ATL : TROPICAL STORM GRACE

[HURAKAN]

01/1745 UTC 38.5N 28.4W ST3.5 90L -- Atlantic

[brunota2003]

Notice the wind gusts at that station were 50 mph, yet it came to a dead calm - signs of a well-defined eye. I've never heard of a TD/STD over water with a pressure of 985mb either.

I think there's an error. If you look at the actual station data, you see that the wind gust was 49 KPH, not mph. That's about 30-31 mph.

http://www.wunderground.com/history/sta ... story.html

I believe he is referring to this station:
http://www.wunderground.com/weatherstat ... =IAZORESH4

[wxman57]

Notice the wind gusts at that station were 50 mph, yet it came to a dead calm - signs of a well-defined eye. I've never heard of a TD/STD over water with a pressure of 985mb either.

But also notice, the temperature peaked at 4 pm and has been falling since, as the pressure continues to fall (now 6 pm). Clearly cold cored.

And as may have been missed above, that gust was 49 kilometers per hour (31 mph), not 50 mph.

[brunota2003]

Notice the wind gusts at that station were 50 mph, yet it came to a dead calm - signs of a well-defined eye. I've never heard of a TD/STD over water with a pressure of 985mb either.

But also notice, the temperature peaked at 4 pm and has been falling since, as the pressure continues to fall (now 6 pm). Clearly cold cored.

And as may have been missed above, that gust was 49 kilometers per hour (31 mph), not 50 mph.

http://www.wunderground.com/weatherstat ... =IAZORESH4

And that one shows 50 mph, along with a clearly falling temperature. That link is posted on page 1.

[wxman57]

The link posted was to station 08506:
http://www.wunderground.com/global/stations/08506.html

The data clearly show that the Azores stations are reporting in Km/h (kph) not mph.
http://www.wunderground.com/history/sta ... story.html

That other station mentioned may have an "issue", as it's reporting sustained wind of 5-10 mph with a gust to 49 mph??
http://www.wunderground.com/weatherstat ... =IAZORESH4

Something's fishy there.

[brunota2003]

True, unless the station is sheltered. Then it would be possible that a freak gust got the anemometer, but the gusts have clearly been increasing.

[wxman57]

Well, I hope they don't waste a name on this. I'd like to see the season end with 6 named storms. Besides, our receptionist picked the least number of named storms for our hurricane pool (9). She stands to win $100 if there are fewer than 10 named storms (my pick). I'm hoping she wins, as she can use the money.

[jconsor]

Looks like this is a classic warm seclusion to me, although some might argue it is marginally subtropical. See http://ams.confex.com/ams/27Hurricanes/ ... 108776.htm

Cyclone phase diagrams from the GFS and NOGAPS show a system that is on the borderline between warm and cold core, although any warm core is shallow: http://moe.met.fsu.edu/cyclonephase/

[wxman57]

Looks like this is a classic warm seclusion to me, although some might argue it is marginally subtropical. See http://ams.confex.com/ams/27Hurricanes/ ... 108776.htm

Cyclone phase diagrams from the GFS and NOGAPS show a system that is on the borderline between warm and cold core, although any warm core is shallow: http://moe.met.fsu.edu/cyclonephase/

Sounds like such a system. I attended that AMS conference in Monterey, CA in 2006. Don't remember much of it, as I'd just been in a major car wreck 2 weeks before and was VERY sore. I'll be at the 29th AMS conference on hurricanes and tropical meteorology next May in Tucson.

[DanieleItalyRm]

E' da ieri che la ciclogenesi a cuore freddo sulle Azzorre sta acquisendo caratteristiche tropicali.
E' evidente che il suo cuore, seppur ancora freddo per le carte a 500 hpa sia invece gia' caldo. E' il tipico esempio in cui una semplice carta non ha senzo, dato che basta un occhio minimamente esperto per osservare in questa ciclogenesi un sistema tropicale in formazione, sia se verra' notato o meno dall' NHC.
Da notare che siamo ancora una volta alle stessa latitudini del Mediterraneo, e su un mare ancor piu' freddo.
Da ex ciclogenesi fredde hanno avuto del resto origine anche cicloni tropicali come Vince, Karl, Charley, ed altri e quasi tutte le piu' famose ciclogenesi tropicali Mediterranee dette TLC o Medicanes. Da notare come questa "seconda opzione" per ottenere cicloni tropicali produca quasi sempre cicloni di piccole dimensioni.
La circolazione è perfettamente chiusa, i venti di 40 knots (le raffiche superano sicuramente i 50 knots) - Tropical Storm intensity.

