WPAC: VAMCO - Post-Tropical

[euro6208]

Reasoning and discussion.....


WDPN32 PGTW 111500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (VAMCO) WARNING NR
010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 25W (VAMCO), LOCATED APPROXIMATELY 110 NM EAST OF
MANILA, PHILIPPINES, HAS TRACKED WEST-NORTHWESTWARD AT 07 KNOTS OVER
THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
SHOWS THE SYSTEM CONTINUED TO INTENSIFY AS EVIDENCED BY COOLING
CONVECTIVE TOPS OVER THE EYEWALL SURROUNDING A PINHOLE 10-NM DEFINED
EYE, EVEN AS ITS WESTERN RAIN BANDS ARE NOW SWEEPING ACROSS THE
PHILIPPINE ARCHIPELAGO. THE INITIAL POSITION IS PLACED WITH HIGH
CONFIDENCE BASED ON THE EYE FEATURE THAT LINED UP WELL WITH A
SHARPLY-OUTLINED CIRCULATION CENTER ON A COMPOSITE RADAR LOOP FROM
PAGASA. THE INITIAL INTENSITY OF 90KTS IS BASED ON THE PGTW DVORAK
ESTIMATE OF T5.0/90KTS AND SATCON ESTIMATE OF 88KTS, AND REFLECTS
THE 6-HR INTENSIFICATION. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM
REMAINS IN A FAVORABLE AREA WITH LOW (05-10KT) VERTICAL WIND SHEAR
(VWS) AND STRONG RADIAL OUTFLOW ASSOCIATED WITH A POINT SOURCE
DIRECTLY OVERHEAD. ADDITIONALLY, SEA SURFACE TEMPERATURES (SST) IN
THE PHILIPPINE SEA REMAIN WARM AND FAVORABLE AT 29-30C. HOWEVER, THE
SYSTEM IS NOW POISED TO MAKE LANDFALL INTO THE RUGGED TERRAIN OF
LUZON. THE CYCLONE IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A
DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 25W WILL CONTINUE ON ITS CURRENT TRACK TOWARD CENTRAL
LUZON, MAKING LANDFALL OVER THE PROVINCE OF BULACAN AROUND TAU 06,
DRAG ACROSS PAMPANGA AND ZAMBALES, BEFORE EXITING INTO THE SOUTH
CHINA SEA (SCS) SHORTLY AFTER TAU 12. AFTERWARD, AS THE STR BUILDS,
IT WILL TRACK MORE WESTWARD. LAND INTERACTION WILL MAINLY WEAKEN IT
TO 65KTS BY TAU 24 AFTER IT EXITS IN THE SCS. THE WARM WATERS OF
THE SCS (29C) AND FAVORABLE VWS WILL FUEL A GRADUAL INTENSIFICATION
TO A SECONDARY PEAK OF 70KTS AT TAUS 36-48. AFTERWARD, TY 25W WILL
TRACK MORE WEST-NORTHWESTWARD, AS THE STR IS WEAKENED BY AN
APPROACHING MIDLATITUDE TROUGH TO THE NORTH, OVER COOLING SST AND
DECREASING OCEAN HEAT CONTENT (OHC) IN THE WESTERN SCS THAT WILL
WEAKEN IT TO 45KTS BY TAU 72 AS IT APPROACHES VIETNAM. NUMERICAL
MODELS ARE IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE IN THIS
PORTION OF THE JTWC FORECAST TRACK WHICH IS PLACED NEAR THE MULTI-
MODEL CONSENSUS.
C. AFTER TAU 72, TY VAMCO WILL CONTINUE ON A WEST-NORTHWESTWARD
TRACK, MAKING LANDFALL OVER CENTRAL VIETNAM, JUST NORTH OF HUE,
AROUND TAU 90. SST DROPS TO 27C AND OHC DOWN TO 25KJ/CM^2 NEAR
VIETNAM. THESE, PLUS THE RUGGED TERRAIN WILL RAPIDLY ERODE THE
SYSTEM TO 25 KTS BY TAU 96 AFTER LANDFALL, THEN TO EVENTUAL
DISSIPATION BY TAU 120 AFTER IT CROSSES INTO CENTRAL LAOS. NUMERICAL
MODELS GRADUALLY AND EVENLY SPREAD TO OVER 500NM BY TAU 120, WITH
AFUM AS THE NOTABLE RIGHT OUTLIER, OFFERING AN UNLIKELY U-TURN TRACK
OVER HAINAN. THERE IS OVERALL FAIR CONFIDENCE IN THE EXTENDED
PORTION OF THE JTWC FORECAST TRACK THAT IS PLACED JUST LEFT OF THE
MULTI-MODEL CONSENSUS TO OFFSET AFUM.//
NNNN

