Tropical Storm Colin

[snowmadchrisuk]

The NHC seem to have been affected by a power failure, meaning the have not as yet been able to publish an advisory for Colin online yet.

Yes they have but the models have updated and the GDFL now shows Colin getting up to cat 2 status , I got the vortex messages earlier from the hurricane hunters and they were reporting wide spread tropical force winds , latest sat pic's show Colin to look more like a hurricane than a tropical storm and an eye has just popped as you can see on my image below . If there are many ships in the area the NHC needs to get this information updated asap.

Although on second thoughts I am not sure if that is an eye as the centre of circulation looks to be to the west and all the convection looks to the east , on my image though almost looks like it has 2 centres of circulation Where's Jim Williams when you need him :lol:

Edited August 5, 2010 by snowmadchrisuk

[Somerset Squall]

Recon have found higher winds than originally thought, and therefore the current intensity has been increased to 50kts.

[Katherine]

60 MPH now!!! Colin's had a mojo injection from somewhere!

[kold weather]

Just a sheared center there with the convection on the eastern side and now starting to wrap up on the northern side.

Anyway Recon just found a flight level wind of 71kts. This would justify an upgrade probably to 60kts next advisory. Colin is strengthening quite a bit faster then was expected and providing it doesn't take another shot of mid level shear we could well see this reach hurricane status in the next 24hrs as it gains latitude and gets closer to Bermuda. Indeed Bermuda will probably mean Hurricane warnings up fairly soon given the current strengthening trend occuring.

URNT12 KBIX 052353

VORTEX DATA MESSAGE AL042010

A. 05/20:48:20Z

B. 24 deg 57 min N

065 deg 57 min W

C. NA

D. 7 kt

E. 234 deg 5 nm

F. 279 deg 9 kt

G. 214 deg 12 nm

H. EXTRAP 1008 mb

I. 24 C / 183 m

J. 25 C / 180 m

K. 22 C / NA

L. NA

M. NA

N. 135 / 01

O. 0.02 / 1 nm

P. AF302 0204A INVEST OB 11

MAX OUTBOUND AND MAX FL WIND 71 KT NE QUAD 20:55:20Z

SLP EXTRAP FROM BELOW 1500 FT

EXTRAP SLP 1005 MB FOUND 14NM AWAY FROM FL CENTER IN NE QUAD

[Iceberg]

Well I have to admit I am little surprised by the latest NHC advisory.

"COLIN HAS MAINTAINED A SATELLITE CLOUD SIGNATURE SIMILAR TO WHEN A

RECONNAISSANCE AIRCRAFT INVESTIGATED THE SYSTEM 6 HOURS AGO. SINCE

THEN...A STRONG BURST OF DEEP CONVECTION HAS DEVELOPED IN THE

NORTHEASTERN QUADRANT...ALTHOUGH THE CONVECTION HAS WANED A LITTLE

DURING THE PAST COUPLE OF HOURS. HOWEVER...THE STRONG PRESSURE

GRADIENT IN THE EASTERN SEMICIRCLE BETWEEN THE CENTER OF COLIN AND

NOAA BUOY 41049 LOCATED 225 NMI TO THE NORTHEAST SUPPORTS KEEPING

THE INTENSITY AT 50 KT."

There is IMO a total decoupling of the LLCC as can be seen below.

Essentially the upper winds are too strong taking the convective mass and winds with it northwards, the LCC has continued on a NW path though.

This is not a TS at the moment......

[Iceberg]

Well they are just keeping him as a TS

"VERTICAL WIND SHEAR...ANALYZED AT 25 KT BY THE SHIPS MODEL...HAS

AGAIN TAKEN A TOLL ON COLIN...WITH THE LOW-LEVEL CENTER NOW

COMPLETELY EXPOSED TO THE WEST OF THE PULSING DEEP CONVECTION. AN

ASCAT PASS AROUND 0118 UTC SHOWED SEVERAL 35-40 KT RETRIEVALS EAST

OF THE CENTER...AND THE INITIAL INTENSITY IS LOWERED TO 40 KT FOR

THIS ADVISORY. "

I have to say that the winds are now quite away from the centre and IMO are more convective based rather than due to any tropical centre, but they are the expects.

It's possible for convection to ignite around the decoupled centre, but as they say this would only be a temporary thing anything way.

If convection does not start up near the centre soon, the LLCC will slowly degrade anyway, with alot of dry air around I am not convinced it will happen.

[Cookie]

not looking great

[Iceberg]

From the below NHC are really struggling to keep this as a TS(I am not sure why tbh).

