ATL: EIGHT - Remnants - Discussion

[znel52]

Wow I went to sleep last night assuming this thing was dead. Goes to show you what the gulf stream can do for a storm.

[tolakram]

Live visible

http://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=34&lon=-75&info=vis&zoom=1&width=1000&height=800&quality=90&type=Animation&palette=ir1.pal&numframes=5&mapcolor=yellow

[Chris_in_Tampa]

Through 8:53am EDT:

[Chris_in_Tampa]

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
1100 AM EDT TUE AUG 30 2016

The center of the depression has been difficult to pinpoint even
with radar and aircraft data concurrently this morning, probably
due to the nearby thunderstorm activity. Overall, the depression
remains disorganized, with no significant wind or pressure changes
noted since the last advisory. The initial wind speed remains 30
kt. The environment seems conducive for some strengthening over the
next couple of days while the depression moves near the Gulf Stream
in light-to-moderate shear. Thus, the latest NHC intensity forecast
shows gradual intensification, and is near, or slightly below the
intensity consensus. Global models indicate the system will become
an extratropical low in 2 or 3 days before the cyclone dissipates
within the frontal zone.

The initial motion is a very uncertain 335/4. The depression
should start a slow northward motion toward a break in the
subtropical ridge later today. After that, it should recurve
northeastward into the westerlies in advance of an approaching
mid- to upper-level trough and an associated surface cold front.
The new forecast track is moved a little to the west of the
previous track during the first 24 hours based primarily on the
initial position, on the western side of the guidance envelope.
After that time, it is similar to the previous track and is blended
back toward the model consensus.

FORECAST POSITIONS AND MAX WINDS

INIT 30/1500Z 34.2N 75.3W 30 KT 35 MPH
12H 31/0000Z 34.8N 75.2W 35 KT 40 MPH
24H 31/1200Z 35.7N 74.1W 35 KT 40 MPH
36H 01/0000Z 37.2N 71.6W 40 KT 45 MPH
48H 01/1200Z 39.4N 67.3W 45 KT 50 MPH
72H 02/1200Z 45.0N 53.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 03/1200Z...DISSIPATED

$$
Forecaster Blake

[capepoint]

No real wind gusts or appreciable tides or waves in eastern Carteret County so far today, only a few downpours as bands rotate over. Behaving pretty much at or below expectations so far.

[syfr]

We had one band of strong rain here on ocracoke island. I went up to Hatteras inlet this morning and while there was a strong breeze the surf is down compared to this time yesterday.

Right now back in Ocracoke village its breezy and partly sunny and 79. Im heading to the beach.....

[OuterBanker]

Apparently the OBX has been spared. Expect ts warning to be dropped at 5. Beautiful sunny day across the OBX with just a touch of rough surf.
Thought that we would also get out of any effects of Hermine to be. with a sharp right out to sea after Fl landfall.
But, most models now back to a coast hugger.

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
500 PM EDT TUE AUG 30 2016

Satellite images indicate that the depression remains disorganized.
The low- and mid-level centers are not well aligned, with
convection continuing only sporadically near the center. The
initial wind speed remains 30 kt. Despite the lack of
strengthening, the environment appears conducive for some
intensification eventually over the next couple of days while the
depression moves near the Gulf Stream in light-to-moderate shear.
The intensity forecast is reduced a little in the short term to
account for the current disorganized structure, then no change was
made to the remainder of the intensity forecast. The system should
become an extratropical low in 2 or 3 days before the cyclone
dissipates within a frontal zone.

The cyclone has been drifting recently, but it should start a slow
north-northeastward motion by tonight as it enters the mid-latitude
westerlies. The mid-latitude flow then increases, which should
cause the depression to accelerate northeastward. Model guidance is
tightly clustered, and little change was made to the previous
forecast.

Model guidance indicates the system is nearing its closest point of
approach to the Outer Banks. We have elected to continue the
Tropical Storm Warning for this advisory, but this could be lowered
tonight if a more consistent motion away from the coast becomes
established.


FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 34.4N 75.1W 30 KT 35 MPH
12H 31/0600Z 35.0N 74.8W 30 KT 35 MPH
24H 31/1800Z 36.3N 72.9W 35 KT 40 MPH
36H 01/0600Z 38.3N 69.4W 40 KT 45 MPH
48H 01/1800Z 41.0N 63.0W 45 KT 50 MPH
72H 02/1800Z 45.0N 49.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 03/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 11
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
1100 PM EDT TUE AUG 30 2016

Aircraft fixes from the Air Force Reserve Hurricane Hunters
indicate that the center of the depression is located near the
southwestern edge of a persistent cluster of deep convection. The
plane did not find any stronger winds than in previous missions,
and the initial intensity remains 30 kt. Westerly vertical shear
affecting the cyclone is not expected to decrease, and in fact it
should increase substantially from 24 hours and beyond. Still, if
the system can maintain deep convection while it remains over warm
sea surface temperatures for the next 36 hours or so, the mere fact
that it is expected to accelerate from this point forward could
allow the maximum winds to increase. The NHC intensity forecast is
very similar to the previous one, but it does allow for possible
strengthening to tropical storm strength in about 12 hours. The
cyclone should become extratropical by 72 hours, but after that
there is some uncertainty whether it will be absorbed by another
cyclone or become the dominant system. For now, the forecast
continues to show it becoming absorbed, which is in line with the
ECMWF.

The aircraft fixes indicate that the depression is beginning to
move away from the Outer Banks with an initial motion of 040/4 kt.
The cyclone is expected to accelerate toward the northeast and then
east-northeast through the forecast period. The track models are
in very good agreement, and no significant changes were required to
the official track forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 31/0300Z 34.5N 74.6W 30 KT 35 MPH
12H 31/1200Z 35.4N 73.6W 35 KT 40 MPH
24H 01/0000Z 37.1N 71.0W 40 KT 45 MPH
36H 01/1200Z 39.3N 66.1W 45 KT 50 MPH
48H 02/0000Z 41.5N 59.3W 45 KT 50 MPH
72H 03/0000Z 45.1N 45.3W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 04/0000Z...DISSIPATED

$$
Forecaster Berg

[arlwx]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 12
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
500 AM EDT WED AUG 31 2016

The low-level center is difficult to find, but given the strong
westerly shear and continuity, it is assumed that it is located to
the west of a large area of deep convection devoid of banding
features. Dvorak numbers have not changed, and the initial intensity
remains at 30 kt. Most of the guidance shows a significant increase
in the shear, but at the same time forecasts a slight increase in
intensity. The NHC forecast follows the guidance and the previous
forecast showing a slight increase in the winds before the cyclone
becomes extratropical in 48 hours.

The depression is moving slowly toward the northeast at 4 kt, and
is already embedded within the southwesterly flow ahead of an
amplifying mid-latitude trough. This pattern favors a continuation
of the northeast track away from the U.S coast with a significant
increase in forward speed.


FORECAST POSITIONS AND MAX WINDS

INIT 31/0900Z 34.8N 74.3W 30 KT 35 MPH
12H 31/1800Z 35.7N 72.8W 35 KT 40 MPH
24H 01/0600Z 37.7N 69.0W 40 KT 45 MPH
36H 01/1800Z 40.0N 63.5W 40 KT 45 MPH
48H 02/0600Z 42.5N 57.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
72H 03/0600Z...DISSIPATED

$$

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
1100 AM EDT WED AUG 31 2016

The depression looks a little better organized this morning, with a
large band on the eastern side of the circulation. However,
satellite classifications still support keeping the system as a
30-kt tropical depression for now. The cyclone has about 36 hours
to intensify over warm water with moderate shear before the
environment becomes less conducive. The latest NHC intensity
forecast blends the previous one with the new consensus guidance,
which results in a slightly higher forecast. The global models
suggest the system will become extratropical in about 48 hours, and
be absorbed within a larger frontal zone in 3 or 4 days.

The latest satellite fixes indicate that the depression has finally
started to move faster toward the northeast. The cyclone should
continue to accelerate to the northeast within the southwesterly
flow ahead of an amplifying mid-latitude trough. This pattern
favors a continuation of the northeast track away from the U.S coast
with a significant increase in forward speed. The guidance is well
clustered, and the new NHC track prediction is basically an update
of the previous one.

