 1330Z.

[gatorcane]

As far as I'm concerned, recon ought to be cancelled today for both this and the mess in the Gulf.

Are you joking?

[Windsurfer_NYC]

I see no reason to change my thinking above. This is a classic fast moving Tropical Cyclone in the Eastern Caribbean. I mean classic. If recon does not find a tropical storm, then the equipment is faulty. I would gladly eat crow on this one. I could care less about the IR, the visible tells the story!

You must be joking.

What do you mean? The flauty equipment part yes, the TC part no.

I think both, but more so the Tropical Storm part.

[Ivanhater]

As far as I'm concerned, recon ought to be cancelled today for both this and the mess in the Gulf.

Im going to have to ask you to stay positive...even if you do have comcast

[bvigal]

OK, so I'll ask again - why did they at 9:30am this morning re-issue the Tropical Cyclone Formation Alert? Remember this?

TCFA CRITERIA LIST
SFC GRADIENT
3 A Circulation is evident in the wind field
6 A Circulation has been evident for 24 hours
3 Westerly SFC/Gradient level wind of at least 5 kts, is south of the tropical disturbance and within five degrees of the center.
2 Any wind associated with cloud system center is at least 20 kts
3 Any wind associated with cloud system center is at least 25 kts
4 Any wind associated with cloud system center is at least 30 kts
3 24 hour pressure decrease at nearby station (within five degrees) equals 2 MB
4 24 hour pressure decrease at nearby station (within five degrees) equals 3 MB
2 Estimated MSLP of disturbance is < 1014 MB
3 Estimated MSLP of disturbance is < 1012 MB
4 Estimated MSLP of disturbance is < 1010 MB
500 MB
2 There is evidence of at least a trough
3 There is evidence of a closed circulation
200 MB
2 Longwave or major shortwave trough to the northwest of the tropical disturbance
4 Evidence of an anticyclone over the center of the tropical disturbance.
3 200MB wind over cloud system center < 25 kts
SST
3 SST 26 C or higher
SATELLITE
DATA
3 The tropical disturbance has persisted for at least 24 hours.
4 The tropical disturbance has persisted for at least 48 hours
5 The tropical disturbance has persisted for at least 72 hours
3 DVORAK classification of T 1.0
Issue TCFA! DVORAK classification of T 1.5 from all agencies
MISCELLANEOUS
3 Cloud system center is north of 5 degrees latitude.
5 Tropical disturbance is within 72 hours of a DOD resource.
2 Cloud system center and satellite fix are consistent in location (within 2 degrees)
1 20 knot synoptic reports within convective cloud pattern of disturbance.
ADD UP THE POINTS. IF VALUE IS 35 OR GREATER, ISSUE THE TCFA!!!