RSS Tropical Cyclone Advisories from NHC

Atlantic Tropical Weather Outlook


000
ABNT20 KNHC 191124
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sat Aug 19 2017

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

The National Hurricane Center is issuing advisories on Tropical
Storm Harvey, located over the eastern Caribbean Sea.

A trough of low pressure located about 300 miles east-northeast of
the northern Leeward Islands continues to produce disorganized
showers and thunderstorms. Environmental conditions are expected to
be only marginally conducive for development during the next few
days while this system moves west-northwestward at about 20 mph.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...40 percent.

A tropical wave located over the eastern Atlantic Ocean about
midway between the Lesser Antilles and Africa is producing some
shower and thunderstorm activity. Environmental conditions appear
somewhat conducive for gradual development over the next few days
while the system moves west-northwestward to northwestward at about
20 mph, but upper-level winds are forecast to become unfavorable by
early next week.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Beven

Summary for Tropical Storm Harvey (AT4/AL092017)

...HEAVY RAINFALL THREAT TODAY IN THE ABC ISLANDS FROM HARVEY...
 As of 5:00 AM AST Sat Aug 19
 the center of Harvey was located near 13.8, -65.9
 with movement W at 21 mph.
 The minimum central pressure was 1005 mb
 with maximum sustained winds of about 40 mph.

Tropical Storm Harvey Public Advisory Number 8

Issued at 500 AM AST Sat Aug 19 2017  

000
WTNT34 KNHC 190841
TCPAT4

BULLETIN
Tropical Storm Harvey Advisory Number   8
NWS National Hurricane Center Miami FL       AL092017
500 AM AST Sat Aug 19 2017

...HEAVY RAINFALL THREAT TODAY IN THE ABC ISLANDS FROM HARVEY...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.8N 65.9W
ABOUT 280 MI...450 KM SSW OF ST. CROIX
ABOUT 235 MI...375 KM ENE OF CURACAO
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 275 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES


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

Interests in the Caribbean Sea and the adjacent land areas of
eastern Central America and northern South America should monitor
the progress of Harvey.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 AM AST (0900 UTC), the center of Tropical Storm Harvey was
located near latitude 13.8 North, longitude 65.9 West. Harvey is
moving toward the west near 21 mph (33 km/h), and this general
motion is expected for the next couple of days. On the forecast
track, the center of Harvey will move across the eastern and central
Caribbean Sea over the weekend.

Maximum sustained winds remain near 40 mph (65 km/h) with higher
gusts. Some strengthening is forecast during the next 48 hours.

Tropical-storm-force winds extend outward up to 70 miles (110 km),
primarily to the north of the center.

The estimated minimum central pressure is 1005 mb (29.68 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL:  Locally heavy rain could occur today over Aruba, Bonaire,
Curacao and the offshore islands of northern Venezuela.


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

$$
Forecaster Blake

Tropical Storm Harvey Forecast Advisory Number 8

Issued at 0900 UTC SAT AUG 19 2017  

000
WTNT24 KNHC 190841
TCMAT4
 
TROPICAL STORM HARVEY FORECAST/ADVISORY NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092017
0900 UTC SAT AUG 19 2017
 
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.
 
INTERESTS IN THE CARIBBEAN SEA AND THE ADJACENT LAND AREAS OF
EASTERN CENTRAL AMERICA AND NORTHERN SOUTH AMERICA SHOULD MONITOR
THE PROGRESS OF HARVEY.
 
TROPICAL STORM CENTER LOCATED NEAR 13.8N  65.9W AT 19/0900Z
POSITION ACCURATE WITHIN  30 NM
 
PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT  18 KT
 
ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB
MAX SUSTAINED WINDS  35 KT WITH GUSTS TO  45 KT.
34 KT....... 60NE   0SE   0SW  60NW.
12 FT SEAS.. 60NE   0SE   0SW  60NW.
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 13.8N  65.9W AT 19/0900Z
AT 19/0600Z CENTER WAS LOCATED NEAR 13.7N  65.0W
 
FORECAST VALID 19/1800Z 14.0N  68.7W
MAX WIND  35 KT...GUSTS  45 KT.
34 KT... 60NE   0SE   0SW  60NW.
 
