ATL : TROPICAL STORM GRACE

[ozonepete]

http://www.metoffice.gov.uk/weather/uk/radar/

British Isles Radar Loop...not a real high quality radar but still

Thanks! MAybe not great, but it tells the story.

[Cryomaniac]

That still looks almost tropical, although looks are often deceiving. It's pretty warm and windy here in the East of England, looks like we'll get the rain tomorrow.

Met office says heavy rain for East Midlands from 19:05 - 22:00 Oct 6th - keep your umbrella handy, Cryomaniac!

http://www.metoffice.gov.uk/weather/uk/ ... nings.html

Pretty accurate. I left the house at 2100 it was humid and breezy, but dry, just walked home and it's pouring with rain lol.

Just amazing. Still has some tropical characteristics like banding into a center.

Yeah. There may be a case for it still being partially tropical. The TCR will be interesting. When we get it lol.

[DanieleItalyRm]

Everybody tropical cyclones that had become in Extratropical had evident Extratropical characteristics.. but GRACE have still some evident tropical caracteristic:

[ozonepete]

Everybody tropical cyclones that had become in Extratropical had evident Extratropical characteristics.. but GRACE have still some evident tropical caracteristic:

I have to agree.

[Epsilon_Fan]

It's crazy to see a storm of that appearance in the NE Atlantic near England! Definately one of the wilder storms I've witnessed

[breeze]

It IS crazy, isn't it? It's been fascinating to follow!

[Cryomaniac]

Everybody tropical cyclones that had become in Extratropical had evident Extratropical characteristics.. but GRACE have still some evident tropical characteristics:

I can't disagree. This is a very interesting system.

[HURAKAN]

Producing more deep convection now than when it was a tropical cyclone!!! Very weird!!!

[leanne_uk]

We managed to have a dry couple of hours here but the rain is just starting up again and I expect it for a good few hours yet.
Grace has been an amazing system to watch and to see that even now as hurakan has pointed out the convection is pretty evident.
So much more to learn

[Ptarmigan]

Grace, Vince, Karl egual at many Mediterranean Hurricane (Medicanes):

Interesting images. They look like hurricanes to me. They look better than some hurricanes I have seen before.

[Ptarmigan]

..Tropical Storm or at least a Subtropical Storm. The satellite presentation appears as if it is a Hurricane.
Kindly, we would like a small explanation of why 90L is just that, an invest and nothing more.
Warm Regards,
Jonathan Belles.
Weather Enthusiast and Future Meteorologist
Storm2k.org member

Respuesta:
Dear Jonathan Belles,
I tried to call the NHC without success. That's why I jumped on my bike to see what was going on.
When I arrived I met the staff in the pool room. They just ordered some pizza and some Johny Walker and were having a great time.
I told them about your e-mail and after drinking 3 cans of coffee they decided to give it a go. I pointed out the position and one of them answered: "There nothing there! " I advised him to take his glasses on as he can't see very well without.
Now everything is under control. Thank you!

Grece es parecida a otros tropical ciclones del Norte este atlántico ignorados:


unnamed 92L Jun.2009 50 knots (tropical storm)




unnamed Sept. 2008 50 knots (tropical storm)


unamed Jun. 2009 30 knots (tropical depression)


unnamed Nov.2004 45 knots (tropical storm)


unnamed Oct.1997 (tropical storm or hurricane)

Some of those storms look well organized.

[breeze]

Gracefully slipping out the back door...

[george_r_1961]

I dont think id ever seen France or Ireland ever used as a reference point in an NHC advisory before

[ozonepete]

eyes are present routinely in tropical storms with winds of about 50KT. Usually, they are not visible due to cirrus overcast, but are on radar and microwave imagery

We don't have cirrus overcast here; thus, we could see the eye earlier

The key phrase you used is cirrus overcast, and the key word left out is "developing." We've all seen hurricanes weakening into a TS that keep their CLEAR eye. But has there ever been a tropical storm DEVELOPING into a hurricane that showed a CLEAR eye BEFORE it made hurricane? I've never seen one in all of the satellite image history we have and all of the storms I've followed. So if Grace was on the upswing, producing a CLEAR eye BEFORE the DEVELOPING TS became a hurricane would be a first. I defer to you on this - you are an expert and I admire your work. But if you have an example I would love to see it.

