Tropical Storm Arthur

[Somerset Squall]

We have the first storm of the Atlantic season (cat 5 take note for the comp :lol: ). The remnant moisture from Alma developed into Tropical Storm Arthur and made landfall in Belize earlier today.

TROPICAL STORM ARTHUR SPECIAL DISCUSSION NUMBER 1

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012008

100 PM EDT SAT MAY 31 2008

THE AREA OF LOW PRESSURE LOCATED IN THE NORTHWESTERN CARIBBEAN

BECAME A TROPICAL STORM AS IT WAS CROSSING THE COAST OF BELIZE

EARLY THIS MORNING. THIS IS BASED ON SATELLITE IMAGERY...SHIP DATA

AND A NOAA BUOY 42056 WHICH REPORTED SUSTAINED WINDS OF TROPICAL

STORM FORCE. INITIAL INTENSITY IS SET AT 35 KNOTS BUT BECAUSE

ARTHUR IS ALREADY INLAND..WEAKENING IS ANTICIPATED. THERE IS A

POSSIBILITY THAT ARTHUR REGAIN TROPICAL STORM STATUS IF IT MOVES

BACK OVER WATER IN THE BAY OF CAMPECHE.

BEST ESTIMATE OF THE INITIAL MOTION IS 290/07. ARTHUR IS ALREADY

SOUTH OF A DEVELOPING RIDGE OVER THE GULF OF MEXICO...THEREFORE A

GENERAL WEST-NORTHWEST TO WEST TRACK IS FORECAST. NONE OF THE

AVAILABLE MODEL GUIDANCE BRINGS ARTHUR NORTHWARD AWAY FROM THE BAY

OF CAMPECHE.

THIS SYSTEM IS NOT DESIGNATED TROPICAL STORM ALMA BECAUSE THE

SURFACE CENTER OF ALMA DISSIPATED OVER THE HIGH TERRAIN OF CENTRAL

AMERICA YESTERDAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 31/1700Z 18.1N 88.5W 35 KT

12HR VT 01/0000Z 19.0N 90.0W 30 KT...INLAND

24HR VT 01/1200Z 19.5N 91.0W 30 KT...OVER WATER

36HR VT 02/0000Z 19.5N 93.0W 30 KT

48HR VT 02/1200Z 19.0N 94.0W 35 KT

72HR VT 03/1200Z 19.0N 95.0W 35 KT

96HR VT 04/1200Z 18.5N 96.5W 20 KT...INLAND

120HR VT 05/1200Z...DISSIPATED

$$

FORECASTER AVILA/RHOME

Edited May 31, 2008 by Somerset Squall

[Iceberg]

Well the first named storm and IMO its rather controversial. Phase analysis indicates that it's not realy a true warm core system. GFDL has it initialised as cold core, UKM marginal.

Bouy data is well from the centre and could be more squal related than from a TS centre.

But whether I agree with the classification or not we certainly have the first named storm of the season.

[kold weather]

Forget the phase cahrts Iceberg they are at best only a haslf decent guide, even without any recon its clear its developing via warm cored processes.

Anyway have to admit I was not expecting to see Aurthur quite so soon. Now that its inland weakening should occur unless we see strong convective bursting...believe it or not but systems have actually strenghened overland when they were weak as short term convective bursting can breifly raise the wind maxes as they drag down the strongest winds.

Track continues to take this system off to the WNW/NW into the Yucatan and probably slow weakening should occur.

After that its totally dependant on the exacts of the track. If it takes a slightly more westerly track it will eventually die out over the Mexico, whilst if it takes a more NW route then it will re-ermge into the BoC and that could lead to some pretty rapid re-development as that region is very prone for rapidly developing storms.

Just will have to wait till tomorrow morning to get a better idea of what is happening with Arthur. I have to admit whilst I did think it was looking increasingly impressive before I went to work this morning, it was clearly further along then I had believed.

[Iceberg]

Certainly stands a good chance of developing once back over water.

Phase charts arn't perfect but they are generally pretty accurate.. My take on it looking at the evidence is that there is broad circulation, without a core which has been left from Alma)the LP clearly shows this. There is also alot of instability associated with this system fed by the moisture available.

The core is in the process of forming, but it certainly isn't the driving force and the winds arn't associated with the warm core, but instead are associated with the broad circulation and heavy scrawly precip. It certainly was/is developing and it's a nice way to start the season with a named storm to watch.

[kold weather]

Yep thats true Iceberg is that ther eis a lot of instability being helped by the general area of voricity present in the region which is also helping to develop the system. Its come from the broad region of lower pressure that Alma did but as you say they are clearly two seperate enterties as Alma's LLC died out over land. i do agree with you that it does have a broad circulation and thats probably aiding its sustained efforts overland at the moment along with the higher voricity is helpin to keep thunderstorms flaring up along the circulation. As lon as that keeps going even if it is downgraded to a TD if it can make it back out to sea then it will quickly re-develop again.

