WTNT33 KNHC 260248
TCPAT3
BULLETIN
Tropical Storm Franklin Advisory Number 22
NWS National Hurricane Center Miami FL AL082023
1100 PM AST Fri Aug 25 2023
...FRANKLIN STRENGTHENS...
SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...22.4N 66.2W
ABOUT 320 MI...515 KM ENE OF GRAND TURK ISLAND
ABOUT 690 MI...1110 KM S OF BERMUDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...ENE OR 60 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...996 MB...29.42 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Franklin was
located near latitude 22.4 North, longitude 66.2 West. Franklin is
moving toward the east-northeast near 8 mph (13 km/h). A sharp turn
toward the north is expected on Saturday, followed by a northward to
north-northwestward motion over the western Atlantic through early
next week.
Maximum sustained winds have increased to near 60 mph (95 km/h) with
higher gusts. Gradual strengthening is forecast during the next day
or so, followed by more significant strengthening on Sunday and
Monday. Franklin is forecast to become a hurricane by early next
week.
Tropical-storm-force winds extend outward up to 115 miles (185 km)
from the center.
The estimated minimum central pressure based on dropsonde data from
the Air Force Hurricane Hunters is 996 mb (29.42 inches).
HAZARDS AFFECTING LAND
----------------------
None.
NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.
$$
Forecaster Reinhart
932
WTNT43 KNHC 260249
TCDAT3
Tropical Storm Franklin Discussion Number 22
NWS National Hurricane Center Miami FL AL082023
1100 PM AST Fri Aug 25 2023
Westerly shear continues to affect Franklin tonight, as evidenced by
the sharp edge to its cold cloud tops on infrared satellite images.
However, the low-level center that was exposed earlier today appears
to have moved under the western edge of the convective canopy. An
Air Force Reserve Hurricane Hunter aircraft flew the storm at 700 mb
this evening and reported peak flight-level winds of 56 kt, with
believable SFMR winds in the 45-55 kt range. These data warrant a
slight increase to the initial intensity (50 kt), especially given a
recent dropsonde that suggests the surface pressure has fallen to
996 mb tonight. A recent ASCAT-B pass over Franklin further supports
this, with peak wind vectors slightly above 45 kt. Note that the
initial intensity of Franklin is more uncertain than normal, with
there being a large spread between some of the aircraft data and the
various objective and subjective satellite estimates.
The intense convection closer to the center of Franklin appears to
have drawn the surface center more northeastward, and the initial
motion is an uncertain 60/7 kt. A high pressure ridge building to
the east of Franklin is expected to steer the cyclone more northward
and north-northwestward this weekend and into early next week. Then,
a deep-layer trough is forecast to move across the northeastern U.S.
and eastern Canada by midweek. This should cause Franklin to
accelerate northeastward deeper into the mid latitudes through the
end of the forecast period. The updated NHC track forecast lies to
the east of the previous one during the first 60-72 h of the period,
mainly a result of the eastward adjustment to the initial position
of Franklin. There are some notable forward speed differences beyond
72 h, with the GFS significantly faster than the rest of the global
and regional models. With the NHC forecast remaining near the
multi-model consensus aids, no notable changes were made to this
portion of the track forecast.
The westerly shear that has plagued Franklin for the past couple of
days is expected to decrease during the next 24-36 h. So while only
modest strengthening is forecast in the near term, more significant
strengthening seems likely thereafter as the cyclone moves over
very warm SSTs (29-30 deg C) and within a more favorable dynamic
environment. The updated forecast shows Franklin becoming a
hurricane by 48 h and peaking near major hurricane intensity in
72-96 h, in good agreement with the latest HCCA and IVCN aids. As
Franklin accelerates to higher latitudes, cooler waters and
increased deep-layer shear will induce weakening and eventually
extratropical transition beyond the end of the forecast period.
FORECAST POSITIONS AND MAX WINDS
INIT 26/0300Z 22.4N 66.2W 50 KT 60 MPH
12H 26/1200Z 23.0N 66.0W 55 KT 65 MPH
24H 27/0000Z 23.9N 66.3W 55 KT 65 MPH
36H 27/1200Z 25.3N 67.0W 60 KT 70 MPH
48H 28/0000Z 27.0N 67.9W 70 KT 80 MPH
60H 28/1200Z 28.8N 68.4W 80 KT 90 MPH
72H 29/0000Z 30.5N 68.4W 95 KT 110 MPH
96H 30/0000Z 34.7N 66.5W 95 KT 110 MPH
120H 31/0000Z 40.0N 60.0W 75 KT 85 MPH
$$
Forecaster Reinhart
12:02 PM ADT Friday 25 August 2023
Tropical Cyclone Information Statement (Franklin) in effect for:
Marine Zone
Maritime Waters
East Scotian Slope
Laurentian Fan
Newfoundland Waters
Southeastern Grand Banks
Southwestern Grand Banks
For Tropical Storm Franklin.
This is the first official CHC bulletin on Tropical Storm Franklin expected to become a strong category-2 hurricane tracking west of Bermuda next week. We have been posting general outlooks on our Twitter/X account @ECCC_CHC since Monday. Computer models can now simulate hurricanes out to 10 days into the future but the scenarios that they depict can be far from reality and generate great speculations.
Now that we are within about 5 days of Franklin entering Canadian offshore waters, we have a somewhat better idea of how the storm may affect our weather around the middle of next week. The most likely track as of now is for Franklin to pass well south of Nova Scotia and close to southeastern Newfoundland with the windiest part of the storm staying offshore. This could certainly change, so check back on this bulletin Saturday and Sunday when it will be updated with the latest forecast discussion. Six-hourly updates are planned to begin early Monday.
Rainfall may be the main aspect of the storm to contend with. The southern portions of the Atlantic Canadian marine district will have a greater probability of strong winds and high seas. There will also be non-tropical weather systems well northwest of the hurricane that will be affecting Atlantic Canada during that timeframe (middle of next week). Whenever there is a possible interaction between non-tropical weather systems and a tropical system there is an increased threat for heavy rain.
The next bulletin from the CHC is planned for Saturday afternoon.
Forecaster: Fogarty
Please continue to monitor alerts issued by the Canadian Hurricane Centre and forecasts issued by Environment Canada.
