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000
ABNT20 KNHC 191737
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
100 PM EST Tue Nov 19 2019

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

The National Hurricane Center is issuing advisories on recently
formed Tropical Storm Sebastien, located a a few hundred miles
northeast of the northern Leeward Islands.

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Latto

Summary for Tropical Storm Sebastien (AT5/AL202019)

...SEBASTIEN CONTINUES NORTHWESTWARD... ...EXPECTED TO TURN TO THE NORTHEAST LATE WEDNESDAY...
 As of 5:00 PM AST Tue Nov 19
 the center of Sebastien was located near 20.6, -59.7
 with movement NW at 12 mph.
 The minimum central pressure was 1006 mb
 with maximum sustained winds of about 45 mph.

Tropical Storm Sebastien Public Advisory Number 2

Issued at 500 PM AST Tue Nov 19 2019  

000
WTNT35 KNHC 192034
TCPAT5

BULLETIN
Tropical Storm Sebastien Advisory Number   2
NWS National Hurricane Center Miami FL       AL202019
500 PM AST Tue Nov 19 2019

...SEBASTIEN CONTINUES NORTHWESTWARD...
...EXPECTED TO TURN TO THE NORTHEAST LATE WEDNESDAY...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...20.6N 59.7W
ABOUT 275 MI...445 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...1006 MB...29.71 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Tropical Storm Sebastien was
located near latitude 20.6 North, longitude 59.7 West. Sebastien is
moving toward the northwest near 12 mph (19 km/h). A turn to
the north is expected on Wednesday followed by a turn to the
northeast with an increase in forward speed Wednesday night.

Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Some strengthening is forecast during the next 48 hours. Sebastien
is expected to become an extratropical cyclone in a couple
of days and will then be absorbed by a cold front late this
week.

Tropical-storm-force winds extend outward up to 105 miles (165 km)
from the center.

The estimated minimum central pressure is 1006 mb (29.71 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 1100 PM AST.

$$
Forecaster Latto


Tropical Storm Sebastien Forecast Advisory Number 2

Issued at 2100 UTC TUE NOV 19 2019  

000
WTNT25 KNHC 192033
TCMAT5
 
TROPICAL STORM SEBASTIEN FORECAST/ADVISORY NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL202019
2100 UTC TUE NOV 19 2019
 
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.
 
TROPICAL STORM CENTER LOCATED NEAR 20.6N  59.7W AT 19/2100Z
POSITION ACCURATE WITHIN  30 NM
 
PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT  10 KT
 
ESTIMATED MINIMUM CENTRAL PRESSURE 1006 MB
MAX SUSTAINED WINDS  40 KT WITH GUSTS TO  50 KT.
34 KT....... 90NE   0SE   0SW   0NW.
12 FT SEAS..120NE   0SE   0SW   0NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT.  RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
 
REPEAT...CENTER LOCATED NEAR 20.6N  59.7W AT 19/2100Z
AT 19/1800Z CENTER WAS LOCATED NEAR 20.4N  59.4W
 
FORECAST VALID 20/0600Z 21.3N  60.7W
MAX WIND  40 KT...GUSTS  50 KT.
34 KT... 90NE  90SE   0SW   0NW.
 
FORECAST VALID 20/1800Z 22.6N  61.9W
MAX WIND  45 KT...GUSTS  55 KT.
34 KT... 90NE 130SE   0SW   0NW.
 
FORECAST VALID 21/0600Z 24.2N  61.0W
MAX WIND  50 KT...GUSTS  60 KT.
50 KT... 50NE  50SE   0SW   0NW.
34 KT...100NE 140SE   0SW   0NW.
 
FORECAST VALID 21/1800Z 26.0N  58.9W...POST-TROP/EXTRATROP
MAX WIND  55 KT...GUSTS  65 KT.
50 KT... 50NE  50SE   0SW   0NW.
34 KT...100NE 150SE   0SW   0NW.
 
FORECAST VALID 22/1800Z...DISSIPATED
 
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.6N  59.7W
 
NEXT ADVISORY AT 20/0300Z
 
$$
FORECASTER LATTO
 
 

Tropical Storm Sebastien Forecast Discussion Number 1

Issued at 1100 AM AST Tue Nov 19 2019  

000
WTNT45 KNHC 191501
TCDAT5

Tropical Storm Sebastien Discussion Number   1
NWS National Hurricane Center Miami FL       AL202019
1100 AM AST Tue Nov 19 2019

Satellite imagery indicates that the overall cloud pattern of the
disturbance has improved since yesterday, and that the low has
become well-defined. In addition, a late-arriving ASCAT-B
scatterometer pass showed 35-38 kt winds extending 90 n mi from the
center in the northeastern quadrant. This pass also revealed that
the low was nearly closed at the surface, and since the
scatterometer may not have resolved the small scale of the low-level
center it is likely that the surface low is indeed closed. Based on
these data, advisories are being initiated on Tropical Storm
Sebastian with an initial advisory intensity of 40 kt.

