60 replies to this topic

[Somerset Squall]

91L becomes the season's fourth tropical depression:

TROPICAL DEPRESSION FOUR ADVISORY NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042010
1100 AM EDT MON AUG 02 2010

...NEW TROPICAL DEPRESSION FORMS IN THE ATLANTIC...


SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.6N 41.1W
ABOUT 1365 MI...2200 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 17 MPH...28 KM/HR
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM EDT...1500 UTC...THE CENTER OF TROPICAL DEPRESSION FOUR
WAS LOCATED NEAR LATITUDE 12.6 NORTH...LONGITUDE 41.1 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 17 MPH...28
KM/HR. A CONTINUED MOTION TOWARD THE WEST-NORTHWEST WITH AN
INCREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...
AND THE DEPRESSION COULD BECOME A TROPICAL STORM BY TONIGHT OR
TUESDAY.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BRENNAN

[summer blizzard]

Good chance of a hurricane, possibly even a major, however it does look like a FISH.

[Rob]

I would say this is already TS Colin to be honest, advisory in about 30 mins

[Paranoid]

Still TD4 for now but NHC did mention that it continues to become more organised. I would be surprised if we dont have Colin by tomorrow morning.

[cookie]

Fingers crossed this stays as a fish system

[Devonian]

cookie, on 02 August 2010 - 21:17 , said:

Fingers crossed this stays as a fish system

FISH?

Edited by Devonian, 02 August 2010 - 21:23 .

[summer blizzard]

Devonian, on 02 August 2010 - 21:23 , said:

FISH?

Basically a storm which stays at sea as opposed to hitting the Gulf.

[Somerset Squall]

The latest discussion is very interesting, and the forecast intensities have been nudged upwards. Track has also shifted slightly southwards. To mention that destructive shear is not as certain as first thought makes me feel this one has a shot at becoming a hurricane.

[Devonian]

summer blizzard, on 02 August 2010 - 21:27 , said:

Basically a storm which stays at sea as opposed to hitting the Gulf.

Cheers.

Not an acronym then?

[cookie]

Devonian, on 02 August 2010 - 21:30 , said:

Cheers.

Not an acronym then?

sorry should have explained that, A fish system is a system that doesn't hit land at all. kind of the pefect hurricane one that we can watch which wouldnt cause any death or destruction,

Latest Water Vapour of TD4

[Rob]

12 hourly recon flights have been scheduled for TD 4

ATLANTIC REQUIREMENTS
1. TROPICAL DEPRRESSION FOUR
FLIGHT ONE -- TEAL 70
A. 04/1200,1800Z
B. AFXXX 0104A CYCLONE
C. 04/1000Z
D. 18.4N 57.4W
E. 04/1130Z TO 04/1800Z
F. SFC TO 15,000 FT

2. SUCCEEDING DAY OUTLOOK: FIXES AT 05/0000Z
AND 05/0600Z. BEGIN 12-HRLY FIXES AT 05/1800Z.

[Katherine]

cookie, on 02 August 2010 - 21:34 , said:

Latest Water Vapour of TD4

Lots of dry air coming up.... but a good circulation developing nevertheless!

[londonsnow]

maybe td4 will stir up the atlantic finally

[Somerset Squall]

TD4 has become TS Colin, with intensity rising to 35kts. NHC are forecasting the favourable environment of low shear and warm sea temperatures to persist for another 36hrs, which should allow Colin to strengthen into a strong TS. Shear is still expected to play a role thereafter, but interestingly, NHC seem to expect the shear to level off the intensity rather than weaken Colin. Track forecast is broadly similar to before, with Colin heading north of the Caribbean Islands and moving northwards between the Bahamas and Bermuda.

Another thing worth mentioning is that Colin is a small storm, so is prone to large intensity changes, up and down. With this in mind, we can't rule out Colin becoming a hurricane even though it's not forecast at this time.

Attached Thumbnails

• 

[Somerset Squall]

How quickly things change! Colin looks a right mess this afternoon, with convection looking disorganised and sporadic around the LLC. Colin's fast motion cannot be helping, and NHC even suggest that this could cause Colin to open up into a wave again if it persists.

[cookie]

Colin looks really poor 2nite, been eaten alive by shear.

[AderynCoch]

The high forward speed does seem to be hindering organisation, though this isn't always necessarily the case (Hurricane Allen anybody?).

A lot will depend on how accurate the shear forecast is, as it's supposed to kick in just as Colin makes an approach to land. Also, a more southerly track than forecast would lessen the influence of the upper low; a more northerly track could easily rip the storm apart.

Edited by AderynCoch, 03 August 2010 - 18:07 .

[Somerset Squall]

Colin's main problem is now defintely speed. The LLC is racing ahead of the MLC looking at latest satellite imagery, indicating that Colin is no longer vertically stacked. The storm is dangerously close to degenerating here. To survive the future progged shear, Colin needs to intensify but this isn't going to happen if he keeps racing westwards in excess of 30mph.

[Rob]

Colin has now degenerated into a Remant Low pressure system, NHC will no longer be issuing advisories for this system unless it regerates.

[cookie]

Rob, on 03 August 2010 - 21:04 , said:

Colin has now degenerated into a Remant Low pressure system, NHC will no longer be issuing advisories for this system unless it regerates.

Doctor we have a very weak pulse all my not be lost!

Quote

INITIAL 03/2100Z 15.8N 53.8W 35 KT...POST-TROP/REMNT LOW
12HR VT 04/0600Z 16.8N 57.2W 30 KT...POST-TROP/REMNT LOW
24HR VT 04/1800Z 18.4N 60.8W 30 KT...POST-TROP/REMNT LOW
36HR VT 05/0600Z 20.0N 63.8W 30 KT...POST-TROP/REMNT LOW
48HR VT 05/1800Z 21.7N 66.5W 30 KT...POST-TROP/REMNT LOW
72HR VT 06/1800Z 25.0N 70.0W 30 KT...POST-TROP/REMNT LOW
96HR VT 07/1800Z 28.0N 72.5W 30 KT...POST-TROP/REMNT LOW
120HR VT 08/1800Z 30.0N 73.5W 30 KT...TROPICAL DEPRESSION