Previsão e Seguimento Furacões (Atlântico 2009)

[Vince]

A depressão tropical nº2 foi considerada pelo NHC como mera baixa em superfície, e foi emitido o ultimo aviso oficial, ficando contudo sob vigilância para um eventual renascimento:

WHILE PERSISTING OVER THE PAST SEVERAL HOURS...THE AREA OF
CONVECTION JUST WEST OF THE CENTER OF TROPICAL DEPRESSION TWO IS
TOO SMALL TO BE CLASSIFIED USING THE DVORAK TECHNIQUE. INDEED...IT
HAS BEEN ALMOST 24 HR SINCE ENOUGH ORGANIZED CONVECTION EXISTED TO
GET A DATA-T NUMBER. BASED ON THIS...THE DEPRESSION HAS DECAYED
INTO A REMNANT LOW PRESSURE AREA. IT IS LIKELY THAT THE SYSTEM
WILL CONTINUE TO PRODUCE BURSTS OF CONVECTION FOR THE NEXT SEVERAL
DAYS...AND A FASTER FORWARD MOTION IS EXPECTED BY THE END OF THE
FORECAST PERIOD. THIS IS THE BASIS FOR KEEPING A 25 KT INTENSITY
FOR THE REMNANTS THROUGH 120 HR. SEVERAL OF THE INTENSITY FORECAST
MODELS CONTINUE TO FORECAST STRENGTHENING...SO IF THE SYSTEM FINDS
A MORE FAVORABLE ENVIRONMENT IT COULD REGENERATE.

As atenções estão todas viradas para a Onda tropical a sul de Cabo Verde, agora cunhada como Invest 90L, que apresenta já forte circulação. Nível de alerta do NHC passou a vermelho, ou seja forte probabilidade (>50%) de formação de ciclone tropical nos próximos 2 dias. A perturbação continua a ser prevista em muitos modelos como podendo evoluir para furacão, contundo variando bastante o seu trajecto, o que é normal dada a incerteza de muitos dias de previsão.

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH THE BROAD LOW PRESSURE
AREA AND TROPICAL WAVE CENTERED ABOUT 250 MILES SOUTH OF THE CAPE
VERDE ISLANDS ARE SLOWLY BECOMING BETTER ORGANIZED. A TROPICAL
DEPRESSION COULD FORM FROM THIS SYSTEM DURING THE NEXT COUPLE OF
DAYS AS IT MOVES WESTWARD AT 10 TO 15 MPH. THERE IS A HIGH
CHANCE...GREATER THAN 50 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

http://www.nhc.noaa.gov/gtwo_atl.shtml

Animação visível (12-19z):

 

[Redfish]

Parece que será daqui a surgir o primeiro Furacão da temporada.
Vamos aguardar as proximas saidas

 

[Vince]

A perturbação 90L continua a evoluir lentamente. As primeiras imagens visível mostram convecção mais forte.
Tem ainda algum trabalho para fazer, existe alguma circulação mas demasiado assimétrica e alargada.

 

[Rog]

Situação actual no Atlântico:

1. (TD2) SHOWER ACTIVITY HAS DECREASED OVER THE PAST SEVERAL HOURS IN
ASSOCIATION WITH THE REMNANT LOW OF FORMER TROPICAL DEPRESSION
TWO...LOCATED ABOUT 1300 MILES EAST OF THE LESSER ANTILLES. WHILE
UPPER-LEVEL CONDITIONS ARE ONLY MARGINALLY FAVORABLE FOR
DEVELOPMENT...SLOW REGENERATION OF THIS SYSTEM INTO A TROPICAL
CYCLONE IS POSSIBLE AS IT MOVES WESTWARD AT 10 TO 15 MPH OVER THE
NEXT COUPLE OF DAYS. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...
OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT
48 HOURS.

