WPAC: JEBI - Post-Tropical

[mrbagyo]

12z GFS has a massive landfall in Shikoku Island (Moruto area)

[euro6208]

WDPN31 PGTW 272100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 25W (TWENTYFIVE)
WARNING NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 25W (TWENTYFIVE), LOCATED APPROXIMATELY
617 NM SOUTH-SOUTHEAST OF MINAMI TORI SHIMA, JAPAN, HAS TRACKED
NORTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED EIR SHOWS
THE SYSTEM HAS MAINTAINED OVERALL CONVECTIVE STRUCTURE, ALBEIT
FORMATIVE BANDS REMAIN FRAGMENTED AND SHALLOW. THE INITIAL POSITION
IS BASED ON THE EIR LOOP SHOWING THE FRAGMENTED BANDS WRAPPING INTO A
DEFINED LLC NORTH OF THE MAIN CLUSTER OF CONVECTION. THE INITIAL
INTENSITY OF 30 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF AGENCY
DVORAK ESTIMATES RANGING FROM T1.5/25 KNOTS TO T2.0/30 KNOTS AND
REFLECTS THE SUSTAINED EIR SIGNATURE. UPPER LEVEL ANALYSIS INDICATES
THE SYSTEM IS JUST SOUTH OF THE STR AXIS IN AN AREA OF LOW VWS AND
MODERATE RADIAL OUTFLOW. ALONG-TRACK SSTS ARE ALSO FAVORABLE AT 29
DEGREES CELSIUS. TD 25W IS TRACKING UNDER THE STEERING INFLUENCE OF
AN EXTENSIVE STR TO THE NORTH AND EAST OF THE SYSTEM.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
WARNING.
B. TD 25W WILL GRADUALLY TURN TOWARD THE WEST-NORTHWEST OVER THE
NEXT 24 TO 36 HOURS UNDER THE STEERING INFLUENCE OF THE STR. THE
FAVORABLE ENVIRONMENTAL CONDITIONS DESCRIBED ABOVE WILL PREVAIL,
TEMPERED ONLY BY THE SUBSIDING EFFECT OF A TUTT CELL TO THE
NORTHWEST, AND PROMOTE STEADY INTENSIFICATION UP TO 95 KNOTS BY TAU
72. THE AVAILABLE NUMERICAL MODEL FORECAST MEMBERS ARE IN TIGHT
AGREEMENT, LENDING HIGH CONFIDENCE IN THIS PORTION OF THE JTWC TRACK
FORECAST.
C. BEYOND TAU 72, TD 25W IS EXPECTED TO TRACK A LITTLE MORE
POLEWARD TOWARD A BREAK IN THE STR, INDUCED BY A DEVELOPING
MID-LATITUDE TROUGH. THE TD WILL PEAK AT 120 KNOTS BY TAU 96.
AFTERWARD, IT WILL FLAT LINE AS OUTFLOW BECOMES RESTRICTED BY ANOTHER
TUTT CELL NEAR TAIWAN AND AS VWS INCREASES SLIGHTLY. MODEL TRACK
FORECASTS ARE IN BETTER AGREEMENT BUT ARE STILL SPREAD BY OVER 330 NM
IN THE EXTENDED TAUS. ALSO, THE ECMWF CONTINUES TO BE THE LEFT
OUTLIER, DEPICTING A WIDER TURN TO THE WEST. GIVEN THE MODEL SPREAD,
THERE IS LOW CONFIDENCE IN THE EXTENDED RANGE JTWC TRACK FORECAST.//
NNNN

[euro6208]

TPPN10 PGTW 272052

A. TROPICAL DEPRESSION 25W (N OF POHNPEI)

B. 27/2030Z

C. 15.10N

D. 127.34E

E. FIVE/HMWRI8

F. T2.5/2.5/D1.5/24HRS STT: D0.5/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 40A/PBO SBC/ANMTN. CNVCTN WRAPS .40 ON LOG10 SPIRAL
YIELDING A DT OF 2.5. PT AGREES WITH DT WHILE MET YIELDS A 2.0.
DBO DT.

