WPAC: BOLAVEN - Post-Tropical

[cycloneye]

Peak is 130kt on first JTWC warning.

WTPN32 PGTW 070300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL DEPRESSION 15W (FIFTEEN) WARNING NR 001//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/061051OCT2023//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL DEPRESSION 15W (FIFTEEN) WARNING NR 001
02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
070000Z --- NEAR 9.8N 154.5E
MOVEMENT PAST SIX HOURS - 290 DEGREES AT 11 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.8N 154.5E
---
FORECASTS:
12 HRS, VALID AT:
071200Z --- 10.1N 153.4E
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
VECTOR TO 24 HR POSIT: 280 DEG/ 05 KTS
---
24 HRS, VALID AT:
080000Z --- 10.3N 152.4E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
060 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 280 DEG/ 05 KTS
---
36 HRS, VALID AT:
081200Z --- 10.5N 151.4E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 285 DEG/ 08 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
090000Z --- 10.9N 149.9E
MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT
000 NM SOUTHEAST QUADRANT
000 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT
060 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 295 DEG/ 10 KTS
---
72 HRS, VALID AT:
100000Z --- 12.6N 146.2E
MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT
015 NM SOUTHEAST QUADRANT
015 NM SOUTHWEST QUADRANT
015 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT
090 NM SOUTHEAST QUADRANT
070 NM SOUTHWEST QUADRANT
090 NM NORTHWEST QUADRANT
VECTOR TO 96 HR POSIT: 320 DEG/ 11 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
110000Z --- 15.9N 143.3E
MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 000 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
020 NM SOUTHWEST QUADRANT
020 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT
140 NM SOUTHEAST QUADRANT
140 NM SOUTHWEST QUADRANT
130 NM NORTHWEST QUADRANT
VECTOR TO 120 HR POSIT: 335 DEG/ 09 KTS
---
120 HRS, VALID AT:
120000Z --- 19.0N 141.6E
MAX SUSTAINED WINDS - 130 KT, GUSTS 160 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
050 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
040 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT
070 NM SOUTHEAST QUADRANT
050 NM SOUTHWEST QUADRANT
050 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT
160 NM SOUTHEAST QUADRANT
130 NM SOUTHWEST QUADRANT
140 NM NORTHWEST QUADRANT
---
REMARKS:
070300Z POSITION NEAR 9.9N 154.2E.
07OCT23. TROPICAL DEPRESSION 15W (FIFTEEN), LOCATED APPROXIMATELY
610 NM EAST-SOUTHEAST OF ANDERSEN AFB, HAS TRACKED WEST-
NORTHWESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS.
MINIMUM CENTRAL PRESSURE AT 070000Z IS 1003 MB. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 070000Z IS 12 FEET. NEXT WARNINGS AT
070900Z, 071500Z, 072100Z AND 080300Z.
REFER TO TYPHOON 14W (KOINU) WARNINGS (WTPN31 PGTW)
FOR SIX-HOURLY UPDATES.
2. THIS CANCELS AND SUPERSEDES REF A (WTPN21 PGTW 061100).
//
NNNN

[xtyphooncyclonex]

First warning and this bullish... we're getting that classic, big-ACE El Niño monster.

[cycloneye]

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THIS INITIAL PROGNOSTIC REASONING
MESSAGE ESTABLISHES THE FORECAST PHILOSOPHY.

