EPAC: ADRIAN - Post-Tropical - Discussion

[Yellow Evan]

TXPZ24 KNES 301819
TCSENP

A. 01E (ADRIAN)

B. 30/1801Z

C. 17.5N

D. 112.5W

E. ONE/GOES-W

F. T5.5/5.5

G. IR/EIR/VIS

H. REMARKS...OW EYE SURROUNDED BY A B RING AND EMBEDDED IN LG YIELDS
A DT OF 5.5 AFTER ADDING 0.5 FOR EYE ADJUSTMENT. THE MET IS 5.5. THE PT
IS 5.0. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...GATLING

[Yellow Evan]

EP, 01, 2023063018, , BEST, 0, 175N, 1125W, 95, 966, HU, 64, NEQ, 15, 15, 10, 15, 1008, 200, 10, 0, 0, E, 0, , 0, 0, ADRIAN, D, 0, , 0, 0, 0, 0, genesis-num, 004,

[Kingarabian]

Think it'll be upgraded in the offseason.

[Sciencerocks]

[cycloneye]

Hurricane Adrian Discussion Number 13
NWS National Hurricane Center Miami FL EP012023
300 PM MDT Fri Jun 30 2023

The satellite structure of Adrian looked its best shortly after the
time of the previous advisory. Since then, the eye has become
obscured by clouds in visible satellite imagery. Although deep
convection still surrounds the ragged eye, infrared cloud top
temperatures have been gradually warming, and the central dense
overcast has become more asymmetric over the past few hours. It
appears that vertical wind shear is finally taking a toll on the
hurricane, and the objective satellite estimates have leveled off or
begun to decrease this afternoon. The initial intensity is held at
90 kt, in best agreement with a blend of recent UW-CIMSS SATCON,
ADT, and AiDT estimates.

Adrian is forecast to cross the 26 deg C SST isotherm tonight and
move over 23 deg C SSTs within the next couple of days. In addition,
the cyclone is expected to encounter moderate easterly shear that
should continue to disrupt its vertical organization. Therefore,
weakening is anticipated during the next several days. The global
and regional models indicate that the cyclone will struggle to
produce organized convection by Sunday. Therefore, the official NHC
forecast shows remnant low status at 48 h and dissipation by day 4.

The hurricane continues to move northwestward, or 310/6 kt. A
general west-northwestward to northwestward motion is expected over
the next couple of days as Adrian is steered by a mid-level ridge
centered over the southern United States. As the cyclone weakens
and spins down, it should turn westward within the low-level trade
wind flow until it dissipates. Based on the latest track guidance
and consensus aids, the updated NHC forecast has once again been
nudged to the right of the previous one.


FORECAST POSITIONS AND MAX WINDS

INIT 30/2100Z 17.7N 112.9W 90 KT 105 MPH
12H 01/0600Z 18.2N 113.7W 80 KT 90 MPH
24H 01/1800Z 18.7N 114.8W 65 KT 75 MPH
36H 02/0600Z 19.1N 115.8W 50 KT 60 MPH
48H 02/1800Z 19.5N 116.8W 35 KT 40 MPH...POST-TROPICAL
60H 03/0600Z 19.7N 117.7W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 03/1800Z 19.7N 118.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 04/1800Z...DISSIPATED

$$
Forecaster Reinhart

[Sciencerocks]

[cycloneye]

Hurricane Adrian Discussion Number 14
NWS National Hurricane Center Miami FL EP012023
900 PM MDT Fri Jun 30 2023

Adrian appears to have begun its anticipated weakening trend. The
eye is no long apparent on geostationary satellite imagery and
cloud top temperatures have warmed overall. Microwave satellite
imagery from 2037 UTC showed deep convection only to the west of
center, implying the easterly shear has increased. Subjective
satellite intensity estimates have also decreased and the final
T-numbers are at T4.5 from both TAFB and SAB. Therefore, the
initial intensity for this advisory has been lowered to 80 kt.

The hurricane has crossed the 26 degree C sea surface temperature
isotherm this evening and SSTs along the track forecast are
projected to decrease steadily. Adrian is also moving into an dry
and stable airmass. Model guidance all predict steady to rapid
weakening in the next couple of days. The NHC intensity forecast is
on the higher end of the model guidance and shows steady weakening.
Adrian is expected to be a tropical storm in the next day or so and
a post-tropical cyclone in 48 h.