I may have been a little harsh on the phase charts they do have their worth but I think at the moment its certainly showing more properties of a warm core then anything else, if it was cold cored at all you'd expect the wind maxima to be well away from any developing system which doesn't appear to be the case here. It may well have a cold core aloft I'm not sure to be honest but from the looks of things the lower level circulation is certainly a warm core.

IF it gets into the BoC watch for quick re-development of the convection and some good strengthening...big IF still of course!

Edited May 31, 2008 by kold weather

[iceageian85]

Im looking to possible development from the wave just of the coast of Africa. With regards to arthur i believe if it does exit into the BoC then we will have a strong T.S or maybe even Cat.1

Edited May 31, 2008 by iceageian85

[Somerset Squall]

Arthur remains a 35kt tropical storm this evening and still looks fairly decent on satellite imagery despite spending around 9 hours over land. The official NHC forecast still indicates slight intensification over the BOC, but it's still a big if whether it actually manages to re-emerge over those waters.

[Cookie]

A bit late but hey

Tropical Storm ARTHUR is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Mexico

probability for TS is 100% currently

Belize

probability for TS is 100% currently

Guatemala

probability for TS is 85% within 9 hours

Yellow Alert City(s) and Town(s)

Cozumel (20.4 N, 87.0 W)

probability for TS is 100% currently

Chetumal (18.5 N, 88.3 W)

probability for TS is 100% currently

Cancun (21.0 N, 87.0 W)

probability for TS is 95% currently

Belize City (17.5 N, 88.2 W)

probability for TS is 95% currently

Belmopan (17.1 N, 88.8 W)

probability for TS is 85% currently

Merida (21.0 N, 89.6 W)

probability for TS is 55% in about 21 hours

Campeche (19.9 N, 90.5 W)

probability for TS is 55% in about 21 hours

Green Alert City(s) and Town(s)

Coatzacoalcos (18.2 N, 94.4 W)

probability for TS is 50% in about 45 hours

Villahermosa (18.0 N, 92.9 W)

probability for TS is 40% in about 33 hours

Veracruz (19.2 N, 96.1 W)

probability for TS is 40% in about 69 hours

THE ATLANTIC LIVES!

[Cookie]

http://www.wunderground.com/tropical/tracking/at200801.html

Storm Alert issued at 1 Jun, 2008 9:00 GMT

Tropical Storm ARTHUR is forecast to strike land to the following likelihood(s) at the given lead time(s):

Yellow Alert Country(s) or Province(s)

Mexico

probability for TS is 100% currently

Belize

probability for TS is 100% currently

Guatemala

probability for TS is 100% currently

Honduras

probability for TS is 80% currently

Yellow Alert City(s) and Town(s)

Chetumal (18.5 N, 88.3 W)

probability for TS is 100% currently

Belize City (17.5 N, 88.2 W)

probability for TS is 100% currently

Belmopan (17.1 N, 88.8 W)

probability for TS is 100% currently

Merida (21.0 N, 89.6 W)

probability for TS is 80% currently

Villahermosa (18.0 N, 92.9 W)

probability for TS is 70% in about 33 hours

San Pedro Sula (15.5 N, 88.0 W)

probability for TS is 65% currently

Coatzacoalcos (18.2 N, 94.4 W)

probability for TS is 60% in about 45 hours

Tuxtla Gutierrez (16.7 N, 93.1 W)

probability for TS is 60% in about 33 hours

Green Alert City(s) and Town(s)

Huehuetenango (15.3 N, 91.5 W)

probability for TS is 40% in about 21 hours

[Somerset Squall]

Arthur has been downgraded to a 30kt tropical depression. The depression is now moving west-southwest and is expected to continue on this track so it's increasingly unlikely that Arthur will emerge into the Bay of Campeche. The NHC say that Arthur may degenerate into a remnant low as early as tonight, as the circulation is now very elongated and increasingly ill defined.

[Cookie]

Taken from metcheck.com

Arthur Rocks On

June 1st and it's start of the Hurricane Season for the North Atlantic. Expected to be an interesting season, we already have Tropical Storm Arthur sitting across the Southern Yucatan Peninsula bringing strong winds and torrential rain. The season runs from June 1st until November 30th and is expected to see an above average season for the named storms. Names we can expect to look forward to this year include Dolly, Nana and Ike. Long term averages show that in an average season we can expect 11 named storms, 6 hurricanes and 2 major hurricanes. The Colorado State University issued their forecast last month and said we can expect 15 named storms, 8 hurricanes and 4 major hurricanes this year.

[Somerset Squall]

Like Alma, Arthur has a couple interesting facts regarding it's formation.

From Wiki:

Arthur is the first tropical storm to form in May since Tropical Storm Arlene in 1981. Other systems have formed (such as Subtropical Storm Andrea in 2007), but they have started out as subtropical. The formation of Arthur also marks the first time that a named storm formed in May for two consecutive years.

[Cookie]

very interesting mate thanks for posting

[Gray-Wolf]

Well that's an interesting start to the season! 2nd of June and one name gone. I'd better get back into my summer routines!