EPAC: FRANK - Post-Tropical

[Kingarabian]

Advanced Dvorak Technique (ADT)
Version 8.2.1
Tropical Cyclone Intensity Estimation Algorithm


Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.2.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 26 JUL 2016 Time : 223000 UTC
Lat : 21:44:13 N Lon : 117:52:56 W


CI# /Pressure/ Vmax
4.5 / 977.5mb/ 77.0kt


Final T# Adj T# Raw T#
3.8 4.2 5.0

Estimated radius of max. wind based on IR : 18 km

Center Temp : -26.4C Cloud Region Temp : -56.7C

Scene Type : EYE

[Ntxw]

I'd say needs colder tops. But yeah, if he can really work on that eye, there is a chance.

[cycloneye]

 https://twitter.com/EricBlake12/status/758098641181487105

[Yellow Evan]

ATCF has 80 knots.

[Yellow Evan]

----- Current Analysis -----
Date : 27 JUL 2016 Time : 013000 UTC
Lat : 21:51:06 N Lon : 118:24:02 W


CI# /Pressure/ Vmax
4.9 / 969.7mb/ 87.4kt


Final T# Adj T# Raw T#
4.9 4.9 4.9

Estimated radius of max. wind based on IR : 14 km

Center Temp : -25.0C Cloud Region Temp : -53.5C

Scene Type : EYE

[cycloneye]

HURRICANE FRANK DISCUSSION NUMBER 22
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
800 PM PDT TUE JUL 26 2016

Frank surprised us tonight with another round of strengthening. The
cloud pattern presentation on satellite is the best so far with a
distinct eye surrounded by moderate convection. Objective and
subjective T-numbers from all agencies are 4.5 on the Dvorak
scale. On this basis, the initial intensity has been adjusted to 75
kt. Most of the circulation of the small cyclone is already moving
over sea surface temperatures below 26C, so one would expect that a
gradual weakening should begin soon. By 48 hours, Frank should have
degenerated into a post-tropical cyclone over increasingly cooler
waters. The NHC forecast is very similar to the previous one, but
adjusted upward at 12 h due to the initial intensity increase.

Satellite fixes indicate that Frank is moving toward the west-
northwest or 290 degrees at 10 kt around the periphery of the
subtropical ridge. Dynamical models and their derived consensus are
in excellent agreement showing the cyclone moving on the same track
for the next 2 days with some decrease in forward speed. The NHC
forecast is then in the middle of the tight guidance envelope. Once
Frank becomes a shallow system, it will probably turn westward while
it becomes steered by the low-level trade winds.


FORECAST POSITIONS AND MAX WINDS

INIT 27/0300Z 22.0N 118.7W 75 KT 85 MPH
12H 27/1200Z 22.6N 120.1W 70 KT 80 MPH
24H 28/0000Z 23.6N 122.0W 60 KT 70 MPH
36H 28/1200Z 24.4N 123.4W 45 KT 50 MPH
48H 29/0000Z 24.8N 124.5W 35 KT 40 MPH...POST-TROPICAL
72H 30/0000Z 25.0N 126.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 31/0000Z...DISSIPATED

$$
Forecaster Avila

[Yellow Evan]

"Objective and subjective T-numbers from all agencies are 4.5 on the Dvorak scale." unless they're talking about internal AODT, CIMSS ADT is at T4.9

[cycloneye]

NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
200 AM PDT WED JUL 27 2016

The eye of Frank disappeared from geostationary imagery around 0600
UTC, indicative of the beginning of a weakening trend. Central
convection has been gradually diminishing, and Dvorak T-numbers
are decreasing. The current intensity is set at 70 kt which is a
blend of Dvorak estimates from TAFB and SAB. Frank is starting to
traverse a gradient of SSTs, so steady weakening is expected as the
cyclone moves over progressively cooler waters. The official
intensity forecast is close to the latest model consensus, IVCN,
and calls for the system to degenerate into a post-tropical remnant
low in about 48 hours.

The initial motion continues west-northwestward, or 295/10 kt.
A mid-level subtropical ridge is forecast by the global models to
remain to the north of Frank for the next few days, with some
weakening of this ridge. Therefore, a continued west-northwestward
motion with some deceleration is forecast for the next couple of
days. After that, the weak and shallow cyclone is expected to move
generally westward following the low level environmental winds.
The official track forecast follows the dynamical consensus aid,
TVCN.

Data from an ASCAT overpass indicated that Frank was smaller than
previously estimated, and the wind radii have been adjusted
accordingly.