FORECAST POSITIONS AND MAX WINDS

INIT 31/1500Z 35.5N 73.1W 30 KT 35 MPH
12H 01/0000Z 36.6N 71.1W 35 KT 40 MPH
24H 01/1200Z 38.8N 66.5W 40 KT 45 MPH
36H 02/0000Z 41.0N 60.7W 45 KT 50 MPH
48H 02/1200Z 43.0N 53.5W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 03/1200Z 46.0N 40.0W 40 KT 45 MPH...POST-TROP/EXTRATROP
96H 04/1200Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
500 PM EDT WED AUG 31 2016

This depression has been a challenging cyclone. After the earlier
apparent improvement in the cloud pattern, recent satellite images
indicate the system has actually become less organized. While there
is a broken band in the eastern semicircle, the depression looks
elongated, with a less well-defined center. The initial wind speed
is reduced to 25 kt on this advisory, which is backed up by ASCAT
data of 20 to 25 kt.

I'm beginning to think that the long-forecast intensification is not
going to occur with this depression. Other than persistence, this
idea is supported by the higher shear values in the recent SHIPS and
global model guidance. While I'm not ready to totally abandon any
strengthening, the new NHC forecast is reduced 5 to 10 kt from
the previous one and is below the model consensus. The cyclone
should become extratropical within 2 days, and be absorbed within a
larger frontal zone in 3 days. An alternative, but realistic,
scenario, is that the cyclone becomes a remnant low tomorrow due to
marginal environmental conditions causing a lack of organized deep
convection.

The cyclone is moving northeastward at about 14 kt. It should
continue to accelerate to the northeast within the southwesterly
flow ahead of an amplifying mid-latitude trough. No significant
change to the previous forecast was made.


FORECAST POSITIONS AND MAX WINDS

INIT 31/2100Z 36.3N 71.9W 25 KT 30 MPH
12H 01/0600Z 37.7N 69.3W 30 KT 35 MPH
24H 01/1800Z 39.9N 64.0W 35 KT 40 MPH
36H 02/0600Z 42.0N 57.5W 35 KT 40 MPH...POST-TROPICAL
48H 02/1800Z 44.0N 51.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
72H 03/1800Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
1100 PM EDT WED AUG 31 2016

Deep convection is becoming increasingly dislocated from the center
of the tropical depression because of the strong westerly vertical
shear. Dvorak classifications from SAB and TAFB continue to drop
as the convection becomes less organized. The initial intensity
remains 25 kt.

The tropical depression should not be long for this world. Last-
light visible imagery suggests that the center may be becoming
diffuse. The deep convection may soon either dissipate or be located
far from the center. The system may shortly become entangled in a
frontal boundary. If the center is no longer well defined, if there
is no associated organized deep convection, or if the cyclone
becomes frontal, then the system will no longer be a tropical
cyclone. One or more of these options should occur within about a
day, if not sooner. In about two days, the post-tropical cyclone is
likely to be absorbed in a separate extratropical low.

The depression is moving toward the east-northeast at about 14 kt,
as it is being swept up by the southwesterlies ahead of a
mid-latitude shortwave trough. The system should accelerate in the
same direction until dissipation. The track is based upon the
consensus of the reliable global models and is nearly the same as
that from the previous advisory.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 36.7N 70.1W 25 KT 30 MPH
12H 01/1200Z 38.2N 66.9W 30 KT 35 MPH
24H 02/0000Z 40.5N 60.5W 35 KT 40 MPH...POST-TROP/EXTRATROP
36H 02/1200Z 43.0N 54.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
48H 03/0000Z...DISSIPATED

$$
Forecaster Landsea

[hurricanes1234]

From the 11 PM discussion:

The tropical depression should not be long for this world.

[cycloneye]

REMNANTS OF EIGHT DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL AL082016
500 AM AST THU SEP 01 2016

Deep convection is now displaced more than 100 nm east of the
location suspected to be the center of the tropical depression.
However, the 0224Z ASCAT scatterometer overpass showed that the
system has opened up into a trough. Thus the system is no longer
considered to be a tropical cyclone. Maximum winds continue to be
around 25 kt, associated with the remnants of the tropical cyclone.

Additional information on this system can be found in High Seas
Forecasts issued by the National Weather Service, under AWIPS
header NFDHSFAT1, WMO header FZNT01 KWBC, and available on the Web
at http://www.opc.ncep.noaa.gov/shtml/NFDHSFAT1.shtml.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 38.2N 69.2W 25 KT 30 MPH...REMNANTS
12H 01/1800Z...DISSIPATED

$$
Forecaster Landsea

[Kazmit]

I'm glad 8 didn't develop. We don't need a nice name like Ian given to a weakling.