EPAC: FERNANDA - Remnants - Discussion

[Ntxw]

Could be the next major.

[ElectricStorm]

Already a warm spot showing up on IR, although it might be a dry slot. If it's an eye though it could be off to the races soon

[Yellow Evan]

Its probably off to the races soon but it needs to shed its banding structure first.

[Yellow Evan]

[Yellow Evan]

TXPZ23 KNES 130637
TCSENP

A. 07E (FERNANDA)
B. 13/0600Z
C. 14.9N
D. 114.8W
E. THREE/GOES-W
F. T3.5/3.5
G. IR/EIR/SWIR
H. REMARKS...CONVECTION WRAPS 9/10 ON A LOG10 SPIRAL FOR A DT OF
3.5. 6 HR AVERAGE DT IS 3.6, WHICH JUSTIFIES BREAKING CONSTRAINTS AT
THIS TIME. THE FT IS BASED ON THE 6 HOUR AVERAGE DT.
I. ADDL POSITIONS
NIL

...KIM

[Extratropical94]

Tropical Storm Fernanda Discussion Number 3
NWS National Hurricane Center Miami FL EP072023
200 AM PDT Sun Aug 13 2023

Geostationary satellite imagery shows that banding associated with
Fernanda has continued to increase overnight with a small central
dense overcast feature recently developing. Unfortunately there
have been no recent microwave or scatterometer overpasses to help
ascertain the inner core structure and wind field of the small
tropical cyclone. The latest subjective Dvorak estimates range
from T2.5 (35 kt) from TAFB to T3.5 (55 kt) from SAB. The initial
intensity for this advisory is set at 45 kt, using a blend of those
subjective estimates.

Fernanda is currently traversing SSTs of around 29 degrees Celsius
and is within an area of low vertical wind shear These conditions
favor steady to rapid strengthening during the next 24 to 36 hours.
The only negative factor is some nearby dry mid-level air, but the
low shear conditions suggest that the small cyclone is likely to
intensify. Although the NHC intensity forecast does not quite
predict rapid strengthening during the next 24 hours, it does
forecast a fairly substantial 40 kt increase in wind speed during
the next 36 hours, showing rapid intensification (RI) between the
12 and 36 hour period. After 60 hours, decreasing SSTs and a more
stable environment along the track of Fernanda are expected to
cause steady weakening later in the period. The latest NHC
intensity forecast is a little above the SHIPS guidance, but lies
near the ICON consensus aid. This is a little below the latest
HFIP corrected consensus model.

The tropical storm is moving west-northwestward at about 9 kt. A
westward to west-northwestward motion is expected to continue
during the next few days at a slightly slower forward speed. After
that time, a faster westward motion is anticipated as the ridge to
the north of Fernanda strengthens. There is some cross-track
spread in the guidance beyond 72 hours which is primarily related
to how much latitude Fernanda gains during the next few days.
The NHC track prediction is near the middle of the guidance
envelope, close to a blend of the GFS and ECMWF models.


FORECAST POSITIONS AND MAX WINDS

INIT 13/0900Z 15.1N 115.1W 45 KT 50 MPH
12H 13/1800Z 15.3N 116.4W 55 KT 65 MPH
24H 14/0600Z 15.6N 118.0W 70 KT 80 MPH
36H 14/1800Z 16.0N 119.7W 85 KT 100 MPH
48H 15/0600Z 16.5N 121.2W 85 KT 100 MPH
60H 15/1800Z 17.0N 123.1W 80 KT 90 MPH
72H 16/0600Z 17.3N 125.5W 70 KT 80 MPH
96H 17/0600Z 17.6N 130.8W 50 KT 60 MPH
120H 18/0600Z 17.7N 137.0W 35 KT 40 MPH

$$
Forecaster Brown

[cycloneye]

EP, 07, 2023081312, , BEST, 0, 153N, 1156W, 50, 1000, TS

[Sciencerocks]

[cycloneye]

Tropical Storm Fernanda Discussion Number 4
NWS National Hurricane Center Miami FL EP072023
800 AM PDT Sun Aug 13 2023

The compact storm is currently exhibiting a CDO-type cloud pattern
with very cold embedded tops to near -80 deg C. Upper-level
outflow is well defined over the western semicircle of the
circulation. The current intensity estimate is set at 50 kt based
on a blend of subjective Dvorak estimates from TAFB and SAB along
with various objective estimates from UW-CIMSS.

Fernanda continues its west-northwestward trek, and the initial
motion estimate remains at around 285/9 kt. A weak mid-level ridge
is currently situated to the north of the system. Over the next
few days, the ridge is expected to strengthen somewhat. This
should result in a gradual increase in forward speed during the
forecast period with a turn toward the west in a few days. The
official forecast track is essentially an update of the previous one
and is very close to the dynamical model consensus, TVCE.

