Previsão e Seguimento Furacões (Atlântico 2013)



Afgdr

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28 Set 2011
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Formou-se a 8ª tempestade tropical da temporada no Atlântico. A Tempestade Tropical Humberto deverá fortalecer ainda mais e atingir a categoria de furacão. Neste momento, prevê-se que se desloque para Oeste/Noroeste e depois para Norte, seguindo depois para Noroeste novamente.


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Daniel253

Cirrus
Registo
9 Out 2010
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62
Local
Açores S.Miguel
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TCDAT4

TROPICAL STORM HUMBERTO DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092013
1100 AM AST MON SEP 09 2013

VISIBLE SATELLITE IMAGERY INDICATES THAT HUMBERTO STILL HAS AN
ELONGATED LOW-LEVEL CIRCULATION...WITH THE CENTER NEAR THE EASTERN
EDGE OF THE DEEP CONVECTION. THIS WAS CONFIRMED BY TWO ASCAT
PASSES FROM EARLIER THIS MORNING...BUT THE SCATTEROMETER DATA ALSO
INDICATED THAT MAXIMUM WINDS HAVE INCREASED TO 40 KT. THIS
ESTIMATE IS ALSO SUPPORTED BY AN AVERAGE OF THE DVORAK ESTIMATES
FROM TAFB AND SAB.

HUMBERTO IS LOCATED TO THE SOUTH OF A STRONG AZORES HIGH AND
CONTINUES TO MOVE 280/10 KT. THE TRACK FORECAST THINKING HAS NOT
CHANGED. THE RIDGE IS EXPECTED TO WEAKEN DURING THE NEXT 48
HOURS...GIVING WAY TO TWO CLOSED MID/UPPER-LEVEL LOWS THAT WILL
DEVELOP NORTH OF THE CANARY ISLANDS AND OVER THE CENTRAL ATLANTIC.
THIS PATTERN SHOULD CAUSE HUMBERTO TO TURN SHARPLY NORTHWARD BY DAY
3. AFTER THAT TIME...HIGH PRESSURE AGAIN BUILDS NEAR THE
AZORES...FORCING HUMBERTO TO TURN BACK TO THE WEST-NORTHWEST BY DAY
5. THE GLOBAL MODELS ARE TIGHTLY CLUSTERED THROUGH THE FIRST 48
HOURS BUT THEN DIVERGE WITH THE GFS...FLORIDA STATE
SUPERENSEMBLE...GFDL...AND HWRF INDICATING A SHARPER TURN TOWARD
THE NORTH. THE GUIDANCE SUPPORTS A SLIGHT NORTHEASTWARD SHIFT FROM
THE PREVIOUS FORECAST AT THE LATTER END OF THE FORECAST PERIOD.

THE EAST-NORTHEASTERLY SHEAR AFFECTING HUMBERTO IS EXPECTED TO ABATE
WITHIN THE NEXT 12 HOURS...AND THE THERMODYNAMICS APPEAR
SUFFICIENTLY CONDUCIVE TO SUPPORT ADDITIONAL INTENSIFICATION DURING
THE NEXT 72 HOURS. THE SHIPS AND LGEM MODELS CONTINUE TO SHOW THE
MOST AGGRESSIVE STRENGTHENING
...BUT THAT IS COUNTERED BY THE
HWRF...GFDL...AND FLORIDA STATE SUPERENSEMBLE WHICH EITHER DO NOT OR
JUST BARELY MAKE HUMBERTO A HURRICANE. THE OFFICIAL FORECAST STILL
LIES BETWEEN THESE TWO SCENARIOS AND IS JUST A TAD HIGHER THAN THE
INTENSITY CONSENSUS. THE OFFICIAL FORECAST IS GENERALLY AN UPDATE
OF THE PREVIOUS ONE...AND IS UNCHANGED FROM DAYS 3 THROUGH 5.

FORECAST POSITIONS AND MAX WINDS

INIT 09/1500Z 13.6N 24.1W 40 KT 45 MPH
12H 10/0000Z 13.9N 25.5W 50 KT 60 MPH
24H 10/1200Z 14.5N 27.3W 60 KT 70 MPH
36H 11/0000Z 15.5N 28.5W 70 KT 80 MPH
48H 11/1200Z 17.3N 29.1W 75 KT 85 MPH
72H 12/1200Z 21.5N 30.0W 80 KT 90 MPH
96H 13/1200Z 24.5N 31.0W 70 KT 80 MPH
120H 14/1200Z 26.0N 34.5W 60 KT 70 MPH

$$
FORECASTER BERG/PASCH
 

Afgdr

Cumulonimbus
Registo
28 Set 2011
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Local
Lagoa - São Miguel, Açores
Esta temporada de furacões poderá trazer um novo recorde devido à ausência de formação de furacões, se até quarta-feira, dia 11 de Setembro, não se formar nenhum furacão no Atlântico. Recordo que nesta época de furacões formaram-se apenas 8 tempestades tropicais até ao momento.


Humberto May Defend an Atlantic Hurricane Season Record

By Alex Sosnowski, Expert Senior Meteorologist
September 09, 2013; 5:57 PM


Whether or not the record holds for the latest first Atlantic hurricane is up to Humberto, currently a strengthening tropical storm.
Since the satellite era began during the early 1960s, the latest the first hurricane of the season formed was 2002's Gustav on Sept. 11. Gustav was upgraded from a tropical storm to a minimal hurricane that Wednesday midday, shortly after 8:00 a.m. EDT.
Meanwhile, there have been no hurricanes thus far during the 2013 season in the Atlantic. However, Humberto, near the Cape Verde Islands Monday has a chance at becoming a hurricane during the middle of this week.


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If Humberto strengthens to a hurricane and does so before Wednesday midday, the late-forming hurricane record will remain intact.
According to Hurricane Expert Dan Kottlowski, "During the middle of this week, Humberto will enter an area of the atmosphere with low disruptive winds."
These diminishing winds could be enough to allow the storm to strengthen to a minimal hurricane.


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"Late this week, Humberto is likely to weaken while moving into a a zone with drier air and more disruptive winds," Kottlowski said.
A curve to the northwest and then the north is forecast this week, which will take Humberto over the open waters of the Central Atlantic with no serious direct impact to mainland areas.


According to Senior Meteorologist Kristina Pydynowski, "the greatest impact from Humberto will be on the Cape Verde Islands this week." Locally gusty thunderstorms, downpours and rough surf and seas will affect the islands.
Prior to the satellite era, the 1941 season did not deliver an Atlantic hurricane until Sept. 16.
Farther back, there were two years that had no reports of hurricanes in the Atlantic. These were in 1907 and 1914. While it is possible there were no hurricanes during both seasons, there were only five reported tropical storms in 1907 and only one in 1914. Especially, during the latter season, a number of storms may have gone undetected without the aid of weather satellite photos.
Beyond Humberto, there are no strong candidates for hurricanes through the middle of September. However, there may be another tropical depression or storm over the next week to ten days. Possible tropical depression/storm breeding areas include the western Caribbean, the southwestern Gulf of Mexico and the continued train of disturbances moving westward off of Africa.


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Residents of southern Texas would welcome any reasonable rain, without damaging winds and surf.


The season thus far has treated most populated areas of North America kindly. Sadly, it has claimed lives in Mexico, due to flooding from Tropical Storm Fernand in August.
Late-season storms in some years have been very destructive.
According to Meteorologist Mark Mancuso, "While 2005's Wilma occurred during the most active Atlantic hurricane season on record, it did not come about until the middle of October."

Wilma became the most intense hurricane on record in the Atlantic basin, in terms of low atmospheric pressure. Maximum sustained winds reached 185 mph. Wilma killed dozens of people and caused nearly $30 billion in damage from the Caribbean, to the eastern United States, Canada and later Europe.

While the season thus far has been tame compared to some years, many meteorologists concur that the 2013 Atlantic hurricane season is not over yet and will not sound the "all-clear" until the weather pattern suggests that.
If Humberto fails as a hurricane, the odds suggest there will be more systems to monitor over the next two months. Alerts to such systems will be sounded, when appropriate.
People should consider hurricanes as being just as much of an autumn weather phenomena as well as a summer phenomena. Hurricane season runs from June 1 to Nov. 30.


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Source: Dr. Chris Landsea, NOAA's Hurricane Research Division. Last updated May 10, 2013.


According to the National Oceanic and Atmospheric Administration, since 1851, there have been 645 hurricanes during the months of September, October and November, compared to 568 hurricanes during June, July and August.
"Even if the large high pressure area and its dry air over the central Atlantic was to hold through the remainder of the season, occasional weaknesses in that system can still allow hurricane formation over the next two months," Kottlowski said.

http://www.accuweather.com/en/weather-news/humberto-may-defend-hurricane-record/17586208





2013 Atlantic Hurricane Season Off To A Slow Start, Despite Forecasts

Reuters | Posted: 09/07/2013 8:00 am EDT | Updated: 09/07/2013 11:52 am EDT

By Tom Brown

MIAMI, Sept 7 (Reuters) - The 2013 Atlantic hurricane season, which forecasters had predicted would be more active than normal, has turned out to be something of a dud so far as an unusual calm hangs over the tropics.

As the season heads into the historic peak for activity, it may even enter the record books as marking the quietest start to any Atlantic hurricane season in decades.

"It certainly looks like pretty much of a forecast bust," said Jeff Masters, a hurricane expert and director of meteorology at the Weather Underground (www.wunderground.com).

"Virtually all the (forecast) groups were calling for above-normal hurricanes and intensive hurricanes and we haven't even had a hurricane at all, with the season half over," he said.

With records going back to 1851, Dennis Feltgen, a spokesman for the U.S. National Hurricane Center, said there had been only 17 years when the first Atlantic hurricane formed after Sept. 4.

The all-time record was set in 1905, he said, when the first hurricane materialized on Oct. 8.

In an average season the first hurricane shows up by Aug. 10, usually followed by a second hurricane on Aug. 28 and the first major hurricane by Sept. 4.

Since the dawn of the satellite era in the mid-1960s, Feltgen said the latest date for the first hurricane to arrive was set by Gustav when it made its debut on Sept. 11, 2002.

If this year's first hurricane comes anytime after 8 a.m. EDT (1200 GMT) on Wednesday, it would replace Gustav as the modern-day record holder, Feltgen said.

Seven named storms have been spawned by the 2013 season so far, including Fernand, which killed 13 people in central Mexico late last month.

Most of the storms have been small, weak systems, however, proving an embarrassment to experts who had predicted an active season in reports that are eagerly awaited by the insurance and energy industries as well as many coastal homeowners.

"Statistical models can generally reasonably well replicate hurricane activity ... but there are always going to be years when you bust," said Phil Klotzbach, a Colorado State University climatologist who heads a team that issues one the most closely watched long-range hurricane forecasts.

"We issue our final seasonal forecast in early August. But if we did put out a mid-season update, I would certainly back down from the prediction considerably," he said.

Colorado State University slightly lowered its seasonal forecast on Aug. 2. But it still said 2013 would see above-average activity, with eight hurricanes and three that develop into major hurricanes of Category 3 or higher on the five-step Saffir-Simpson intensity scale.

Other prominent forecasts, including the National Oceanic and Atmospheric Administration (NOAA), were predicting an "above normal" season last month. An average season has six hurricanes.


'A HEAD SCRATCHER'

The jury is still out on what exactly has put such a damper this year over the Atlantic basin and the Caribbean, where tens of millions of people live in hurricane danger zones.

Tuesday marks the statistical "peak day" of the season, which runs from June 1 through Nov. 30, and researchers say significant amounts of dry air and wind shear have helped keep a lid on hurricane formation.

The El Nino weather phenomenon - a warming of the tropical Pacific - which is part of the mix of unstable ingredients that can affect hurricane formation, is also not a factor this year, making the lack of storm activity harder to explain.

"It's certainly a head scratcher," said Masters, who said he thought wind shear had been near normal this year and warmer than average sea temperatures in the Atlantic favored storms.

He noted that dry air, from Africa as well as rarely mentioned flows associated with an extreme drought in northeast Brazil, may be a factor "helping to shut down this year's hurricane season."

Forecasters say a system expected to emerge off the coast of Africa may strengthen into a hurricane by early next week. But whatever happens in the coming days, Feltgen cautioned it was still too early to write off 2013 as a year when tropical weather was unpredictable.

"We are at mid-point of the six-month hurricane season," he said. "It is a mistake to believe that the second half of the season would resemble the first half," he said.

The first hurricane in 2001, Erin, only formed on Sept. 9, Feltgen said. "That season ended with 15 named storms including nine hurricanes, four of which became major hurricanes." (Reporting by Tom Brown; editing by Christopher Wilson)

http://www.huffingtonpost.com/2013/09/07/2013-atlantic-hurricane-season_n_3885392.html
 

Daniel253

Cirrus
Registo
9 Out 2010
Mensagens
62
Local
Açores S.Miguel
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central convection has been on the increase with Humberto during the
last few hours...with a large curved band wrapping around the
cyclone also becoming better defined. The Dvorak estimates at 6z
supported anything from 55-65 kt...and given the notable
strengthening of the central deep convection and overall increase
in organization...the initial winds are raised to 65 kt. Humberto
has about a day to strengthen before an increase in shear and
cooler waters should cause a weakening trend. In a few days...
although water temperatures begin to rise...strong westerly shear
and entrainment of drier air will probably keep the cyclone
gradually weakening. The intensity guidance seems to be well
clustered...so the latest NHC wind speed prediction is close to the
previous forecast and the model consensus.


Humberto appears to be turning to the right...now moving 330/7. The
cyclone should turn to the north soon and accelerate some while it
moves between a ridge over northwestern Africa and a trough over
the central Atlantic Ocean. In a couple of days...Humberto is
likely to take a hard left turn due to it running against a rather
Stout Ridge in the subtropical eastern Atlantic. With Humberto
becoming a more shallow system in the longer range...it makes sense
to stay on the southern side of the guidance envelope given the
strong low-level ridge forecast. The latest NHC forecast is
basically an update of the previous one...staying equatorward of
the model consensus in the medium range.




Forecast positions and Max winds


init 11/0900z 16.0n 28.9w 65 kt 75 mph
12h 11/1800z 17.2n 29.2w 70 kt 80 mph
24h 12/0600z 19.0n 29.3w 75 kt 85 mph
36h 12/1800z 20.9n 29.6w 70 kt 80 mph
48h 13/0600z 22.5n 30.3w 65 kt 75 mph
72h 14/0600z 23.8n 33.9w 50 kt 60 mph
96h 15/0600z 24.2n 39.1w 45 kt 50 mph
120h 16/0600z 25.5n 44.0w 40 kt 45 mph


$$
forecaster Blake
 

Afgdr

Cumulonimbus
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28 Set 2011
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Lagoa - São Miguel, Açores
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Está a ser vigiado um novo sistema, o Invest 95L.



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1. AN AREA OF LOW PRESSURE CENTERED NEAR CHETUMAL MEXICO IS ACCOMPANIED
BY CLOUDINESS AND THUNDERSTORMS. ENVIRONMENTAL CONDITIONS ARE
LIKELY TO BE CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM OVER THE
BAY OF CAMPECHE DURING THE NEXT COUPLE OF DAYS AFTER THE LOW MOVES
INTO THE REGION ON WEDNESDAY. THIS SYSTEM HAS A HIGH CHANCE...60
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
CONDITIONS SHOULD CONTINUE TO BE CONDUCIVE FOR ADDITIONAL
DEVELOPMENT DURING THE NEXT SEVERAL DAYS WHILE THE DISTURBANCE
MOVES SLOWLY ACROSS THE SOUTHWESTERN GULF OF MEXICO. THIS SYSTEM
HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE
DURING THE NEXT 5 DAYS. REGARDLESS OF TROPICAL CYCLONE
FORMATION...THIS DISTURBANCE WILL LIKELY SPREAD HEAVY RAINS OVER
EASTERN MEXICO. THESE RAINS COULD CAUSE LIFE-THREATENING FLOODS AND
MUDSLIDES OVER AREAS ALREADY IMPACTED BY THE TORRENTIAL RAINS
ASSOCIATED WITH INGRID AND MANUEL.
 

Kamikaze

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14 Mai 2012
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Angra do Heroísmo - Terceira - Açores
Entretanto, neste preciso momento...

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O seguinte parece ser para seguir com atenção devido à sua rota:

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2. DISORGANIZED CLOUDINESS AND SHOWERS LOCATED ABOUT MIDWAY BETWEEN THE
BAHAMAS AND BERMUDA ARE ASSOCIATED WITH A TROUGH OF LOW PRESSURE.
ALTHOUGH UPPER-LEVEL WINDS DO NOT APPEAR CONDUCIVE FOR SIGNIFICANT
TROPICAL DEVELOPMENT...AN AREA OF LOW PRESSURE IS FORECAST TO FORM
IN THIS AREA DURING THE NEXT COUPLE OF DAYS. THIS SYSTEM COULD
ACQUIRE SOME SUBTROPICAL CHARACTERISTICS WHILE IT MOVES GENERALLY
NORTHEASTWARD OVER THE WESTERN ATLANTIC THROUGH EARLY NEXT WEEK.
THIS SYSTEM HAS A LOW CHANCE...20 PERCENT...OF BECOMING A
SUBTROPICAL CYCLONE DURING THE NEXT 48 HOURS AND A LOW CHANCE...20
PERCENT...OF BECOMING A SUBTROPICAL CYCLONE DURING THE NEXT 5 DAYS.

Cumps,
 

Afgdr

Cumulonimbus
Registo
28 Set 2011
Mensagens
2,129
Local
Lagoa - São Miguel, Açores
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Está sob vigilância uma área de baixas pressões, o Invest 96L.




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1. A SMALL LOW PRESSURE SYSTEM LOCATED ABOUT 850 MILES EAST-NORTHEAST
OF THE NORTHERN LEEWARD ISLANDS IS PRODUCING WINDS TO NEAR GALE
FORCE. HOWEVER...THE ASSOCIATED SHOWERS AND THUNDERSTORMS REMAIN
DISPLACED TO THE NORTHEAST OF THE CENTER OF THE LOW. UPPER-LEVEL
WINDS COULD BECOME MORE CONDUCIVE FOR DEVELOPMENT OVER THE NEXT
COUPLE OF DAYS WHILE THE LOW MOVES NORTHWARD AND THEN NORTHEASTWARD
AT 10 TO 15 MPH...AND THIS SYSTEM HAS A MEDIUM CHANCE...40
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
AFTER THAT TIME...ENVIRONMENTAL CONDITIONS APPEAR MARGINALLY
CONDUCIVE FOR DEVELOPMENT...AND THE SYSTEM HAS A MEDIUM CHANCE...50
PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 5 DAYS.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE.




Alguns modelos indicam a sua possível aproximação aos Açores.


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Daniel253

Cirrus
Registo
9 Out 2010
Mensagens
62
Local
Açores S.Miguel
TROPICAL STORM JERRY

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TCDAT1

TROPICAL STORM JERRY DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112013
1100 AM AST MON SEP 30 2013

DEEP CONVECTION HAS BECOME MORE PERSISTENT...AND VISIBLE SATELLITE
IMAGES INDICATE THAT THE LOW-LEVEL CENTER IS NEAR THE WESTERN EDGE
OF THE MAIN AREA OF CONVECTION. DVORAK INTENSITY ESTIMATES FROM
TAFB AND SAB ARE BOTH 35 KT...AND THE CYCLONE IS BEING UPGRADED TO
A TROPICAL STORM ON THIS ADVISORY. WATER VAPOR IMAGERY SHOWS
DIFFLUENT UPPER-LEVEL FLOW OVER THE AREA...HOWEVER THE DYNAMICAL
GUIDANCE INDICATES THAT WESTERLY TO NORTHWESTERLY VERTICAL SHEAR
SHOULD CONTINUE TO AFFECT THE STORM FOR THE NEXT SEVERAL DAYS. AT
THIS TIME...THE ENVIRONMENT IS NOT EXPECTED TO BE HOSTILE ENOUGH TO
PREVENT AT LEAST A LITTLE STRENGTHENING DURING THE NEXT DAY OR SO.
IN THE LATTER PART OF THE FORECAST PERIOD...THERE IS QUITE A BIT OF
SPREAD IN THE NUMERICAL INTENSITY GUIDANCE...AND THEREFORE THE WIND
SPEED FORECAST FOR THAT TIME IS OF LOW CONFIDENCE.

CENTER FIXES FROM VISIBLE SATELLITE IMAGES INDICATE THAT THE STORM
HAS MOVED A LITTLE MORE TO THE EAST THAN EARLIER ESTIMATED...AND
THE INITIAL MOTION IS NEAR 090/6. THE DYNAMICAL MODELS CONTINUE TO
PREDICT AN AMPLIFYING MID-TROPOSPHERIC RIDGE TO THE NORTHWEST AND
NORTH OF JERRY OVER THE NEXT SEVERAL DAYS. THIS STEERING SCENARIO
SHOULD RESULT IN THE STORM DECELERATING AND MOVING IN A CLOCKWISE
LOOP DURING THE NEXT 48-72 HOURS...AS SHOWN IN THE OFFICIAL TRACK
FORECAST. IN THE LATTER PART OF THE PERIOD...THE GLOBAL MODELS ARE
SUGGESTING THAT JERRY MAY NOT GET PICKED UP BY THE NEXT TROUGH IN
THE WESTERLIES...AND THIS IS ALSO REFLECTED IN THE CURRENT OFFICIAL
FORECAST.

FORECAST POSITIONS AND MAX WINDS

INIT 30/1500Z 27.0N 45.7W 35 KT 40 MPH
12H 01/0000Z 26.6N 45.5W 35 KT 40 MPH
24H 01/1200Z 26.3N 45.5W 40 KT 45 MPH
36H 02/0000Z 26.2N 46.5W 40 KT 45 MPH
48H 02/1200Z 26.3N 47.9W 40 KT 45 MPH
72H 03/1200Z 27.3N 49.8W 40 KT 45 MPH
96H 04/1200Z 28.5N 49.0W 35 KT 40 MPH
120H 05/1200Z 30.5N 46.0W 35 KT 40 MPH

$$
FORECASTER PASCH