225
WTNT31 KNHC 100853
TCPAT1
BULLETIN
Hurricane Florence Advisory Number 44
NWS National Hurricane Center Miami FL AL062018
500 AM AST Mon Sep 10 2018
...FLORENCE RAPIDLY STRENGTHENING...
...EXPECTED TO BECOME A MAJOR HURRICANE VERY SOON...
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...24.9N 58.9W
ABOUT 625 MI...1005 KM SE OF BERMUDA
ABOUT 535 MI...860 KM NNE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...969 MB...28.62 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
Interests in the southeastern and mid-Atlantic states should monitor
the progress of Florence.
DISCUSSION AND OUTLOOK
----------------------
At 500 AM AST (0900 UTC), the center of Hurricane Florence was
located near latitude 24.9 North, longitude 58.9 West. Florence is
moving toward the west-northwest near 9 mph (15 km/h). A
west-northwestward motion with an increase in forward speed is
expected during the next couple of days. A turn toward the
northwest is forecast to occur Wednesday night or Thursday. On the
forecast track, the center of Florence will move over the
southwestern Atlantic Ocean between Bermuda and the Bahamas Tuesday
and Wednesday, and approach the southeastern coast of the United
States on Thursday.
Satellite imagery indicates that the maximum sustained winds have
increased to near 105 mph (165 km/h) with higher gusts. Rapid
strengthening is forecast, and Florence is forecast to become a
major hurricane this morning, and is expected to remain an extremely
dangerous major hurricane through Thursday.
Hurricane-force winds extend outward up to 25 miles (35 km) from the
center and tropical-storm-force winds extend outward up to 125 miles
(205 km).
The estimated minimum central pressure is 969 mb (28.62 inches).
HAZARDS AFFECTING LAND
----------------------
SURF: Swells generated by Florence are affecting Bermuda and
portions of the U.S. East Coast. 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 1100 AM AST.
=================================================
431
WTNT31 KNHC 091448
TCPAT1
BULLETIN
Hurricane Florence Advisory Number 41
NWS National Hurricane Center Miami FL AL062018
1100 AM AST Sun Sep 09 2018
...FLORENCE FORECAST TO RAPIDLY INTENSIFY INTO A MAJOR HURRICANE BY
MONDAY...
SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...24.4N 56.3W
ABOUT 750 MI...1210 KM SE OF BERMUDA
ABOUT 610 MI...985 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...984 MB...29.06 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the center of Hurricane Florence was
located by a NOAA Hurricane Hunter aircraft near latitude 24.4
North, longitude 56.3 West. Florence is moving toward the west near
6 mph (9 km/h), and this general motion is expected to continue
today. A west-northwestward motion with an increase in forward
speed is expected by Monday, and that motion is forecast to continue
through mid-week. On the forecast track, the center of Florence
will move over the southwestern Atlantic Ocean between Bermuda and
the Bahamas Tuesday and Wednesday, and approach the southeastern
U.S. coast on Thursday.
Aircraft data indicate that maximum sustained winds have increased
to near 75 mph (120 km/h) with higher gusts. Florence is forecast
to rapidly strengthen to a major hurricane by Monday, and is
expected to remain an extremely dangerous major hurricane through
Thursday.
Hurricane-force winds extend outward up to 15 miles (30 km) from the
center and tropical-storm-force winds extend outward up to 115 miles
(185 km).
The latest minimum central pressure reported by a NOAA Hurricane
Hunter Aircraft is 984 mb (29.06 inches).
HAZARDS AFFECTING LAND
----------------------
SURF: Swells generated by Florence are affecting Bermuda and are
beginning to reach portions of the U.S. East Coast. These swells
are likely to cause life-threatening surf and rip current
conditions. Please consult products from your local weather office.
===============================
442
WTNT31 KNHC 090843
TCPAT1
BULLETIN
Tropical Storm Florence Advisory Number 40
NWS National Hurricane Center Miami FL AL062018
500 AM AST Sun Sep 09 2018
...FLORENCE EXPECTED TO BECOME A HURRICANE TODAY...