2. (90L) SHOWER AND THUNDERSTORM ACTIVITY IS GRADUALLY BECOMING BETTER
ORGANIZED IN ASSOCIATION WITH A BROAD AREA OF LOW PRESSURE CENTERED
ABOUT 200 MILES SOUTH-SOUTHWEST OF THE SOUTHERN CAPE VERDE ISLANDS.
CONDITIONS APPEAR FAVORABLE FOR FURTHER DEVELOPMENT OF THIS
SYSTEM...AND A TROPICAL DEPRESSION COULD FORM DURING THE NEXT DAY
OR TWO AS IT MOVES WESTWARD AT 10 TO 15 MPH. THERE IS A HIGH
CHANCE...GREATER THAN 50 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

3. A TROPICAL WAVE INTERACTING WITH AN UPPER-LEVEL LOW IS PRODUCING A
LARGE AREA OF CLOUDINESS AND SHOWERS OVER HISPANIOLA...AND THE
SOUTHEASTERN BAHAMAS. THIS ACTIVITY IS EXPECTED TO SPREAD SLOWLY
WEST OR WEST-NORTHWESTWARD DURING THE NEXT COUPLE OF DAYS. THERE
ARE NO SIGNS OF ORGANIZATION AND UPPER-LEVEL WINDS ARE NOT
FAVORABLE FOR SIGNIFICANT DEVELOPMENT OF THIS SYSTEM. THERE IS A
LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

TD2



90L

 

[S.Miguel-Azores]

Tudo indica que uma actividade depressionária a sudoeste de Cabo Verde está a ganhar força e desenvolvimento ainda que mal organizada. A ver vamos! Quem sabe não será o primeiro grande Furacão da temporada!?
Além desse sistema depressionário existe um outro a meio Atlântico que também parece estar a dar indícios e sinais de desenvolvimento estando associado a uma zona de forte instabilidade tropical.

Vamos lá ver se até Novembro os Açores serão presenteados (ou não), pela passagem desses mesmos sistemas

 

[Vince]

ex-DT#2

No Atlântico a ex-Depressão Tropical nº2 recompôs-se e provavelmente serão retomados os avisos e previsões do NHC em breve. Estou até surpeendido ainda não o terem feito pois o sistema está com bom aspecto. A maioria dos modelos não o desenvolve muito mais, mas veremos se assim será.

90L

Mais a leste a perturbação 90L continua lentamente a evoluir sendo notória alguma dificuldade com o windshear de S/SE como é facilmente perceptível nas imagens com a convecção a ser remetida para oeste do centro, afinal o mesmo windshear que quase ia destruindo o DT#2. Uma circulação talvez demasiado alargada também tem contribuído para que esta não esteja ainda perfeitamente fechada.

Os modelos continuam a prever um grande furacão a partir daqui, variando a trajectória. O GFS por exemplo traça um trajecto rumo ao NE das Caraibas, o ECM fa-lo curvar para norte antes das Caraíbas pois prevê o enfraquecimento do Anticiclone dos Açores a Oeste. Vale sempre a pena repetir, modelos a tantos dias estão sujeitos a enormes erros, e para já não temos o ciclone sequer formado, embora penso que não deva demorar muito mais. Mas é também possível que enfrente dificuldades com o shear tal como a DT2 enfrentou.


GFS 12z 144 horas
NE Caraíbas

ECM 12z 144 horas
Curva para norte antes das Caraíbas

 

[Vince]

No Atlântico a 1500km a Oeste das Caraíbas a Depressão Tropical nº2 após uns dias meio moribunda evoluiu para Tempestade Tropical «Ana», tornando-se finalmente o primeiro sistema nomeado esta época tropical no Atlântico.

O seguimento da «Ana» passa a ser feito em tópico dedicado:
Tempestade Tropical ANA (Atlântico 2009 #1)

 

[Rog]

Formou-se no Atlântico a Depressão Tropical n.º 3.

...TROPICAL DEPRESSION THREE FORMS IN THE EASTERN ATLANTIC...

AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL DEPRESSION THREE
WAS LOCATED NEAR LATITUDE 11.5 NORTH...LONGITUDE 34.0 WEST OR ABOUT
740 MILES...1190 KM...WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS.

