National Hurricane Center (Atlantic)

Atlantic Tropical Weather Outlook


000
ABNT20 KNHC 210558
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Sat Sep 21 2019

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

The National Hurricane Center is issuing advisories on recently
downgraded Tropical Storm Jerry, located more than a hundred miles
north of the northern Leeward Islands.

A tropical wave located several hundred miles east of the Windward
Islands continues to produce a large area of disorganized showers
and thunderstorms. Environmental conditions are currently conducive
for some development, and a tropical depression could form on Sunday
or early next week while the system moves quickly westward to
west-northwestward at 15 to 20 mph, crossing the Windward Islands on
Sunday. Upper-level winds are forecast to become less conducive for
development by the middle of next week once the wave moves out of
the northeastern Caribbean Sea. A NOAA Hurricane Hunter aircraft
is scheduled to investigate this system this afternoon, if
necessary. Regardless of development, heavy rainfall is possible
over much of the Lesser Antilles over the weekend, and interests on
those islands and Puerto Rico should monitor the progress of this
disturbance.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...50 percent.

A broad area of low pressure located just south of Haiti continues
to produce only disorganized showers and thunderstorms. Due to
strong upper-level winds, significant development of this system is
not expected while it moves slowly west-northwestward during the
next couple of days. Regardless of development, locally heavy
rainfall is likely over portions of Hispaniola, Jamaica, and Cuba
through the weekend, potentially causing flash flooding and
mudslides in areas of high terrain.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

A tropical wave is forecast to move off the west coast of Africa
by Sunday. Environmental conditions are expected to be conducive
for development, and a tropical depression or tropical storm is
likely to form early next week while the wave moves westward across
the eastern tropical Atlantic.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...90 percent.

$$
Forecaster Stewart

Tropical Storm Jerry Graphics

Tropical Storm Jerry 5-Day Uncertainty Track Image
5-Day Uncertainty Track last updated Sat, 21 Sep 2019 05:57:24 GMT

Tropical Storm Jerry 34-Knot Wind Speed Probabilities
Wind Speed Probabilities last updated Sat, 21 Sep 2019 03:24:53 GMT

Summary for Tropical Storm Jerry (AT5/AL102019)

...JERRY WEAKENS TO A TROPICAL STORM WHILE IT MOVES AWAY FROM THE NORTHERN LEEWARD ISLANDS AND PUERTO RICO... As of 2:00 AM AST Sat Sep 21 the center of Jerry was located near 21.0, -63.5 with movement NW at 16 mph. The minimum central pressure was 995 mb with maximum sustained winds of about 65 mph.

Tropical Storm Jerry Public Advisory Number 15A

Issued at 200 AM AST Sat Sep 21 2019

000
WTNT35 KNHC 210556
TCPAT5

BULLETIN
Tropical Storm Jerry Intermediate Advisory Number 15A
NWS National Hurricane Center Miami FL       AL102019
200 AM AST Sat Sep 21 2019

...JERRY WEAKENS TO A TROPICAL STORM WHILE IT MOVES AWAY FROM THE
NORTHERN LEEWARD ISLANDS AND PUERTO RICO...


SUMMARY OF 200 AM AST...0600 UTC...INFORMATION
----------------------------------------------
LOCATION...21.0N 63.5W
ABOUT 240 MI...385 KM NE OF SAN JUAN PUERTO RICO
ABOUT 260 MI...420 KM NNW OF ANGUILLA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 305 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

The Tropical Storm Watch for St. Maarten, St. Martin, and St.
Barthelemy have been discontinued.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

There are no coastal watches or warnings in effect.


DISCUSSION AND OUTLOOK
----------------------
At 200 AM AST (0600 UTC), the center of Tropical Storm Jerry was
located by an Air Force Reserve reconnaissance aircraft near
latitude 21.0 North, longitude 63.5 West. Jerry is moving toward
the west-northwest near 16 mph (26 km/h).  The tropical storm is
forecast to recurve over the western Atlantic during the next few
days.  On the forecast track, the center of Jerry will continue to
pass well north of the Virgin Islands and Puerto Rico today, pass
well east of the southeastern Bahamas on Sunday, and turn northward
over the western Atlantic on Monday.

Data from the reconnaissance aircraft indicate that maximum
sustained winds have decreased to near 65 mph (100 km/h) with
higher
gusts.  Some fluctuations in strength are likely during the next
several days.

Tropical-storm-force winds extend outward up to 90 miles (150 km).

The minimum central pressure based on data from the aircraft is
estimated to be 995 mb (29.38 inches).