FORECAST VALID 20/0600Z 14.3N  72.7W
MAX WIND  40 KT...GUSTS  50 KT.
34 KT... 60NE   0SE   0SW  60NW.
 
FORECAST VALID 20/1800Z 14.6N  76.7W
MAX WIND  45 KT...GUSTS  55 KT.
34 KT... 70NE   0SE   0SW  70NW.
 
FORECAST VALID 21/0600Z 15.2N  80.1W
MAX WIND  50 KT...GUSTS  60 KT.
50 KT... 30NE   0SE   0SW  30NW.
34 KT... 90NE  50SE  40SW  70NW.
 
FORECAST VALID 22/0600Z 17.0N  86.5W
MAX WIND  55 KT...GUSTS  65 KT.
50 KT... 30NE  20SE   0SW  30NW.
34 KT... 90NE  50SE  40SW  70NW.
 
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
 
OUTLOOK VALID 23/0600Z 18.3N  90.5W...INLAND
MAX WIND  35 KT...GUSTS  45 KT.
 
OUTLOOK VALID 24/0600Z 19.3N  93.0W...OVER WATER
MAX WIND  40 KT...GUSTS  50 KT.
 
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 13.8N  65.9W
 
NEXT ADVISORY AT 19/1500Z
 
$$
FORECASTER BLAKE
 
 

Tropical Storm Harvey Forecast Discussion Number 8

Issued at 500 AM AST Sat Aug 19 2017  

000
WTNT44 KNHC 190842
TCDAT4

Tropical Storm Harvey Discussion Number   8
NWS National Hurricane Center Miami FL       AL092017
500 AM AST Sat Aug 19 2017

GOES-16 shortwave infrared imagery shows the partially exposed
center of Harvey on the eastern edge of a large area of deep
convection. While the center is closer to the convection than a few
hours ago, cirrus clouds be clearly seen moving from northeast to
southwest across the system; an indication of the persistent shear.
Satellite estimates suggest the maximum winds of Harvey remain 35
kt.

The storm has picked up some forward speed with a recent motion
estimate of 275/18.  A low- to mid-level ridge extending across the
western Atlantic should keep Harvey on a fast westward course across
the Caribbean Sea for the next 48 hours.  Thereafter, the ridge
weakens across the Gulf of Mexico due to a strong mid/upper-level
low currently seen there on water vapor images.  This steering flow
change should cause Harvey to slow down and turn a little more to
the west-northwest in the northwestern Caribbean Sea, with an even
slower motion forecast for Harvey in the Bay of Campeche.  Model
guidance is in fairly good agreement on this scenario, and no
significant changes were made to the previous forecast.

Harvey should be moving into a more conducive environment for
strengthening early next week since the strong northeasterly shear
that has been affecting the cyclone is forecast by almost all of the
guidance to weaken within about 24 hours.  In a few days, most of
the global models show a favorable upper-level environment for
intensification, and Harvey could be near hurricane strength between
the 72 hour forecast period and landfall.  There has been little
change to the guidance so the new intensity forecast is similar to
the previous one, close to the model consensus.  However, with
a weak storm moving so quickly across the central Caribbean, one
always has to be careful of the system opening up into a wave. This
is a plausible alternative scenario still suggested by the GFS and
ECMWF models.


FORECAST POSITIONS AND MAX WINDS

INIT  19/0900Z 13.8N  65.9W   35 KT  40 MPH
 12H  19/1800Z 14.0N  68.7W   35 KT  40 MPH
 24H  20/0600Z 14.3N  72.7W   40 KT  45 MPH
 36H  20/1800Z 14.6N  76.7W   45 KT  50 MPH
 48H  21/0600Z 15.2N  80.1W   50 KT  60 MPH
 72H  22/0600Z 17.0N  86.5W   55 KT  65 MPH
 96H  23/0600Z 18.3N  90.5W   35 KT  40 MPH...INLAND
120H  24/0600Z 19.3N  93.0W   40 KT  45 MPH...OVER WATER

$$
Forecaster Blake

Tropical Storm Harvey Wind Speed Probabilities Number 8

Issued at 0900 UTC SAT AUG 19 2017


000
FONT14 KNHC 190841
PWSAT4
                                                                    
TROPICAL STORM HARVEY WIND SPEED PROBABILITIES NUMBER   8           
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092017               
0900 UTC SAT AUG 19 2017                                            
                                                                    