The tropical cyclone should continue to traverse sea surface
temperatures near 29 deg C for the next 36 hours or so with very
low vertical wind shear. Rapid intensification (RI) seems likely,
and the SHIPS RI indices show a significant likelihood of an
increase of intensity of around 30 kt during the next day or so.
The official forecast goes along with this guidance and calls for
Fernanda to become a hurricane in 12 hours or so, and to reach
category 2 strength within the next couple of days. By 48 hours and
beyond a drier air mass, seen in GOES-18 low-level water vapor
imagery to the west-northwest of the cyclone, should result in
weakening. The official forecast is near or a little below the
latest corrected consensus, HCCA, prediction.


FORECAST POSITIONS AND MAX WINDS

INIT 13/1500Z 15.4N 115.9W 50 KT 60 MPH
12H 14/0000Z 15.6N 117.2W 65 KT 75 MPH
24H 14/1200Z 16.0N 118.7W 80 KT 90 MPH
36H 15/0000Z 16.4N 120.4W 90 KT 105 MPH
48H 15/1200Z 16.9N 122.2W 90 KT 105 MPH
60H 16/0000Z 17.3N 124.3W 80 KT 90 MPH
72H 16/1200Z 17.5N 126.5W 70 KT 80 MPH
96H 17/1200Z 17.8N 132.0W 50 KT 60 MPH
120H 18/1200Z 18.0N 138.0W 35 KT 40 MPH

$$
Forecaster Pasch

[cycloneye]

An eye feature tries to pop.

[Sciencerocks]

65kts

[aspen]

This is pulling together quick. There might be enough time for this to become a major before it runs into cooler waters and that super dry air mass.

[Yellow Evan]

Clear hurricane with eye sometimes visible. Dvorak has a lot of catch up to play.

[Yellow Evan]

Rotating VHTs. With low shear this probably clears this evening or overnight and peaks tomorrow as a major hurricane.

[Yellow Evan]

TXPZ23 KNES 131826
TCSENP

A. 07E (FERNANDA)

B. 13/1800Z

C. 15.4N

D. 116.1W

E. THREE/GOES-W

F. T4.0/4.0

G. IR/EIR/VIS

H. REMARKS...12/10 BANDING YIELDS A DT OF 4.0. THE MET IS 3.0 BASED ON
A 24HR RAPID DEVELOPING TREND. THE PT IS 3.5. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...GATLING

[cycloneye]

Up to Hurricane.

EP, 07, 2023081318, , BEST, 0, 155N, 1161W, 65, 995, HU

[cycloneye]

Will the 2023 Fernanda be like the 2017 one as cat 4 but on a smaller versión?

[Ntxw]

Another microcane. 100kts seems doable. Has about 48 hours I think of good conditions and SSTs, can it push for 115kts?



Euro also has what's left to effect Hawaii.

[cycloneye]

Hurricane Fernanda Discussion Number 5
NWS National Hurricane Center Miami FL EP072023
200 PM PDT Sun Aug 13 2023

Satellite imagery indicates that small Fernanda has been
strengthening rapidly today. A faint eye has become apparent on
visible satellite imagery, and outer banding features are becoming
better defined. Since the presence of a visible eye is usually a
good indicator that a tropical cyclone has become a hurricane, the
system is being upgraded on this advisory. This intensity is also
in agreement with a Dvorak classification from SAB. The upper-level
outflow pattern has also become more symmetric over the circulation.

Fernanda continues moving west-northwestward at a slightly slower
pace with an estimated motion of 285/8 kt. The mid-level ridge to
the north of the tropical cyclone is currently rather weak due to
the presence of a cutoff low near the California coast. Over
the next few days, the ridge to the north of Fernanda is forecast
to strengthen as the influence of the cutoff low lessens. As a
result, the system should move somewhat faster to the
west-northwest during the next 72 hours or so while turning
westward later in the forecast period. The official track forecast
remains very close to the previous one and is also very similar to
the dynamical model consensus aid TVCE.

The hurricane should continue to pass over SSTs of around 29 deg C
for the next day or two while remaining in a very low vertical shear
environment. The rapid intensification (RI) indices such as SHIPS,
RII, and DTOPS continue to show a good chance of RI continuing over
the next day or so. Thus, the official forecast will again call for
RI over the next 24 hours. However, in about 48 hours, drier
mid-level air should halt the strengthening process. The numerical
guidance is in good agreement that Fernanda will steadily weaken in
2-5 days, and this is reflected in the NHC intensity forecast, which
is fairly close to the latest corrected consensus prediction.


FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 15.5N 116.5W 65 KT 75 MPH
12H 14/0600Z 15.8N 117.6W 80 KT 90 MPH
24H 14/1800Z 16.2N 119.0W 95 KT 110 MPH
36H 15/0600Z 16.7N 120.6W 95 KT 110 MPH
48H 15/1800Z 17.3N 122.5W 85 KT 100 MPH
60H 16/0600Z 17.5N 124.9W 75 KT 85 MPH
72H 16/1800Z 17.7N 127.2W 65 KT 75 MPH
96H 17/1800Z 18.0N 132.5W 45 KT 50 MPH
120H 18/1800Z 18.0N 138.0W 35 KT 40 MPH

$$
Forecaster Pasch

[Yellow Evan]

Clear dry air intrusion on IR. Typical for a TC of this intensity.