WESTERN PACIFIC: TY 17W(SAUDEL) CAT 3 US failed to reach STY Intensity,to track close North of OKINAWA by 36h/TS 18W(NARRA)/TD 19W(ATSANI)/98W/CPA:TS 01C(LALA)/TS 02C(MOKE)//EPA:TS 09E(ISELLE)/91E/ATL:95L//24@1100UTC

WDPN31 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 17W (SAUDEL) WARNING NR 024//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 24.5N 134.7E
   INITIAL INTENSITY: 105 KTS
   GEOGRAPHIC REFERENCE: 392 NM EAST-SOUTHEAST OF KADENA AB
   MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 16 KTS
   SIGNIFICANT WAVE HEIGHT: 46 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TYPHOON 17W
(SAUDEL) WITH SIGNIFICANTLY WARMING CLOUD TOPS SURROUNDING THE EYEWALL 
OVER THE PAST 6 HOURS. ON THE OTHER HAND, THE CENTRAL DENSE OVERCAST 
(CDO) HAS BECOME MORE SYMMETRIC AND THE EYE HAS WARMED TO 12 C. THIS 
STRUCTURE INDICATES THAT THE EYEWALL REPLACEMENT CYCLE (ERC) HAS 
LIKELY CONCLUDED WITH 17W SHOWING A MORE REGULAR APPEARANCE. THE 
INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE DEFINED 
EYE IN ANIMATED MSI. THE INITIAL INTENSITY OF 105 KTS IS ASSESSED WITH 
MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK AND CIMSS INTENSITY 
ESTIMATES LISTED BELOW. THE INITIAL INTENSITY IS SET CLOSER TO THE 
CIMSS ESTIMATES AND AGENCY DATA NUMBERS OF 5.5 RATHER THAN THE CI OF 
6.0. ENVIRONMENTAL ANALYSIS INDICATES THAT 17W REMAINS PLACED WITHIN A 
FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG RADIAL OUTFLOW ALOFT, 
LOW (5-10 KTS) VERTICAL WIND SHEAR, AND WARM (29-30 C) SEA SURFACE 
TEMPERATURES.

INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK 

CURRENT STEERING MECHANISM: THE SOUTHWESTERN FLANK OF A DEEP-LAYER 
SUBTROPICAL RIDGE (STR) WHICH EXTENDS FROM SOUTHERN JAPAN 
SOUTHEASTWARD TO A POINT NORTHEAST OF GUAM.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T6.0 - 115 KTS
   RJTD: T6.0 - 115 KTS
   RCTP: T6.0 - 115 KTS
   KNES: T6.0 - 115 KTS
   CIMSS ADT: 109 KTS AT 240600Z
   CIMSS AIDT: 106 KTS AT 240600Z
   CIMSS D-MINT: 101 KTS AT 240445Z
   CIMSS D-PRINT: 105 KTS AT 240600Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 5-10 KTS
   SST: 29-30 CELSIUS
   OUTFLOW: STRONG RADIAL

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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: TY 17W IS FORECAST TO CONTINUE TRACKING WEST-
NORTHWESTWARD THROUGH TAU 48, PASSING JUST NORTH OF OKINAWA AT AROUND 
TAU 36. NEAR TAU 38, 17W WILL APPROACH A WEAKNESS IN THE STEERING 
RIDGE TO THE NORTH, CAUSING IT TO MARKEDLY SLOW AS THE PRIMARY 
STEERING MECHANISM SHIFTS TO A SUBTROPICAL RIDGE (STR) CENTERED OVER 
EASTERN CHINA. TRACK SPEEDS ARE EXPECTED TO REMAIN SLOW THROUGH TAU 72 
BEFORE THE STEERING GRADIENT BECOMES STRONGER. AFTER TAU 72, THE SPEED 
OF ADVANCE OF 17W IS FORECAST TO INCREASE WITH A SOUTHWESTWARD 
TRAJECTORY AS IT TRACKS ALONG THE SOUTHEASTERN PERIPHERY OF THE STR 
OVER CHINA THROUGH THE REMAINDER OF THE FORECAST PERIOD. LANDFALL OVER 
EASTERN CHINA IS CURRENTLY FORECAST TO OCCUR NEAR TAU 96. IN TERMS OF 
INTENSITY, 17W IS FORECAST TO MAINTAIN ITS CURRENT INTENSITY FOR ONLY 
ANOTHER 12 HOURS BEFORE IT STARTS TO WEAKEN UNDER THE EFFECTS OF 
INCREASED NORTHWESTERLY SHEAR AND DRY AIR ENTRAINMENT. ADDITIONALLY, 
THE UPPER-LEVEL TROUGH CURRENTLY TO THE WEST OF THE SYSTEM IS EXPECTED 
TO MOVE WESTWARD AND FILL, REDUCING OUTFLOW ALOFT. AROUND TAU 72, 
NORTHEASTERLY SHEAR WILL GREATLY INCREASE, INDUCED BY THE STRONG RIDGE 
OVER EASTERN CHINA CAUSING A MORE RAPID RATE OF WEAKENING AS THE 
SYSTEM APPROACHES THE COAST. AFTER LANDFALL, RUGGED TERRAIN 
INTERACTION WILL CAUSE THE VORTEX TO RAPIDLY WEAKEN.

