Tropical Storm Grace

[The PIT]

It'll be interesting if it's still there tomorrow morning. Now that would get the experts puzzled.

[Jack Wales]

I think there is plenty to say....

This is the first time that a tropical cyclone has been recorded in this part of the Atlantic.

I believe that this is the furthest north a tropical cyclone has ever formed.

I believe this may even be the first time a tropical cyclone (warm core intact) has approached 50ºN since hurricane faith in the 1960’s.

Absolutely intriguing!

[Marcus_surfer]

Beautiful images of Grace on the satellite this morning, i've never seen a tropical storm so close to us, it seems likely she will affect us later on though, no wind to mention though, just heavy rain and very mild air for the time of year, up to 21 Degrees in Jersey

[Somerset Squall]

I think there is plenty to say....

This is the first time that a tropical cyclone has been recorded in this part of the Atlantic.

I believe that this is the furthest north a tropical cyclone has ever formed.

I believe this may even be the first time a tropical cyclone (warm core intact) has approached 50ºN since hurricane faith in the 1960's.

Absolutely intriguing!

According to Jeff Masters on Wunderground, Alberto developed into a tropical storm further north but this was near the Canadian Coast. As I thought however, Grace is the furthest northeast a tropical storm has formed since the satellite era in the 1960's. Amazing!

Still got some thunderstorms near the centre and an eye like feature looking at this satellite image:

[The PIT]

The latest sat seems to show an eye once again.

[Tn9]

The latest sat seems to show an eye once again.

Looks a bit fragmented at six this evening

[Nick F]

Ex Grace seen on the 18z UKMO fax:

Some thunderstorms ahead of the low in the Tm airmass as it destabilises along frontal boundary across Bay of Biscay:

http://meteocentre.com/lightning/map_sfuk.php?time=0〈=en&map=EuropeNW

http://www.euclid.org/realtime.html

[A.J]

looking at lot less organized on the latest satellite imagery....some nice convection on the SW flank, but not a lot else by the looks of it...bear in mind, I'm far from being an expert!....opinions on this system anyone?

1845 BST image..

2100 BST image..

Edited October 5, 2009 by ajpoolshark

[Somerset Squall]

Latest discussion from NHC on Grace:

TROPICAL STORM GRACE DISCUSSION NUMBER 4

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092009

500 PM AST MON OCT 05 2009

GRACE CONTINUES TO HAVE THE SATELLITE APPEARANCE OF A TROPICAL

CYCLONE AND A MODERATE TO DEEP WARM CORE AS INDICATED BY RECENT

AMSU PASSES. HOWEVER...CLOUD TOP TEMPERATURES HAVE CONTINUED TO

WARM OVER THE PAST FEW HOURS AS THE CYCLONE IS NOW OVER SSTS OF

17-18C. THE INTENSITY IS DECREASED TO 50 KT BASED A SUBTROPICAL

CLASSIFICATION OF 3.5 FROM TAFB AND A DVORAK CI-NUMBER OF 3.0 FROM

SAB. A QUIKSCAT PASS SHOULD PROVIDE SOME INFORMATION ON THE

INTENSITY AND STRUCTURE OF GRACE SOON. THE CENTRAL PRESSURE IS HELD

AT 990 MB BASED ON AN 1800 UTC OBSERVATION OF 992 MB AND A WIND OF

20 KT FROM SHIP A8I02 ABOUT 30 NM NORTH OF THE CENTER OF GRACE.

THE INITIAL MOTION ESTIMATE IS 025/26 KT...AS GRACE IS BEING STEERED

BY DEEP-LAYER SOUTHWESTERLY FLOW AHEAD OF A MID- TO UPPER-LEVEL

TROUGH ALONG 27W. BY TUESDAY MORNING...ALL OF THE GLOBAL MODELS

SHOW GRACE BEING ABSORBED BY A FRONT ASSOCIATED WITH A DEEPENING

EXTRATROPICAL CYCLONE TO THE NORTHWEST OF THE BRITISH ISLES.

IT IS WORTH NOTING THAT OTHER ATLANTIC TROPICAL STORMS HAVE FORMED

FARTHER NORTH THAN GRACE DID. IN 2008 TROPICAL STORM LAURA WAS

FIRST CLASSIFIED AS A TROPICAL STORM AT 40.6N....SLIGHTLY FARTHER

NORTH THAN THE LATITUDE OF 40.2N WHERE GRACE WAS FIRST CLASSIFIED

AS A TROPICAL STORM AT 0000 UTC TODAY. ALSO...IT IS LIKELY THAT

POST-STORM ANALYSIS WILL SHOW GRACE BECOMING A TROPICAL STORM

EARLIER...AND FARTHER SOUTH...THAN INDICATED OPERATIONALLY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 05/2100Z 47.7N 14.8W 50 KT

12HR VT 06/0600Z 50.6N 12.0W 50 KT

24HR VT 06/1800Z...DISSIPATED

$$

FORECASTER BRENNAN

It could still end up being the farthest northeasterly formation though, we will have to wait and see.

[Somerset Squall]

Grace has now merged with the cold front over Ireland and Northern England, though some rotation is still visable in latest satellite imagery. However, Grace no longer qualifies as a tropical cyclone due to it's frontal nature:

[The PIT]

Now are the remains going to move along the front? If it does it should produce some heavy rain along it.