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...24.5N 55.8W
ABOUT 765 MI...1235 KM SE OF BERMUDA
ABOUT 640 MI...1030 KM NE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...989 MB...29.21 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 Storm Florence was
located near latitude 24.5 North, longitude 55.8 West. Florence is
moving toward the west near 6 mph (9 km/h), and this general motion
is expected to continue today. A west-northwestward motion with an
increase in forward speed is expected by Monday, and that motion is
forecast to continue through mid-week. On the forecast track, the
center of Florence will move over the southwestern Atlantic Ocean
between Bermuda and the Bahamas Tuesday and Wednesday, and approach
the southeastern U.S. coast on Thursday.
Maximum sustained winds are near 70 mph (110 km/h) with higher
gusts. Florence is expected to become a hurricane today and rapid
intensification is likely to begin by tonight. Florence is forecast
to become a major hurricane on Monday.
Tropical-storm-force winds extend outward up to 125 miles (205 km)
from the center.
The estimated minimum central pressure is 989 mb (29.21 inches).
HAZARDS AFFECTING LAND
----------------------
SURF: Swells generated by Florence are affecting Bermuda and are
beginning to reach portions of the U.S. East Coast. 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 1100 AM AST.
=======================================
Tropical Storm Florence Discussion Number 35
NWS National Hurricane Center Miami FL AL062018
1100 PM AST Fri Sep 07 2018
Florence remains a sheared tropical cyclone. Satellite images
indicate that the low-level center is partially exposed on the
southwesterly edge of a large convective mass, with the overall
circulation somewhat elongated from southwest to northeast.
A blend of the latest Dvorak wind speed estimates from TAFB/SAB and
the CIMSS SATCON gives a value of 50 kt for this advisory.
While the winds at 200 mb are already from an easterly direction
near the center of Florence, there is significant shear from
northwesterly winds from 300-500 mb, undercutting the outflow layer.
This shear is forecast to relax by the global models over the next
36 hours as an anticyclone builds to the north of the storm, which
should promote some strengthening by Sunday. After 48 hours, the
deep-layer flow becomes easterly near the cyclone, with very little
shear while the system is over very warm waters. This pattern
favors significant intensification, and most of the guidance brings
Florence back to a category 4 hurricane in 4 or 5 days. The
intensity forecast is very similar to the last one, and is raised
slightly at days 3 and 4 to come into better agreement with the
guidance. It is interesting to note that even with a lower initial
intensity, the guidance is higher than the last cycle, which speaks
to the strength of the signal for intensification in the long range.
The initial motion estimate is 265 degrees at 6 kt. Florence is
expected to continue moving slowly westward for the next 48 hours
under the influence of a weak mid-level ridge over the western
Atlantic. By days 4 and 5, an exceptionally strong blocking ridge
is forecast to develop between Bermuda and the Northeast U.S. and
build westward, keeping Florence on a west-northwestward trajectory
with a notable increase in forward speed by the end of the forecast
period. It feels like a broken record to mention that the overall
guidance envelope keeps shifting southwestward, and the official
forecast is moved in that direction. Unfortunately with such a
large well-defined steering current from the ridge becoming likely,
the extended-range risk to the United States keeps rising, which is
confirmed by the majority of the latest ensemble guidance.
Key Messages:
1. Regardless of Florence's eventual track, large swells are
affecting Bermuda and will begin to affect portions of the U.S.
East Coast this weekend, resulting in life-threatening surf and rip
currents.
2. The risk of other direct impacts associated with Florence along
the U.S. East Coast next week has increased. However, there is
still very large uncertainty in model forecasts of Florence's track
beyond day 5, making it too soon to determine the exact location,
magnitude, and timing of these impacts. Interests near and along
the U.S. East Coast should monitor the progress of Florence through
the weekend and ensure they have their hurricane plans in place.