AT 0900Z THE CENTER OF TROPICAL STORM HARVEY WAS LOCATED NEAR       
LATITUDE 13.8 NORTH...LONGITUDE 65.9 WEST WITH MAXIMUM SUSTAINED    
WINDS NEAR 35 KTS...40 MPH...65 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           
        06Z SAT 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       06Z SAT 18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED
PERIODS         TO      TO      TO      TO      TO      TO      TO  
             18Z SAT 06Z SUN 18Z SUN 06Z MON 06Z TUE 06Z WED 06Z THU
                                                                    
FORECAST HOUR    (12)   (24)    (36)    (48)    (72)    (96)   (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
LOCATION       KT                                                   
                                                                    
TUXPAN MX      34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   2( 3)
 
VERACRUZ MX    34  X   X( X)   X( X)   X( X)   X( X)   1( 1)   4( 5)
 
FRONTERA MX    34  X   X( X)   X( X)   X( X)   X( X)   9( 9)   5(14)
FRONTERA MX    50  X   X( X)   X( X)   X( X)   X( X)   2( 2)   1( 3)
 
MERIDA MX      34  X   X( X)   X( X)   X( X)   1( 1)  10(11)   1(12)
 
COZUMEL MX     34  X   X( X)   X( X)   X( X)   8( 8)   5(13)   1(14)
 
BELIZE CITY    34  X   X( X)   X( X)   X( X)  11(11)  18(29)   1(30)
BELIZE CITY    50  X   X( X)   X( X)   X( X)   2( 2)   5( 7)   1( 8)
BELIZE CITY    64  X   X( X)   X( X)   X( X)   X( X)   1( 1)   X( 1)
 
PUERTO BARRIOS 34  X   X( X)   X( X)   X( X)   5( 5)   8(13)   1(14)
PUERTO BARRIOS 50  X   X( X)   X( X)   X( X)   1( 1)   2( 3)   X( 3)
 
GUANAJA        34  X   X( X)   X( X)   X( X)  29(29)   4(33)   X(33)
GUANAJA        50  X   X( X)   X( X)   X( X)   9( 9)   2(11)   X(11)
GUANAJA        64  X   X( X)   X( X)   X( X)   2( 2)   X( 2)   1( 3)
 
PUERTO CABEZAS 34  X   X( X)   X( X)   1( 1)  10(11)   1(12)   X(12)
 
SAN ANDRES     34  X   X( X)   X( X)   1( 1)   2( 3)   X( 3)   X( 3)
 
CP SAN ANTONIO 34  X   X( X)   X( X)   X( X)   3( 3)   2( 5)   X( 5)
 
ISLE OF PINES  34  X   X( X)   X( X)   X( X)   2( 2)   1( 3)   X( 3)
 
GRAND CAYMAN   34  X   X( X)   X( X)   3( 3)   7(10)   X(10)   X(10)
 
MONTEGO BAY    34  X   X( X)   2( 2)   4( 6)   X( 6)   X( 6)   X( 6)
 
KINGSTON       34  X   X( X)   3( 3)   3( 6)   1( 7)   X( 7)   X( 7)
 
LES CAYES      34  X   1( 1)   1( 2)   1( 3)   X( 3)   X( 3)   X( 3)
 
$$                                                                  
FORECASTER BLAKE                                                    

Tropical Storm Harvey Graphics


Tropical Storm Harvey 5-Day Uncertainty Track Image
5-Day Uncertainty Track last updated Sat, 19 Aug 2017 08:45:50 GMT

Tropical Storm Harvey 34-Knot Wind Speed Probabilities
Wind Speed Probabilities last updated Sat, 19 Aug 2017 09:22:40 GMT