[doomhaMwx]

 https://twitter.com/gmanews/status/1326556100771020800

[1900hurricane]

SMAP got a direct hit on Vamco a few hours back. The proximity to land unfortunately means that a lot of the data is unusable, but it did manage to get the NE eyewall, where there is an estimated 92 kt maximum ten minute sustained winds. Also worthy of note is the size of the wind field, both overall and with the inner core. While not crazy intense, this thing is going to be packing a punch over a large area, which itself is going to be a sharp contrast with the recent Goni.

WP, 25, 202011110935, 30, SMAP, IR, , 1460N, 12290E, , 1, 92, 1, , , , 34, NEQ, 0, 0, 0, 0, , , , , 1, 0, , , NASA, RSS, , , , , , , , , , , , , , , , , , , , , , , , , , , , 1, max. wind is 10 minute sustained
WP, 25, 202011110935, 30, SMAP, IR, , 1460N, 12290E, , 1, 92, 1, , , , 50, NEQ, 0, 0, 0, 0, , , , , 1, 0, , , NASA, RSS, , , , , , , , , , , , , , , , , , , , , , , , , , , , 1, max. wind is 10 minute sustained
WP, 25, 202011110935, 30, SMAP, IR, , 1460N, 12290E, , 1, 92, 1, , , , 64, NEQ, 0, 0, 0, 0, , , , , 1, 0, , , NASA, RSS, , , , , , , , , , , , , , , , , , , , , , , , , , , , 1, max. wind is 10 minute sustained

[mrbagyo]

before Vamco's landfall over the Polilio Island, eye temp via ADT managed to jumped to double digit positive territory.
2020NOV11 143000 5.4 960.3 99.6 5.4 6.1 6.1 NO LIMIT OFF OFF OFF OFF 14.70 -68.06 EYE 28 IR 9.8 14.85 -122.04 ARCHER HIM-8 27.7

[1900hurricane]

 https://twitter.com/1900hurricane/status/1326566224734662657

[oaba09]

Just lost power Wind is still picking up.

Location: Valenuela City Metro Manila

[Hayabusa]

18Z JMA analyzed 5.0, 80 knots upgrade coming?

[mrbagyo]

18Z JMA analyzed 5.0, 80 knots upgrade coming?

they retained it at 70

TY 2022 (Vamco)
Issued at 18:45 UTC, 11 November 2020

<Analysis at 18 UTC, 11 November>
Scale -
Intensity -
Center position N15°05' (15.1°)
E121°20' (121.3°)
Direction and speed of movement W 25 km/h (14 kt)
Central pressure 970 hPa
Maximum wind speed near center 35 m/s (70 kt)
Maximum wind gust speed 50 m/s (100 kt)
≥ 50 kt wind area ALL 110 km (60 NM)
≥ 30 kt wind area NE 500 km (270 NM)
SW 280 km (150 NM)

[underthwx]

Looks as if Vamco will be tracking just North of Manila... And ultimately track towards Vietnam, what intensity is Vamco forecast to be at when it is near Manila?....