FORECAST POSITIONS AND MAX WINDS

INIT 27/0900Z 22.5N 119.7W 70 KT 80 MPH
12H 27/1800Z 23.3N 121.2W 60 KT 70 MPH
24H 28/0600Z 24.3N 122.9W 50 KT 60 MPH
36H 28/1800Z 25.0N 124.3W 35 KT 40 MPH
48H 29/0600Z 25.3N 125.5W 25 KT 30 MPH...POST-TROPICAL
72H 30/0600Z 25.3N 127.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 31/0600Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

TROPICAL STORM FRANK DISCUSSION NUMBER 24
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
800 AM PDT WED JUL 27 2016

Frank is quickly weakening today, with a shrinking area of deep
convection near and northwest of the center. A blend of the
TAFB/SAB Dvorak T/CI numbers gives an initial wind speed of 55 kt
for this advisory. Steady weakening is expected due to the cyclone
moving over progressively colder waters and into a more stable
airmass. The official intensity forecast remains near the latest
model consensus, IVCN, and Frank should degenerate into a remnant
low by tomorrow afternoon.

Microwave data indicate the storm continues moving 295/10 kt. Frank
should turn westward and slow down as the cyclone becomes a weak and
shallow remnant low steered by the low-level ridge. Models have
shifted a little southward on this cycle, and the official forecast
follows that trend.

FORECAST POSITIONS AND MAX WINDS

INIT 27/1500Z 22.7N 120.8W 55 KT 65 MPH
12H 28/0000Z 23.4N 122.2W 45 KT 50 MPH
24H 28/1200Z 24.2N 123.6W 35 KT 40 MPH
36H 29/0000Z 24.8N 124.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 29/1200Z 25.0N 125.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 30/1200Z 24.8N 127.5W 15 KT 15 MPH...POST-TROP/REMNT LOW
96H 31/1200Z...DISSIPATED

$$
Forecaster Blake

[cycloneye]

TROPICAL STORM FRANK DISCUSSION NUMBER 25
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
200 PM PDT WED JUL 27 2016

Frank has continued its weakening trend with only a small area of
convection now displaced to the northwest of the low-level center.
Although subjective and objective satellite intensity estimates
support an intensity of about 60 kt, the initial intensity has been
lowered to 50 kt based on a partial ASCAT-B scatterometer pass
that showed winds of only about 40 kt in the eastern semicircle.
Even though the western half of the cyclone was not sampled, it is
assumed that some stronger winds exist in that part of the
circulation, but not as strong as the satellite estimates due to the
cooler waters creating a more stable boundary layer.

The initial motion estimate is now 295/09 kt. Frank should move
west-northwestward for the next 24 hours or so before turning
westward by 36 hours after the cyclone degenerates into a shallow
remnant low, which will be steered by the low-level easterly trade
wind flow. The new NHC model guidance is in good agreement on this
track scenario, although there is significant cross-track spread in
the models after 48 hours. The official forecast track is similar
to the previous advisory track and lies a little south of the
consensus track model TVCN.

Microwave imagery indicates that Frank's circulation has a
northwestward tilt due to some southeasterly mid-level wind shear.
The cyclone is also moving over sub-24C SSTs at this time, and
cooler waters lie ahead of Frank. The combination of increasing
shear, decreasing water temperatures, and a drier and more stable
airmass should result in rapid weakening during the next 24 hours.
Therefore, Frank is forecast to degenerate into a remnant low on
Thursday and dissipate on Saturday. The official intensity forecast
follows the intensity consensus model IVCN.

FORECAST POSITIONS AND MAX WINDS

INIT 27/2100Z 23.1N 121.8W 50 KT 60 MPH
12H 28/0600Z 23.8N 122.9W 40 KT 45 MPH
24H 28/1800Z 24.5N 124.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 29/0600Z 24.9N 125.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 29/1800Z 24.9N 126.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 30/1800Z 24.4N 128.0W 15 KT 15 MPH...POST-TROP/REMNT LOW
96H 31/1800Z...DISSIPATED

$$
Forecaster Stewart

[cycloneye]

TROPICAL STORM FRANK DISCUSSION NUMBER 26
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
800 PM PDT WED JUL 27 2016

The cloud pattern is gradually deteriorating, and microwave data
show that the low-level center is becoming even more separated from
the residual thunderstorm activity. However, the circulation is
still vigorous, and subjective satellite intensity estimates from
TAFB and SAB and objective numbers from CIMSS support an initial
intensity of 45 kt.

Given that Frank's entire circulation is moving over waters with
temperatures of less than 24C, the thunderstorm activity should
diminish resulting in gradual weakening. Frank is anticipated to
become a remnant low by Thursday.

