Sunday, August 20, 2023

Tropical Storm Franklin Forms In The Caribbean, Could Threaten The Region By Early Next Week










































149 
WTNT33 KNHC 210251
TCPAT3

BULLETIN
Tropical Storm Franklin Advisory Number   2
NWS National Hurricane Center Miami FL       AL082023
1100 PM AST Sun Aug 20 2023

...FRANKLIN A LITTLE STRONGER...
...TROPICAL STORM WARNINGS ISSUED FOR THE SOUTHERN COAST OF
HISPANIOLA...

SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...14.9N 68.3W
ABOUT 270 MI...435 KM SSE OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES

WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
The government of the Dominican Republic has issued a Tropical
Storm Warning along the south coast of the Dominican Republic from
the border with Haiti eastward to Isla Saona.  A Tropical Storm
Watch has been issue for the eastern and northern coast of the
Dominican Republic from Isla Saona eastward and northward to the
northern border with Haiti.

A Tropical Storm Warning has been issued for the entire south coast
of Haiti from Anse d'Hainault eastward to the Dominican Republic
border.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
* Dominican Republic entire south coast from Haiti border eastward
to Isla Saona
* Haiti entire south coast from Anse d'Hainault eastward to the
Dominican Republic border

A Tropical Storm Watch is in effect for...
* Dominican Republic entire north and east coast from the Haiti
border eastward and southward to Isla Saona

A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area within 36 hours.

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 1100 PM AST (0300 UTC), the center of Tropical Storm Franklin was 
located near latitude 14.9 North, longitude 68.3 West. Franklin is 
moving toward the west near 12 mph (19 km/h). A westward to 
west-northwestward track is expected to continue into Monday. A 
sharp turn to the north is expected Monday night and a northward 
motion is expected on Tuesday.  On the forecast track, the center of 
Franklin is forecast to reach the southern coast of Hispaniola late 
Tuesday or Tuesday night.

Maximum sustained winds are near 50 mph (85 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 estimated minimum central pressure is 999 mb (29.50 inches).

HAZARDS AFFECTING LAND
----------------------
Key messages for Franklin can be found in the Tropical Cyclone
Discussion under AWIPS header MIATCDAT3 and WMO header WTNT43 KNHC
and on the web at hurricanes.gov/text/MIATCDAT3.shtml.

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.

WIND:  Tropical storm conditions are expected to begin within the 
warning area on Tuesday and are possible within the watch area 
beginning late Tuesday.

STORM SURGE: A storm surge will raise water levels by as much as 1
to 3 feet above ground level along the immediate coast near and to
the east of where the center makes landfall in Hispaniola.


NEXT ADVISORY
-------------
Next intermediate advisory at 200 AM AST.
Next complete advisory at 500 AM AST.

$$
Forecaster Brown


000
WTNT33 KNHC 202053
TCPAT3

BULLETIN
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


000
WTNT43 KNHC 210255
TCDAT3

Tropical Storm Franklin Discussion Number   2
NWS National Hurricane Center Miami FL       AL082023
1100 PM AST Sun Aug 20 2023

Deep convection continues to burst near and to the east of the
center of Franklin. Earlier NOAA aircraft fixes and more recent
microwave satellite data indicate that the center of Franklin is
located near the northwestern edge of the deep convection due to
moderate westerly shear. The latest Dvorak T-number from TAFB is
T3.0 (45 kt) and SAB provided a data T-number of T2.5 (35 kt).  A 
very recently arriving ASCAT pass revealed peak winds of 40-45 kt, 
therefore the initial intensity has been raised to 45 kt. 

Franklin is moving west-northwestward at about 11 kt. A slower
westward to west-northwest motion is forecast overnight.  By late
Monday, a deepening trough over the western Atlantic is forecast to
cause Franklin to turn northwestward and then northward toward
Hispaniola.  The tropical storm is forecast to pass over that
island Tuesday night, and then move off the north coast of
Hispaniola by early Wednesday.  After that time, the amplifying
trough is forecast to turn Franklin northeastward.  There is still 
a fair amount of spread on where the northward turn will take place 
and the official forecast remains near the middle of the guidance 
envelope. 

Franklin is expected to remain in an environment of moderate 
westerly shear during the next couple of days, but it is not likely 
to prevent some modest strengthening before Franklin reaches the 
southern coast of Hispaniola. Interaction with the mountainous 
terrain of Hispaniola is expected to cause some weakening.  Once 
Franklin moves into the western Atlantic, most of the intensity 
guidance suggests additional strengthening is likely and the NHC 
forecast follows suit. The NHC intensity forecast is a blend of 
the HFIP corrected consensus model and the IVCN multi-model 
consensus aid.  

Based on the current track forecast, a tropical storm warning 
has been issued for the entire southern coastline of Haiti and the
Dominican Republic.


KEY MESSAGES:

1. 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.

2. Franklin is expected to bring tropical storm conditions to
portions of the Dominican Republic and Haiti beginning on Tuesday
where Tropical Storm Warnings are in effect.


FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 14.9N  68.3W   45 KT  50 MPH
 12H  21/1200Z 15.0N  70.0W   50 KT  60 MPH
 24H  22/0000Z 15.3N  71.0W   50 KT  60 MPH
 36H  22/1200Z 16.2N  71.5W   55 KT  65 MPH
 48H  23/0000Z 18.1N  71.4W   55 KT  65 MPH...INLAND
 60H  23/1200Z 20.0N  70.9W   45 KT  50 MPH...OVER WATER
 72H  24/0000Z 21.9N  69.9W   50 KT  60 MPH
 96H  25/0000Z 24.3N  67.0W   60 KT  70 MPH
120H  26/0000Z 26.2N  64.4W   70 KT  80 MPH

$$
Forecaster Brown


000
FXUS61 KCAR 210157
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
957 PM EDT Sun Aug 20 2023

.SYNOPSIS...
A cold front approaches this evening, then crosses the region
late tonight into Monday. High pressure then builds in through
Wednesday night, then slowly slides to the east on Thursday......

......LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Upr trof moves into the Maritimes Wed night with 596 ridge
setting up shop over the southern Plains. CWA will be on the
periphery of the ridge through Thursday before it begins to
flatten and re-strengthen back over the Rockies on Friday.

Still remains unclear if moisture from TC Hilary gets caught up
in flow around H5 pressure but most deterministic and ensemble
runs suggest that it will. At the sfc, high pressure will be
shoving east Wed night through Thu with showers possibly
sneaking into wrn areas Thu evening. 12z GFS remains the
quickest with system as it brings cold front thru Fri night,
whereas EC moves upr trof thru on Sat evening. Interesting to
note that 12z deterministic GEM develops closed low over the
Great Lakes next weekend while perhaps pulling moisture in from
tropical system moving closer to the CONUS late next weekend.

For now have sided with NBM pops but capped pops at high chance
Fri and Fri night. Significant uncertainties continue at week/s
end, both between deterministic and ensemble guidance with
latest GEM ensemble not showing any signs of a closed low at
this point.......