EPAC: HOWARD - Post-Tropical

[cycloneye]

BULLETIN
Hurricane Howard Advisory Number 10
NWS National Hurricane Center Miami FL EP092022
300 PM MDT Mon Aug 08 2022

...HOWARD RAPIDLY INTENSIFIES INTO THE SEVENTH HURRICANE OF THE
EASTERN NORTH PACIFIC SEASON...


SUMMARY OF 300 PM MDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...20.6N 114.4W
ABOUT 330 MI...530 KM WSW OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES



Hurricane Howard Discussion Number 10
NWS National Hurricane Center Miami FL EP092022
300 PM MDT Mon Aug 08 2022

Howard has continued to become better organized today, with an eye
now making an appearance on infrared and visible satellite imagery.
A 1433 UTC SSMIS pass indicated that deeper convective banding
surrounded the center more so than it did in the earlier AMSR-2
microwave pass. The latest subjective intensity estimates are 65 and
77 kt from TAFB and SAB, respectively. The above data support
raising the current intensity to 70 kt. A slight adjustment to the
wind radii was performed based on recent ASCAT passes.

Howard is still moving northwestward at 315/11 kt. The track
guidance remains in good agreement that the northwestward motion
will continue into Tuesday, as Howard is steered by a mid- to
upper-level ridge to its northeast. After that time, the cyclone
should gradually turn west-northwestward as the cyclone becomes
more vertically shallow and is increasingly steered by the
low-level trade wind flow. Only a slight adjustment to the left was
made to the track forecast for this advisory. The NHC track lies
between the middle of the guidance envelope and the previous
official forecast.

Howard likely has about another 12 hours to strengthen before it
crosses the 26 C sea surface temperature (SST) isotherm. After that
time, progressively cooler SSTs and drier mid-level air should cause
weakening. By 60 h, Howard is forecast to lose its convection and
become post-tropical. The NHC intensity forecast has been increased
during the first day to better match current intensity trends and
the latest IVCN and HCCA intensity guidance, but then falls in line
with the previous NHC forecast from 36 h onward. It should be noted
that the GFS-SHIPS rapid intensification guidance indicates a 32
percent chance of a 20 kt increase during the next 12 h, so it is
possible that the 12 h intensity forecast could be somewhat
conservative.

FORECAST POSITIONS AND MAX WINDS

INIT 08/2100Z 20.6N 114.4W 70 KT 80 MPH
12H 09/0600Z 21.5N 115.7W 75 KT 85 MPH
24H 09/1800Z 22.6N 117.4W 70 KT 80 MPH
36H 10/0600Z 23.4N 119.1W 60 KT 70 MPH
48H 10/1800Z 24.0N 120.8W 50 KT 60 MPH
60H 11/0600Z 24.5N 122.3W 40 KT 45 MPH...POST-TROPICAL
72H 11/1800Z 24.7N 123.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 12/1800Z 24.9N 125.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
120H 13/1800Z...DISSIPATED

$$
Forecaster Hagen/Papin/Pasch

[Ntxw]

Took forever but eye is warm enough, donut.

[Sciencerocks]

[Yellow Evan]

Free donut in the Pacific Ocean.

[Yellow Evan]

TXPZ21 KNES 082355
TCSENP

A. 09E (HOWARD)

B. 08/2330Z

C. 20.9N

D. 114.7W

E. ONE/GOES-W

F. T4.5/4.5

G. IR/EIR/VIS

H. REMARKS...A WMG EYE SURROUNDED BY MG AND EMBEDDED IN DG YIELDS A DT
OF 4.5. THE MET IS 4.0 BASED ON A RAPID DEVELOPMENT TREND OVER THE PAST
24 HOURS. THE PT IS 4.5. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

NIL


...COVERDALE

[InfernoFlameCat]

Howard, you look good, I stand corrected.

[cycloneye]

EP, 09, 2022080900, , BEST, 0, 209N, 1148W, 70, 987, HU

[ElectricStorm]

Nice to see this become a hurricane after that slow start

[Kingarabian]

[cycloneye]

Hurricane Howard Discussion Number 11
NWS National Hurricane Center Miami FL EP092022
800 PM PDT Mon Aug 08 2022

Howard's structure has evolved over the past several hours.
Although the overall amount of deep convection has decreased,
thunderstorm activity in the eyewall appears better organized and
more symmetric during the past few hours. Water vapor images show a
pronounced dry slot channeling into the system's east side, which is
likely the reason why the rainbands have become less convective.
Despite the structural change, the Dvorak classifications have
remained steady at 4.0/65 kt and 4.5/77 kt from TAFB and SAB,
respectively. Based on that data, the initial intensity is held at
70 kt.