[CrazyC83]

AL, 90, 2009100118, , BEST, 0, 386N, 285W, 45, 984, EX, 34, NEQ, 30, 40, 40, 30, 1008, 350, 0, 0, 0, L, 0, , 0, 0, INVEST, D,

[breeze]

Google translation of DanieleItalyRm's post:

E 'from yesterday that ciclogenesi a cold heart on the Azores is acquiring tropical characteristics.
It 'obvious that his heart, though still cold for the cards at 500 hPa is already rather' hot. It 'a typical example where a simple card does not have without it, just as an eye specialist to observe at least this ciclogenesi a tropical system in training, whether they will' notice or less from the 'NHC.
Note that we are once again the same latitude as the Mediterranean, a sea even more 'cool.
As a former ciclogenesi cold had indeed originally tropical cyclones also like Vince, Karl, Charley, and others, and almost all the most 'famous ciclogenesi Mediterranean tropical cyclone or TLC said. Note how this "second option" for tropical cyclones producing cyclones almost always small.
The movement is fully closed, winds of 40 knots (gusts exceed 50 knots surely) - Tropical Storm intensity.

[DanieleItalyRm]

Many Thanks..

[littlevince]

As wxman57 said before, wind observations are not expressive.
But pressure is surprising although it has risen 2mb in the last hour in Faial.

A map to put thinks in context:
Also note that Pico Island is a big mountain, 2351 m high




Faial

Wind (km/h)


Pressure:


Rain (mm/h)


Webcam:
http://www.gisclimaat.angra.uac.pt/weat ... _small.jpg




Pico

Wind (km/h)


Rain (mm)



Pressure
Not available

Webcam
http://www.climaat.angra.uac.pt/WebCams/index14.htm
http://www.climaat.angra.uac.pt/WebCams/index6.htm


Terceira

Wind (km/h)


Webcam:
http://www.climaat.angra.uac.pt/WebCams/index1.htm
http://www.climaat.angra.uac.pt/WebCams/index12.htm

Terceira (US Lajes Airfield)

[wxman57]

Similar origin to the "Unnamed Hurricane of 1991" that formed from the core of the Perfect Storm:

[HURAKAN]

Latest

[pepeavilenho]

as we say in spain...
la hostia!!!

[DanieleItalyRm]

The NHC will never give a name to this storm, gust like they did with other storm over the Nord est Atlantic.
If it occured over the nord owest atlantic it would already have a name.

90L is similiar to all Unnamed tropical cyclones over the North east Atlantic /owest Spain:

unnamed 92L Jun.2009 50 knots



unnamed Sept. 2008 50 knots



unamed Jun. 2009 30 knots



unnamed Nov.2004 45 knots



90 L INVEST 45 KNOTS 984 HPA

[littlevince]

The NHC will never give a name to this storm, gust like they did with other storm over the Nord est Atlantic.
If it occured over the nord owest atlantic it would already have a name.

I understand your point of view, for me this is some kind of a tropical system too. And there are plenty of interesting storms in the Atlantic and Mediterranean. A whole "new" kind of hybrid systems with no precise boundaries to define their nature. And in this age of "satellite era" and all this massive weather enthusiast observers as we all are, these cases come up more and more.

Anyway, even in this case, where we have an unusual pressure drop (in contrast to what happened on other occasions) for me it doesn't make much sense to name it as a tropical system. The Azores at this moment is quiet, a few thunderstorms and some rain, but little more than that. Tropical cyclones for me are serious and potentiality dangerous systems where exist along a time frame conditions to intensify and generate a dangerous situation. I don't think that this is the case, and so, don't think that this reserve a name.

That does not mean that there is necessary a careful monitoring for these situations, in the past history there are some extra-tropical cyclones in this location that at some time probably acquired some tropical or subtropical characteristics in a much frightening form, such as the 1997 storm in Azores that killed 20 people or for example the Madeira system in 1993 with 8 deaths. Last century there were many more storms like these.

But I think that today is not the case with 90L, and for my humble opinion, the trivialization use of system naming can be harmful in the future.


PS:Sorry for my bad english. I'm not a english native speaker.

[brunota2003]

This storm does not have any deep convection near the center. Even Vince's convection was deeper than this system.