HAZARDS AFFECTING LAND
----------------------
Key messages for Jerry can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC
and on the web at www.hurricanes.gov/text/MIATCDAT5.shtml.

RAINFALL: Jerry is expected to produce additional rain
accumulations
of 1 to 2 inches over Barbuda, St. Maarten, Anguilla, and Anegada.
This rainfall may produce life-threatening flash floods.

Jerry is also forecast to produce total rainfall accumulations of 1
to 2 inches across the Virgin Islands and Puerto Rico.

SURF: Swells generated by Jerry are affecting portions of the
northern Leeward Islands. These swells are likely to cause
life-threatening surf and rip current conditions.  Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Stewart

Tropical Storm Jerry Forecast Discussion Number 15

Issued at 1100 PM AST Fri Sep 20 2019

000
WTNT45 KNHC 210259
TCDAT5

Hurricane Jerry Discussion Number  15
NWS National Hurricane Center Miami FL       AL102019
1100 PM AST Fri Sep 20 2019

Jerry has been displaying a classic bursting convective pattern
with
a nearly circular CDO that expanded over the circulation since the
last advisory.  An Air Force Hurricane Hunter mission that just
arrived in Jerry indicated that the center is farther northeast
than
previously estimated, which appears coincident with the location of
the most recent bursts of convection. Since subjective and
objective Dvorak intensity estimates range from 61 kt to 77 kt, the
initial intensity remains 70 kt. This intensity could be adjusted
based on what the plane finds while investigating the circulation.
The central pressure is estimated to be 993 mb based on the center
drop from the plane.

The hurricane is still moving quickly west-northwestward with an
initial motion of 295/15 kt.  The track forecast is fairly
straightforward.  Jerry is approaching a break in the subtropical
ridge, created by a deep-layer trough currently moving across the
northwestern Atlantic. This pattern is expected to cause Jerry to
gradually recurve around the ridge during the next 5 days, with its
forward motion reaching a minimum between 48-72 hours when it moves
near the ridge axis.  There is very good agreement among the track
guidance on this scenario, and the only notable spread is related
to the system's forward speed when it accelerates on day 5.  The
consensus aids are holding tough on a relatively consistent
trajectory, so little change was made from the previous official
forecast.

Dropsonde data from a NOAA G-IV synoptic surveillance mission
indicate that anticyclonic flow continues over the hurricane at the
200-mb outflow level (except it's restricted a bit to the west),
but
15-25 kt of northeasterly flow is cutting through the circulation
just below 250 mb.  Despite this flow, Jerry's structure does not
appear to have degraded too much.  Since the hurricane appears that
it will move beneath an upper-level anticyclone in about 24 hours,
its intensity may not decrease too much over the next several days.
And despite an increase in westerly shear after 48 hours, enhanced
upper-level divergence to the east of an upper-level trough could
offset the potential for weakening.  Accounting for uncertainties,
the NHC intensity forecast maintains a fairly steady strength for
the entire forecast period, keeping Jerry as a hurricane for the
next 5 days.  This forecast is close to the HCCA model and the
simple consensus aids, but it's notable that it's up to 20 kt lower
than the statistical-dynamical models by the end of the forecast
period.

Key Messages:

1. Although the core of Jerry is passing north of the northern
Leeward Islands, heavy rainfall and flash floods are possible there
overnight.


FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 20.5N  62.8W   70 KT  80 MPH
 12H  21/1200Z 21.4N  64.4W   65 KT  75 MPH
 24H  22/0000Z 22.6N  66.6W   65 KT  75 MPH
 36H  22/1200Z 24.0N  68.1W   65 KT  75 MPH
 48H  23/0000Z 25.3N  68.7W   70 KT  80 MPH
 72H  24/0000Z 27.9N  68.2W   70 KT  80 MPH
 96H  25/0000Z 30.8N  66.3W   65 KT  75 MPH
120H  26/0000Z 34.5N  62.1W   65 KT  75 MPH

$$
Forecaster Berg

Tropical Storm Jerry Wind Speed Probabilities Number 15

Issued at 0300 UTC SAT SEP 21 2019

000
FONT15 KNHC 210258
PWSAT5
                                                                   

HURRICANE JERRY WIND SPEED PROBABILITIES NUMBER  15                

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102019              

0300 UTC SAT SEP 21 2019                                           

                                                                   

