53driver
09-10-2018, 06:28 PM
Members,
Hurricane Florence is now a full blown Cat 4 and shows no signs of weakening.
From the NOAA National Hurricane Center:
"Hurricane Florence Discussion Number 46
NWS National Hurricane Center Miami FL AL062018
500 PM AST Mon Sep 10 2018
Unfortunately, the models were right. Florence has rapidly
intensified into an extremely dangerous hurricane, with 30-second
GOES-16 visible imagery showing well-defined eyewall mesovortices
rotating inside of the eye. A NOAA Hurricane Hunter aircraft found
peak SFMR winds of about 120 kt, with flight-level winds and
dropsonde measurements also supporting that value for the initial
wind speed estimate. Notably, the aircraft data also show the size
of the hurricane-force winds has doubled in the past 12 hours.
None of the guidance suggest that Florence has peaked in intensity,
and this is supported by a continuation of a low-shear environment,
and even warmer waters over the next 36 hours. Thus, the intensity
forecast is raised from the previous one, bringing Florence close
to category 5 strength tomorrow. Near landfall, the vertical wind
shear could increase, along with the increasing likelihood of
eyewall cycles. While the intensity forecast shows some weakening
of the maximum winds near landfall, the wind field is expected to
grow with time, which increases the storm surge and inland wind
threats. The bottom line is that there is high confidence that
Florence will be a large and extremely dangerous hurricane,
regardless of its exact intensity.
Florence has recently turned west-northwestward, still moving at 11
kt. The hurricane is expected to accelerate in that direction over
the next day or two due to building mid-level ridge over the
northwestern Atlantic Ocean. By late Wednesday, a turn toward the
northwest is forecast due to the orientation of the Atlantic ridge,
along with a decrease in forward speed due to a new ridge building
over the Great Lakes. There is a new player in the forecast as
well, with the disturbance over the northwestern Caribbean adding
some uncertainty in the ridge strength over the southeastern United
States. Perhaps it isn't surprising that the model spread has
increased on this cycle, with a small eastward shift overall. The
official forecast is nudged in the direction of the trend, but is
west of the model consensus. It is important not to focus on the
exact forecast track as average NHC errors at days 4 and 5 are about
140 and 180 n mi, respectively, and dangerous hazards will extend
well away from the center."
Various links:
https://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/102055.shtml
https://www.nhc.noaa.gov/#Florence
http://www.spaghettimodels.com
https://www.tropicaltidbits.com/storminfo/#06L
Hurricane Florence is now a full blown Cat 4 and shows no signs of weakening.
From the NOAA National Hurricane Center:
"Hurricane Florence Discussion Number 46
NWS National Hurricane Center Miami FL AL062018
500 PM AST Mon Sep 10 2018
Unfortunately, the models were right. Florence has rapidly
intensified into an extremely dangerous hurricane, with 30-second
GOES-16 visible imagery showing well-defined eyewall mesovortices
rotating inside of the eye. A NOAA Hurricane Hunter aircraft found
peak SFMR winds of about 120 kt, with flight-level winds and
dropsonde measurements also supporting that value for the initial
wind speed estimate. Notably, the aircraft data also show the size
of the hurricane-force winds has doubled in the past 12 hours.
None of the guidance suggest that Florence has peaked in intensity,
and this is supported by a continuation of a low-shear environment,
and even warmer waters over the next 36 hours. Thus, the intensity
forecast is raised from the previous one, bringing Florence close
to category 5 strength tomorrow. Near landfall, the vertical wind
shear could increase, along with the increasing likelihood of
eyewall cycles. While the intensity forecast shows some weakening
of the maximum winds near landfall, the wind field is expected to
grow with time, which increases the storm surge and inland wind
threats. The bottom line is that there is high confidence that
Florence will be a large and extremely dangerous hurricane,
regardless of its exact intensity.
Florence has recently turned west-northwestward, still moving at 11
kt. The hurricane is expected to accelerate in that direction over
the next day or two due to building mid-level ridge over the
northwestern Atlantic Ocean. By late Wednesday, a turn toward the
northwest is forecast due to the orientation of the Atlantic ridge,
along with a decrease in forward speed due to a new ridge building
over the Great Lakes. There is a new player in the forecast as
well, with the disturbance over the northwestern Caribbean adding
some uncertainty in the ridge strength over the southeastern United
States. Perhaps it isn't surprising that the model spread has
increased on this cycle, with a small eastward shift overall. The
official forecast is nudged in the direction of the trend, but is
west of the model consensus. It is important not to focus on the
exact forecast track as average NHC errors at days 4 and 5 are about
140 and 180 n mi, respectively, and dangerous hazards will extend
well away from the center."
Various links:
https://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/102055.shtml
https://www.nhc.noaa.gov/#Florence
http://www.spaghettimodels.com
https://www.tropicaltidbits.com/storminfo/#06L