Tropical Depression Nine Advisory Number 1
NWS National Hurricane Center Miami FL AL092022
500 AM AST Fri Sep 23 2022
...TROPICAL DEPRESSION FORMS OVER THE CENTRAL CARIBBEAN SEA...
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.9N 68.6W
ABOUT 615 MI...985 KM ESE OF KINGSTON JAMAICA
ABOUT 1105 MI...1780 KM ESE OF HAVANA CUBA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 13 MPH...20 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 AM AST (0900 UTC), the center of Tropical Depression Nine was
located near latitude 13.9 North, longitude 68.6 West. The
depression is moving toward the west-northwest near 13 mph (20
km/h). A turn more westward is forecast over the next next day
or so followed by a turn back to the west-northwest and
northwest by this weekend.
Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Only slow intensification is forecast over the next day or so,
followed by more significant intensification over the weekend and
early next week.
The estimated minimum central pressure is 1006 mb (29.71 inches).
HAZARDS AFFECTING LAND
----------------------
Key messages for TD Nine can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT4 and WMO header
WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml.
RAINFALL: Tropical Depression Nine is expected to produce the
following rainfall:
Aruba, Bonaire, and Curacao: Additional 1 to 2 inches
Northern Venezuela: 2 to 5 inches
Northern Columbia: 3 to 6 inches
Jamaica: 4 to 8 inches with local maximum up to 12 inches
Cayman Islands: 4 to 8 inches
Southern Haiti and Southern Dominican Republic: 2 to 4 inches with
local maximum up to 6 inches
These rains may produce flash flooding and mudslides in areas of
higher terrain, particularly over Jamaica.
SURF: Swells generated by this system will begin affecting Jamaica,
the Cayman Islands and Cuba over the next several days. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products form your local weather office.
NEXT ADVISORY
-------------
Next complete advisory at 1100 AM AST.
$$
Forecaster Papin
Tropical Depression Nine Discussion Number 1...Corrected
NWS National Hurricane Center Miami FL AL092022
500 AM AST Fri Sep 23 2022
Corrected location of convection in first paragraph.
Convection this morning has increased primarily to the west of the
area of low pressure we have been monitoring in the central
Caribbean Sea, currently passing by to the north of Curacao island.
The system already possessed a well-defined circulation for the last
12 to 18 hours, but it was only overnight that the ongoing
convective activity was able to persist long enough near the center
to be considered a tropical cyclone. The most recent satellite
intensity estimate from TAFB was up to T2.5/35-kt. However the
GOES-16 derived motion winds from the meso sector over the system
have only been 25-30 kt in the 925-850 mb layer on the northeastern
periphery of the circulation. In addition, buoy 42059 located to the
northeast of the center has been reporting winds up to only 27-kt.
The combination of all these data provide enough justification to
upgrade this system to Tropical Depression Nine, with the initial
winds set at 30 kt for this advisory. An Air Force Reserve
Reconnaissance mission will be investigating the system later this
morning to provide more in-situ information of the system's
structure and intensity.
The current motion right now is estimated to be off to the
west-northwest at 290/12 kt. In the short-term, the depression is
forecast to bend back more westward as a narrow east-to-west
oriented mid-level ridge builds in behind the weakness left behind
from Fiona. The current eastward displaced convection may also tug
the broad center in that direction as well. However, after 48 hours,
this ridge will start to decay as a longwave deep-layer trough over
the eastern United States begins to amplify southward. This synoptic
evolution should then allow the cyclone to begin gaining latitude,
though the exact timing at which this occurs could be somewhat
related to the vertical depth of the cyclone and how it interacts
with a weak upper-level trough expected to be over the far western
Caribbean in the day 3-4 time-frame. The model guidance early on is
in fairly good agreement, but larger across-track spread begins to
take shape by 48 hours, with the GFS and its ensemble mean located
further south and west, and with the ECMWF and its ensemble mean
located further north and east. The initial track forecast has
decided to split the difference between these two model suites, and
lies fairly close to the consensus aids TVCN and HCCA. There is
still a healthy amount of uncertainty in the track forecast at the
day 4-5 timeframe.
Currently the structure of the depression is quite disheveled, with
the low-level circulation mostly exposed, with deep convective
activity displaced to its west-southeast. This structure is due to
25-30 kt of northeasterly 200-850 mb vertical wind shear caused from
the equatorward outflow channel of Fiona, resulting in significant
upper-level flow over the system. However, as the depression moves
westward, it will move out form under this unfavorable flow and into
a lighter upper-level northeasterlies. However, it may take time for
the low-level center to become better aligned with the convective
activity, and thus only slow intensification is forecast over the
next 24-48 hours. After that period, most of the guidance shows
environmental conditions becoming much more favorable as shear drops
under 10 kt and the cyclone is over the warm 29-30 C waters of the
northwestern Caribbean. Thereafter, potential land interaction with
Cuba, and the potential for an increase in southerly shear at
day 5 may cap off the intensity at the end of the forecast. The
initial NHC forecast shows the depression intensifying up to a
category 2 hurricane by the time it nears the coast of Cuba.
Key Messages:
1. Tropical Depression Nine is expected to produce heavy rainfall
and instances of flash flooding and possible mudslides in areas of
higher terrain in Aruba, Bonaire, and Curacao. Heavy rains are also
likely to spread into Jamaica and the Cayman Islands in the coming
days.
2. The depression is expected to approach Jamaica and the Cayman
islands as an intensifying tropical storm. Watches and warnings for
these locations may be required in subsequent forecast cycles.
3. This system is forecast to approach western Cuba and enter the
southeastern Gulf of Mexico by the end of the forecast period.
Interests in Cuba and those along the Eastern Gulf Coast of the
United States should closely monitor this system, though at this
juncture forecast uncertainty remains fairly high.
FORECAST POSITIONS AND MAX WINDS
INIT 23/0900Z 13.9N 68.6W 30 KT 35 MPH
12H 23/1800Z 14.4N 70.2W 35 KT 40 MPH
24H 24/0600Z 14.7N 72.6W 35 KT 40 MPH
36H 24/1800Z 14.8N 75.0W 35 KT 40 MPH
48H 25/0600Z 15.5N 77.1W 40 KT 45 MPH
60H 25/1800Z 17.0N 78.8W 55 KT 65 MPH
72H 26/0600Z 18.9N 80.5W 65 KT 75 MPH
96H 27/0600Z 22.6N 82.6W 90 KT 105 MPH...NEAR CUBA
120H 28/0600Z 26.0N 82.3W 95 KT 110 MPH
$$
Forecaster Papin