Howard is just about out of time to strengthen any further. The
hurricane is approaching the 26 degree C SST isotherm and dry air is
already entraining into the circulation. These factors should cause
a weakening trend to begin on Tuesday, and Howard will likely become
a remnant low in a couple of days. The NHC intensity forecast is a
little lower than the previous one and near the IVCN and HCCA
consensus models.

Over the past 12 hours, Howard has been moving to the northwest
at 10 kt. A west-northwest to northwest motion is expected during
the next couple of days as the system moves on the southwestern
periphery of a subtropical ridge centered over the south-central
and southwestern United States. A turn to the west within the
low-level flow is forecast in a few days when Howard is expected to
be a weak and shallow system. The NHC track forecast is similar to
the previous one and near the model consensus TVCE.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0300Z 21.2N 115.2W 70 KT 80 MPH
12H 09/1200Z 22.0N 116.6W 70 KT 80 MPH
24H 10/0000Z 22.9N 118.4W 65 KT 75 MPH
36H 10/1200Z 23.6N 120.0W 55 KT 65 MPH
48H 11/0000Z 24.2N 121.6W 45 KT 50 MPH
60H 11/1200Z 24.6N 123.0W 35 KT 40 MPH...POST-TROPICAL
72H 12/0000Z 24.8N 124.3W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 13/0000Z...DISSIPATED

$$
Forecaster Cangialosi

[cycloneye]

Hurricane Howard Discussion Number 12
NWS National Hurricane Center Miami FL EP092022
200 AM PDT Tue Aug 09 2022

Howard has been generally steady state in strength over the past
few hours and the hurricane has likely peaked in intensity.
Very recently, satellite imagery has shown a few breaks in the
convection in the northern semicircle. However, a blend of Dvorak
T- and CI-numbers from TAFB and SAB, along with objective SATCON
estimates, still support Howard as a 70-kt hurricane.

The cyclone is expected to begin weakening shortly. Though the
vertical wind shear is forecast to remain low for another day or
so, Howard has moved over waters cooler than 26 degrees C and is
pushing farther into a dry and stable environment. The official
forecast now predicts the storm to degenerate into a post-tropical
cyclone in a couple of days.

The initial motion estimate is 305/10 kt. A ridge to the northeast
of the hurricane should continue to steer Howard on a northwestward
trajectory. As Howard weakens, its motion will likely gain a more
westerly component when the shallower vortex is guided by the
low-level tradewinds. The NHC track forecast is largely unchanged
from the previous advisory and remains within the tightly-clustered
model guidance, closest to TVCE and HCCA.


FORECAST POSITIONS AND MAX WINDS

INIT 09/0900Z 21.6N 116.1W 70 KT 80 MPH
12H 09/1800Z 22.3N 117.5W 65 KT 75 MPH
24H 10/0600Z 23.2N 119.2W 60 KT 70 MPH
36H 10/1800Z 23.9N 120.9W 50 KT 60 MPH
48H 11/0600Z 24.4N 122.5W 40 KT 45 MPH...POST-TROPICAL
60H 11/1800Z 24.8N 123.9W 35 KT 40 MPH...POST-TROPICAL
72H 12/0600Z 25.0N 125.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
96H 13/0600Z...DISSIPATED

$$
Forecaster Bucci/Brown

[Yellow Evan]

TXPZ21 KNES 090613
TCSENP

A. 09E (HOWARD)

B. 09/0531Z

C. 21.4N

D. 115.6W

E. ONE/GOES-W

F. T4.0/4.5

G. IR/EIR/SWIR

H. REMARKS...LARGE WMG EYE SURROUNDED BY MG AND EMBEDDED IN OW RESULTS
IN AN E# OF 4.0 WITH NO EADJ FOR A DT OF 4.0. MET=4.0 AND PT=4.5. SYSTEM
PSBLY TAKING ON MORE ANNULAR STRUCTURE. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...KONON

[cycloneye]

Annular.

 https://twitter.com/pppapin/status/1556985530885165057

[Yellow Evan]

EP, 09, 2022080912, , BEST, 0, 219N, 1166W, 75, 983, HU

[Yellow Evan]

TXPZ21 KNES 091209
TCSENP

A. 09E (HOWARD)

B. 09/1130Z

C. 21.9N

D. 116.1W

E. ONE/GOES-W

F. T4.5/4.5

G. IR/EIR/SWIR/AMSR2

H. REMARKS...EYE PATTERN WITH AN EYE TEMP OF OW, SURROUNDED BY A DG
RING, EMBEDDED IN DG RESULTS IN A DT OF 4.5. THE MET IS 4.5 BASED ON A
24HR DEVELOPING TREND. THE PT IS 4.0. THE FT IS BASED ON THE DT.