Adrian is moving west-northwestward at about 7 kt. A general
west-northwestward motion is expected over the next couple of days
as the storm is steered by a ridge to the northeast. A gradual turn
to the west is forecast as the decaying vortex is caught in the
low-level flow. The latest track prediction is similar to the
previous advisory and close to the corrected consensus track
guidance.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0300Z 18.1N 113.5W 80 KT 90 MPH
12H 01/1200Z 18.5N 114.4W 70 KT 80 MPH
24H 02/0000Z 19.0N 115.5W 60 KT 70 MPH
36H 02/1200Z 19.4N 116.5W 50 KT 60 MPH
48H 03/0000Z 19.7N 117.6W 35 KT 40 MPH...POST-TROPICAL
60H 03/1200Z 19.9N 118.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 04/0000Z 20.0N 120.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 05/0000Z...DISSIPATED

$$
Forecaster Bucci

[Sciencerocks]

[cycloneye]

Hurricane Adrian Discussion Number 15
NWS National Hurricane Center Miami FL EP012023
300 AM MDT Sat Jul 01 2023

Adrian's structure on both microwave and geostationary satellite has
continued to deteriorate overnight. While a small cluster of deep
convection remains, it is becoming increasingly separated to the
northwest of the low-level center which is becoming exposed on
nighttime GOES-18 shortwave-IR imagery. An earlier F-16 microwave
pass at 0020 UTC also showed this increasingly detached convection,
possibly a result of increasing easterly vertical wind shear
decoupling the vertical structure of Adrian. Subjective satellite
intensity estimates are quickly decreasing, though the CI numbers
are constrained by the Dvorak technique. The initial intensity has
been set to 70 kt for this advisory, closer to unconstrained data-T
Dvorak values from TAFB and SAB, in addition to experimental D-PRINT
and AiDT intensity estimates provided by UW-CIMSS. Adrian is now
over sub-26 C sea-surface temperatures, which cool to below 24 C in
24 hours, and steady to rapid weakening is likely to continue. The
latest intensity forecast is in line with the intensity consensus,
with both regional-hurricane and global model guidance suggesting
Adrian will become a post-tropical cyclone devoid of deep convection
by Sunday.

Adrian continues to move west-northwestward at a slightly slower
pace than before, estimated at 300/6 kt. This general
west-northwestward motion should continue, with a gradual turn
westward as Adrian becomes a shallow cyclone steered by the
low-level trade wind flow. Aside from some initial position
adjustments southward, the track forecast is quite similar to the
prior advisory, following the reliable HCCA and TVCE consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 01/0900Z 18.1N 114.0W 70 KT 80 MPH
12H 01/1800Z 18.5N 114.8W 55 KT 65 MPH
24H 02/0600Z 19.0N 116.0W 45 KT 50 MPH
36H 02/1800Z 19.4N 117.2W 35 KT 40 MPH...POST-TROPICAL
48H 03/0600Z 19.6N 118.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 03/1800Z 19.6N 119.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 04/0600Z 19.5N 121.3W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 05/0600Z...DISSIPATED

$$
Forecaster Papin

[Sciencerocks]

[cycloneye]

Tropical Storm Adrian Discussion Number 16
NWS National Hurricane Center Miami FL EP012023
900 AM MDT Sat Jul 01 2023

Adrian is rapidly weakening. The cyclone is only producing a small
area of deep convection, which is displaced to the west of its
center due to some easterly shear. The significantly degraded
satellite structure of Adrian indicates it is no longer a hurricane,
and the initial intensity is lowered to 55 kt based on the latest
Dvorak data-T numbers (T3.5) from TAFB and SAB. The center of Adrian
is passing very near Clarion Island, where a Mexican navy automated
weather station has reported sustained winds of 25-30 kt and gusts
of 40-50 kt during the past several hours.

The initial motion of Adrian is west-northwestward at 300/6 kt.
Additional weakening is expected as Adrian continues to move
generally west-northwestward toward cooler waters and into a drier,
more stable environment. As a result, simulated satellite imagery
from the global and hurricane models suggest that Adrian could
become devoid of organized convection within the next 24 h. The NHC
forecast shows Adrian weakening to a tropical depression by early
Sunday and degenerating to a remnant low soon thereafter. Then, the
shallow low should turn more westward within the low-level flow and
eventually dissipate by Tuesday. Overall, no significant changes
were made to the official forecast with this advisory.