The highest flight winds were 36Kts which isn't enough to justify a TS, they could be right that the deep convection has stronger winds, but hey ho.

DATA FROM THE AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT SHOW THAT

COLIN REMAINS POORLY ORGANIZED...WITH THE THE SURFACE CENTER

DISPLACED NORTH OF THE 850-MB FLIGHT LEVEL CENTER FIX. THE HIGHEST

FLIGHT LEVEL AND SFMR WINDS SAMPLED BY THE AIRCRAFT WERE 36 KT.

THE INITIAL INTENSITY WILL BE HELD GENEROUSLY AT 40 KT FOR THIS

PACKAGE...ASSUMING SOME HIGHER WINDS REMAIN IN THE DEEP CONVECTION

TO THE SOUTHEAST OF THE CENTER.

THE OUTFLOW HAS BECOME RESTRICTED IN THE NORTHEASTERN QUADRANT OVER

THE PAST FEW HOURS...AND DEEP CONVECTION IS NOW CONFINED TO THE

SOUTHEASTERN QUADRANT. WHILE THE SHIPS MODEL ANALYZES ONLY ABOUT

10 KT OF SHEAR OVER COLIN...SATELLITE IMAGERY SUGGESTS THAT SHEAR

AND DRY AIR CONTINUE TO INHIBIT DEEP CONVECTION WEST AND NORTH OF

THE CENTER. SHIPS SHOWS THE SHEAR REMAINING LOW FOR THE NEXT 24

HOURS...WHICH MAY ALLOW FOR SOME STRENGTHENING AS COLIN WILL REMAIN

OVER WARM WATERS AND IN A DIVERGENT UPPER-LEVEL ENVIRONMENT. AFTER

48 HOURS...THE SHEAR INCREASES RAPIDLY AND COLIN SHOULD GRADUALLY

WEAKEN AS THE CYCLONE MOVES OVER COOLER WATERS AND BECOMES

EXTRATROPICAL. THE NEW NHC INTENSITY FORECAST IS IN BEST AGREEMENT

WITH ICON.

[BornFromTheVoid]

Now just a tropical depression and expected to dissipate with 72 hours.

VISIBLE SATELLITE IMAGERY...RADAR DATA AND SURFACE OBSERVATIONS FROM

BERMUDA INDICATE THAT THE LOW-LEVEL CIRCULATION OF COLIN IS

BECOMING ELONGATED NORTH TO SOUTH AND THAT THE CONVECTIVE ACTIVITY

HAS LITTLE...IF ANY...ORGANIZATION. DVORAK DATA T-NUMBERS FROM SAB

AND TAFB HAVE DECREASED TO BELOW TROPICAL STORM STRENGTH. BASED ON

THE ABOVE...COLIN IS DOWNGRADED TO A TROPICAL DEPRESSION AT THIS

TIME.

ALTHOUGH THE INTENSITY GUIDANCE STILL SHOWS STRENGTHENING...THIS

SEEMS UNLIKELY AS SHEAR AND DRY AIR CONTINUE TO TAKE A TOLL ON

COLIN. THE NEW INTENSITY FORECAST KEEPS COLIN AS A TROPICAL

DEPRESSION UNTIL DISSIPATION. IF THE CIRCULATION CONTINUES TO

ELONGATE...IT IS POSSIBLE THAT COLIN WILL DEGENERATE INTO A TROUGH

OF LOW PRESSURE LATER TODAY. THIS SCENARIO IS SUPPORTED BY MOST OF

THE GLOBAL MODELS.

COLIN IS MOVING A LITTLE FASTER TOWARD THE NORTH OR 360 DEGREES

AT 10 KT. THE TRACK GUIDANCE IS IN GOOD AGREEMENT ON TAKING COLIN

OR ITS REMNANTS NORTHWARD...THEN NORTHEASTWARD AHEAD OF A DEEP LAYER

TROUGH ALONG THE EAST COAST OF THE UNITED STATES. THE NEW TRACK

FORECAST IS VIRTUALLY AN UPDATE OF THE PREVIOUS NHC ADVISORY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 08/1500Z 32.0N 65.6W 30 KT

12HR VT 09/0000Z 33.3N 65.5W 30 KT

24HR VT 09/1200Z 35.3N 64.8W 30 KT

36HR VT 10/0000Z 37.9N 63.0W 30 KT

48HR VT 10/1200Z 41.2N 58.8W 30 KT

72HR VT 11/1200Z...DISSIPATED

[Somerset Squall]

Could only last 6 hours. Colin has ceased to be, again. But regeneration is not expected this time.

[Cookie]

interesting little system to track, thanks for all the hard work everyone put in :blush: