Saturday, August 11, 2018

TROPICAL UPDATE AUG 11, 2018... 0713 PM EDT

National Hurricane Center
925 
AXNT20 KNHC 111720
TWDAT 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
120 PM EDT Sat Aug 11 2018

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through 
1700 UTC.

...SPECIAL FEATURE...

GALE-FORCE WINDS NEAR THE COAST OF COLOMBIA AND IN THE GULF OF
VENEZUELA...

The 12-hour forecast, meaning on Saturday night, consists of 
frequent gusts to GALE-FORCE, near the coast of Colombia and in 
the Gulf of Venezuela. Expect NE to E winds 20 to 30 knots, from 
11N to 13N between 70W and 76W. Sea heights will range from 9 feet
to 12 feet. The 36-hour forecast, meaning on Sunday night,
consists of GALE-FORCE NE winds within 90 nm of the coast of
Colombia, and frequent gusts to GALE-FORCE winds in the Gulf of
Venezuela. The sea heights are forecast to range from 9 feet to 13
feet. Please read the High Seas Forecast, that is listed under the
WMO/AFOS headers, as FZNT02 KNHC/MIAHSFAT2, for more details.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 34W/35W from 21N
southward. Widely scattered moderate to isolated strong
rainshowers are from 10N to 16N between 30W and 40W. It is easily
possible that some of this precipitation also is related to the
monsoon trough.

An Atlantic Ocean tropical wave is along 44W/45W from 21N
southward. Widely scattered moderate to isolated strong
rainshowers are from 09N to 12N between 40W and 43W. It is easily
possible that some of this precipitation also is related to the
monsoon trough.

A Caribbean Sea tropical wave is along 62W/63W from 21N southward.
Widely scattered moderate to isolated strong rainshowers are from
18N to 23N between 60W and 65W. Isolated moderate rainshowers are
elsewhere in the Caribbean Sea between 60W and 67W.

...MONSOON TROUGH/ITCZ...

The monsoon trough passes through the coastal sections of
Mauritania near 19N16W, to 13N30W, and 08N46W. The ITCZ continues
from 08N46W to 04N50W. Precipitation: broken to overcast
multilayered clouds and isolated moderate rainshowers are
elsewhere, away from the precipitation that is attributed to the
tropical waves, from 18N16W 16N33W 12N60W southward. 

...DISCUSSION...

GULF OF MEXICO...

An upper level cyclonic circulation center is near 24N87W. Upper
level cyclonic wind flow covers the Gulf of Mexico from 90W
eastward. Isolated moderate rainshowers are to the east of the
line that runs from SE Louisiana to the Florida Keys, and from
26N northward from 90W westward.

A surface trough is in the SW corner of the Gulf of Mexico, along
92W/94W, from 22N southward into the Isthmus of Tehuantepec of
southern Mexico. Upper level anticyclonic wind flow covers the
Gulf of Mexico from 26N southward from 90W westward. Scattered
moderate to isolated strong rainshowers are along the coast of
Mexico from 26N southward from 94W westward. Other broken 
multilayered clouds and possible rainshowers are elsewhere from 
26N southward from 88W westward.

A surface ridge passes across the NW Bahamas, to a 1018 mb high
pressure center that is near 27N88W, and it continues to the lower
Rio Grande Valley of Texas. Gentle to moderate anticyclonic wind
flow covers much of the Gulf of Mexico. Light to gentle winds 
cover the NE part of the area. The sea heights are in the range of
1 foot to 2 feet in the NE corner of the area, and in the range 
of 2 feet to 4 feet elsewhere. 

The current surface ridge will prevail across the area through 
early next week. The ridge will support moderate to fresh SE 
winds in the west-central and NW Gulf. A nocturnal trough moving 
off the Yucatan peninsula will induce a surge of fresh to strong 
NE to E winds in the Bay of Campeche each night. 

CARIBBEAN SEA...

An upper level cyclonic circulation center is near 23N73W in the
Atlantic Ocean. A trough extends from the 23N73W cyclonic center 
to 14N76W in the Caribbean Sea. Upper level cyclonic wind flow 
covers the Caribbean Sea from 14N northward between 63W and 84W. 
Isolated moderate rainshowers are from 15N northward between the 
Mona Passage and 83W.

The monsoon trough is along 08N/09N, from 73W in Colombia beyond 
southern Costa Rica. Widely scattered moderate to isolated strong
rainshowers are from 12N southward from 80W westward, in the
coastal plains/coastal waters from Panama to Costa Rica to
Nicaragua.

High pressure, that is to the north of the area, will support 
fresh to strong winds in the south central Caribbean Sea through 
Tuesday. Frequent gusts to gale force are expected in the Gulf of 
Venezuela and near the coast of Colombia tonight and Sunday night.
It is possible that sustained wind speeds may reach gale force 
along the coast of Colombia on Sunday night. One tropical wave is 
entering the eastern Caribbean Sea. The next tropical wave will 
enter the Caribbean Sea on Monday night.

ATLANTIC OCEAN...

An upper level cyclonic circulation center is near 23N73W. A
trough extends from the 23N73W cyclonic center to 14N76W in the
Caribbean Sea. Upper level cyclonic wind flow covers the Caribbean
Sea from 14N northward between 63W and 84W. Isolated moderate to
locally strong rainshowers cover the Atlantic Ocean from the
Greater Antilles northward elsewhere from 60W westward.
Rainshowers that are associated with a 62W/63W tropical wave are
from 18N to 23N between 60W and 65W. 

An upper level cyclonic circulation center is near 36N49W. Upper
level cyclonic wind flow covers the Atlantic Ocean from 28N
northward between 40W and 58W. Isolated moderate rainshowers are
from 28N northward between 44W and 57W.

A surface ridge extends from a 1030 mb high pressure center that 
is near 35N30W, through 32N42W, to 27N56W 27N73W, across the south
Florida peninsula, to a Gulf of Mexico 1020 mb high pressure 
center that is near 25N87W. 

The current surface ridge will remain in place during the next 
several days. The ridge will help to maintain gentle to moderate 
anticyclonic flow N of 22N, and mainly moderate easterly winds 
will prevail S of 22N. This scenario will support fresh to 
locally strong winds along the N coast of Hispaniola and the 
approaches to the Windward Passage during the evening and
nighttime hours. 

For additional information please visit 
http://www.hurricanes.gov/marine

$$
MT 
https://www.nhc.noaa.gov/ 
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STORM INVESTIGATION
055 
ABNT20 KNHC 111725
TWOAT 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sat Aug 11 2018

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A disorganized area of showers and thunderstorms is located about
midway between Africa and the Lesser Antilles. Some slight
development of this disturbance is possible during the next day or
two while it remains nearly stationary.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

A non-tropical area of low pressure is forecast to form over the
central Atlantic in a few days. After it forms, the low could
gradually acquire subtropical or tropical characteristics while it
meanders over the central Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Zelinsky
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The tropics remain quiet for now!
https://ralphstropicalweather.com/