FORECAST DISCUSSION: TROPICAL DEPRESSION (TD) 15W HAS FORMED AND IS
TRACKING TOWARD THE WEST-NORTHWEST, STEERED BY A SUBTROPICAL RIDGE
(STR) TO THE NORTHWEST. SATELLITE ANALYSES AND SCATTEROMETRY DATA
INDICATE THAT THE LLCC IS STILL SOMEWHAT ELONGATED, WITH THE
DEEPEST CONVECTION DISPLACED SLIGHTLY POLEWARD OF THE LLCC. THE
SYSTEM IS CURRENTLY IN A FAVORABLE ENVIRONMENT FOR INTENSIFICATION,
WITH WARM SEA SURFACE TEMPERATURES (30 TO 31 DEGREES CELSIUS), WEAK
VERTICAL WIND SHEAR (5 TO 10 KNOTS), AND MODERATE RADIAL OUTFLOW.
HOWEVER, NEAR-TERM INTENSIFICATION WILL BE SLOW UNTIL THE LLCC
CONSOLIDATES AND BECOMES VERTICALLY STACKED WITH THE FLARING
CONVECTION, THUS ALLOWING THE WARM CORE TO DEEPEN. THE OFFICIAL
FORECAST CALLS FOR GRADUAL INTENSIFICATION THROUGH TAU 48 TO AN
INTENSITY OF APPROXIMATELY 55 KNOTS. AFTER THAT, THE MORE ORGANIZED
INNER CORE STRUCTURE OF THE SYSTEM SHOULD ALLOW FOR MORE RAPID
DEEPENING. BEYOND TAU 48, THE STEERING STR IS FORECAST TO
SLIDE EASTWARD, WITH A MIDLATITUDE TROUGH PASSING THROUGH JAPAN
INDUCING A SLIGHT BREAK IN THE RIDGE AXIS, WHICH WILL ALLOW TD 15W
TO TURN MORE NORTHWESTWARD. DURING THIS TIME, THE SYNOPTIC SETUP
WILL FAVOR AN ENHANCEMENT OF UPPER-TROPOSPHERIC OUTFLOW, AND TD 15W
IS LIKELY TO EXPERIENCE RAPID INTENSIFICATION. WITH LOW VERTICAL
WIND SHEAR, INCREASING OUTFLOW, AND ABUNDANT WARM WATER, THE
OFFICIAL FORECAST CALLS FOR TD 15W TO REACH SUPER TYPHOON INTENSITY
BY TAU 120.

MODEL DISCUSSION: GLOBAL NUMERICAL MODELS ARE IN GENERAL AGREEMENT
WITH TD 15W TRACKING TOWARD THE WEST-NORTHWEST THROUGH TAU 48
FOLLOWED BY A TURN TOWARD THE NORTHWEST THROUGH THE REST OF THE
FORECAST PERIOD. THE DETERMINISTIC ECMWF AND GFS ARE THE
WESTERNMOST OUTLIERS, TAKING THE CORE OF THE SYSTEM OVER OR NEAR
THE ISLAND OF GUAM. HOWEVER, THE REST OF THE GUIDANCE ENVELOPE,
INCLUDING THE ENSEMBLE GUIDANCE, TAKE TD 15W TO THE EAST OF GUAM.
GIVEN THE PERSISTENCE OF THE LAST TWO GFS RUNS THAT NOTABLY SHIFTED
WESTWARD STARTING AT 12Z, COMBINED WITH THE STEADY WEST-NORTHWESTWARD
MOTION OF TD 15W OVER THE LAST 12 HOURS, THE PERSISTENT STR TO THE
NORTH OF THE MARIANAS ISLANDS, AND THE ROBUST UPPER-LEVEL EQUATORWARD
FLOW EVIDENT IN THE WATER VAPOR SATELLITE IMAGERY ALONG THE EASTERN
FLANK OF THE STEERING STR, THE MORE POLEWARD TRACK APPEARS UNLIKELY.
AS SUCH, THE OFFICIAL TRACK FORECAST IS PLACED TO THE LEFT OF
CONSENSUS, FAVORING THE WESTERN PORTION OF THE GUIDANCE ENVELOPE. THE
INTENSITY GUIDANCE IS RATHER AGGRESSIVE FOR A NEW TD, WITH ALL RAPID
INTENSIFICATION INDICATORS ACTIVATED. THE INITIAL INTENSITY FORECAST
THROUGH TAU 48 IS RATHER CONSERVATIVE AS THE SYSTEM ORGANIZES.
HOWEVER, GIVEN THE AFOREMENTIONED FAVORABLE ENVIRONMENTAL CONDITIONS,
RAPID INTENSIFICATION IS LIKELY THEREAFTER, AND THE OFFICIAL INTENSITY
FORECAST TRACKS CLOSELY ALONG WITH HWRF AND COAMPS-TC, BOTH OF WHICH
ACTUALLY EXCEED THE OFFICIAL JTWC FORECAST OF 130 KNOTS BY TAU 120.
THE HAFS GUIDANCE IS ON THE LOWER END OF THE INTENSITY GUIDANCE
ENVELOPE, SUGGESTING THAT TYPHOON INTENSITY WILL NOT BE REACHED UNTIL
AFTER TAU 96. HOWEVER, THE SHIPS GUIDANCE IS MORE AGGRESSIVE THAN
CONSENSUS AND LENDS CREDENCE TO THE HWRF AND COAMPS-TC SOLUTIONS. THE
TRACK FORECAST CONFIDENCE IS MEDIUM THROUGHOUT, AND THE INTENSITY
FORECAST CONFIDENCE IS MEDIUM THROUGH TAU 72 AND LOW BEYOND, GIVEN THE
UNCERTAINTIES ASSOCIATED WITH THE BEGINNING OF THE PERIOD OF RAPID
INTENSIFICATION.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

