WPAC: BOLAVEN - Post-Tropical

[doomhaMwx]

It appears that the highest rainfall totals will occur north of 99W's center, partly due to the presence of the seasonal NE winds/monsoon. Some parts of the Visayas may see total accumulations of 100-200mm(4-8in) or more within the next 3 days. Some parts of Mindanao, especially the northern part of the island, may also receive total amounts around 100mm during 99W's passage.

[1900hurricane]

Here's the most recent ASCAT pass:

[euro6208]

TXPQ29 KNES 312118
TCSWNP

A. TROPICAL DISTURBANCE (99W)

B. 31/2030Z

C. 9.3N

D. 130.7E

E. FIVE/HIMAWARI-8

F. T1.0/1.0/D1.0/24HRS

G. IR/EIR/SWIR

H. REMARKS...SLIGHTLY GREATER THAN 2/10 BANDING YIELDS A DT OF 1.0. MET
IS 1.0 AND PT IS LESS THAN 1.0. FT IS BASED ON DT.

I. ADDL POSITIONS

NIL


...WHISNANT

[doomhaMwx]

It's now Jan 01, 2018 (Z / UTC). So 99W will become 01W once upgraded into a TD by JTWC, and potentially the WPac's first named storm this 2018.

[Digital-TC-Chaser]

Large monsoonal looking low These usually take quite some time to tighten up and reach formation status Dvorak is not usually good for intensity estimates with these types of systems i recently read .They can be stronger than they look on appearance.

[euro6208]

AN AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR
9.6N 133.7E, IS NOW LOCATED NEAR 8.9N 129.6E, APPROXIMATELY 605 NM
SOUTHEAST OF MANILA, PHILIPPINES. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY AND A 312211Z 89GHZ SSMIS MICROWAVE IMAGE SHOW FORMATIVE
BANDING, AND SCATTERED, ISOLATED AREAS OF DEEP CONVECTION WRAPPING
INTO A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC). A
010053Z OSCAT IMAGE DEPICTS 10-15 KT WINDS IN THE VICINITY OF THE
LLCC, WITH STRONGER 20-25 KT WINDS TO THE NORTHWEST RELATED TO A
NORTHEASTERLY COLD SURGE EVENT BEING GENERATED BY A SURFACE HIGH
PRESSURE SYSTEM IN THE EAST CHINA SEA. UPPER LEVEL ANALYSIS
INDICATES THAT THE SYSTEM IS LOCATED IN AN AREA OF LOW (5-10 KNOTS)
VERTICAL WIND SHEAR. OUTFLOW ALOFT HAS DECREASED IN THE PAST DAY,
AND IS LESS SUPPORTIVE OF DEEP CONVECTION. THE DISTURBANCE IS
LOCATED IN AN AREA WITH SUPPORTIVE SEA SURFACE TEMPERATURES (29-30
DEGREES CELSIUS). GLOBAL MODELS PREDICT THE SYSTEM TRACKING
GENERALLY WESTWARD ACROSS THE PHILIPPINES IN THE NEXT FEW DAYS, THEN
DIVERGE IN TRACK AND INTENSITY GUIDANCE. SOME MODELS PREDICT 99W
CONTINUING WESTWARD THROUGH THE SOUTH CHINA SEA, WHILE OTHERS DEPICT
A NORTHWARD TURN; SIMILARLY, NOT ALL MODELS FORECAST 99W REACHING
TROPICAL STORM STRENGTH. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.

[euro6208]

Even the EURO barely develops this now. Just more rain for the Philippines and Vietnam.

[xtyphooncyclonex]

TD
Issued at 12:50 UTC, 1 January 2018

<Analysis at 12 UTC, 1 January>
Scale -
Intensity -
TD
Center position N8°55' (8.9°)
E126°30' (126.5°)
Direction and speed of movement W 20 km/h (12 kt)
Central pressure 1004 hPa
Maximum wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)

<Forecast for 00 UTC, 2 January>
Intensity -
TD
Center position of probability circle N8°55' (8.9°)
E122°50' (122.8°)
Direction and speed of movement W 35 km/h (18 kt)
Central pressure 1004 hPa
Maximum wind speed near center 15 m/s (30 kt)
Maximum wind gust speed 23 m/s (45 kt)
Radius of probability circle 110 km (60 NM)

