1. An elongated area of low pressure located several hundred miles
southwest of the Cabo Verde Islands continues to produce
disorganized showers and thunderstorms. Environmental conditions
are expected to be conducive for gradual development, and a tropical
depression is likely form later this week while the system moves
west-northwestward at 10 to 15 mph over the tropical Atlantic Ocean.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...high...70 percent.
1. An elongated area of low pressure located several hundred miles
southwest of the Cabo Verde Islands continues to produce
disorganized showers and thunderstorms. Environmental conditions
are expected to be conducive for gradual development, and a tropical
depression is likely to form later this week while the system moves
west-northwestward at 10 to 15 mph over the tropical Atlantic Ocean.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...80 percent.
1. Showers and thunderstorms associated with an area of low pressure
located about 1000 miles west-southwest of the Cabo Verde Islands
are gradually becoming better organized. Conditions appear
conducive for continued development of this system. There is a
high likelihood that a tropical depression or tropical storm will
form within the next day or two while the disturbance moves
west-northwestward at 10 to 15 mph over the tropical Atlantic Ocean.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...90 percent.
Tropical Storm Jose Discussion Number 1
NWS National Hurricane Center Miami FL AL122017
1100 AM AST Tue Sep 05 2017
Deep convection associated with the disturbance in the central
Atlantic has become more organized overnight. Banding features
are starting to develop as seen in the first-light visible pictures
from the GOES and METEOSAT imagery. Additionally, the ASCAT
scatterometers sampled the system at 1140Z and 1234Z, showing that a
well-defined - though slightly elongated - center had formed. The
maximum believable winds from ASCAT were 35 kt. Thus advisories
are being started on Tropical Storm Jose, the 10th named storm of
the Atlantic season.
With no history on the center location, the motion is estimated to
be west-northwest at 11 kt. Jose should move toward the west or
west-northwest for the next three to four days at a slightly faster
rate of forward speed as it moves south of the deep-layer
Azores-Bermuda high. In about four to five days, Jose should turn
toward the northwest and slow as it reaches the southwestern
periphery of the high. The model guidance is in good agreement
with this scenario and the official forecast is based upon a blend
of the ECMWF-GFS-UKMET deterministic and ensemble model output.
The environment in which Jose is located in appears to be quite
conducive for development for the next three days as the SSTs are
very warm, the vertical shear is very low, and there is abundant
mid-level moisture. By days four and five, however, the vertical
shear may increase in part due to the outflow from Hurricane Irma to
its west. Thus the official intensity forecast show steady
intensification until day three, then remains flat through day
five. This forecast is based upon the IVCN multi-model consensus
technique, but has the usual - large - uncertainties at the long
forecast range.
The ASCAT observations indicate that the tropical-storm-force winds
extend out about 40 nm from the center in the southeastern
quadrant. The official size forecast suggests a gradual increase in
size, based upon the RVCN multi-model consensus approach.
Hurricane Jose Discussion Number 6
NWS National Hurricane Center Miami FL AL122017
500 PM AST Wed Sep 06 2017
Jose has continued to become better organized. Banding convection
has become very symmetric around the center, and the upper-level
outflow has become well established in all quadrants, despite the
presence of Hurricane Irma to the west. An eye-like dimple has
occasionally been observed in visible imagery during the afternoon.
The initial intensity is now 65 kt, based on the latest Dvorak
intensity estimate from TAFB. There is no reason to believe that
the recent intensification trend will end soon. In fact, the SHIPS
Rapid Intensification Index gives a 48 percent chance of
intensification of 30 kt (or more) in the next 24 h. My forecast is
just shy of that, and is close to the intensification rate shown by
the HWRF for the next 36 h. After about 48-72 h, the vertical wind
shear is forecast to increase, and all of the models forecast
weakening. Overall, the NHC forecast is a little above the model
consensus for the first 72 h, but close to IVCN by the end of the
forecast.
A pair of late-arriving ASCAT passes and recent visible imagery
indicate that Jose is a little farther north than previously
estimated. The initial motion estimate is 285/14 kt. Due to the
northward shift of the initial position, the forecast has been
adjusted in that direction for the first 48 h. However, the
reasoning behind the forecast has not changed, and Jose should
continue on a fairly steady west-northwest track, steered primarily
by the subtropical ridge. After that time, a mid-level trough should
cause the ridge to retreat eastward, allowing Jose to gain more
latitude. The global models, especially the ECMWF, are suggesting
that this turn may occur a little later than previously expected,
and have shifted westward a little bit. The new NHC forecast at 96
and 120 h is very close to a blend of the GFS and ECMWF models, and
is about a degree west of the previous forecast.
