WESTERN PACIFIC:TY 17W(SAUDEL) CAT 3 US,RI past 24 hours,forecast to peak at Super Typhoon Intensity by 36h/TS 18W(NARRA)/Invest 94W/CENTRAL PACIFIC:TD 19W/94W/CENTRAL PACIFIC:HU 01C(LALA) /TS 02C(MOKE)//22@1630 UTC

WDPN31 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 17W (SAUDEL) WARNING NR 017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.6N 144.8E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 1025 NM EAST-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: NORTHWESTWARD AT 14 KTS
   SIGNIFICANT WAVE HEIGHT: 38 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TYPHOON
17W (SAUDEL) WITH A SLIGHTLY RAGGED EYE THAT HAS CONTINUED TO WARM
OVER THE PAST 6 HOURS AS IT PASSES WEST OF THE NORTHERNMOST MARIANA
ISLANDS. THE STRONGEST CONVECTIVE ACTIVITY IS LOCATED WITHIN THE 
WESTERN SEMICIRCLE OF THE EYEWALL WITH A WEAKNESS IN THE NORTHERN
SEMICIRCLE. ANIMATED WATER VAPOR IMAGERY SHOWS DEFINED CIRRUS 
FILAMENTS EXPANDING OUTWARD TO THE NORTH, AND IS INDICATIVE OF A 
STRONG POLEWARD OUTFLOW CHANNEL. 17W HAS CONTINUED TO RAPIDLY 
INTENSIFY, NOW HAVING INTENSIFIED 35 KTS OVER THE PAST 24 HOURS. THE 
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE EYE IN 
ANIMATED EIR IMAGERY. THE INITIAL INTENSITY OF 105 KTS IS ASSESSED 
WITH MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES AND CIMSS 
INTENSITY ESTIMATES LISTED BELOW. ENVIRONMENTAL ANALYSIS INDICATES 
THAT 17W IS IN A HIGHLY FAVORABLE ENVIRONMENT CHARACTERIZED BY ROBUST 
POLEWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR, AND VERY 
WARM (30-31 C) SEA SURFACE TEMPERATURES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A SUBTROPICAL
RIDGE (STR) POSITIONED TO THE NORTHEAST


AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T5.0 - 90 KTS
   RCTP: T5.5 - 102 KTS
   KNES: T6.0 - 115 KTS
   CIMSS SATCON: 96 KTS AT 221040Z
   CIMSS ADT: 90 KTS AT 221200Z
   CIMSS AIDT: 86 KTS AT 221200Z
   CIMSS D-MINT: 106 KTS AT 221222Z
   CIMSS D-PRINT: 105 KTS AT 221200Z

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

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

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TY 17W IS FORECAST TO TRACK WEST-NORTHWESTWARD
ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE TO THE 
NORTHEAST THROUGH TAU 48. NEAR TAU 48, THE STR IS EXPECTED TO MERGE
WITH ANOTHER STR POSITIONED OVER SOUTHERN JAPAN. THE COMBINED STEERING 
INFLUENCE OF THE RIDGING COMPLEX WILL KEEP 17W ON A WEST-NORTHWESTWARD 
TRAJECTORY THROUGH TAU 96. THE TIMING OF LANDFALL OVER OKINAWA HAS 
REMAINED CONSISTENT WITH THE PREVIOUS FORECASTS, AND IS EXPECTED TO 
OCCUR JUST BEFORE TAU 96. AFTERWARD, TRACK SPEEDS ARE EXPECTED TO SLOW 
THROUGH TAU 120 AS THE PRIMARY STEERING MECHANISM TRANSITIONS TO A 
SUBTROPICAL RIDGE POSITIONED OVER EASTERN CHINA. A TURN TO THE 
SOUTHWEST, TOWARD NORTHERN TAIWAN IS THEN LIKELY IN THE EXTENDED 
FORECAST. IN TERMS OF INTENSITY, 17W IS FORECAST TO CONTINUE 
INTENSIFYING THROUGH TAU 36 TO A PEAK OF AROUND 130 KTS AS THE 
ENVIRONMENT REMAINS HIGHLY CONDUCIVE. AFTER TAU 36, THE POLEWARD 
OUTFLOW CHANNEL WILL WEAKEN AND NORTHWESTERLY SHEAR WILL BEGIN TO 
INCREASE, CAUSING 17W TO START ON A GRADUAL WEAKENING TREND AS IT 
APPROACHES OKINAWA. FURTHER WEAKENING WITHIN THE EAST CHINA SEA IS 
EXPECTED DUE TO INCREASING SHEAR AND DRY AIR INDUCED BY A STRONG RIDGE 
OVER EASTERN CHINA. 

MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN GOOD AGREEMENT THROUGH
TAU 72 WITH THE ONLY NOTABLE OUTLIER BEING NAVGEM, WHICH TRACKS THE
VORTEX MUCH FURTHER SOUTH. DISCOUNTING NAVGEM, CROSS-TRACK SPREAD AT 
TAU 72 IS MEASURED TO BE 160 NM. AFTER TAU 72, CROSS-TRACK SPREAD 
INCREASES TO AROUND 200 NM WITH THE ECMWF AND GFS BOTH MAKING A FASTER 
SOUTHWESTWARD TURN THAN THE EC-AIFS AND EXPERIMENTAL GOOGLE DEEPMIND. 
THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE ADJUSTED CONSENSUS WITH 
HIGH CONFIDENCE THROUGH TAU 72 AND THEN HEDGED SLIGHTLY CLOSER TO THE 
GOOGLE DEEPMIND AND EC-AIFS THROUGH TAU 120 WITH MEDIUM CONFIDENCE. 
INTENSITY GUIDANCE REMAINS SPLIT BETWEEN THE RAPID INTENSIFICATION 
(RI) AIDS AND THE NON-RI AIDS. THE RI AIDS SHOW A PEAK OF 130-150 KTS 
AT TAU 36 WHILE HAFS-A ONLY SHOWS A PEAK OF 115 KTS. THE JTWC 
INTENSITY FORECAST IS PLACED CLOSER TO THE RI AIDS THROUGH TAU 36 DUE  
TO THE EXPECTED HIGHLY FAVORABLE ENVIRONMENT. MODELS THEN AGREE ON 
STEADY WEAKENING FROM TAU 48 ONWARD AND THE JTWC INTENSITY FORECAST 
FOLLOWS SUIT.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM
   INTENSITY 72-120 HR: MEDIUM//
NNNN

 

TPPN10 PGTW 221508

A. TYPHOON 17W (SAUDEL)

B. 22/1430Z

C. 19.93N

D. 144.34E

E. ONE/GK2A

F. T6.0/6.0/D1.5/24HRS  STT: S0.0/03HRS

G. IR/EIR

H. REMARKS: 01A/PBO EYE/ANMTN. WMG EYE SURROUNDED BY DG YIELDS AN
E# OF 4.5. ADDED 1.0 EYE ADJUSTMENT FOR B, TO YIELD A DT OF 5.5.
MET AND PT YIELDS 6.0. DBO PT.

I. ADDITIONAL POSITIONS: NONE


   THOMPSON

Platform: RCM-2
Acquisition Date: 2026-08-21 20:11:12 UTC
Storm Name: WP172026 / SAUDEL
Storm ID: WP17
Storm Center Longitude: 146.942
Storm Center Latitude: 17.353
Incidence Angle (Degrees): 29.125
Quadrant 1 NE VMax (kts): 83.53
Quadrant 2 SE VMax (kts): 75.54
Quadrant 3 SW VMax (kts): 84.21
Quadrant 4 NW VMax (kts): 89.43
RMax (nmi): 16.00 - 33.00

 

WDPN32 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 18W (NARRA) WARNING 
NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 21.0N 108.0E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 118 NM EAST OF HANOI, VIETNAM
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 01 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: 
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS TROPICAL
DEPRESSION 18W WITH DEEP FLARING CONVECTION DISPLACED TO THE WEST
OF THE PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) OVER
NORTHEASTERN VIETNAM. CLOUD TOPS ARE MEASURED TO BE NEARLY -90 C IN
SOME AREAS. SURFACE OBSERVATIONS FROM BACH LONG VI REPORTED 29 KTS 
FROM THE WEST-NORTHWEST AT 221200Z, SUPPORTING THE INITIAL INTENSITY 
OF 30 KTS WITH MEDIUM CONFIDENCE. CIMSS INTENSITY ESTIMATES ARE 
ANALYZED TO BE OVERESTIMATING THE CURRENT INTENSITY, LIKELY DUE TO THE 
VIGOROUS BURSTS OF CONVECTION ASSOCIATED WITH THE CIRCULATION. 
ENVIRONMENTAL ANALYSIS INDICATES THAT 18W IS IN A MARGINAL ENVIRONMENT 
CHARACTERIZED BY WEAK EQUATORWARD OUTFLOW ALOFT, LOW TO MODERATE (15-
20 KTS) NORTHEASTERLY SHEAR, AND VERY WARM (30-31 C) SEA SURFACE 
TEMPERATURES.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: COMPETING STEERING ENVIRONMENT WITH A
NEAR EQUATORIAL RIDGE (NER) TO THE SOUTH AND A SUBTROPICAL RIDGE
(STR) TO THE NORTHWEST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: NO CURRENT ESTIMATE
   CIMSS ADT: 39 KTS AT 221210Z
   CIMSS AIDT: 38 KTS AT 221210Z
   CIMSS D-MINT: 41 KTS AT 221016Z
   CIMSS D-PRINT: 41 KTS AT 221210Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINAL
   VWS: 15-20 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: DRY AIR ENTRAINMENT FROM THE SOUTH