I. ADDL POSITIONS

09/0926Z 21.9N 116.1W AMSR2


...GATLING

[cycloneye]

Hurricane Howard Discussion Number 13
NWS National Hurricane Center Miami FL EP092022
800 AM PDT Tue Aug 09 2022

Howard has been maintaining a ragged-looking eye on geostationary
imagery, but an AMSR-2 microwave overpass showed a well-defined
ring of convection in the core. The current intensity is set at 75
kt in agreement with the latest Dvorak estimates from both TAFB and
SAB. The hurricane continues to exhibit a fairly well-defined
upper-level outflow pattern, indicative of low vertical wind shear.

The system is currently over marginally warm sea surface
temperatures (SSTs) and vertical wind shear is not predicted to
increase much over the next couple of days. However Howard will be
passing over increasingly cooler ocean waters and into a drier, more
stable air mass. These conditions should lead to steady weakening,
with the cyclone becoming post-tropical over 22 deg C SSTs in about
48 hours. The official intensity forecast is very close to the
latest corrected consensus guidance, HCCA.

The hurricane is moving west-northwestward, or at about 300/9 kt.
A generally west-northwestward track is likely over the next few
days while the cyclone moves along the southwestern side of a
mid-level ridge. A westward turn is expected late in the forecast
period when the the increasingly shallow system becomes steered by
the lower-tropospheric flow. The official track forecast is very
similar to the previous NHC prediction, and remains close to the
simple and corrected dynamical model consensus solutions.


FORECAST POSITIONS AND MAX WINDS

INIT 09/1500Z 22.0N 116.9W 75 KT 85 MPH
12H 10/0000Z 22.8N 118.3W 70 KT 80 MPH
24H 10/1200Z 23.5N 120.0W 60 KT 70 MPH
36H 11/0000Z 24.2N 121.7W 50 KT 60 MPH
48H 11/1200Z 24.6N 123.3W 40 KT 45 MPH...POST-TROPICAL
60H 12/0000Z 24.9N 124.6W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 12/1200Z 25.0N 126.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 13/1200Z...DISSIPATED

$$
Forecaster Pasch

[Sciencerocks]

[Kingarabian]

Winding now.

[cycloneye]

Hurricane Howard Discussion Number 14
NWS National Hurricane Center Miami FL EP092022
200 PM PDT Tue Aug 09 2022

Deep convection associated with Howard has decreased in intensity
and become less organized today while the cyclone moves over cooler
waters. Dvorak T-numbers from both TAFB and SAB have been lowered
from earlier today, and the objective Dvorak intensity estimate
from UW-CIMSS is below hurricane strength. Based on these values,
the advisory intensity is reduced to 65 kt.

Although the vertical wind shear is not forecast to increase, Howard
will continue to pass over cooler ocean waters during the next
couple of days. Moreover, model analyses and the presence of a
field of stratocumulus clouds just to the west of the cyclone
indicate that the system should soon be encountering a more stable
air mass. Therefore, continued steady weakening is forecast, and
the official intensity forecast is near or slightly above the model
consensus. Howard should make the transition into a post tropical
cyclone in 48 hours, or less.

Howard remains on a west-northwestward track, and continues moving
at around 300/9 kt. The track forecast philosophy is essentially
unchanged from the previous few advisories. A mid-level ridge
extending westward from a high pressure system over the southwestern
United States should keep the system on a west-northwestward course
for the next day or two. Late in the forecast period, weak
post-tropical Howard should turn westward following the near-surface
winds. The NHC track forecast is basically an update of the
previous one.

FORECAST POSITIONS AND MAX WINDS

INIT 09/2100Z 22.5N 117.7W 65 KT 75 MPH
12H 10/0600Z 23.1N 119.0W 60 KT 70 MPH
24H 10/1800Z 23.8N 120.6W 50 KT 60 MPH
36H 11/0600Z 24.3N 122.3W 40 KT 45 MPH
48H 11/1800Z 24.7N 123.8W 30 KT 35 MPH...POST-TROP/REMNT LOW
60H 12/0600Z 24.9N 125.1W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 12/1800Z 24.9N 126.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 13/1800Z...DISSIPATED

$$
Forecaster Pasch

[Sciencerocks]