<Forecast for 12 UTC, 2 January>
Intensity -
Center position of probability circle N9°05' (9.1°)
E118°30' (118.5°)
Direction and speed of movement W 40 km/h (21 kt)
Central pressure 998 hPa
Maximum wind speed near center 18 m/s (35 kt)
Maximum wind gust speed 25 m/s (50 kt)
Radius of probability circle 200 km (110 NM)

[xtyphooncyclonex]

WTPN21 PGTW 011330
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
125 NM EITHER SIDE OF A LINE FROM 8.9N 127.8E TO 10.1N 118.4E
WITHIN THE NEXT 06 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT
IMAGERY AND RADAR DATA AT 011300Z INDICATE THAT A CIRCULATION
CENTER IS LOCATED NEAR 9.1N 126.9E. THE SYSTEM IS MOVING WESTWARD
AT 13 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED
NEAR 9.6N 133.7E, IS NOW LOCATED NEAR 9.1N 126.9E, APPROXIMATELY 480
NM EAST OF PUERTO PRINCESA, PHILIPPINES. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY SHOWS RESURGENT DEEP CONVECTION COVERING A LOW
LEVEL CIRCULATION CENTER. A 011000Z 91GHZ SSMIS MICROWAVE IMAGE
INDICATES ORGANIZING BANDING AND DEEPER CONVECTION THAN PREVIOUS.
UPPER LEVEL ANALYSIS REVEALS THAT THE SYSTEM IS LOCATED IN AN AREA
OF LOW (5-10 KNOTS) VERTICAL WIND SHEAR. RADIAL OUTFLOW ALOFT HAS
IMPROVED, SUPPORTING DEEP CONVECTION. THE DISTURBANCE IS LOCATED IN
AN AREA WITH SUPPORTIVE SEA SURFACE TEMPERATURES (29-30 DEGREES
CELSIUS). GLOBAL MODELS PREDICT THE SYSTEM TRACKING WESTWARD ACROSS
THE PHILIPPINES IN THE NEXT DAY, THEN DIVERGE IN TRACK AND INTENSITY
GUIDANCE. SOME MODELS PREDICT 99W CONTINUING WESTWARD THROUGH THE
SOUTH CHINA SEA, WHILE OTHERS DEPICT A NORTHWARD TURN AT LATER TAUS.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1006 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
021330Z.
//
NNNN

[xtyphooncyclonex]

Pressure dropping fast. Down to 997.5 hPa in a nearby station

https://www.wunderground.com/personal-w ... wx_pwsdash

[xtyphooncyclonex]

So, the red warning alert was issued. No one predicted this rainfall here. Mindanao was anticipating the worse, but lucky for them this wasn't as bad as Vinta/Tembin so far. Meanwhile, the sirens are sounding over Mananga River and the rainfall is getting heavier and has been relentless since early evening. Strong gusts are being reported

Evacuations here started only now! 3:30 AM, with intense rains and gale-force winds. This is dangerous already.

[cycloneye]

JTWC upgrades to TD 01W.

WTPN31 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/011321ZJAN2018//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL DEPRESSION 01W (ONE) WARNING NR 001
01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
011800Z --- NEAR 9.4N 124.6E
MOVEMENT PAST SIX HOURS - 275 DEGREES AT 16 KTS
POSITION ACCURATE TO WITHIN 060 NM
POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
SATELLITE, RADAR AND SYNOPTIC DATA
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
WIND RADII VALID OVER OPEN WATER ONLY
REPEAT POSIT: 9.4N 124.6E
---
FORECASTS:
12 HRS, VALID AT:
020600Z --- 9.7N 120.6E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 275 DEG/ 19 KTS
---
24 HRS, VALID AT:
021800Z --- 10.1N 116.8E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
030 NM SOUTHWEST QUADRANT
095 NM NORTHWEST QUADRANT
VECTOR TO 36 HR POSIT: 280 DEG/ 16 KTS
---
36 HRS, VALID AT:
030600Z --- 10.6N 113.5E
MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT
030 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
080 NM NORTHWEST QUADRANT
VECTOR TO 48 HR POSIT: 285 DEG/ 12 KTS
---
EXTENDED OUTLOOK:
48 HRS, VALID AT:
031800Z --- 11.1N 111.2E
MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT
035 NM SOUTHEAST QUADRANT
045 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 72 HR POSIT: 295 DEG/ 07 KTS
---
72 HRS, VALID AT:
041800Z --- 12.3N 108.6E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 96 HR POSIT: 310 DEG/ 07 KTS
---
LONG RANGE OUTLOOK:
---
96 HRS, VALID AT:
051800Z --- 14.1N 106.3E
MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
012100Z POSITION NEAR 9.5N 123.6E.
TROPICAL DEPRESSION 01W (ONE), LOCATED APPROXIMATELY 377 NM
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 16
KNOTS OVER THE PAST SIX HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT
011800Z IS 8 FEET. NEXT WARNINGS AT 020300Z, 020900Z, 021500Z AND
022100Z. THIS CANCELS AND SUPERSEDES REF A (WTPN21 PGTW 011330).//
NNNN

