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KF5JRV > WX 11.10.18 12:44l 165 Lines 6852 Bytes #999 (0) @ NA
BID : 22876_KF5JRV
Read: GUEST
Subj: NWS NHC Atlantic WX - Oct 11
Path: IW8PGT<CX2SA<SV1CMG<PI8BDG<AB0AF<KF5JRV
Sent: 181011/1123Z 22876@KF5JRV.#NWAR.AR.USA.NA BPQ6.0.16
000
WTNT43 KNHC 110849
TCDAT3
Hurricane Leslie Discussion Number 60
NWS National Hurricane Center Miami FL AL132018
500 AM AST Thu Oct 11 2018
The cloud pattern of Leslie has not changed significantly
overnight. The hurricane has a large and ragged eye with deep
convection most organized on its east side. The Dvorak CI-numbers
are unchanged at 4.0/65 kt from TAFB and 4.5/77 kt from SAB, and
based on these data, the initial intensity is held at 70 kt.
Leslie will remain in low wind shear conditions and over relatively
warm waters for another day or two, so little change in strength is
expected during that time. Thereafter, the hurricane is forecast
to move over waters as cool as 24 deg C and into an atmospheric
environment of stronger shear and drier air. All of these
conditions point to a weakening trend, which is likely to begin by
the weekend. Most of the guidance shows a cold front approaching
Leslie, but not quite merging with it so extratropical transition is
not expected. However, it seems likely that Leslie will lose its
convection and become a weaker post-tropical low in about 4 days.
This scenario is supported by the latest runs of the GFS, ECMWF, and
HWRF models.
Leslie has made the expected east-northeastward turn with the latest
initial motion estimated to be 065/9. This east-northeastward motion
with an increase in forward speed is forecast to continue for the
next 2 days while the steering pattern holds. After that time,
however, it becomes much less clear. The models continue to
struggle and keep changing their tune cycle to cycle on whether or
not Leslie continues east-northeastward toward Morocco or Portugal,
or gets left behind and moves west-southwestward due to a building
ridge. The ensemble members of both the GFS and ECMWF favor the
left behind (or southwestward) solution, and the NHC track forecast
continues to lean in that direction. This forecast does show Leslie
moving farther east before it makes the southwestward turn to be in
better agreement with the latest consensus aids.
FORECAST POSITIONS AND MAX WINDS
INIT 11/0900Z 28.4N 40.1W 70 KT 80 MPH
12H 11/1800Z 29.3N 37.8W 75 KT 85 MPH
24H 12/0600Z 30.9N 33.3W 75 KT 85 MPH
36H 12/1800Z 32.1N 27.5W 70 KT 80 MPH
48H 13/0600Z 32.7N 22.3W 70 KT 80 MPH
72H 14/0600Z 31.3N 18.7W 50 KT 60 MPH
96H 15/0600Z 29.0N 19.5W 35 KT 40 MPH...POST-TROPICAL
120H 16/0600Z 27.5N 24.5W 30 KT 35 MPH...POST-TROP/REMNT LOW
$$
Forecaster Cangialosi
000
WTNT44 KNHC 110849
TCDAT4
Tropical Storm Michael Discussion Number 19
NWS National Hurricane Center Miami FL AL142018
500 AM EDT Thu Oct 11 2018
Surface observations and WSR-88D Doppler radar data indicate that
Michael continues to weaken as the center moves through eastern
Georgia, and based on these data the initial intensity is decreased
to 45 kt. There is currently a small area of tropical-storm-force
winds near the center, with a second area over the Atlantic well to
the southeast of the center. Michael should continue to weaken for
the next 12 h or so as the center moves through South Carolina
and into North Carolina. After that time, the cyclone should start
to intensify due to baroclinic forcing, and it is expected to become
a gale- or storm-force extratropical low around the 24-h point. The
new intensity forecast is an update of the previous forecast, and
it leans heavily on global model guidance during the extratropical
phase.
The initial motion is now 045/18. Michael will accelerate toward
the northeast and east-northeast as it becomes further embedded in
the mid-latitude westerlies. The new track forecast track is near
the various consensus models and has no significant changes from the
previous forecast.
Gale- to storm-force winds are expected over portions of the
Mid-Atlantic coast as Michael exits the U.S. east coast and becomes
post-tropical. Non-tropical high wind watches, warnings, and
advisories have been issued by local NWS offices for wind hazards in
these areas north of Duck, North Carolina.
Key Messages:
1. Heavy rainfall from Michael could produce life-threatening flash
flooding over portions of Georgia, the Carolinas, and southeastern
Virginia.
2. Tropical storm conditions will continue to affect portions of the
southeast U.S. coast from Georgia through North Carolina, and
tropical storm warnings remain in effect for these areas.
FORECAST POSITIONS AND MAX WINDS
INIT 11/0900Z 33.5N 82.5W 45 KT 50 MPH...INLAND
12H 11/1800Z 35.4N 79.4W 40 KT 45 MPH...INLAND
24H 12/0600Z 37.9N 74.1W 45 KT 50 MPH...POST-TROPTRATROP
36H 12/1800Z 40.9N 65.8W 50 KT 60 MPH...POST-TROPTRATROP
48H 13/0600Z 44.1N 55.0W 55 KT 65 MPH...POST-TROPTRATROP
72H 14/0600Z 48.0N 29.5W 55 KT 65 MPH...POST-TROPTRATROP
96H 15/0600Z 49.0N 9.0W 45 KT 50 MPH...POST-TROPTRATROP
120H 16/0600Z...DISSIPATED
$$
Forecaster Beven
000
WTNT45 KNHC 110850
TCDAT5
Tropical Storm Nadine Discussion Number 9
NWS National Hurricane Center Miami FL AL152018
500 AM AST Thu Oct 11 2018
Nadine is a sheared tropical storm with the low-level center located
near the western edge of the main area of deep convection. An ASCAT
pass from several hours ago showed maximum winds in the 50-55 kt
range, and since the satellite appearance has not changed much, the
initial intensity is held at 55 kt. This value is near the high end
of the satellite-based intensity estimates. The environment near
Nadine is expected to become even more hostile during the next
couple of days due to the combined effects of strong west-
southwesterly shear and drier air. Therefore, steady weakening is
forecast, and dissipation is expected to occur in 2 to 3 days when
the shear is forecast to be in excess of 30 kt. The models are in
good agreement, and little change was made to the previous NHC
intensity forecast.
The storm is moving northwestward at 7 kt. The track forecast
reasoning is unchanged from previous advisories. Nadine is expected
to continue moving northwestward for about another day while the
tropical storm remains relatively deep, or vertically coherent.
After that time, the weakening and increasingly shallow cyclone is
forecast to turn to the left in the low-level flow, and that motion
should continue until the system dissipates. The NHC track forecast
lies near the middle of the guidance envelope, and it is not too
different than the previous one.
FORECAST POSITIONS AND MAX WINDS
INIT 11/0900Z 14.1N 33.3W 55 KT 65 MPH
12H 11/1800Z 14.9N 34.1W 45 KT 50 MPH
24H 12/0600Z 15.7N 35.4W 40 KT 45 MPH
36H 12/1800Z 16.3N 37.0W 35 KT 40 MPH
48H 13/0600Z 16.7N 39.0W 30 KT 35 MPH
72H 14/0600Z...DISSIPATED
$$
Forecaster Cangialosi
73 de Scott KF5JRV
Pmail: KF5JRV@KF5JRV.#NWAR.AR.USA.NA
email: KF5JRV@ICLOUD.COM
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