I. ADDITIONAL POSITIONS:
27/1531Z 14.58N 157.98E AMS2


LEMBKE

[1900hurricane]

There is quite a bit of divergence in guidance tracks by the time this reaches 140ºE. The left and right sides of the envelope split off at a right angle northward along the aforementioned 140ºE and westwards near 20ºN.

[euro6208]

20th TS of the season.

25W TWENTYFIVE 180828 0000 15.5N 157.0E WPAC 35 1001

[1900hurricane]

Including Hector, I actually count 22 JTWC tropical storms so far this season now.

[cycloneye]

JMA upgrades to TS JEBI.

TS 1821 (Jebi)
Issued at 01:05 UTC, 28 August 2018

<Analysis at 00 UTC, 28 August>
Scale -
Intensity -
Center position N15°25' (15.4°)
E157°00' (157.0°)
Direction and speed of movement NW 20 km/h (12 kt)
Central pressure 1004 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
≥ 30 kt wind area E 170 km (90 NM)
W 110 km (60 NM)

<Forecast for 00 UTC, 29 August>
Intensity -
Center position of probability circle N16°55' (16.9°)
E153°35' (153.6°)
Direction and speed of movement WNW 15 km/h (9 kt)
Central pressure 998 hPa
Maximum wind speed near center 23 m/s (45 kt)
Maximum wind gust speed 35 m/s (65 kt)
Radius of probability circle 90 km (50 NM)

<Forecast for 00 UTC, 30 August>
Intensity Strong
Center position of probability circle N17°40' (17.7°)
E149°40' (149.7°)
Direction and speed of movement W 20 km/h (10 kt)
Central pressure 985 hPa
Maximum wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
Radius of probability circle 180 km (95 NM)
Storm warning area ALL 220 km (120 NM)

<Forecast for 00 UTC, 31 August>
Intensity Very strong
Center position of probability circle N18°25' (18.4°)
E145°30' (145.5°)
Direction and speed of movement W 20 km/h (10 kt)
Central pressure 965 hPa
Maximum wind speed near center 45 m/s (85 kt)
Maximum wind gust speed 60 m/s (120 kt)
Radius of probability circle 240 km (130 NM)
Storm warning area ALL 310 km (170 NM)

[1900hurricane]

JMA has a 1.5 T intensity increase between tau 48 and 72. It isn't all that common for them to be that aggressive out of the gate.

[euro6208]

Peak up to 120 knots.

WDPN31 PGTW 280300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (JEBI) WARNING NR
04//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 25W (JEBI), LOCATED APPROXIMATELY 648 NM EAST
OF SAIPAN, CNMI, HAS TRACKED NORTHWESTWARD AT 14 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MSI SHOWS THE SYSTEM HAS CONSOLIDATED AS
CONVECTIVE BANDS, ESPECIALLY FROM THE SOUTHERN PERIPHERY, HAVE BECOME
MORE SOLID AND WRAPPED TIGHTER INTO AN OBSCURED LLC. THE INITIAL
POSITION IS EXTRAPOLATED FROM THE MSI LOOP AND LINED UP WITH A
DEFINED LLC FEATURE IN THE 272137Z AMSU MICROWAVE PASS. THE INITIAL
INTENSITY OF 35 KNOTS IS BASED ON CONGRUENT DVORAK ESTIMATES OF
T2.5/35 KNOTS FROM PGTW AND KNES AND REFLECTS THE IMPROVED STATUS OF
THE SYSTEM. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS JUST SOUTH
OF THE STR AXIS IN AN AREA OF LOW VWS AND GOOD RADIAL DIFFLUENCE WITH
A RECENT SURGE IN THE POLEWARD OUTFLOW. THE CYCLONE IS TRACKING ALONG
THE SOUTHWEST PERIPHERY OF A DEEP-LAYERED STR TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
WARNING.
B. TS 25W WILL GRADUALLY TURN TO A WEST-NORTHWEST TRAJECTORY AFTER
TAU 12 AS THE STR BUILDS. THE FAVORABLE ENVIRONMENTAL CONDITIONS
DESCRIBED ABOVE WILL PREVAIL, TEMPERED ONLY BY THE SUBSIDING EFFECT
OF A TUTT CELL TO THE NORTHWEST, AND PROMOTE STEADY INTENSIFICATION
UP TO 100 KNOTS BY TAU 72. THE AVAILABLE NUMERICAL MODEL FORECAST
MEMBERS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THIS
PORTION OF THE JTWC TRACK FORECAST.
C. BEYOND TAU 72, TS JEBI IS EXPECTED TO TRACK ON A MORE POLEWARD
TRAJECTORY TOWARD A BREAK IN THE STR, INDUCED BY A DEVELOPING
MID-LATITUDE TROUGH. THE MORE POLEWARD TRACK WILL EXPOSE THE SYSTEM
TO INCREASING VWS; HOWEVER, A SUSTAINED ROBUST POLEWARD OUTFLOW WILL
PARTLY OFFSET THE VWS AND PROMOTE A SLOWER INTENSIFICATION RATE TO
120 KNOTS BY TAU 120. MODEL TRACK FORECASTS ARE IN OVERALL GOOD
AGREEMENT BUT ARE STILL SPREAD BY OVER 260 NM IN THE EXTENDED TAUS.
ALSO, THE ECMWF SUITE (ECM2 AND EMX2) CONTINUE TO BE THE LEFT
OUTLIERS, DEPICTING A WIDER TURN TO THE WEST. GIVEN THE MODEL SPREAD,
THERE IS LOW CONFIDENCE IN THE EXTENDED RANGE JTWC TRACK FORECAST.//
NNNN

[mrbagyo]

[doomhaMwx]

00Z ECMWF ensemble tracks.

[euro6208]

WDPN31 PGTW 280900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (JEBI) WARNING NR
05//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM (TS) 25W (JEBI), LOCATED APPROXIMATELY 604 NM EAST
OF SAIPAN, CNMI, HAS TRACKED NORTHWESTWARD AT 10 KNOTS OVER THE PAST
SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS
FLARING CONVECTION WRAPPING INTO A LOW-LEVEL CIRCULATION CENTER
(LLCC) THAT IS OBSCURED BY A CIRRUS CANOPY. A 280728Z SSMIS 91GHZ
MICROWAVE IMAGE DEPICTS DEEP CONVECTION SURROUNDING THE LLCC TO THE
NORTH AND EAST. THE INITIAL POSITION IS PLACED ACCORDING TO ANIMATED
MSI AND EXTRAPOLATED FROM THE SSMIS IMAGE. THERE WAS NO SIGNIFICANT
IMPROVEMENT IN THE CONVECTIVE STRUCTURE OF TS 25W SINCE THE LAST
WARNING, SO THE CURRENT INTENSITY IS KEPT AT 35 KNOTS AND IS
SUPPORTED BY DVORAK ESTIMATES OF T2.5 FROM ALL AGENCIES. UPPER-LEVEL
ANALYSIS INDICATES THAT TS 25W REMAINS SOUTH OF THE SUBTROPICAL
RIDGE (STR) AXIS, WHICH IS STEERING THE SYSTEM TOWARD THE WEST-
NORTHWEST, WITH LOW VERTICAL WIND SHEAR AND GOOD RADIAL OUTFLOW.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
WARNING.
B. TS 25W WILL CONTINUE TRACKING TOWARD THE WEST-NORTHWEST
THROUGH TAU 24, AFTER WHICH A SLIGHT BEND TOWARD THE WEST IS
FORECAST AS THE STR BUILDS. WITH PLENTY OF WARM WATER AND FAVORABLE
UPPER-LEVEL CONDITIONS, STEADY INTENSIFICATION IS EXPECTED THROUGH
TAU 72. NUMERICAL MODEL FORECASTS ARE IN GOOD AGREEMENT, LENDING
HIGH CONFIDENCE IN THIS PORTION OF THE JTWC TRACK FORECAST.
C. BEYOND TAU 72, TS 25W IS FORECAST TO TURN TOWARD THE NORTHWEST
AS A BREAK IN THE STR DEVELOPS IN RESPONSE TO AN AMPLIFYING MID-
LATITUDE TROUGH PASSING THROUGH JAPAN. AS TS 25W MOVES INTO THIS
WEAKNESS IN THE STR, IT IS EXPECTED TO REACH AN INTENSITY OF 120
KNOTS BY THE END OF THE FORECAST PERIOD. NUMERICAL MODEL SPREAD
INCREASES DRAMATICALLY IN THE LATER TAUS, WITH THE ECMF/EEMN TO THE
WEST AND NVGM/CTCX TO THE EAST. THE JTWC FORECAST TRACK LIES CLOSE
TO THE CONSENSUS, BUT GIVEN THE MODEL SPREAD, THERE IS LOW
CONFIDENCE IN THE TRACK FORECAST BEYOND TAU 72.//
NNNN