And of course, a DEVELOPING TS often has an "EYE" detectible by SSMI because the "eye" circulation it shows is a developing area of subsidence that forms from the lower levels up as the radius of maximum winds consolidates. In that DEVELOPMENT situation we'd always expect a cirrus canopy until the winds have reached a critical number (about 89mph) where the cirrus can clear out.

it is quite common to have an eye with this type of tropical cyclone prior to hurricane status

see Vince and Michael

OK, Derek. I found some time to look them up. From what the TCRs say, Michael was designated a hurricane on 17 October 2000 at 18Z. The eye was first observed and verified at 18 October 0615Z. And here's the TCR on Vince: "Later on 9 October a banding eye developed, and Vince became a hurricane near 1800 UTC about 135 n mi northwest of Funchal in the Madeira Islands."

Here's the text from the two TCRs:

Vince 2005 from the NHC:

a. Synoptic History
Vince originated from an occluded deep-layer frontal low that moved southeastward
across the Azores Islands on 6 October. Over the next couple of days, the frontal structure
gradually dissipated and banded convection became more concentrated near the circulation
center. It is estimated that this convection became sufficiently persistent and organized to
designate the cyclone as a subtropical storm near 0600 UTC 8 October, when the system was
centered about 500 n mi southeast of Lajes in the Azores. Although by this time the core
convective signature and surface wind field resembled a fully tropical cyclone, the system still
had a very prominent cold-core cyclonic circulation in the upper-troposphere – hence the
subtropical designation.
The “best track” chart of Vince’s path is given in Fig. 1, with the wind and pressure
histories shown in Figs. 2 and 3, respectively. The best track positions and intensities are listed
in Table 1. The subtropical storm moved little over the next day or so, but then began to move
slowly northeastward on 9 October. An AMSU overpass at 1527 UTC that day showed that a
mid- to upper-level warm core was forming, and it is estimated that Vince became a tropical
storm near 1200 UTC while over sea-surface temperatures of 23-24C. Later on 9 October a
banding eye developed, and Vince became a hurricane near 1800 UTC about 135 n mi northwest
of Funchal in the Madeira Islands.

Michael 2000 from NHC:
Prior to tropical cyclone development, Dvorak satellite intensity estimates from the Tropical Analysis and Forecast Branch (TAFB), the Satellite Analysis Branch (SAB), and the Air Force Weather Agency (AFWA) indicated subtropical cyclone classifications as high as ST 2.5 or 35 kt (from the TAFB). However, by 0000 UTC, 17 October, satellite classifications suggested the low pressure system had acquired enough tropical characteristics to become Tropical Storm Michael. The transition from a subtropical to a tropical system was further supported by an earlier Advanced Microwave Sounder Unit (AMSU) satellite overpass, which indicated a weak warm core aloft and upper-level outflow had developed. Two QuikSCAT overpasses on the 16th also showed the radius of maximum winds had contracted from 150 n mi to less than 60 n mi between 1029 and 2252 UTC.
Later that day, U. S. Air Force Reserve (USAFR) reconnaissance aircraft indicated that Michael had strengthened based on 1500 ft flight-level wind reports of 60 kt and 990 mb surface pressure at 1717 UTC, and 72 kt and 988 mb pressure at 1906 UTC. Those values correspond to surface wind speed estimates of 51 kt and 61 kt, respectively, using a standard reduction of 0.85 for that altitude. Also, experienced hurricane hunter personnel estimated surface winds of 70 kt. Based on the reconnaissance data, it is estimated that Michael became a hurricane at 1800 UTC, 17 October. By 0615 UTC, 18 October, reconnaissance aircraft noted a 20 n mi circular closed eye at 850 mb, and observed a minimum surface pressure of 984 mb and flight-level winds of 73 kt. There were slight fluctuations in the flight-level winds and surface pressures for the next 36 hours until rapidly deepening occurred on the 19th. As Michael began to interact with the approaching strong mid-tropospheric trough, baroclinic effects may have played a role in Michael's 21 mb pressure drop from 986 mb at 1200 UTC to 965 mb at 1800 UTC. During the rapid deepening phase, the maximum flight-level wind and minimum pressure observed by reconnaissance aircraft was 95 kt (1500 ft) at 1829 UTC, from the NOAA Aircraft Operations Center (NAOC), and 979 mb from the USFAR, respectively, on 18 October.


