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KF5JRV > WX 24.09.18 12:43l 102 Lines 4245 Bytes #999 (0) @ NA
BID : 21958_KF5JRV
Read: GUEST
Subj: NWS NHC Atlantic WX - Sept 24
Path: IW8PGT<CX2SA<HP2BWJ<LU4ECL<PI8CDR<PI8HGL<PI8BDG<AB0AF<KF5JRV
Sent: 180924/1115Z 21958@KF5JRV.#NWAR.AR.USA.NA BPQ6.0.16
632
WTNT42 KNHC 240833
TCDAT2
Tropical Depression Kirk Discussion Number 8
NWS National Hurricane Center Miami FL AL122018
500 AM AST Mon Sep 24 2018
After having a minimal amount of deep convection late yesterday,
Kirk is now producing some thunderstorm activity in fragmented bands
around the estimated center. However, earlier ASCAT data and low
cloud motion suggest that the circulation resembles a sharp trough
instead of a closed low that is necessary for a tropical cyclone.
Hopefully more visible satellite images and additional scatterometer
data will help better assess the circulation and status of Kirk.
For now, advisories are being maintained on the system, and the
initial intensity is held at 30 kt based on the earlier ASCAT data
and a blend of the Dvorak estimates.
Kirk is moving very quickly to the west at about 21 kt, which is
likely the reason why the system has been struggling. A continued
westward motion but at a decreasing forward speed is expected during
the next two to three days while the cyclone remains on the south
side of a low- to mid-level ridge. After that time, a large
deep-layer low pressure system over the central Atlantic should
cause Kirk to gain more latitude. The NHC track forecast is largely
an update of the previous one, and remains near the southern side of
the guidance envelope near the GFS and ECMWF models. This forecast
takes Kirk toward the Lesser Antilles in 3 to 4 days and interests
there should monitor the progress of this system.
Although Kirk will be moving over warmer SSTs and remain in
relatively moist conditions, its fast forward speed will likely
limit the system from strengthening significantly during the next
few days, so only a little intensification is predicted. The global
models show a notable increase in westerly shear when Kirk reaches
the eastern Caribbean Sea in about 4 days, and that should cause
weakening and possibly even dissipation by the end of the forecast
period. The NHC intensity forecast lies near the lower side of the
guidance envelope, in best agreement with the NOAA HCCA model.
FORECAST POSITIONS AND MAX WINDS
INIT 24/0900Z 9.5N 37.4W 30 KT 35 MPH
12H 24/1800Z 9.9N 40.5W 30 KT 35 MPH
24H 25/0600Z 10.2N 44.6W 35 KT 40 MPH
36H 25/1800Z 10.5N 48.4W 35 KT 40 MPH
48H 26/0600Z 10.9N 51.7W 40 KT 45 MPH
72H 27/0600Z 12.1N 57.1W 40 KT 45 MPH
96H 28/0600Z 13.2N 61.5W 35 KT 40 MPH
120H 29/0600Z 14.0N 66.0W 30 KT 35 MPH
$$
Forecaster Cangialosi
385
WTNT43 KNHC 240832
TCDAT3
Subtropical Storm Leslie Discussion Number 4
NWS National Hurricane Center Miami FL AL132018
500 AM AST Mon Sep 24 2018
Leslie has changed little overnight. The large subtropical cyclone
continues to produce patches of deep convection, mostly to the south
and east of the center. The initial intensity is again held at 35
kt, which is near the upper end of the satellite intensity
estimates.
The subtropical storm is moving southward at 5 kt. The steering
currents around Leslie are expected to collapse later today and
little overall motion is forecast during the next 12-18 hours.
After that time, a cold front is expected to approach the system,
and that should cause Leslie to move eastward tonight and Tuesday.
The front is expected to merge with Leslie by Tuesday night, causing
it to become extratropical. While little change in intensity is
expected during the next day or so, due to dry air and moderate
shear, some strengthening as an extratropical low is likely due to
baroclinic forcing. In fact, after becoming extratropical, the
models show Leslie merging with another frontal low to its north,
leading to the formation of a powerful slow-moving non-tropical low
with gale- or storm-force winds over the central Atlantic later this
week.
FORECAST POSITIONS AND MAX WINDS
INIT 24/0900Z 32.6N 48.6W 35 KT 40 MPH
12H 24/1800Z 32.6N 48.3W 35 KT 40 MPH
24H 25/0600Z 32.6N 46.9W 35 KT 40 MPH
36H 25/1800Z 32.5N 44.8W 35 KT 40 MPH
48H 26/0600Z 32.7N 42.0W 45 KT 50 MPH...POST-TROPTRATROP
72H 27/0600Z...MERGED WITH FRONTAL SYSTEM
$$
Forecaster Cangialosi
73 de Scott KF5JRV
Pmail: KF5JRV@KF5JRV.#NWAR.AR.USA.NA
email: KF5JRV@ICLOUD.COM
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