The cyclone is moving toward the west-northwest or 300 degrees at 7
kt, steered by the deep-layer flow around the subtropical high.
This motion will likely continue for a day until Frank becomes a
shallow system and moves westward within t
he trade winds. There is
good agreement in the track models, and the NHC forecast is in the
middle the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT 28/0300Z 23.4N 122.7W 45 KT 50 MPH
12H 28/1200Z 23.9N 123.8W 35 KT 40 MPH
24H 29/0000Z 24.3N 124.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 29/1200Z 24.4N 125.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 30/0000Z 24.5N 126.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 31/0000Z...DISSIPATED

$$
Forecaster Avila

[cycloneye]

TROPICAL STORM FRANK DISCUSSION NUMBER 27
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
200 AM PDT THU JUL 28 2016

All of the deep convection associated with Frank has dissipated,
and since the cyclone is moving over waters cooler than 23 deg C,
regeneration of thunderstorms within the circulation is not
anticipated. Therefore, the cyclone is likely to degenerate into a
post-tropical remnant low pressure area later today. A partial
ASCAT pass suggested that the maximum winds were near 35 kt and
these tropical-storm-force winds were likely contained to the
northeast quadrant of Frank. A continued spin down of the
circulation should occur over the next few days with the system
dissipating in 72 hours or so.

The center is difficult to locate but the best guess of initial
motion is about 290/8 kt. Frank, or its remnant, is forecast to
turn toward the west and then west-southwest and decelerate,
following the relatively weak low-level tradewind flow. The
official forecast is a blend of the latest GFS and ECMWF tracks.

FORECAST POSITIONS AND MAX WINDS

INIT 28/0900Z 23.6N 123.7W 35 KT 40 MPH
12H 28/1800Z 24.0N 124.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 29/0600Z 24.2N 126.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 29/1800Z 24.3N 126.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 30/0600Z 24.0N 127.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 31/0600Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

TROPICAL DEPRESSION FRANK DISCUSSION NUMBER 28
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
800 AM PDT THU JUL 28 2016

Frank has only been devoid of organized deep convection since about
0400 UTC, so the system is still being maintained as a tropical
cyclone for this advisory. However, if this downward convective
trend continues, which appears likely since Frank is now moving
over sub-23 deg C sea-surface temperatures, then the cyclone will
become a remnant low pressure system this afternoon in the next
advisory package. Continued spin down should result in dissipation
of the low-level circulation by 72 hours.

Microwave satellite fixes indicate that Frank is now moving at
290/07 kt. The weakening cyclone is forecast to become more
vertically shallow over the next 48 hours, which should result in a
turn toward the west and then west-southwest, accompanied by gradual
deceleration due to weak easterly tradewind flow. The official
forecast is similar to the previous track and lies close to the TVCN
consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT 28/1500Z 23.7N 124.4W 30 KT 35 MPH
12H 29/0000Z 24.0N 125.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
24H 29/1200Z 24.1N 126.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/0000Z 24.0N 127.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 30/1200Z 23.7N 127.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 31/1200Z...DISSIPATED

$$
Forecaster Stewart

[cycloneye]

POST-TROPICAL CYCLONE FRANK DISCUSSION NUMBER 29
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072016
200 PM PDT THU JUL 28 2016

Frank has been devoid of deep convection for more than 12 hours, and
is now just a large swirl of low-level stratocumulus clouds. Since
the cyclone continues to move into an environment of very dry
mid-level air and near 22 deg C SSTs, redevelopment of organized
deep convection is unlikely. On this basis, Frank has been
declared a remnant low. The initial wind speed of 30 kt is based on
an average of subjective T/CI numbers from TAFB and SAB. Given the
very stable conditions ahead of the cyclone, the remnant low should
continue to spin down and dissipate by 72 h.

The initial motion estimate is 295/06 kt. The vertically shallow
remnant low should move westward through 24 h, and then toward the
west-southwest by weak easterly to northeasterly low-level tradewind
flow. The NHC track forecast is similar to the previous advisory
track and lies close to the TVCN consensus track
model.

This is the last advisory issued by the National Hurricane Center on
this system. Additional information on the remnant low can be found
in High Seas Forecasts issued by the National Weather Service, under
AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and on the web at
http://www.opc.ncep.noaa.gov/shtml/NFDHSFEPI.shtml.

FORECAST POSITIONS AND MAX WINDS

INIT 28/2100Z 24.1N 124.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
12H 29/0600Z 24.2N 125.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 29/1800Z 24.1N 126.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 30/0600Z 23.9N 127.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 30/1800Z 23.6N 127.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 31/1800Z...DISSIPATED

$$
Forecaster Stewart