[MarioProtVI]

Getting Hagibis vibes from this for some reason..

[ElectricStorm]

I'm getting pretty concerned for Guam and the surrounding islands here. No reason why this won't become a STY, and I wouldn't be surprised if it intensifies faster than forecast. Hope everyone there is getting prepared.

[Guamphoon]

I'm getting pretty concerned for Guam and the surrounding islands here. No reason why this won't become a STY, and I wouldn't be surprised if it intensifies faster than forecast. Hope everyone there is getting prepared.

People here are getting worried as well. Lines at gas stations, grocery stores getting packed, etc.

Mawar is still a recent memory, so I don't think anyone will be skimping on preparation.

[Hayabusa]

T2315(Bolaven)
Issued at 2023/10/07 07:10 UTC
Analysis at 10/07 06 UTC
Grade TS
Scale -
Intensity -
Center position N9°40′ (9.7°)
E153°40′ (153.7°)
Direction and speed of movement W Slow
Central pressure 1000 hPa
Maximum sustained wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of 30-kt wind area 150 km (80 NM)

[cycloneye]

JTWC upgrades.

15W BOLAVEN 231007 1200 9.8N 153.2E WPAC 35 998

[cycloneye]

WDPN32 PGTW 071500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN) WARNING NR
003//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 9.8N 153.2E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 541 NM EAST-SOUTHEAST OF ANDERSEN AFB,
GUAM
MOVEMENT PAST 6 HOURS: WESTWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 13 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY SHOWS A
DISORGANIZED, ALBEIT CONSOLIDATING SYSTEM WITH DEEP FLARING
CONVECTION OBSCURING THE LOW LEVEL CIRCULATION. THE INITIAL
POSITION IS PLACED WITH LOW CONFIDENCE BASED ON CURRENT STORM
MOTION AND LOW CLOUD TRACING IN THE EIR LOOP. THE INITIAL INTENSITY
OF 35KTS IS BASED ON THE HIGH END OF AGENCY DVORAK AND AUTOMATED
DVORAK ESTIMATES AND REFLECTS THE GRADUAL CONSOLIDATION. ANALYSIS
INDICATES A FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VWS,
MODERATE POLEWARD OUTFLOW, AND VERY WARM ALONG-TRACK SST.