THE DEPRESSION IS MOVING TOWARD THE WEST NEAR 17 MPH...27 KM/HR...
AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE
OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. SLOW STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...
AND THE DEPRESSION IS EXPECTED TO BECOME A TROPICAL STORM LATER
TODAY OR ON SUNDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

...SUMMARY OF 1100 AM AST INFORMATION...
LOCATION...11.5N 34.0W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...WEST OR 265 DEGREES AT 17 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

 

[Vince]

Não há fome que não dê em fartura, no mesmo dia em que foi nomeada a «Ana», a depressão tropical #03 acabou de ser considerada Tempestade Tropical «Bill». Está previsto que Bill evolua para Furacão daqui a 3 ou 4 dias.

O seguimento do «Bill» passa a ser feito em tópico dedicado:
Tempestade Tropical BILL (Atlântico 2009 #2)

 

[Vince]

Continua agitado o dia, decretado um novo Invest, 91L, no Golfo do México. Uma perturbação associada a uma onda tropical parenta alguma circulação nos níveis médios, a probabilidade de ciclogenese tropical para já baixa segundo o NHC, mas o Golfo do México é bem conhecido pela rapidez com que tudo se precipita.

A LARGE AREA OF CLOUDINESS AND THUNDERSTORMS OVER THE SOUTHEASTERN
GULF OF MEXICO IS PRIMARILY ASSOCIATED WITH A TROPICAL WAVE
INTERACTING WITH A MID- TO UPPER-LEVEL TROUGH. THIS ACTIVITY HAS
BECOME A LITTLE MORE CONCENTRATED OVER THE SOUTHEASTERN GULF OF
MEXICO WHERE SURFACE PRESSURES ARE BEGINNING TO FALL. THERE ARE NO
SIGNS OF A SURFACE CIRCULATION AT THIS TIME AND ANY ADDITIONAL
DEVELOPMENT...IF ANY...SHOULD BE SLOW TO OCCUR. THIS SYSTEM SHOULD
MOVES TOWARD THE NORTHWEST OVER THE EASTERN GULF OF MEXICO ON
SUNDAY. THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
http://www.nhc.noaa.gov/gtwo_atl.shtml

 

[Vince]

No golfo do México formou-se uma depressão tropical, a nº4 desta temporada.
O sistema é saudável mas pequeno e compacto, é provável que se intensifique para Tempestade Tropical mas não deverá ter tempo para se desenvolver muito mais do que isso antes de entrar em Terra.

TROPICAL DEPRESSION FOUR ADVISORY NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042009
500 AM EDT SUN AUG 16 2009

...TROPICAL STORM WARNING ISSUED FOR NEW DEPRESSION IN THE EASTERN
GULF OF MEXICO...

AT 5 AM EDT...0900 UTC...A TROPICAL STORM WARNING HAS BEEN ISSUED
FROM THE ALABAMA/FLORIDA BORDER EASTWARD TO THE SUWANNEE RIVER
FLORIDA. A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM
CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 24
HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA PLEASE MONITOR PRODUCTS
ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.

AT 500 AM EDT...0900 UTC...THE CENTER OF TROPICAL DEPRESSION FOUR
WAS LOCATED NEAR LATITUDE 27.7 NORTH...LONGITUDE 83.9 WEST OR ABOUT
90 MILES...140 KM...WEST-SOUTHWEST OF TAMPA FLORIDA AND ABOUT 155
MILES...245 KM...SOUTH-SOUTHEAST OF APALACHICOLA FLORIDA.

THE DEPRESSION IS MOVING TOWARD THE NORTH-NORTHWEST NEAR 16
MPH...AND THIS MOTION IS EXPECTED TO CONTINUE TODAY. ON THE
FORECAST TRACK...THE CENTER OF THE DEPRESSION SHOULD BE VERY NEAR
THE NORTHERN GULF COAST OF FLORIDA BY LATE THIS AFTERNOON.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. STRENGTHENING IS EXPECTED AND THE DEPRESSION IS FORECAST TO
BECOME A TROPICAL STORM PRIOR TO REACHING THE COASTLINE.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1011 MB...29.85 INCHES.

RAINFALL ACCUMULATIONS OF 3 TO 5 INCHES...WITH ISOLATED MAXIMUM
AMOUNTS OF 10 INCHES ACROSS PORTIONS OF NORTH FLORIDA NEAR THE PATH
OF THE CENTER.