[euro6208]

WDPN31 PGTW 012100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING
NR 01//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 377 NM
SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 16 KNOTS
OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH A SYMMETRIC AREA OF DEEP
CONVECTION OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) AND
IMPROVED CONVECTIVE BANDING OVER THE NORTHERN SEMI-CIRCLE. A 011829Z
SSMI 85GHZ IMAGE SHOWS CURVED DEEP CONVECTIVE BANDING WRAPPING INTO
THE NORTHWEST AND WEST QUADRANTS OF THE SYSTEM WITH A PARTIALLY-
EXPOSED LLCC POSITIONED ON THE SOUTHEAST EDGE OF THE CENTRAL
CONVECTION. THEREFORE, THERE IS FAIR CONFIDENCE IN THE INITIAL
POSITION. A 011331Z ASCAT PARTIAL IMAGE REVEALED 25-30 KNOT
NORTHERLY WINDS OVER THE BOHOL SEA, JUST NORTH OF MINDANAO, WHICH
SUPPORTS THE INITIAL INTENSITY ASSESSMENT OF 30 KNOTS. UPPER-LEVEL
ANALYSIS INDICATES A MARGINALLY FAVORABLE ENVIRONMENT WITH LOW TO
MODERATE (10 TO 20 KNOTS) VERTICAL WIND SHEAR (VWS) OFFSET BY STRONG
EASTERLY DIFFLUENT FLOW ALOFT. TD 01W IS TRACKING QUICKLY WESTWARD
ACROSS THE PHILIPPINES UNDER THE STEERING INFLUENCE OF AN EAST-WEST
ORIENTED LOW-LEVEL SUBTROPICAL RIDGE POSITIONED TO THE NORTH.
3. FORECAST REASONING.
A. THIS IS THE FIRST PROGNOSTIC REASONING MESSAGE AND SETS THE
FORECAST PHILOSOPHY.
B. TD 01W IS FORECAST TO CONTINUE TRACKING QUICKLY WESTWARD
THROUGH TAU 36 UNDER THE STEERING INFLUENCE OF THE DEEP-LAYERED LOW-
TO MID-LEVEL SUBTROPICAL RIDGE (STR) ENTRENCHED TO THE NORTH.
ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN GENERALLY FAVORABLE
THROUGH TAU 36, HOWEVER, INTERACTION WITH LAND SHOULD SLOW
DEVELOPMENT WITH A PEAK INTENSITY OF 45 KNOTS FORECAST AT TAU 24 AND
TAU 36 AS THE SYSTEM TRACKS OVER THE SOUTH CHINA SEA. AFTER TAU 36,
TD 01W SHOULD TURN WEST-NORTHWESTWARD AND SLOW AS IT TRACKS ALONG
THE WESTERN PERIPHERY OF THE STR. GRADUAL WEAKENING IS EXPECTED DUE
TO INCREASING VWS AND COOLER SST (25-26C).
C. AFTER THE SYSTEM MAKES LANDFALL OVER VIETNAM NEAR TAU 72, TD
01W WILL WEAKEN RAPIDLY AND SHOULD DISSIPATE BY TAU 96. DYNAMIC
MODEL GUIDANCE IS IN TIGHT AGREEMENT THROUGH TAU 36 THEN RAPIDLY
DIVERGES WITH GFS AND THE GFS ENSEMBLE DEPICTING AN UNLIKELY RE-
CURVE NORTHWARD DIRECTLY INTO THE STR. THE JTWC FORECAST TRACK
FAVORS THE ECMWF SOLUTION AND IS POSITIONED JUST WEST OF THE MULTI-
MODEL CONSENSUS AT TAU 72 AND TAU 96. OVERALL, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO UNCERTAINTY IN THE
INITIAL POSITION AND THE LARGE SPREAD IN MODEL SOLUTIONS AFTER TAU
36.//
NNNN

[mrbagyo]

[euro6208]

Impressive for something that just got upgraded. ^ That looks like a healthy TS already. That earlier curve band to the north was wow.