INITIAL WIND RADII BASIS: SCATTEROMETER DATA

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T1.5 - 25 KTS
RJTD: T2.0 - 30 KTS
KNES: T2.5 - 35 KTS
CIMSS ADT: 35 KTS AT 071140Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 5-10 KTS
SST: 30-31 CELSIUS
OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: LOW
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TS 15W WILL TRACK WEST-NORTHWESTWARD THEN
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE
NORTHEAST AND WILL COME TO WITHIN 32NM OF ANDERSEN AFB AS IT TRACKS
NORTHEAST OF GUAM AND ROTA JUST BEFORE TAU 72. AFTERWARD, A
MID-LATITUDE TROUGH EXITING JAPAN TO THE NORTHWEST WILL WEAKEN THE
STR AND ALLOW THE SYSTEM TO TRACK MORE NORTHWARD TOWARD IWO TO. THE
FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO 80KTS
AT TAU 72. AFTERWARD, INCREASE POLEWARD OUTFLOW AHEAD OF THE
MID-LATITUDE TROUGH WILL PROMOTE A RAPID INTENSIFICATION, AND BY
TAU 120, REACHING 120 KTS.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL GOOD AGREEMENT
WITH A GRADUAL SPREAD TO 265NM BY TAU 72 THEN TO 370NM BY TAU 120
WITH NAVGEM THE SOLE LEFT OF TRACK OUTLIER. GIVEN THE FORMATIVE
NATURE OF THE SYSTEM, THERE IS ONLY MEDIUM CONFIDENCE IN THE JTWC
TRACK FORECAST THAT IS LAID JUST TO THE RIGHT OF CONSENSUS TO
OFFSET NAVGEM.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN

[Sciencerocks]

[Sciencerocks]

 https://twitter.com/VortixWx/status/1710657004950147355

[cycloneye]

Does anyone know of web cams in Guam, Rota and Saipan?

[afswo]

Does anyone know of web cams in Guam, Rota and Saipan?

The one that I used during Marwar is not working right now, it is based in Hagatna and has been offline for about a month.

There is one is Saipan (https://www.earthcam.com/world/northern ... cam=saipan) that is working. Very grainy right now but it is night there and the lighting is poor.

If I find any working ones, I will post them.

[cycloneye]

WDPN32 PGTW 072100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN)
WARNING NR 004//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 10.0N 153.3E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 541 NM EAST-SOUTHEAST OF ANDERSEN AFB
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 KTS
SIGNIFICANT WAVE HEIGHT: 15 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A SLOWLY
CONSOLIDATING LOW-LEVEL CIRCULATION WITH A BROAD, WEAKLY DEFINED
CENTER. A 071811Z SSMIS 91 GHZ COLOR COMPOSITE MICROWAVE IMAGE SHOWS
CONVECTIVE BANDING AND THE BULK OF THE ASSOCIATED DEEP CONVECTION
DISPLACED TO THE NORTH AND WEST OF AN ELONGATED CENTER. A 071513Z
AMSR2 WINDSPEED IMAGE INDICATES GALE-FORCE WINDS ASSOCIATED WITH THE
DEEP CONVECTION AND A WEAKER WIND BAND TO THE SOUTH, WITH AN
ELONGATED AREA OF LIGHT CORE WINDS ORIENTED EAST-WEST. CONSEQUENTLY,
THERE IS LOW CONFIDENCE IN THE INITIAL POSITION. SIGNIFICANT
RELOCATIONS OF THE INITIAL POSITION ARE VERY POSSIBLE OVER THE NEXT
DAY, WHICH COULD LEAD TO SHIFTS IN THE FORECAST TRACK. THE INITIAL
INTENSITY OF 35 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON THE
PGTW AND KNES DVORAK ESTIMATES.

INITIAL WIND RADII BASIS: AMSR2 WINDSPEED IMAGE.