AT 0300Z THE CENTER OF HURRICANE JERRY WAS LOCATED NEAR LATITUDE   

20.5 NORTH...LONGITUDE 62.8 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 

70 KTS...80 MPH...130 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          

        00Z 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       00Z SAT 12Z SAT 00Z SUN 12Z SUN 00Z MON 00Z TUE 00Z
WED
PERIODS         TO      TO      TO      TO      TO      TO      TO 

             12Z SAT 00Z SUN 12Z SUN 00Z MON 00Z TUE 00Z WED 00Z
THU
                                                                   

FORECAST HOUR    (12)   (24)    (36)    (48)    (72)    (96)  
(120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

LOCATION       KT                                                  

                                                                   

BERMUDA        34  X   X( X)   X( X)   X( X)   2( 2)  32(34) 
34(68)
BERMUDA        50  X   X( X)   X( X)   X( X)   X( X)   9( 9) 
21(30)
BERMUDA        64  X   X( X)   X( X)   X( X)   X( X)   3( 3)  
8(11)
 
MAYAGUANA      34  X   X( X)   2( 2)   1( 3)   1( 4)   X( 4)   X(
4)
 
GRAND TURK     34  X   1( 1)   2( 3)   2( 5)   1( 6)   X( 6)   X(
6)
 
$$                                                                 

FORECASTER BERG                                                    

Tropical Storm Jerry Forecast Advisory Number 15

Issued at 0300 UTC SAT SEP 21 2019

000
WTNT25 KNHC 210258
TCMAT5
 
HURRICANE JERRY FORECAST/ADVISORY NUMBER  15
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102019
0300 UTC SAT SEP 21 2019
 
CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY...
 
NONE.
 
SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
 
A TROPICAL STORM WATCH IS IN EFFECT FOR...
* ST. MAARTEN
* ST. MARTIN
* ST. BARTHELEMY
 
A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT FEW
HOURS.
 
HURRICANE CENTER LOCATED NEAR 20.5N  62.8W AT 21/0300Z
POSITION ACCURATE WITHIN  20 NM
 
PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT  14 KT
 
ESTIMATED MINIMUM CENTRAL PRESSURE  993 MB
MAX SUSTAINED WINDS  70 KT WITH GUSTS TO  85 KT.
64 KT....... 15NE   0SE   0SW  15NW.
50 KT....... 30NE  30SE  10SW  30NW.
34 KT....... 80NE  60SE  30SW  60NW.
12 FT SEAS..240NE 150SE  90SW 180NW.
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 20.5N  62.8W AT 21/0300Z
AT 21/0000Z CENTER WAS LOCATED NEAR 19.9N  62.5W
 
FORECAST VALID 21/1200Z 21.4N  64.4W
MAX WIND  65 KT...GUSTS  80 KT.
64 KT... 10NE   0SE   0SW  10NW.
50 KT... 30NE  20SE  10SW  20NW.
34 KT... 80NE  60SE  30SW  60NW.
 
FORECAST VALID 22/0000Z 22.6N  66.6W
MAX WIND  65 KT...GUSTS  80 KT.
64 KT... 10NE   0SE   0SW  10NW.
50 KT... 30NE  20SE  10SW  20NW.
34 KT... 90NE  60SE  30SW  70NW.
 
FORECAST VALID 22/1200Z 24.0N  68.1W
MAX WIND  65 KT...GUSTS  80 KT.
64 KT... 10NE   0SE   0SW  10NW.
50 KT... 30NE  20SE  10SW  30NW.
34 KT...100NE  70SE  30SW  70NW.
 
FORECAST VALID 23/0000Z 25.3N  68.7W
MAX WIND  70 KT...GUSTS  85 KT.
64 KT... 15NE  10SE   0SW  10NW.
50 KT... 30NE  30SE  10SW  30NW.
34 KT...100NE  80SE  30SW  70NW.
 
FORECAST VALID 24/0000Z 27.9N  68.2W
MAX WIND  70 KT...GUSTS  85 KT.
50 KT... 40NE  40SE  30SW  30NW.
34 KT...120NE 120SE  60SW  90NW.
 
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH
DAY
 
OUTLOOK VALID 25/0000Z 30.8N  66.3W
MAX WIND  65 KT...GUSTS  80 KT.
 
OUTLOOK VALID 26/0000Z 34.5N  62.1W
MAX WIND  65 KT...GUSTS  80 KT.
 
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.5N  62.8W
 
INTERMEDIATE PUBLIC ADVISORY...WTNT35 KNHC/MIATCPAT5...AT 21/0600Z
 
NEXT ADVISORY AT 21/0900Z
 
$$
FORECASTER BERG