Tropical Storm Franklin Advisory Number 1
NWS National Hurricane Center Miami FL AL082023
500 PM AST Sun Aug 20 2023
...TROPICAL STORM FRANKLIN FORMS IN THE CARIBBEAN SEA..
...TROPICAL STORM WATCHES ISSUED FOR THE SOUTH COAST OF HAITI AND
THE DOMINICAN REPUBLIC...
SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...14.6N 67.1W
ABOUT 270 MI...435 KM SSE OF ISLA SAONA DOMINICAN REPUBLIC
ABOUT 270 MI...435 KM SSW OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1002 MB...29.59 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
The government of the Dominican Republic has issued a Tropical
Storm Watch for the entire south coast of the from the Haiti border
eastward to Isla Saona.
The government of Haiti has issued a Tropical Storm Watch for
the south coast of Anse d'Hainault eastward to the
Dominican Republic Border.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Watch is in effect for...
* Haiti entire south coast from Anse d'Hainault eastward to the
Dominican Republic border.
* Dominican Republic entire south coast from Haiti border eastward
to Isla Saona.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests elsewhere in Haiti and the Dominican Republic should
monitor the progress of this system.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
----------------------
At 500 PM AST (2100 UTC), the center of Tropical Storm Franklin was
located near latitude 14.6 North, longitude 67.1 West. Franklin is
moving toward the west-northwest near 14 mph (22 km/h). A
west-northwestward track is expected to continue for the next day or
so followed by a sharp turn to the north. On the forecast track,
Franklin should approach the coast of Hispaniola on Wednesday.
Maximum sustained winds measured by NOAA reconnaissance aircraft
are near 45 mph (75 km/h) with higher gusts. Some strengthening is
forecast during the next 48 hours.
Tropical-storm-force winds extend outward up to 60 miles (95 km)
from the center.
The minimum central pressure measured by NOAA reconnaissance
aircraft is 1002 mb (29.59 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are possible within the watch
area beginning late Tuesday.
RAINFALL: Franklin is expected to produce rainfall amounts of 2 to 4
inches, with isolated higher amounts of 6 inches, across Puerto Rico
through the middle of the week. Rainfall amounts of 4 to 8 inches,
with isolated higher amounts up to 12 inches, will be possible
across portions of Hispaniola.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM AST.
Next complete advisory at 1100 PM AST.
$$
Forecaster Papin
Tropical Storm Franklin Discussion Number 1
NWS National Hurricane Center Miami FL AL082023
500 PM AST Sun Aug 20 2023
This afternoon we have received a wealth of data from both a NOAA
reconnaissance mission and satellite imagery near the area of low
pressure located in the eastern Caribbean Sea. Earlier visible
satellite imagery showed the system had likely formed a tight
low-level vortex based on the earlier cloud motions before a
convective burst obscured the center. Scatterometer data that
clipped the system on the east side also showed winds near tropical
storm intensity. The NOAA aircraft flew through the system shortly
thereafter, and found the system had indeed formed a well-defined
center, with 950-mb flight level winds of 51 kt just to the
northeast of the center. All this information confirms that
Tropical Storm Franklin has formed this afternoon, with an initial
intensity set at 40 kt.
The initial motion is off to the west-northwest at 290/12 kt. Over
the next 24 hours this general motion should continue while the
system remains steered by a narrow mid-level ridge. Thereafter, a
large mid-ocean trough over the western Atlantic will produce a
pronounced weakness in this ridging, likely causing the tropical
storm to make a sharp turn northward, bringing the storm near or
over the large island of Hispaniola in about 48-60 h. Afterwards,
another mid-latitude trough is forecast to amplify southward,
maintaining this weakness, and resulting in Franklin turning
northeastward towards the end of the forecast period. There is a
decent amount of spread in the track guidance, related to just when
Franklin will make the initial northward turn. For this initial
forecast, the NHC track forecast will stick close to the track
consensus TVCN, which favors a track in between the latest ECMWF and
GFS solutions, favoring the GFS a bit more.
Intensity wise, Franklin may have to deal with a bit of westerly
wind shear in the short-term, limiting more robust intensification
early on. However, this shear drops off as the system makes its turn
northward towards Hispaniola a bit more intensification is shown
with a 55-kt intensity peak as Franklin approaches the coast. The
intensity forecast then is complicated by the fact that Franklin
will likely pass near or over the island sometime in the 2-3 day
time period, and some weakening is shown during this time.
However, the forecast environment after the system re-emerges into
the Western Atlantic looks mostly favorable, with reintensification
likely as long as the system is not too disrupted by the higher
terrain of Hispaniola. The NHC intensity forecast is in good
agreement with the consensus aids, and lies closest to the HFIP
corrected consensus approach through the forecast period.
Based on the current track forecast, a tropical storm watch has
been issued for the entire southern coastline of Haiti and the
Dominican Republic.
KEY MESSAGES:
1. Franklin is forecast to approach Hispaniola late on Tuesday and
move across the island on Wednesday as a tropical storm, bringing a
risk of flooding from heavy rainfall, strong winds, and dangerous
waves along the coast.
2. Heavy rainfall from Franklin is expected across portions of
Puerto Rico and Hispaniola through the middle of the week. The heavy
rainfall may produce areas of flash and urban flooding as well as
river rises and mudslides. Across Hispaniola, significant and
potentially life-threatening flash flooding is possible Tuesday into
Wednesday.
FORECAST POSITIONS AND MAX WINDS
INIT 20/2100Z 14.6N 67.1W 40 KT 45 MPH
12H 21/0600Z 15.0N 68.9W 45 KT 50 MPH
24H 21/1800Z 15.4N 70.7W 45 KT 50 MPH
36H 22/0600Z 15.8N 71.5W 50 KT 60 MPH
48H 22/1800Z 17.2N 71.5W 55 KT 65 MPH
60H 23/0600Z 19.1N 71.1W 50 KT 60 MPH...INLAND
72H 23/1800Z 21.0N 70.6W 55 KT 65 MPH...OVER WATER
96H 24/1800Z 23.9N 67.5W 65 KT 75 MPH
120H 25/1800Z 25.4N 65.0W 75 KT 85 MPH
$$
Forecaster Papin
Tropical Storm Franklin Intermediate Advisory Number 1A
NWS National Hurricane Center Miami FL AL082023
800 PM AST Sun Aug 20 2023
...NOAA AIRCRAFT DATA SHOWS FRANKLIN MAINTAINING STRENGTH...
SUMMARY OF 800 PM AST...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...14.8N 67.8W
ABOUT 240 MI...385 KM SSE OF ISLA SAONA DOMINICAN REPUBLIC
ABOUT 280 MI...450 KM SSW OF SAN JUAN PUERTO RICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
None