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
KNES: T2.5 - 35 KTS
CIMSS SATCON: 34 KTS AT 071533Z
CIMSS ADT: 47 KTS AT 071730Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 0-5 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: LOW
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: ALTHOUGH TS 15W IS CONSOLIDATING SLOWLY NOW,
ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR STEADY DEVELOPMENT
THROUGH TAU 36 AS THE SYSTEM TRACKS WEST-NORTHWESTWARD. ANIMATED
WATER VAPOR IMAGERY INDICATES EXPANDING POLEWARD OUTFLOW JUST
BEGINNING TO LINK UP WITH THE WESTERLY FLOW OVER THE SOUTH AND
SOUTHWEST PERIPHERY OF A TUTT CELL LOCATED NEAR 20N 158E. AFTER TAU
36, ROBUST POLEWARD OUTFLOW INTO THE TUTT ENHANCED BY JET-STRENGTH
WESTERLIES WILL LEAD TO A PERIOD OF RAPID OR NEAR-RAPID
INTENSIFICATION. CONSEQUENTLY, TS 15W SHOULD NOT BE UNDERESTIMATED
AS IT TRACKS TOWARD AND OVER THE GUAM REGION WITH PEAK INTENSITY
VALUES INCREASING FROM 75 KNOTS AT TAU 48 TO 100 KNOTS AT TAU 72.
ADDITIONAL INTENSIFICATION WILL OCCUR AFTER TAU 72 AS THE SYSTEM
RECURVES NORTHWARD TOWARD A BREAK IN THE STR, WITH ENHANCED
POLEWARD OUTFLOW INTO A MIDLATITUDE SHORTWAVE TROUGH.

MODEL DISCUSSION: AS EMPHASIZED EARLIER, THERE IS UNCERTAINTY IN
THE INITIAL POSITION AT LEAST OVER THE NEXT DAY AND FAIR AGREEMENT
IN THE DETERMINISTIC GUIDANCE, THUS THERE IS MEDIUM CONFIDENCE IN
THE JTWC TRACK FORECAST. THE 071200Z GEFS AND EPS ENSEMBLES ALSO
INDICATE A LARGE SPREAD IN SOLUTIONS FROM JUST SOUTH OF GUAM TO
ABOUT 18N LATITUDE. RELIABLE INTENSITY GUIDANCE SUPPORTS THE JTWC
INTENSITY FORECAST WITH MEDIUM CONFIDENCE WITH THE HAFS-A AND
COAMPS-TC (NAVGEM AND GFS VERSIONS) ALL INDICATING RAPID
INTENSIFICATION AFTER TAU 48. ADDITIONALLY, RAPID INTENSIFICATION
GUIDANCE HAS TRIGGERED REFLECTING THE VERY FAVORABLE ENVIRONMENT
FORECAST TO EVOLVE IN THE NEXT DAY OR SO. THE 071200Z COAMPS-TC
INTENSITY PROBABILITY IMAGE ALSO PROVIDES EXCELLENT SUPPORT FOR RAPID
INTENSIFICATION AFTER TAU 40 WITH PROBABILITIES JUMPING AS HIGH AS 85
PERCENT FROM TAU 66 TO TAU 90.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//
NNNN

[Goomba]

[cycloneye]

Typhoon Watch issued for Guam, Rota, Saipan

Tropical Storm Bolaven (15W) Local Statement
National Weather Service TIYAN GU
934 AM ChST Sun Oct 8 2023

...TROPICAL STORM BOLAVEN MOVING WEST-NORTHWEST TOWARDS THE MARIANAS...

.NEW INFORMATION...
A Typhoon Watch has now been issued.

.AREAS AFFECTED...
This local statement provides important information and
recommended actions for people in Guam, Rota, Tinian, Saipan, and
the surrounding coastal waters of the Marianas.

.Watches/Warnings...
A Typhoon watch is in effect for the following locations: Guam,
Rota, Tinian, Saipan, and the surrounding coastal waters of the
Marianas.

A Typhoon Watch means that Typhoon conditions are possible within the
next 48 hours somewhere within the area.

.STORM INFORMATION...
At 7 AM ChST...the center of Tropical Storm Bolaven (15W) was
located near LATITUDE 10.0N...LONGITUDE 153.0E. This was about 600
miles east-southeast of Guam. Storm motion was west-northwest. Storm
intensity was 40 mph.