[euro6208]

TS 1821 (Jebi)
Issued at 12:45 UTC, 28 August 2018

<Analysis at 12 UTC, 28 August>
Scale -
Intensity -
Center position N16°35' (16.6°)
E155°35' (155.6°)
Direction and speed of movement NW 20 km/h (10 kt)
Central pressure 1000 hPa
Maximum wind speed near center 20 m/s (40 kt)
Maximum wind gust speed 30 m/s (60 kt)
≥ 30 kt wind area E 220 km (120 NM)
W 170 km (90 NM)

[euro6208]

TPPN10 PGTW 281212

A. TROPICAL STORM 25W (JEBI)

B. 28/1150Z

C. 16.49N

D. 155.41E

E. FIVE/HMWRI8

F. T3.0/3.0/D1.0/24HRS STT: D0.5/03HRS

G. IR/EIR

H. REMARKS: 38A/PBO SBC/ANMTN. CNVCTN WRAPS .70 ON LOG10 SPIRAL
YIELDING A DT OF 3.0. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS:
28/0728Z 16.20N 156.10E SSMS
28/0826Z 16.33N 155.98E SSMS


RICHARDSON

[euro6208]

Been busy with work. What an impressive band to it's south...

[euro6208]

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 9.0
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 28 AUG 2018 Time : 121000 UTC
Lat : 16:38:29 N Lon : 155:23:11 E


CI# /Pressure/ Vmax
3.4 / 995.3mb/ 53.0kt


Final T# Adj T# Raw T#
3.4 3.5 3.5

Center Temp : -69.8C Cloud Region Temp : -67.8C

Scene Type : UNIFORM CDO CLOUD REGION

Subtropical Adjustment : OFF

Extratropical Adjustment : OFF

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : WEST PACIFIC
Dvorak CI > MSLP Conversion Used : CKZ Method

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

C/K/Z MSLP Estimate Inputs :
- Average 34 knot radii : 60nmi
- Environmental MSLP : 1011mb

Satellite Name : HIM-8
Satellite Viewing Angle : 25.8 degrees

****************************************************

[euro6208]

CURRENT ESTIMATE
Date (mmddhhmm): 08280246
SATCON: MSLP = 997 hPa MSW = 50 knots
SATCON Member Consensus: 49.0 knots
Pressure -> Wind Using SATCON MSLP: 55 knots
Distance to Outer Closed Isobar Used is 125 nm
Eye Size Correction Used is 0 knots Source: NA

Member Estimates

ADT: 997 hPa 49 knots Scene: CDO Date: AUG280440
CIMSS AMSU: 997 hPa 44 knots Bias Corr: 0 (MW) Date: 08272136
ATMS: 996.1 hPa 47.0 knots Date: 08280246
SSMIS: 996.1 hPa 47.0 knots Date: 08280246
CIRA ATMS: 999 hPa 43 knots Date: 08271448

[mrbagyo]

40 knots

25W JEBI 180828 1200 16.6N 155.3E WPAC 40 1004

[euro6208]

A Typhoon Watch is now in effect for Agrihan, Pagan and Alamagan
in the CNMI.

A Typhoon Watch means destructive winds of 74 mph or more are
possible within the next 48 hours.

[mrbagyo]

Is there any human/ weather instruments there?