[Iceberg]

It is moving along the front, but I disagree with NHC that it nolonger has it's own entity.

It clearly has it's own centre still, it's own rotation and it's own banding and is still an extropical system IMO.

Currently the Centre is 100 miles SW of Ireland and moving quite quickly, the outer bands are perhapes 50 miles or so from SW Ireland.

[Cookie]

it amazing this thread has had reply's then a powerful cat 4 and cat 5 super typhoon combined.

[johnholmes]

It is moving along the front, but I disagree with NHC that it nolonger has it's own entity.

It clearly has it's own centre still, it's own rotation and it's own banding and is still an extropical system IMO.

Currently the Centre is 100 miles SW of Ireland and moving quite quickly, the outer bands are perhapes 50 miles or so from SW Ireland.

I agree there Ice the IR Sat picc shows it currently about 49.5N and around 13-14W.

I suspect what it will do is slow up the arrival of the main cold front, acting as a wave on it, and enhancing the rainfall ahead and on that front.

Cold air is very reluctant to make much southward progress over Ireland as a result of the ex tropical storm if you look at latest observations. How much it may deepen is open to a lot of doubt, just a flat wave on the cold front or perhaps something more marked. As ever time will tell.

[Iceberg]

It seems to be getting more organised.

Latest pictures show a tighter circulation again and even a black space in the centre(I might be tempted to call it an eye, but feel I might get mobbed).

It should move into close up visual in the next 1 hr or so.

But things are getting very interesting.

[londonsnow]

it certainly looks like an eye. extraordinary

[BornFromTheVoid]

It must be minutes away from the Irish coast now. Any idea if there are any high wind speeds being brought along with Grace still?

In Cork City at the moment, so hoping it still has some strength left in it!

[Coast]

Yikes!!!! One of the spaghetti models takes her track right over my house!!!! Can anybody more knowledgeable tell us what affects landfall would have on her intensity etc?

[Iceberg]

It's certiantly still growing in size. No reports yet as it's just a little too far away.

High res Quickscat this morning still had quite a few 40-45Kt barbs in the SW quad, which is where the strongest winds will be.

This is only a rough estimate but probably hitting Southern Ireland around 2.30-3.00pmish. Passing over Cork at 17-18.00, speed is very difficult to judge though as she's riding the wave.

She is also a very small creature so nowcasting will be critical in where gets what.

I think the HWRF looks a good track, but probably a little further south as she crosses England.

As to what happens when she hits land, not much would be my take. Unlike tropical storms the energy isn't been derived from the sea so cutting off the sea probably won't have much effect.

[londonsnow]

it's a bit surreal looking at the met office sattelite loop. grace appears to reorganise as she approaches eire. how is this possible? obviously extra tropical sytems are common here at this time of year, but i've never seen one looking like grace on the satellite imagery

[pyrotech]

It's certiantly still growing in size. No reports yet as it's just a little too far away.

High res Quickscat this morning still had quite a few 40-45Kt barbs in the SW quad, which is where the strongest winds will be.

This is only a rough estimate but probably hitting Southern Ireland around 2.30-3.00pmish. Passing over Cork at 17-18.00, speed is very difficult to judge though as she's riding the wave.

She is also a very small creature so nowcasting will be critical in where gets what.

I think the HWRF looks a good track, but probably a little further south as she crosses England.

As to what happens when she hits land, not much would be my take. Unlike tropical storms the energy isn't been derived from the sea so cutting off the sea probably won't have much effect.

Grace does appear on the latest satalite loop to be trying to reform, the definition is definitly clearer.

Still no one on the BBC has said those famous words from October 1987 yet, so we are ok for now.

Got the latest infrared and visible loops from http://www.floodwarn.co.uk/weather_charts.htm

Think i may just have computer close by all day to watch how this pans out.

[Iceberg]

I am just waiting for her to show up on the sat24 one here.

http://www.sat24.com/Region.aspx?country=gb&sat=vis&type=loop

She's just entered the bottom left hand side.

Lots of sat watching for sure, makes life more interesting than looking at the fog and drizzle outside.

Edited October 6, 2009 by Iceberg

[Somerset Squall]

Still no mention by the Met Office, a little surprising really as it seems to have the potential to perhaps deliver some very heavy rain or even gales later on.

[johnholmes]

I doubt if any of the models, UK Met or GFS will have any of the detail correct.

I would suggest that the GFS idea of it as a wave on a slowish moving cold front with anticyclonic curvature behind slowing it up-almost a classic case of the two being show, with prolonged and for some heavy rain fall as the front moves ESE is the most likely happening.

Detail will slowly emerge through the afternoon; the chances of it deepening a lot seem only slight. The heavier bursts of rain MIGHT be linked with isolated thunderstorms although that again seems only a slight risk. The 12z ascent from Valentia would be nice to see and maybe the Brest ascent for an idea of the moisture and any instability within the warm sector as well.

Interesting to watch anyway.

[pyrotech]

Just wondered if John Holmes could give his take on the latest sat pics, does look like an eye of some sort has reformed. John do you think Grace is likly to be reforming to any degree, could she depeen now or do you think will just totally disipate?

Sorry posted this same time as john posted!

Edited October 6, 2009 by pyrotech