[Digital-TC-Chaser]

https://v2.meteopilipinas.gov.ph//#



some low pressure if correct.

[WAcyclone]

https://v2.meteopilipinas.gov.ph//#

https://i.imgur.com/xuVeh8W.gif

some low pressure if correct.

This is almost certainly an incorrect measurement. Maybe it's the station pressure instead of the sea level pressure? The pressure at Tagbilaran City Airport never dropped below 1007 mb and sustained winds did not exceed 10 kt at the hourly measurement intervals. There were some stronger gusts to around 40-45 kt around Cebu and parts of the Western Visayas though.

[xtyphooncyclonex]

Woke up to heavy flooding and some parts of Cebu have power outages and downed trees

[doomhaMwx]

Now centered over the Sulu Sea, moving towards Palawan.

[euro6208]

WDPN31 PGTW 020900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 01W (ONE) WARNING
NR 03//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL DEPRESSION (TD) 01W (ONE), LOCATED APPROXIMATELY 318 NM
SOUTH OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 18 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
A PARTIALLY-EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP
CONVECTION SHEARED OVER THE WESTERN SEMI-CIRCLE DUE TO MODERATE (15
TO 20 KNOTS) EASTERLY VERTICAL WIND SHEAR (VWS). A 020600Z HIMAWARI
VISIBLE SATELLITE IMAGE SHOWS THE AFOREMENTIONED PARTIALLY-EXPOSED
LLCC WITH THE MAJORITY OF THE CONVECTION SHEARED TO THE WEST. THE
INITIAL INTENSITY IS ASSESSED AT 30 KNOTS, HEDGED SLIGHTLY ABOVE THE
RJTD DVORAK ESTIMATE OF T1.5 (25 KNOTS). TD 01W IS TRACKING WESTWARD
ACROSS THE SULU SEA UNDER THE STEERING INFLUENCE OF AN EAST-WEST
ORIENTED SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTH.
3. FORECAST REASONING.
A. THERE IS NO CHANGE IN THE FORECAST PHILOSOPHY SINCE THE
PREVIOUS PROGNOSTIC REASONING MESSAGE.
B. TD 01W IS FORECAST TO CONTINUE TRACKING WESTWARD UNDER THE
INFLUENCE OF THE STR WHICH IS LOCATED TO THE NORTH AND GRADUALLY
INCREASE IN INTENSITY TO 35 KNOTS BY TAU 12. MODERATE VERTICAL WIND
SHEAR WILL PREVENT ADDITIONAL INTENSIFICATION. AS TD 01W ENTERS THE
SOUTH CHINA SEA IT WILL INITIALLY ENCOUNTER FAVORABLE SEA SURFACE
TEMPERATURES (28 TO 29 DEGREES CELSIUS). HOWEVER, AS TD 01W TRACKS
WESTWARD IT WILL ENCOUNTER COOLER SEA SURFACE TEMPERATURES WHICH
WILL LIMIT DEVELOPMENT. SEA SURFACE TEMPERATURES WILL BECOME
UNFAVORABLE (25 DEGREES CELSIUS) BY TAU 48. SHORTLY AFTER TAU 48 TD
01W WILL MAKE LANDFALL OVER SOUTHERN VIETNAM AND SLOW IN FORWARD
SPEED. BY TAU 72, TD WILL DISSIPATE OVER VIETNAM DUE TO LAND
INTERACTION. NUMERICAL MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT
THROUGH TAU 24. BEYOND TAU 24, THERE IS A LARGE SPREAD IN THE MODEL
GUIDANCE AS TD 01W APPROACHES VIETNAM. OVERALL, THERE IS LOW
CONFIDENCE IN THE JTWC FORECAST TRACK DUE TO THE LARGE SPREAD IN
MODEL SOLUTIONS AFTER TAU 24.//
NNNN