.SITUATION OVERVIEW...
A Typhoon Watch has now been issued. When making decisions, do not
focus on the exact forecast track. TS Bolaven (15W) continues to
strengthen over northern Chuuk State and is moving slowly west-
northwest. It is too early to provide exact wind and coastal
inundation forecast values for specific locations in the Marianas. A
general concern should be for the possibility of at least extensive
damage somewhere within the Mariana Islands.

.PRECAUTIONARY/PREPAREDNESS ACTIONS...
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For those under a watch, now is the time to begin preparing your
home or business according to your typhoon disaster plan. Listen for
possible warnings, and be ready to evacuate if necessary. Heed the
advice of local officials and comply with any orders that are issued.

For interests at ports, docks and marinas, it is recommended that you
perform the prescribed preparations according to your emergency
operations plan for tropical cyclones. If you live on a boat, begin
to safely secure your craft and make plans to leave it for adequate
land-based shelter. Listen for possible warnings.

Regarding the Guam, Rota, Tinian and Saipan coastal waters, small
craft should return to port or seek safe harbor.

Closely monitor NOAA weather radio or other local news outlets for
official storm information. Listen for possible changes to the
forecast.

For additional precautionary and preparedness information, please
refer to the detailed recommendations relative to your location as
further described by your local emergency management agencies.

&&

.NEXT UPDATE...
The next local statement will be issued by the National Weather
Service in Tiyan, Guam around 3PM ChST, or sooner, if conditions
warrant.

[cycloneye]

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN)
WARNING NR 005//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 9.5N 153.2E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 549 NM EAST-SOUTHEAST OF ANDERSEN AFB
MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 04 KTS
SIGNIFICANT WAVE HEIGHT: 16 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A SLOWLY
CONSOLIDATING LOW-LEVEL CIRCULATION WITH A BROAD, PARTIALLY EXPOSED
CENTER POSITIONED ALONG THE EASTERN EDGE OF THE CONVECTIVE MASS.
ANIMATED ENHANCED INFRARED SATELLITE IMAGERY INDICATES VORTICAL HOT
TOWERS PERSISTING OVER THE WESTERN QUADRANT WITH CLOUD TOP
TEMPERATURES NEAR -83 C CORRESPONDING TO APPROXIMATELY 53,000 FEET.
ANIMATED WATER VAPOR IMAGERY REVEALS A DEVELOPING POLEWARD OUTFLOW
CHANNEL INTO THE SOUTHERN PERIPHERY OF A TUTT CELL LOCATED NEAR 19N
158E, WITH SOUTHEASTERLY VERTICAL WIND SHEAR (VWS) IMPINGING ON THE
SOUTHEASTERN QUADRANT OF THE SYSTEM. A 072342Z ASCAT-C BULLSEYE IMAGE
SHOWS A WELL-DEFINED, ELONGATED CIRCULATION WITH 30 TO 35 KNOT WINDS
OVER THE WESTERN QUADRANT. THIS ASCAT-C IMAGE SUPPORTS THE INITIAL
POSITION WITH MEDIUM CONFIDENCE AND THE INITIAL INTENSITY ASSESSMENT
OF 35 KNOTS WITH HIGH CONFIDENCE. ADT AND AIDT OBJECTIVE ESTIMATES
REMAIN UNREALISTICALLY HIGH BUT THE 080100Z DPRINT ESTIMATE OF 34
KNOTS AND THE PGTW DVORAK ESTIMATE ALSO BOLSTER THE INITIAL INTENSITY
CONFIDENCE.

INITIAL WIND RADII BASIS: PERSISTENCE

CURRENT STEERING MECHANISM: DEEP-LAYERED SUBTROPICAL RIDGE (STR)
ENTRENCHED TO THE NORTH.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.0 - 30 KTS
KNES: T3.5 - 55 KTS
CIMSS ADT: 57 KTS AT 072330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 10-15 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE POLEWARD

ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: HIGH
INITIAL WIND RADII: LOW

