霧峰追風者

18Z 強度升"一級颶風"，也是今年東太首颶。

t02436

03Z報直升C2，評價85節，巔峰上望95節。

000
WTPZ42 KNHC 080236
TCDEP2

Hurricane Aletta Discussion Number   9
NWS National Hurricane Center Miami FL       EP022018
900 PM MDT Thu Jun 07 2018

Based on how Aletta looked last evening, it would have been hard to
imagine the cyclone improving in structure so drastically.  Yet, the
hurricane has continued to improve in organization and has deep
convection with cloud tops as cold as -85C completely surrounding a
ragged, cloud-filled eye.  Dvorak classifications have increased to
T5.0/90 kt from TAFB and SAB, while objective guidance from the
UW-CIMSS ADT and SATCON have increased more modestly to between
75-80 kt.  Based on these data, Aletta's current intensity is
estimated to be 85 kt.  Since Aletta's estimated intensity 24 hours
ago was 45 kt, the cyclone's recent strengthening meets the
criterion for rapid intensification.

Aletta appears to have another 24 hours or so before vertical shear
gradually increases, and 48 hours before sea surface temperatures
become marginal to support further strengthening.  Therefore,
additional intensification is anticipated during the next 24 hours,
and the new NHC official forecast brings Aletta's intensity to just
below major hurricane status.  The chance of a another 20-kt
increase in the next 12 hours is just under 50 percent, so it's not
out of the question that Aletta could reach major hurricane
strength on Friday.  Weakening is anticipated to begin by 36 hours,
and the weakening rate should be rather fast in 3 to 4 days due to
stronger shear and colder waters.  The updated NHC forecast is
close to HCCA and the intensity consensus for the first couple of
days but then is above most of the guidance after 48 hours to
maintain continuity with the previous forecast.  The GFS and ECMWF
models show Aletta's convection dissipating in about 4 days, so the
NHC forecast now calls for the cyclone to become a remnant low by
day 5.

Aletta is being steered slowly west-northwestward, or 300/5 kt,
around a mid-level ridge located over northwestern Mexico and
toward a break in the ridge located west of the Baja California
peninsula.  Because the hurricane has strengthened more than
previously expected, it has taken a jog toward the north, closer to
where more aggressive models such as the GFS and HWRF had been
predicting.  With the additional strengthening anticipated, the NHC
track forecast largely discounts the ECMWF solution, which is an
outlier to the south of the other models, and lies farther north
close to the TVCE model consensus and HCCA models.

FORECAST POSITIONS AND MAX WINDS

INIT  08/0300Z 15.6N 110.3W   85 KT 100 MPH
12H  08/1200Z 16.0N 111.0W   95 KT 110 MPH
24H  09/0000Z 16.6N 111.9W   95 KT 110 MPH
36H  09/1200Z 17.2N 112.8W   90 KT 105 MPH
48H  10/0000Z 17.8N 113.7W   75 KT  85 MPH
72H  11/0000Z 19.1N 115.4W   50 KT  60 MPH
96H  12/0000Z 20.0N 117.5W   30 KT  35 MPH
120H  13/0000Z 20.5N 119.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Berg

霧峰追風者

06Z強度升三級颶風，巔峰上望四級颶風，快速增強中。

000
WTPZ42 KNHC 080559
TCDEP2

Hurricane Aletta Special Discussion Number  10
NWS National Hurricane Center Miami FL       EP022018
1200 AM MDT Fri Jun 08 2018

Satellite images indicate that Aletta has continued to rapidly
intensify, with very deep convection in the eyewall and a warm eye.
The initial intensity is set to 105 kt, on the low end of a range of
estimates from 105 kt from CIMSS-SATCON to 115 kt at 0500 UTC from a
special TAFB Dvorak classification.

This special advisory is being issued to update Aletta's current
and forecast intensity.  The intensity forecast is raised to 115 kt,
which is close to a persistence forecast. Afterwards a combination
of increasing shear and cooling waters should begin to weaken the
cyclone, and no changes were required to the forecast beyond 24
hours.

There are no changes to track forecast from the last advisory.


FORECAST POSITIONS AND MAX WINDS

INIT  08/0600Z 15.6N 110.5W  105 KT 120 MPH
12H  08/1200Z 16.0N 111.0W  115 KT 130 MPH
24H  09/0000Z 16.6N 111.9W  105 KT 120 MPH
36H  09/1200Z 17.2N 112.8W   90 KT 105 MPH
48H  10/0000Z 17.8N 113.7W   75 KT  85 MPH
72H  11/0000Z 19.1N 115.4W   50 KT  60 MPH
96H  12/0000Z 20.0N 117.5W   30 KT  35 MPH
120H  13/0000Z 20.5N 119.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Blake

霧峰追風者

12Z 強度升四級颶風120節...分析到達T6.0。

TXPZ21 KNES 081222
TCSENP

A.  02E (ALETTA)

B.  08/1200Z

C.  15.8N

D.  111.0W

E.  ONE/GOES-W

F.  T6.0/6.0/D2.5/24HRS

G.  IR/EIR

H.  REMARKS...AN EYE EMBEDDED WITHIN BLACK GIVES AN EYE NUMBER OF 5.5. AN
OFF WHITE EYE WITH A BLACK SURROUNDING RING GOVES AN EYE ADJUSTMENT OF
+0.5, RESULTING IN A DT OF 6.0. MET IS 5.0 AND PT IS 5.5. FT IS BASED
ON DT.

I.  ADDL POSITIONS

    NIL


...HOSLEY

霧峰追風者

環境轉差，強度減弱到一級颶風，將持續減弱。

000
WTPZ42 KNHC 092031
TCDEP2

Hurricane Aletta Discussion Number  17
NWS National Hurricane Center Miami FL       EP022018
300 PM MDT Sat Jun 09 2018

Aletta has rapidly weakened during the past several hours, with the
main convection currently dissipating to the north and northeast of
the now-exposed low-level center.  The initial intensity is reduced
to a possibly generous 65 kt based on a combination of subjective
and objective satellite intensity estimates.  Rapid weakening should
continue due to a combination of shear, decreasing sea surface
temperatures along the forecast track, and entrainment of dry air.
Based on current trends, the new intensity forecast shows a faster
demise for Aletta than the previous advisory, with the system now
forecast to weaken to a depression by 36 h, and degenerate to a
remnant low by 48 h.

The initial motion is quite uncertain due to Aletta being south of
where the earlier microwave fixes indicated it to be and due to the
exposed center moving southwestward.  This advisory will use a
longer-term motion of 275/5.  Most of the track guidance forecasts
the cyclone to resume a west-northwestward motion over the next few
hours, then again turn westward by 24-36 h.  After that time the
remnants of Aletta are expected to move slowly west-southwestward.
The new forecast track follows this basic scenario, but it lies well
to the south of the center of the guidance envelope and the
consensus models based on the current trends.  An alternate scenario
is that Aletta never makes the west-northwestward turn, which would
result in the decaying system tracking south of the new forecast
track.


FORECAST POSITIONS AND MAX WINDS

INIT  09/2100Z 16.1N 113.9W   65 KT 75 MPH
12H  10/0600Z 16.6N 114.7W   50 KT  60 MPH
24H  10/1800Z 17.0N 115.7W   35 KT  40 MPH
36H  11/0600Z 17.1N 117.0W   25 KT  30 MPH
48H  11/1800Z 16.9N 118.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
72H  12/1800Z 16.6N 120.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  13/1800Z 16.0N 121.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  14/1800Z 15.5N 122.5W   15 KT  15 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

霧峰追風者

06/08 18Z 東太巔峰中AIETTA