BULLETIN
Hurricane Jose Intermediate Advisory Number 9A
NWS National Hurricane Center Miami FL AL122017
200 PM AST Thu Sep 07 2017
...JOSE NOW A CATEGORY 2 HURRICANE...
SUMMARY OF 200 PM AST...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...15.2N 51.4W
ABOUT 660 MI...1060 KM E OF THE LESSER ANTILLES
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...978 MB...28.88 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
None.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Hurricane Watch is in effect for...
* Antigua and Barbuda
A Tropical Storm Watch is in effect for...
* Anguilla, Montserrat, St Kitts, and Nevis
* Saba and St. Eustatius
A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours
before the anticipated first occurrence of tropical-storm-force
winds, conditions that make outside preparations difficult or
dangerous.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 200 PM AST (1800 UTC), the center of Hurricane Jose was located
near latitude 15.2 North, longitude 51.4 West. Jose is moving
toward the west-northwest near 18 mph (30 km/h). The hurricane is
expected to continue on this heading with a slight decrease in
forward speed during the next couple of days.
Maximum sustained winds have increased to near 105 mph (165 km/h)
with higher gusts. Additional strengthening is forecast during the
next 48 hours, and Jose is expected to become a major hurricane on
Friday.
Hurricane-force winds extend outward up to 15 miles (30 km) from
the center and tropical-storm-force winds extend outward up to 100
miles (160 km).
The estimated minimum central pressure is 978 mb (28.88 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Hurricane conditions are possible within the hurricane watch
area on Saturday, and tropical storm conditions are possible within
the hurricane watch and tropical storm watch areas by Saturday
morning.
RAINFALL: Jose is expected to produce total rain accumulations of
2 to 6 inches in the Leeward Islands from Dominica to Anguilla.
Isolated maximum amounts of 10 inches are possible in the northern
Leeward Islands from Antigua and Barbuda to Anguilla. This rainfall
will maintain any ongoing flooding and may cause additional
life-threatening flooding.
SURF: Swells generated by Jose are likely to affect portions of
the Leeward Islands by Saturday. 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 PM AST.
Hurricane Jose Discussion Number 10
NWS National Hurricane Center Miami FL AL122017
Issued by the NWS Weather Prediction Center College Park MD
500 PM AST Thu Sep 07 2017
Jose has continued to develop a well-defined eye on satellite
imagery this afternoon, with the eye now established in the center
of a ring of strong convection. 18 UTC Dvorak fixes from TAFB and
SAB came in at T5.5, which suggests 100 knot intensity. However,
given the ongoing improvements in satellite presentation and CIMSS
ADT numbers which have since climbed higher, the initial intensity
for this advisory is set at 105 knots. This makes Jose a Category 3
hurricane on the Saffir-Simpson Hurricane Wind Scale. It is the
third major hurricane in the 2017 Atlantic hurricane season
(Harvey, Irma). It also means we have two major hurricanes
simultaneously in the Atlantic basin, which is not too common --
especially in such close proximity. The last time this happened was
in 2010 when Igor and Julia were both major hurricanes on September
15-16, and then Igor and Karl were both major hurricanes briefly on
September 17.
In the near-term, most factors appear aligned for continued
intensification. Outflow remains well-established in all quadrants,
and Jose has thus far not felt negative impacts from the dry air
situated just to its west and northwest. For this reason, we are
taking the intensity up to 120 knots at the 24 hour forecast point.
After that, a gradual decrease in intensity is shown, in line with
most intensity guidance. However, the intensity forecast generally
lies above most of the guidance in deference to the ongoing rapid
intensification trend. Global models do show that some of the dry
air to the west of Jose may wrap into the circulation in about
24-36 hours. That may be a contributing factor to the decrease in
intensity, as well as some increasing shear at the base of an upper
level low in the central Atlantic and perhaps the periphery of
Irma's upper level outflow. The smaller size of Jose may make it a
little more vulnerable to effects of dry air and shear.
The initial motion remains at 285/16kt, and Jose will continue to
be steered by a well established subtropical ridge. It should not
reach the ridge axis until about 36-48 hours, at which point the
ridge begins to erode a bit and Jose may turn a bit more toward the
northwest and eventually the north. The forecast track remains very
similar to the previous official forecast through 48 hours --
roughly between the operational GFS and ECMWF and close to the
multi-model consensus. After that time, the steering flow becomes
weaker and the forward motion should slow down. Models begin to
diverge more significantly at 96hr and especially 120hr. The
forecast at these time ranges lies closer to the multi-model
consensus and the operational ECMWF than models that show a quicker
exit to the east.
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