ATL: EDOUARD - Post-Tropical - Discussion

[HurricaneBelle]

WTNT41 KNHC 190852
TCDAT1

TROPICAL STORM EDOUARD DISCUSSION NUMBER 32
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014
500 AM AST FRI SEP 19 2014

Satellite images indicate that Edouard has become much less
organized during the past several hours. The low-level center is
now exposed with no associated deep convection, with the old mid-
level circulation decoupled well to the southeast. With the
absence of deep convection, Edouard is probably losing strength
quickly, so the initial wind speed is lowered to 50 kt, a little
higher than the average of the satellite estimates in consideration
of the earlier Global Hawk/ASCAT data. Edouard is unlikely to
redevelop organized deep convection since it is over 23C water with
strong shear. Thus, the storm should continue to weaken and will
likely become post-tropical in about 12 hours. Extratropical
transition is indicated in a couple of days since most of the global
models are now showing the former tropical cyclone developing
frontal features by that time.

Edouard has slowed down considerably during the past few hours, with
initial motion estimate of 090/6 kt. A continued eastward
motion is predicted for the next day or so, followed by a turn to
the southeast when the cyclone becomes embedded in the flow between
the subtropical high and a deep-layer low over the northeast
Atlantic Ocean. The latest NHC forecast is blend of the previous
NHC prediction and the latest dynamical model consensus, which
results in a small westward shift in the 48-72 hour time frame.


FORECAST POSITIONS AND MAX WINDS

INIT 19/0900Z 39.8N 38.5W 50 KT 60 MPH
12H 19/1800Z 39.7N 37.5W 40 KT 45 MPH...POST-TROPICAL
24H 20/0600Z 39.7N 35.9W 35 KT 40 MPH...POST-TROPICAL
36H 20/1800Z 39.5N 33.5W 35 KT 40 MPH...POST-TROPICAL
48H 21/0600Z 38.5N 31.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
72H 22/0600Z 34.5N 30.0W 30 KT 35 MPH...POST-TROP/EXTRATROP
96H 23/0600Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

TROPICAL STORM EDOUARD DISCUSSION NUMBER 33
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014
1100 AM AST FRI SEP 19 2014

Edouard is weakening rapidly. Strong northwesterly shear has
caused the low- and mid-level centers of the cyclone to decouple
during the last 12 hours. The system has also been devoid of any
deep convection for some time, and unless it returns, Edouard
will be declared a post-tropical cyclone later today. Using a blend
of Dvorak CI and Final T numbers, the initial intensity estimate is
lowered to 40 kt. A 1214 UTC ASCAT pass showed believable 33-kt wind
vectors in the southwestern quadrant, suggesting that somewhat
higher winds are possible elsewhere in the southern half of the
circulation. Edouard is expected to spin down further during the
next couple of days due to a continuation of strong northwesterly
shear and its passage over cold water. Extratropical transition is
indicated by the global models in about 48 hours. The intensity
forecast is a bit lower than the previous one and now shows
remnant low status sooner. Dissipation is expected in about 3 days.

Edouard has significantly decelerated during the last 6-12 hours,
and the initial motion estimate is 110/03. The cyclone is expected
to move eastward with some increase in forward speed during the next
day or so as it rounds the northern side of a low-level ridge to
the south. A turn toward the southeast and south is shown after
that time as the extratropical cyclone dives into the flow on the
west side of a low pressure area over the northeastern Atlantic.
The track forecast is basically an update of the previous one, only
shifted a bit to the left but not as far left as the ECMWF and GFS
solutions.


FORECAST POSITIONS AND MAX WINDS

INIT 19/1500Z 39.5N 38.3W 40 KT 45 MPH
12H 20/0000Z 39.6N 37.0W 40 KT 45 MPH
24H 20/1200Z 39.5N 35.0W 30 KT 35 MPH...POST-TROPICAL
36H 21/0000Z 38.9N 32.4W 30 KT 35 MPH...POST-TROP/REMNT LOW
48H 21/1200Z 37.3N 30.5W 30 KT 35 MPH...POST-TROP/EXTRATROP
72H 22/1200Z 33.0N 30.2W 25 KT 30 MPH...POST-TROP/EXTRATROP
96H 23/1200Z...DISSIPATED

$$
Forecaster Kimberlain/Huffman

[cycloneye]

POST-TROPICAL CYCLONE EDOUARD DISCUSSION NUMBER 34
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062014
500 PM AST FRI SEP 19 2014

Satellite imagery indicates that Edouard consists of a large but
tight swirl of low-level clouds. Since the cyclone has been absent
any deep convection for more than 12 hours, Edouard is being
declared a post-tropical cyclone at this time. A blend of the 1800
UTC TAFB Dvorak CI and Final-T numbers suggests an initial intensity
of 35 kt, which is in basic agreement with a morning ASCAT pass.
Post-tropical cyclone Edouard should continue moving over cooler
waters and in an environment of strong northwesterly wind shear.
Thus, additional weakening is expected during the next day or so
prior to Edouard becoming extratropical in about 36 hours when it
merges with a front.

Although the center of the cyclone jogged southeastward earlier this
morning, it has since resumed an eastward motion at a faster forward
speed or 090/06. Now a shallow feature, Edouard should accelerate
eastward on the north side of a low-level ridge of high pressure
during the next 24 hours. The track should then bend southeastward
and southward around the flow associated with a mid-latitude cyclone
over the northeastern Atlantic. The track forecast is basically an
update of the previous one, only shifted slightly to the left to be
in line with the TVCA multi-model consensus.

This is the last advisory issued by the National Hurricane Center
on Edouard. Additional information on this system can be found in
High Seas Forecasts issued by the National Weather Service...under
AWIPS header NFDHSFAT1 and WMO header FZNT01 KWBC.

FORECAST POSITIONS AND MAX WINDS

INIT 19/2100Z 39.5N 37.5W 35 KT 40 MPH...POST-TROPICAL
12H 20/0600Z 39.4N 36.0W 30 KT 35 MPH...POST-TROPICAL
24H 20/1800Z 39.0N 33.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 21/0600Z 38.0N 31.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
48H 21/1800Z 36.3N 30.0W 25 KT 30 MPH...POST-TROP/EXTRATROP
72H 22/1800Z...DISSIPATED

$$
Forecaster Kimberlain/Huffman

[galaxy401]

Bye Edouard. Least we got a major from you even if only briefly.