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: ALTHOUGH TS 15W IS CONSOLIDATING SLOWLY NOW,
ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR STEADY DEVELOPMENT
THROUGH TAU 36 AS THE SYSTEM TRACKS WEST-NORTHWESTWARD. AFTER TAU 36,
THE UPPER-LEVEL AND LOW-LEVEL WILL BECOME VERTICALLY ALIGNED AND
POLEWARD OUTFLOW WILL CONTINUE IMPROVING WITH A VERY FAVORABLE UPPER-
LEVEL TUTT PATTERN TO THE NORTHEAST AND EAST, WHICH WILL FUEL RAPID
INTENSIFICATION (RI) AFTER TAU 48. ADDITIONALLY, WARM, DEEP WATER
(HIGH OCEAN HEAT CONTENT) ALONG THE CURRENT FORECAST TRACK WILL
SUPPORT RI. CONSEQUENTLY, TS 15W SHOULD NOT BE UNDERESTIMATED
AS IT TRACKS TOWARD AND OVER THE GUAM REGION WITH PEAK INTENSITY
VALUES INCREASING FROM 75 KNOTS AT TAU 48 TO 110 KNOTS AT TAU 72.
ADDITIONAL INTENSIFICATION WILL OCCUR AFTER TAU 72 AS THE SYSTEM
RECURVES NORTHWARD TOWARD A BREAK IN THE STR, WITH ENHANCED
POLEWARD OUTFLOW INTO A MIDLATITUDE SHORTWAVE TROUGH.

MODEL DISCUSSION: DUE TO THE TIMELY ASCAT-C PASS, THERE IS INCREASED
CONFIDENCE IN THE INITIAL POSITION AND, WITH THE EXCEPTION OF NAVGEM
TRACKING THE CENTER DIRECTLY OVER GUAM, THE DETERMINISTIC GUIDANCE IS
IN TIGHTER AGREEMENT WITH A 93 NM CROSS-TRACK SPREAD IN SOLUTIONS AT
TAU 48, WITH THE MAJORITY OF TRACKERS NORTH OF GUAM. THE 071800Z GEFS
AND EPS ENSEMBLES ALSO SHOW THE BULK OF THEIR SOLUTIONS NORTH OF
GUAM, HOWEVER, THERE IS STILL SOME POTENTIAL FOR A TRACK CLOSER TO
GUAM CONSIDERING THE UNCERTAINTY IN ASCERTAINING THE INITIAL
POSITION. RELIABLE INTENSITY GUIDANCE SUPPORTS THE JTWC INTENSITY
FORECAST WITH MEDIUM CONFIDENCE WITH THE COAMPS-TC (NAVGEM AND GFS
VERSIONS) INDICATING RAPID INTENSIFICATION AFTER TAU 48.
ADDITIONALLY, RAPID INTENSIFICATION GUIDANCE HAS TRIGGERED REFLECTING
THE VERY FAVORABLE ENVIRONMENT FORECAST TO EVOLVE IN THE NEXT DAY OR
SO. THE 071200Z COAMPS-TC INTENSITY PROBABILITY DATA ALSO PROVIDES
EXCELLENT SUPPORT FOR RAPID INTENSIFICATION AFTER TAU 36 WITH
PROBABILITIES JUMPING AS HIGH AS 85 PERCENT FROM TAU 60 TO TAU 84.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//

[cycloneye]

WDPN32 PGTW 080900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 15W (BOLAVEN) WARNING NR
006//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 9.6N 152.5E
INITIAL INTENSITY: 40 KTS
GEOGRAPHIC REFERENCE: 510 NM EAST-SOUTHEAST OF ANDERSEN AFB,
GUAM
MOVEMENT PAST 6 HOURS: WESTWARD AT 07 KTS
SIGNIFICANT WAVE HEIGHT: 17 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS A
CONSOLIDATING SYSTEM WITH DEEP OVERSHOOTING CONVECTION IN THE
CENTRAL DENSE OVERCAST THAT IS OBSCURING THE LOW LEVEL CIRCULATION.
THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON LOW
LEVEL NOTCH FEATURES IN THE 080341Z AMSR2 AND 080518Z SSMIS
MICROWAVE IMAGES. THE INITIAL INTENSITY OF 40KTS IS BASED ON OVERALL
ASSESSMENT OF AGENCY AND AUTOMATED DVORAK ESTIMATES AND REFLECTS THE
GRADUAL CONSOLIDATION. ANALYSIS INDICATES A FAVORABLE ENVIRONMENT
WITH MODERATE POLEWARD OUTFLOW AND VERY WARM ALONG-TRACK SST OFFSET
BY MODERATE VWS.