So you'll have to show me a satellite image of Vince with a RELATIVELY CLEAR eye at least a few hours before 2005-10-09 18Z and one of Michael from at least a few hours before 18Z on 17 October 2005. You can't. They didn't have one. TS's DEVELOPING into HURRICANES don't get an eye visible from satellite until they have become hurricanes. Never seen one.

Interestingly enough, especially because they were similar in time of year and origin to Grace, this strengthens my speculation that Grace very well may have been a hurricane for a time.

[CrazyC83]

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

If I wrote the best track, here is what I think it should be:

30/1200 - 38.8N / 34.6W - 40 kt - 996mb - Extratropical
30/1800 - 37.4N / 33.1W - 40 kt - 997mb
1/0000 - 36.7N / 31.6W - 40 kt - 996mb - Tropical Storm
1/0600 - 36.9N / 29.8W - 45 kt - 993mb
1/1200 - 37.7N / 29.0W - 60 kt - 986mb
1/1800 - 38.7N / 28.5W - 65 kt - 984mb - Hurricane
2/0000 - 39.5N / 28.8W - 60 kt - 986mb - Tropical Storm
2/0600 - 40.0N / 29.5W - 50 kt - 989mb
2/1200 - 40.2N / 30.0W - 40 kt - 992mb
2/1800 - 41.0N / 30.4W - 40 kt - 993mb
3/0000 - 41.4N / 31.0W - 40 kt - 994mb
3/0600 - 41.4N / 31.8W - 40 kt - 994mb
3/1200 - 40.8N / 32.5W - 40 kt - 993mb
3/1800 - 39.9N / 32.3W - 45 kt - 991mb
4/0000 - 39.1N / 31.3W - 45 kt - 990mb
4/0600 - 38.5N / 29.5W - 50 kt - 988mb
4/1200 - 38.3N / 26.8W - 55 kt - 986mb
4/1800 - 38.8N / 23.9W - 60 kt - 984mb
5/0000 - 40.2N / 21.3W - 60 kt - 984mb
5/0600 - 42.0N / 19.0W - 65 kt - 982mb - Hurricane
5/1200 - 44.3N / 17.2W - 65 kt - 981mb - Peak Intensity
5/1800 - 46.7N / 15.6W - 55 kt - 984mb - Tropical Storm
6/0000 - 48.7N / 14.4W - 50 kt - 986mb
6/0600 - 50.1N / 12.6W - 45 kt - 988mb
6/1200 - 50.7N / 10.8W - 45 kt - 990mb
6/1800 - 51.5N / 7.0W - 40 kt - 994mb
6/2030 - 51.7N / 5.2W - 35 kt - 995mb - Landfall near Marloes, Wales
7/0000 - 52.2N / 2.4W - 30 kt - 998mb - Extratropical
7/0600 - Absorbed into frontal zone

[ozonepete]

Thanks for doing all of that work and showing us what may really have happened! That's not an easy job to track all of that. It looks really right to me. Let's see what the NHC comes up with in the end, but I'm willing to bet they just might agree with you.

[Ptarmigan]

I think CrazyC83 is correct. Grace was a hurricane. So it would be 8/3/2.

[HURAKAN]

Grace moving across England

[HURAKAN]

Final track

[leanne_uk]

thanks hurakan for the above info. Interesting to see the full track and the system passing across the Uk