Sebastien will not be in an ideal environment for significant
intensification, as it will be battling dry air to its west and
about 20 kt of northwesterly shear for the next couple of days.
However, due to the presence of an upper trough to the west of the
system, a diffluent environment aloft may aid in some slight
strengthening over the next day or so. After that time, the
storm will begin to interact with an approaching cold front,
and some additional intensification may occur due to baroclinic
processes. The cyclone is then expected to become absorbed by the
front in about 48 hours. The various intensity guidance solutions
are in decent agreement, and the official forecast is near the mean
of these forecasts. There are some timing variations among the
models on when the cyclone will become absorbed by the front, and it
is possible that the storm could be absorbed sooner than indicated.

The initial motion is 330/07 kt. Sebastien will be steered to
the northwest in the near term around a deep-layer ridge over the
central Atlantic. By Wednesday, the cyclone should turn north, and
then should accelerate northeastward by Wednesday night as the
cyclone gets caught up in the flow between the retreating ridge and
ahead of the approaching cold front. The model guidance is in good
agreement on this scenario, and on the official forecast track the
cyclone will remain over open waters for the duration of its
existence.


FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 20.1N  58.7W   40 KT  45 MPH
 12H  20/0000Z 21.0N  59.2W   40 KT  45 MPH
 24H  20/1200Z 22.2N  60.0W   45 KT  50 MPH
 36H  21/0000Z 23.5N  60.0W   45 KT  50 MPH
 48H  21/1200Z 25.5N  58.3W   45 KT  50 MPH...POST-TROP/EXTRATROP
 72H  22/1200Z...DISSIPATED

$$
Forecaster Latto


Tropical Storm Sebastien Wind Speed Probabilities Number 2

Issued at 2100 UTC TUE NOV 19 2019


557 
FONT15 KNHC 192034
PWSAT5
                                                                    
TROPICAL STORM SEBASTIEN WIND SPEED PROBABILITIES NUMBER   2        
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL202019               
2100 UTC TUE NOV 19 2019                                            
                                                                    
AT 2100Z THE CENTER OF TROPICAL STORM SEBASTIEN WAS LOCATED NEAR    
LATITUDE 20.6 NORTH...LONGITUDE 59.7 WEST WITH MAXIMUM SUSTAINED    
WINDS NEAR 40 KTS...45 MPH...75 KM/H.                               
                                                                    
Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH)                  
   ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME      
   EASTERN  DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME      
   CENTRAL  DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME      
                                                                    
WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS                 
                                                                    
CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST     
   ...34 KT (39 MPH... 63 KM/H)...                                  
   ...50 KT (58 MPH... 93 KM/H)...                                  
   ...64 KT (74 MPH...119 KM/H)...                                  
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS               
                                                                    
PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE               
    OP  IS THE PROBABILITY OF THE EVENT BEGINNING DURING            
        AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY)               
   (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN           
        18Z TUE AND THE FORECAST HOUR (CUMULATIVE PROBABILITY)      
                                                                    
PROBABILITIES ARE GIVEN IN PERCENT                                  
X INDICATES PROBABILITIES LESS THAN 1 PERCENT                       
PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN
THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT.             
PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY              
64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT.                 
                                                                    
                                                                    
  - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - -   
                                                                    
               FROM    FROM    FROM    FROM    FROM    FROM    FROM 
  TIME       18Z TUE 06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT
PERIODS         TO      TO      TO      TO      TO      TO      TO  
             06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT 18Z SUN
                                                                    
FORECAST HOUR    (12)   (24)    (36)    (48)    (72)    (96)   (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
LOCATION       KT                                                   
                                                                    
$$                                                                  
FORECASTER LATTO                                                    


Tropical Storm Sebastien Graphics


Tropical Storm Sebastien 5-Day Uncertainty Track Image
5-Day Uncertainty Track last updated Tue, 19 Nov 2019 15:01:57 GMT

Tropical Storm Sebastien 34-Knot Wind Speed Probabilities
Wind Speed Probabilities last updated Tue, 19 Nov 2019 15:24:20 GMT