WPAC: SAOLA - Post-Tropical

[Hayabusa]

Eps 00z

[Hayabusa]

T2309(Saola)
Issued at 2023/08/25 13:05 UTC
Analysis at 08/25 12 UTC
Grade TY
Scale -
Intensity -
Center position N19°35′ (19.6°)
E123°35′ (123.6°)
Direction and speed of movement Almost stationary
Central pressure 980 hPa
Maximum sustained wind speed near center 35 m/s (65 kt)
Maximum wind gust speed 50 m/s (95 kt)
Radius of 50-kt wind area 55 km (30 NM)
Radius of 30-kt wind area 280 km (150 NM)

[Hayabusa]

Eps 06z

[Foxfires]

09W SAOLA 230825 1200 19.4N 123.8E WPAC 90 964

[Sciencerocks]

[doomhaMwx]

After shifting east, the last few GFS runs have been trending west closer to Luzon again in the near term (latest run is essentially back to where it was 24hrs ago). Proximity to the Sierra Madre mountain range along the east coast might have implications for near-term intensity.

[ElectricStorm]

Latest JTWC forecast has 130kts near Taiwan

[Sciencerocks]

 https://twitter.com/VortixWx/status/1695152564159889411

[Sciencerocks]

 https://twitter.com/Yellow_Evan/status/1695164807698337926

[Sciencerocks]

 https://twitter.com/135knots/status/1695196383534362753

[ElectricStorm]

09W SAOLA 230826 0000 18.7N 123.3E WPAC 100 960

[cycloneye]

[cycloneye]

WDPN32 PGTW 260300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 09W (SAOLA) WARNING NR 010//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
INITIAL POSITION: 18.4N 123.4E
INITIAL INTENSITY: 100 KTS
GEOGRAPHIC REFERENCE: 267 NM NORTH-NORTHEAST OF MANILA,
PHILIPPINES
MOVEMENT PAST 6 HOURS: SOUTHWARD AT 05 KTS
SIGNIFICANT WAVE HEIGHT: 30 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TYPHOON (TY) 09W HAS INTENSIFIED SLIGHTLY SINCE THE PREVIOUS JTWC
FORECAST WITH IMPROVED, MORE SYMMETRIC CORE CONVECTION. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A CENTRAL DENSE
OVERCAST AND WHAT APPEARS TO BE A DEVELOPING EYE. RECENT ENHANCED
INFRARED SATELLITE IMAGERY HAD BRIEFLY DEPICTED A SMALL EYE (AND AN
UNOFFICIAL DVORAK ESTIMATE AS HIGH AS T5.5 (102 KNOTS)), HOWEVER,
THE EYE HAS YET TO MAINTAIN, LIKELY DUE TO UPWELLING COOLER WATER
AND MID-LEVEL DRY ENTRAINMENT AS SUGGESTED BY THE 251800Z HAFS-A
RUN. A 252244Z SSMIS COLOR COMPOSITE 91 GHZ MICROWAVE IMAGE DEPICTS
TIGHTLY CURVED BANDING WRAPPING INTO A MICROWAVE EYE FEATURE, WHICH
SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. THE INITIAL
INTENSITY OF 100 KTS IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A
252146Z RCM-2 SAR IMAGE SHOWING MAXIMUM SUSTAINED WINDS OF 98 KNOTS.
THIS ESTIMATE IS SLIGHTLY HIGHER THAN THE PGTW, KNES, RCTP DVORAK
ESTIMATES AS WELL AS A 252247Z DMINT ESTIMATE OF 92 KNOTS. CIMSS ADT
ESTIMATES HAVE REMAINED TOO LOW BUT HAVE STEADILY INCREASED OVER THE
PAST SIX HOURS. ALL WIND RADII HAVE BEEN ADJUSTED BASED ON A DETAILED
ANALYSIS OF THE RCM-2 SAR IMAGE.

INITIAL WIND RADII BASIS: SAR DATA

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

AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T5.0 - 90 KTS
RJTD: T4.5 - 77 KTS
RCTP: T5.0 - 90 KTS
KNES: T5.0 - 90 KTS
CIMSS ADT: 82 KTS AT 252330Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 15-20 KTS
SST: 30-31 CELSIUS
OUTFLOW: MODERATE RADIAL
OTHER FACTORS: DYNAMIC OCEAN COOLING AND DRY AIR ENTRAINMENT

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: DESPITE THE POSSIBLE UPWELLING COOLER WATER
AND DRY AIR ENTRAINMENT, ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE
OVERALL WITH RADIAL OUTFLOW, LOW TO MODERATE VWS, WARM SST (30 C) AND
HIGH OCEAN HEAT CONTENT VALUES. AS THE SYSTEM TRACKS SLOWLY SOUTHWARD
OVER THE NEXT 24 HOURS, FURTHER DEVELOPMENT IS LIKELY, TEMPERED BY THE
COOLER SST AND MID-LEVEL DRY AIR ENTRAINMENT ADVECTING OFF OF LUZON,
WITH A PEAK OF 115 KNOTS ANTICIPATED NEAR TAU 12. FROM TAU 12 TO TAU
36, TY 09W SHOULD WEAKEN SLIGHTLY AS IT STALLS EAST OF LUZON. AFTER TAU
36, TY 09W WILL STEADILY INTENSIFY AS IT TRACKS POLEWARD. AFTER TAU 72,
THE WESTERN STR WILL WEAKEN AND A STR IS EXPECTED TO BUILD TO THE
NORTH, WHICH WILL DRIVE THE SYSTEM ONTO A NORTHWESTWARD TRACK TOWARD
TAIWAN. ENVIRONMENTAL CONDITIONS WILL IMPROVE STEADILY ALLOWING THE
SYSTEM TO REINTENSIFY TO A SECONDARY PEAK OF 130 KNOTS BY TAU 96.

MODEL DISCUSSION: DUE TO THE COMPLEX, EVOLVING STEERING PATTERN,
THERE IS MEDIUM OVERALL CONFIDENCE IN THE JTWC TRACK FORECAST. THE
251800Z EPS AND GEFS ENSEMBLES ALSO SUPPORT THE JTWC TRACK FORECAST
WITH MEDIUM CONFIDENCE. THE 251800Z COAMPS-TC ENSEMBLE SUPPORTS THE
SECONDARY REINTENSIFICATION PHASE AND SHOWS INCREASING RI
PROBABILITIES OF 40 TO 60 PERCENT IN THE TAU 60 TO TAU 90
TIMEFRAME.

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

[doomhaMwx]

09W SAOLA 230826 1200 17.5N 123.1E WPAC 110 949

Satellite presentation has remarkably improved in the last few hours.



 https://twitter.com/Yellow_Evan/status/1695419512533958813

[Hayabusa]

06z eps

[Sciencerocks]

[Sciencerocks]

 https://twitter.com/VortixWx/status/1695492416424337800

[Hayabusa]

Cat 4

09W SAOLA 230826 1800 17.2N 122.9E WPAC 115 942

[ElectricStorm]

Cat 4

09W SAOLA 230826 1800 17.2N 122.9E WPAC 115 942

updated

09W SAOLA 230826 1800 17.1N 123.0E WPAC 120 942

[doomhaMwx]

Radar shows the eyewall currently passing very close to the coast of Palanan, Isabela.



Looks like proximity to the mountainous terrain is having adverse effects on the storm for now, but this is expected to abate once it turns east later today.