COASTAL STORM SURGE FLOODING OF 3 TO 5 FEET ABOVE NORMAL TIDE
LEVELS CAN BE EXPECTED NEAR AND TO THE EAST OF WHERE THE CENTER
MAKES LANDFALL.

...SUMMARY OF 500 AM EDT INFORMATION...
LOCATION...27.7N 83.9W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTH-NORTHWEST OR 330 DEGREES AT 16 MPH
MINIMUM CENTRAL PRESSURE...1011 MB

O seguimento das duas Tempestades Tropicais está a ser feito em tópico próprio:

Tempestade Tropical ANA (Atlântico 2009 #1)
Tempestade Tropical BILL (Atlântico 2009 #2)

 

[MSantos]

Formou-se a 3ªTempestade da Temporada
Tantos meses sem actividade e de repente temos 3 sistemas activos

Este sistema deverá atingir a costa da Florida na categoria de Tempestade Tropical

000
WTNT64 KNHC 161616
TCUAT4
TROPICAL STORM CLAUDETTE TROPICAL CYCLONE UPDATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042009
1215 PM EDT SUN AUG 16 2009

CORRECTED FOR ISSUANCE TIME

...DEPRESSION BECOMES TROPICAL STORM CLAUDETTE...

DATA FROM THE NOAA DOPPLER RADAR IN TALLAHASSEE FLORIDA INDICATE
THAT SURFACE WINDS ASSOCIATED WITH THE DEPRESSION HAVE INCREASED TO
40 MPH...65 KM/HR...MAKING THE DEPRESSION TROPICAL STORM CLAUDETTE.
DETAILS WILL FOLLOW IN THE 2 PM EDT INTERMEDIATE ADVISORY.

$$
FORECASTER ROBERTS/BRENNAN

Tempestade Tropical CLAUDETTE (Atlântico 2009 #3)

 

[stormy]

Atlantic Graphical Tropical Weather Outlook

This product is updated at approximately 2 AM, 8 AM, 2 PM, and 8 PM EDT from June 1 to November 30. Special outlooks may be issued as conditions warrant.
Place your mouse cursor over areas of interest for more information Archived Outlooks




ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED AUG 26 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. SATELLITE IMAGERY INDICATES THAT THE AREA OF DISTURBED WEATHER
CENTERED ABOUT 470 MILES EAST OF NASSAU IN THE BAHAMAS IS
DEVELOPING A WELL-DEFINED CIRCULATION. THE SYSTEM COULD DEVELOP
INTO A TROPICAL DEPRESSION...OR MORE LIKELY A TROPICAL STORM...AT
ANY TIME AS IT MOVES WEST-NORTHWESTWARD AT ABOUT 15 MPH...AND IF
CURRENT TRENDS CONTINUE ADVISORIES WILL BE INITIATED LATER TODAY.
THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL
CYCLONE FORMATION DURING THE NEXT 48 HOURS. INTERESTS IN THE
BAHAMAS SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. A NOAA
HURRICANE HUNTER AIRCRAFT IS CURRENTLY ENROUTE TO INVESTIGATE THIS
SYSTEM.

ADDITIONAL INFORMATION ON MARINE WARNINGS ASSOCIATED WITH THIS
SYSTEM CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL
WEATHER SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER
FZNT01 KWBC.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN

 

[Vince]

No Atlântico a leste das Bahamas formou-se a Tempestade Tropical DANNY a partir da perturbação 92L. Passa a tópico dedicado:

Tempestade Tropical DANNY (Atlântico 2009 #4)

 

[Vince]

A sudeste de Cabo Verde mais uma onda tropical que nas últimas horas apresenta alguns sinais de desenvolvimento. Já tem cor amarela no NHC mas ainda não é um Invest.

A TROPICAL WAVE LOCATED JUST SOUTHEAST OF THE CAPE VERDE ISLANDS
OVER THE FAR EASTERN ATLANTIC IS PRODUCING AN AREA OF DISORGANIZED
SHOWERS AND THUNDERSTORMS. CONDITIONS APPEAR FAVORABLE FOR SOME
SLOW DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS.
THERE IS A LOW CHANCE...LESS THAN 30 PERCENT...OF THIS SYSTEM
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.