INITIAL WIND RADII BASIS: PERSISTENCE.

CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) TO THE
NORTH-NORTHEAST.

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.5 - 35 KTS
RJTD: T2.5 - 35 KTS
KNES: T3.5 - 55 KTS
CIMSS SATCON: 54 KTS AT 080329Z
CIMSS ADT: 57 KTS AT 080530Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 15-20 KTS
SST: 29-30 CELSIUS
OUTFLOW: MODERATE POLEWARD
OTHER FACTORS: ENVIRONMENT BECOMES HIGHLY FAVORABLE AFTER TAU 72
WITH INCREASED POLEWARD OUTFLOW

ANALYSIS CONFIDENCE:
INITIAL POSITION: MEDIUM
INITIAL INTENSITY: MEDIUM
INITIAL WIND RADII: MEDIUM

3. FORECAST REASONING.

SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO
THE FORECAST FROM THE PREVIOUS WARNING.

FORECAST DISCUSSION: TS 15W WILL TRACK WEST-NORTHWESTWARD THEN
NORTHWESTWARD UNDER THE STEERING INFLUENCE OF THE STR TO THE
NORTH-NORTHEAST AND WILL COME TO WITHIN 57NM OF ANDERSEN AFB AS IT
TRACKS NORTHEAST OF GUAM JUST AFTER TAU 48. AFTERWARD, A
MID-LATITUDE TROUGH EXITING JAPAN TO THE NORTHWEST WILL WEAKEN THE
STR AND ALLOW THE SYSTEM TO TRACK MORE NORTHWARD TOWARD IWO TO. THE
FAVORABLE ENVIRONMENT WILL FUEL A STEADY INTENSIFICATION TO 80KTS
AT TAU 48. AFTERWARD, LOW VWS AS THE CYCLONE ROUNDS THE STR AXIS
AND INCREASING POLEWARD OUTFLOW AHEAD OF THE MID-LATITUDE TROUGH
WILL PROMOTE A RAPID INTENSIFICATION TO A PEAK OF 125KTS BY TAU 96.
AFTERWARD, INCREASING VWS WILL BEGIN TO ERODE THE SYSTEM DOWN TO
120KTS BY TAU 120.

MODEL DISCUSSION: NUMERICAL MODELS HAVE COME INTO TIGHTER AGREEMENT
WITH A GRADUAL AND EVEN SPREAD TO 124NM BY TAU 72 THEN TO 269NM BY
TAU 120 WITH NAVGEM THE SOLE LEFT OF TRACK OUTLIER IN THE EXTENDED
TAUS. GIVEN THE FORMATIVE NATURE OF THE SYSTEM, THERE IS ONLY MEDIUM
CONFIDENCE IN THE JTWC TRACK FORECAST THAT IS LAID JUST TO THE RIGHT
OF CONSENSUS AFTER TAU 72 TO OFFSET NAVGEM.

FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: MEDIUM
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: MEDIUM//
NNNN

[mrbagyo]

looks like a developing classic WPAC pinhole eye popper

[cycloneye]

T2315(Bolaven)
Issued at 2023/10/08 19:10 UTC
Analysis at 10/08 18 UTC
Grade STS
Scale -
Intensity -
Center position N10°00′ (10.0°)
E151°00′ (151.0°)
Direction and speed of movement W Slow
Central pressure 992 hPa
Maximum sustained wind speed near center 25 m/s (50 kt)
Maximum wind gust speed 35 m/s (70 kt)
Radius of 30-kt wind area 440 km (240 NM)