[Hayabusa]

18Z JMA analyzed 5.0, 80 knots upgrade coming?

they retained it at 70

TY 2022 (Vamco)
Issued at 18:45 UTC, 11 November 2020

<Analysis at 18 UTC, 11 November>
Scale -
Intensity -
Center position N15°05' (15.1°)
E121°20' (121.3°)
Direction and speed of movement W 25 km/h (14 kt)
Central pressure 970 hPa
Maximum wind speed near center 35 m/s (70 kt)
Maximum wind gust speed 50 m/s (100 kt)
≥ 50 kt wind area ALL 110 km (60 NM)
≥ 30 kt wind area NE 500 km (270 NM)
SW 280 km (150 NM)

019111 CURRENT INTENSITY (CI) NUMBER OF THE TROPICAL CYCLONE 5.0
019112 DATA TROPICAL (DT) NUMBER OF THE TROPICAL CYCLONE 5.0
019113 CLOUD PATTERN TYPE OF THE DT- NUMBER 3
019114 MODEL EXPECTED TROPICAL (MET) NUMBER OF THE TROPICAL CYCLONE 5.0
019115 TREND OF PAST 24-HOUR CHANGE (+: DEVELOPED, -: WEAKENED) 1.5
019116 PATTERN TROPICAL (PT) NUMBER OF THE TROPICAL CYCLONE 5.0
019117 CLOUD PICTURE TYPE OF THE PT- NUMBER 2
019118 FINAL TROPICAL (T) NUMBER OF THE TROPICAL CYCLONE 5.0

Welp, I guess wait for JTWC but they don't do dvorak over land.

[doomhaMwx]

SATCON was at 100kts before landfall.

CURRENT ESTIMATE
Date (mmddhhmm): 11111648
SATCON: MSLP = 954 hPa MSW = 102 knots
SATCON Member Consensus: 100.0 knots
Pressure -> Wind Using SATCON MSLP: 101 knots
Distance to Outer Closed Isobar Used is 220 nm
Eye Size Correction Used is 2.0 knots Source: IR

[Hayabusa]

25W VAMCO 201111 1800 15.0N 121.3E WPAC 90 956

[ElectricStorm]

25W VAMCO 201111 1800 15.0N 121.3E WPAC 90 956

That is a very low pressure for a Cat 2...

[doomhaMwx]

Microwave pass at landfall.

[mrbagyo]

[Hayabusa]

25W VAMCO 201111 1800 15.0N 121.3E WPAC 90 956

That is a very low pressure for a Cat 2...

Got revised to 95 knots

25W VAMCO 201111 1800 15.0N 121.3E WPAC 95 961

Also revision of best track

25W VAMCO 201111 1800 15.0N 121.3E WPAC 95 961
25W VAMCO 201111 1200 14.8N 122.8E WPAC 90 970
25W VAMCO 201111 0600 14.6N 123.6E WPAC 90 970
25W VAMCO 201111 0000 14.7N 124.6E WPAC 75 982

[mrbagyo]

Widespread flooding being reported in many parts of NCR

[Hayabusa]