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: MEDIUM
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 18W IS FORECAST TO MAKE A SLOW 
COUNTERCLOCKWISE LOOP OVER THE NEXT 72 HOURS AS THE SYSTEM REMAINS
PLACED WITHIN A COMPETING STEERING PATTERN WITH RIDGING TO BOTH THE
NORTH AND SOUTH. IN REALITY THE ACTUAL TRACK OF 18W IS LIKELY TO BE
HIGHLY ERRATIC DURING THIS TIME. AFTER TAU 72, 18W IS FORECAST TO
BE DRIVEN NORTHWARD INTO SOUTHERN CHINA UNDER THE INFLUENCE OF THE
LOW-LEVEL FLOW. THE ENVIRONMENT IS EXPECTED TO REMAIN MARGINAL WITH
MODERATE NORTHEASTERLY SHEAR CONTINUING TO IMPACT THE VORTEX WITH
DRY AIR ENTRAINMENT FROM THE SOUTH. HOWEVER, THESE FACTORS ARE
OFFSET BY THE VERY WARM WATERS WITHIN THE GULF OF TONKIN, WHICH IS
FORECAST TO ALLOW FOR SLIGHT DEVELOPMENT OVER THE NEXT 36 HOURS.
SOME MODELS, SUCH AS ECMWF, SHOW THE NORTHEASTERLY SHEAR DECREASING
AND THE SYSTEM REMAINING QUASISTATIONARY OVER THE GULF OF TONKIN.
IF THE SHEAR LESSENS, THEN FURTHER INTENSIFICATION IS POSSIBLE. AS IT 
STANDS, A PEAK INTENSITY OF 40 KTS IS FORECAST BEFORE 18W IS DRIVEN 
NORTH-NORTHEASTWARD INTO SOUTHERN CHINA. DISSIPATION OVER LAND IS 
EXPECTED TO OCCUR AROUND TAU 96, QUICKLY AFTER LANDFALL.

MODEL DISCUSSION: MODEL TRACK GUIDANCE CONTINUES TO BE IN VERY POOR
AGREEMENT, BUT IT GENERALLY SHOWS A SOUTHWARD TURN THROUGH TAU 48
FOLLOWED BY A TURN BACK TO THE NORTH. THE JTWC TRACK FORECAST IS
PLACED NEAR THE MULTI-MODEL CONSENSUS WITH VERY LOW CONFIDENCE DUE
TO THE LARGE SPREAD IN GUIDANCE. GFS SHOWS A TRACK THAT SKIRTS THE
COAST OF VIETNAM, AND THEREFORE WEAKENS THE VORTEX MUCH MORE QUICKLY 
THAN ECMWF, WHICH KEEPS THE SYSTEM CENTERED OVER WATER. INTENSITY 
GUIDANCE IS ALSO IN POOR AGREEMENT DUE TO DIFFERING AMOUNTS OF LAND 
INTERACTION AND AMOUNT OF TIME OVER WATER BETWEEN MODELS. THE JTWC 
INTENSITY FORECAST IS ALSO PLACED NEAR THE CONSENSUS THROUGHOUT THE 
FORECAST PERIOD WITH LOW CONFIDENCE.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: LOW
   TRACK 72-120 HR: LOW
   INTENSITY 00-72 HR: LOW
   INTENSITY 72-120 HR: LOW//
NNNN

 

WDPN33 PGTW 221500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W (NINETEEN) 
WARNING NR 001//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 12.2N 135.4E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 543 NM WEST OF NAVSTA GUAM
   MOVEMENT PAST 6 HOURS: NORTH-NORTHWESTWARD AT 09 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BROAD
AND POORLY ORGANIZED TROPICAL DEPRESSION (TD) 19W, WITH THE MAJORITY 
OF THE DEEP CONVECTION LOCATED IN THE NORTHWESTERN QUADRANT. OVER THE 
LAST 6 HOURS, CENTRAL CONVECTION HAS PERSISTED AND THE OUTER BANDING 
HAS STARTED TO WRAP TIGHTER INTO A NEARLY FULLY OBSCURED LOW-LEVEL 
CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY 
FAVORABLE CONDITIONS FOR DEVELOPMENT, WITH WARM (29-30 C) SEA SURFACE 
TEMPERATURES (SST), A GOOD EQUATORWARD OUTFLOW CHANNEL, AND LOW (10-15 
KTS) VERTICAL WIND SHEAR (VWS). THE NORTHWESTERN QUADRANT CONTAINS 
HIGH MOISTURE LEVELS THROUGHOUT THE ATMOSPHERIC COLUMN, HOWEVER, MUCH 
DRIER AIR SURROUNDS THE SYSTEM TO THE EAST AND NORTHEAST. THE INITIAL 
POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED ON A 221130Z METOP-B 
ASCAT PASS, SUPPORTED BY EXTRAPOLATION FROM A 221023Z F16 SSMIS 
MICROWAVE SUITE. THE INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH HIGH 
CONFIDENCE BASED ON THE SAME ASCAT PASS, AS WELL AS 220908Z SMOS WIND 
SPEED DATA, AND THE OBJECTIVE AND AUTOMATED FIXES LISTED BELOW.

INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND
RADII).

CURRENT STEERING MECHANISM: NEAR-EQUATORIAL RIDGE (NER) TO THE
EAST-SOUTHEAST

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.0 - 30 KTS
   RJTD: T1.5 - 25 KTS
   KNES: T2.0 - 30 KTS
   CIMSS D-MINT: 35 KTS AT 221024Z
   CIMSS D-PRINT: 29 KTS AT 221200Z

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

ANALYSIS CONFIDENCE:
   INITIAL POSITION: MEDIUM
   INITIAL INTENSITY: HIGH
   INITIAL WIND RADII: NOT APPLICABLE

3. FORECAST REASONING.

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

FORECAST DISCUSSION: TD 19W IS FORECAST TO BEGIN TURNING NORTHWARD
AND NORTHEASTWARD UNDER THE STEERING INFLUENCE OF A NER CENTERED TO
THE EAST-SOUTHEAST OVER THE NEXT 6 TO 12 HOURS. AROUND TAU 48, A
SUBTROPICAL RIDGE TO THE NORTHEAST WILL TAKE OVER AS THE PRIMARY
STEERING MECHANISM, RESULTING IN TD 19W TURNING NORTHWARD AND
NORTHWESTWARD, TRANSITING IN THE WAKE OF TYPHOON 17W (SAUDEL). 
INITIALLY MARGINALLY FAVORABLE ENVIRONMENTAL CONDITIONS WILL RESULT
IN SLIGHT INTENSIFICATION, WITH THE SYSTEM ATTAINING 35 KTS OVER
THE NEXT 12-24 HOURS. HOWEVER, AS TD 19W TRANSITS NORTHEASTWARD AND
TOWARD AN UPPER-LEVEL LOW, THE WIND SHEAR IS EXPECTED TO INCREASE
SIGNIFICANTLY, LIKELY TO 25-30 KTS AROUND TAU 36. AT THE SAME TIME,
THE SYSTEM WILL ENCOUNTER DRIER AIR, WHICH WILL ENTRAIN INTO THE CORE 
OF THE VORTEX. AS A RESULT, THE INTENSITY IS EXPECTED TO DROP TO 20-25 
KTS BY TAU 48. AFTERWARD, THE SYSTEM WILL FOLLOW THE TAIL END OF
THE WIND FIELD BELONGING TO TYPHOON 17W AND WILL STRUGGLE TO MAINTAIN 
VERTICAL STRUCTURE. DISSIPATION OVER WATER IS EXPECTED NO LATER THAN 
TAU 72, BUT IS POSSIBLE MUCH EARLIER IF THE VWS AND DRY AIR ERODE THE 
STRUCTURE OF THE STORM SOONER.

MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE IS IN OVERALL FAIR
AGREEMENT, AS EVIDENCED BY A 90 NM CROSS-TRACK SPREAD AT TAU 48,
WITH ALL MODELS DEPICTING A SIMILAR RESPONSE TO THE CURRENT STEERING
ENVIRONMENT. AFTER TAU 48, THE GUIDANCE ENVELOPE INCREASES
SIGNIFICANTLY AS A RESULT OF SOME MODELS (GFS, HAFS) PREDICTING
DISSIPATION AS EARLY AS TAU 48, WHILE OTHERS (COAMPS-TC AND
STATISTICAL-DYNAMICAL GUIDANCE) PRESERVE BORDERLINE INTENSITY
THROUGHOUT THE CURRENT FORECAST PERIOD. AS SUCH, BOTH THE TRACK AND 
INTENSITY FORECASTS ARE ASSESSED WITH MEDIUM CONFIDENCE. WHILE THE
SYSTEM IS NOT EXPECTED TO REACH WIND SPEEDS HIGHER THAN 35 KTS, THE
TIMING OF DISSIPATION IS THE MAIN UNCERTAINTY FACTOR.

FORECAST CONFIDENCE:
   TRACK 00-72 HR: MEDIUM
   INTENSITY 00-72 HR: MEDIUM//
NNNN