FORECAST POSITIONS AND MAX WINDS

INIT 01/1500Z 18.4N 114.5W 55 KT 65 MPH
12H 02/0000Z 18.8N 115.3W 40 KT 45 MPH
24H 02/1200Z 19.2N 116.5W 30 KT 35 MPH
36H 03/0000Z 19.6N 117.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 03/1200Z 19.8N 119.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 04/0000Z 19.8N 120.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 04/1200Z...DISSIPATED

$$
Forecaster Reinhart

[Sciencerocks]

[Sciencerocks]

[cycloneye]

Tropical Storm Adrian Discussion Number 17
NWS National Hurricane Center Miami FL EP012023
200 PM PDT Sat Jul 01 2023

Adrian continues to weaken. The low-level center is decoupled from
a limited area of active convection over the western portion of
the circulation. Adrian is passing just to the north of Clarion
Island, and a Mexican Navy automated weather station has recently
reported sustained tropical-storm-force winds with a gust of 48 kt.
The objective and subjective satellite estimates have continued to
fall this afternoon, with T3.0 Dvorak data-T numbers from TAFB and
SAB along with ADT, AiDT, and SATCON objective estimates between
47-53 kt. Based on these data, the initial intensity is lowered to
50 kt for this advisory.

The storm is still moving west-northwestward at around 300/6 kt. A
gradual turn toward the west is expected over the next couple of
days as the vortex spins down and becomes increasingly steered by
the low-level trade wind flow. Further weakening is expected due to
continued easterly shear, decreasing SSTs, and a drier and more
stable air mass along the forecast track. The official NHC forecast
now shows Adrian degenerating to a remnant low in 24 h, with
dissipation early next week. This updated forecast is very similar
to the previous one with no other notable changes.


FORECAST POSITIONS AND MAX WINDS

INIT 01/2100Z 18.7N 115.0W 50 KT 60 MPH
12H 02/0600Z 19.1N 115.9W 35 KT 40 MPH
24H 02/1800Z 19.6N 117.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 03/0600Z 19.9N 118.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 03/1800Z 20.0N 119.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 04/0600Z...DISSIPATED

$$
Forecaster Reinhart

[Yellow Evan]

Still has some convection so probably can sustain itself for another day.

[Sciencerocks]

[cycloneye]

Tropical Storm Adrian Discussion Number 18
NWS National Hurricane Center Miami FL EP012023
800 PM PDT Sat Jul 01 2023

Adrian continues to gradually weaken. Satellite imagery shows the
center remains decoupled from the region of active convection,
located in the northwest quadrant. The center is now to the
northwest of Clarion Island, where a Mexican Navy automated weather
station shows 20-kt sustained winds. The Dvorak Data T-number from
TAFB is lower at 2.5/35 kt, and the estimates from the CIMSS
ADT and SAB also support a weaker intensity. With this information,
the initial intensity is estimated to be 45 kt for this advisory.

Adrian is moving west-northwestward at approximately 305/7 kt. The
tropical cyclone is expected to turn more westward as it becomes
more influenced from the low-level subtropical ridge. The system is
predicted to enter a region of even drier air with decreasing
sea-surface temperatures, which should contribute to continued
weakening for the remainder of the forecast. Adrian is forecast to
transition to a remnant low by tomorrow night with total dissipation
expected in the early part of next week.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0300Z 19.2N 115.6W 45 KT 50 MPH
12H 02/1200Z 19.6N 116.5W 35 KT 40 MPH
24H 03/0000Z 20.1N 117.9W 30 KT 35 MPH...POST-TROP/REMNT LOW
36H 03/1200Z 20.3N 119.3W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 04/0000Z 20.2N 120.9W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 04/1200Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

Tropical Depression Adrian Discussion Number 19
NWS National Hurricane Center Miami FL EP012023
200 AM PDT Sun Jul 02 2023

Adrian's structure continues decaying. Most of the remaining deep
convection that was displaced to the northwest of the low-level
center has dissipated. In response, both subjective and objective
intensity estimates continue to decrease. In addition, an 0519 UTC
ASCAT-B pass over Adrian had a peak wind retrieval of only 30-kt.
Based primarily on the scatterometer data, Adrian is being
downgraded to a tropical depression this advisory with 30-kt winds.
Further weakening is anticipated in a dry and stable environment
with sea-surface temperatures below 24 C that cool further along the
cyclone's track. If deep convection does not return later today,
Adrian could be declared a post-tropical remnant low as soon as this
afternoon.

Adrian continues moving west-northwestward at about 300/6 kt. This
motion should continue with a gradual turn westward, following the
trade wind flow south of a low-level anticyclone. The latest NHC
track is quite similar to the prior one, and lies near the
various consensus aids.


FORECAST POSITIONS AND MAX WINDS

INIT 02/0900Z 19.3N 116.1W 30 KT 35 MPH
12H 02/1800Z 19.7N 117.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
24H 03/0600Z 20.1N 118.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 03/1800Z 20.2N 120.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 04/0600Z 20.1N 121.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
60H 04/1800Z...DISSIPATED

$$
Forecaster Papin

[Yellow Evan]

01E ADRIAN 230702 1200 19.4N 116.4W EPAC 30 1005

[Yellow Evan]

Fwiw 30 knots on ASCAT supports 35 given low bias.