WDPN32 PGTW 112100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 25W (VAMCO) WARNING NR 011//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 25W (VAMCO), LOCATED APPROXIMATELY 30 NM NORTHEAST
OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 15 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY
INDICATES THE SYSTEM INTENSIFIED SLIGHTLY JUST PRIOR TO LANDFALL,
WHICH OCCURRED AT ABOUT 11/1630Z TO 11/17Z. BASED ON A 15-20NM
RAGGED EYE, ADT ESTIMATES AT THAT TIME RANGED FROM 5.7-5.9 (105-115
KNOTS); UNOFFICIAL PGTW SUBJECTIVE DVORAK ESTIMATES RANGED FROM T5.0
(90 KNOTS) TO A WEAK T5.5 (102 KNOTS); A PARTIAL 111716Z ASMR2
WINDSPEED PRODUCT INDICATED MAXIMUM WINDS OF 88 KNOTS OVER THE
NORTHEAST QUADRANT; AND AN EARLIER 110935Z SMAP ESTIMATE INDICATED
MAXIMUM WINDS OF 99 KNOTS (10-MINUTE AVERAGE). OVERALL, THIS
SUPPORTS THE 11/18Z INTENSITY ESTIMATE OF 95 KNOTS. AFTER LANDFALL,
EIR AND A 111716Z AMSR2 89GHZ IMAGE REVEAL AN ABRUPT WEAKENING TREND
WITH THE LOSS OF THE EYE FEATURE AND TIGHTLY-CURVED BANDING WRAPPING
INTO A DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC), WHICH SUPPORTS
THE INITIAL POSITION WITH GOOD CONFIDENCE. UPPER-LEVEL ANALYSIS
DEPICTS A FAVORABLE ENVIRONMENT WITH RADIAL OUTFLOW AND ENHANCED
POLEWARD OUTFLOW ASSOCIATED WITH THE WESTERLIES TO THE NORTH, AND
LOW VERTICAL WIND SHEAR (VWS). HOWEVER, INTERACTION WITH THE
MOUNTAIN RANGES OVER SOUTHERN LUZON IS CONTRIBUTING TO THE CURRENT
WEAKENING TREND. TY 25W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY
OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) POSITIONED TO THE
NORTHEAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY 25W IS FORECAST TO TRACK WESTWARD THROUGH TAU 48 UNDER THE
STEERING INFLUENCE OF THE STR POSITIONED TO THE NORTH. TRACK SPEEDS
ARE EXPECTED TO DECREASE AS THE SYSTEM TRANSITS SOUTH OF A BREAK IN
THE STR. AFTER TAU 48, TY 25W SHOULD TURN WEST-NORTHWESTWARD AS IT
TRACKS ALONG THE SOUTHWEST PERIPHERY OF THE STR. AFTER TRACKING OVER
WARM WATER (28-29C), TY 25W SHOULD RE-INTENSIFY TO A PEAK OF 80
KNOTS BY TAU 36. HOWEVER, SST VALUES ARE EXPECTED TO COOL TO 26-27C,
WITH VERY LOW OCEAN HEAT CONTENT VALUES, WHICH SUPPORTS THE GRADUAL
WEAKENING TREND THROUGH TAU 72. NUMERICAL MODEL GUIDANCE DIVERGES
THROUGH THE FORECAST PERIOD WITH A 175NM SPREAD IN SOLUTIONS AT TAU
72.
C. AFTER TAU 72, TY 25W WILL WEAKEN AS IT APPROACHES THE COAST OF
VIETNAM AND SHOULD MAKE LANDFALL NEAR TAU 84. AFTER TAU 84, THE
SYSTEM WILL RAPIDLY DISSIPATE AS IT TRACKS WEST-NORTHWESTWARD OVER
THE MOUNTAINOUS TERRAIN OF VIETNAM AND CAMBODIA. NUMERICAL MODEL
GUIDANCE IS IN FAIR AGREEMENT LENDING MODERATE CONFIDENCE IN THE
JTWC FORECAST TRACK.//
NNNN

[phwxenthusiast]

As far as Synop Reports are concerned, there were plenty of sustained winds between 50-80kph recorded around Quezon and NCR areas... Infanta had a max gust of 115kph at 16z with a minimum SLP 980.8; unfortunately, there was a data gap at 17z just as the center was coming ashore so there's a good likelihood they recorded lower pressure and higher winds... Tayabas also had a wind report of 148kph but the station is at 158m ASL..

[underthwx]

25W VAMCO 201111 1800 15.0N 121.3E WPAC 90 956

That is a very low pressure for a Cat 2...

Got revised to 95 knots

25W VAMCO 201111 1800 15.0N 121.3E WPAC 95 961

Also revision of best track

25W VAMCO 201111 1800 15.0N 121.3E WPAC 95 961
25W VAMCO 201111 1200 14.8N 122.8E WPAC 90 970
25W VAMCO 201111 0600 14.6N 123.6E WPAC 90 970
25W VAMCO 201111 0000 14.7N 124.6E WPAC 75 982

I thought maybe a little higher in windspeed, looking at satellite imagery...