MODEL DISCUSSION: MODEL TRACK GUIDANCE IS IN VERY GOOD AGREEMENT 
THROUGH TAU 48 WITH A CROSS-TRACK SPREAD OF ONLY 50 NM. AFTER TAU 48, 
TWO OUTLIERS ARISE IN GFS AND GALWEM. THE GFS SHOWS A SIGNIFICANTLY 
SHARPER TURN TO THE SOUTHWEST, MAKING LANDFALL IN NORTHERN TAIWAN 
WHILE, GALWEM SHOWS NO SOUTHWESTWARD TURN AT ALL. DISCOUNTING THOSE 
TWO OUTLIERS, MODELS GENERALLY AGREE ON A TRAJECTORY SIMILAR TO THE 
JTWC OFFICIAL FORECAST. THE FORECAST IS PLACED NEAR THE MULTI-MODEL 
CONSENSUS THROUGH TAU 72 AND THEN CLOSER TO THE ECMWF AND EXPERIMENTAL 
GOOGLE DEEPMIND ENSEMBLE MEAN THROUGH TAU 120. INTENSITY GUIDANCE 
AGREES ON STEADY WEAKENING THROUGHOUT THE ENTIRE FORECAST PERIOD WITH 
NO NOTABLE OUTLIERS PRESENT. THE JTWC INTENSITY FORECAST IS PLACED 
SLIGHTLY HIGHER THAN THE CONSENSUS WITH OVERALL MEDIUM CONFIDENCE.

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 240842

A. TYPHOON 17W (SAUDEL)

B. 24/0830Z

C. 24.57N

D. 134.29E

E. ONE/GK2A

F. T5.5/6.0/S0.0/24HRS  STT: S0.0/03HRS

G. IR/EIR/VIS/MSI

H. REMARKS: 03A/PBO EYE/ANMTN. WMG EYE SURROUNDED BY MG YIELDS AN
E# OF 4.5. ADDED 0.5 EYE ADJUSTMENT FOR LG, AND ADDED 0.5 FOR BF,
TO YIELD A DT OF 5.5. MET AND PT AGREE. DBO DT.

I. ADDITIONAL POSITIONS:
   24/0254Z  24.23N  135.33E  AMS2


   RUCKER

WP, 17, 202608232054,  30, SMAP,         IR,  , 2320N, 13790E,      , 1,  92, 1,     ,  ,     ,  34,  NEQ,    0,   99,  146,    0,  ,  ,  ,  , 1,   0,    , W,  NASA, RSS,  ,    ,       ,   ,     ,     ,     ,    ,       ,    ,     ,     ,     ,     ,     ,     ,     ,     ,     ,  ,  ,  ,  ,  ,  ,  ,  , 1,  max. wind is 10 minute sustained                    
WP, 17, 202608232054,  30, SMAP,         IR,  , 2320N, 13790E,      , 1,  92, 1,     ,  ,     ,  50,  NEQ,   91,   59,  104,  119,  ,  ,  ,  , 1,   0,    , W,  NASA, RSS,  ,    ,       ,   ,     ,     ,     ,    ,       ,    ,     ,     ,     ,     ,     ,     ,     ,     ,     ,  ,  ,  ,  ,  ,  ,  ,  , 1,  max. wind is 10 minute sustained                    
WP, 17, 202608232054,  30, SMAP,         IR,  , 2320N, 13790E,      , 1,  92, 1,     ,  ,     ,  64,  NEQ,   76,   36,   54,   97,  ,  ,  ,  , 1,   0,    , W,  NASA, RSS,  ,    ,       ,   ,     ,     ,     ,    ,       ,    ,     ,     ,     ,     ,     ,     ,     ,     ,     ,  ,  ,  ,  ,  ,  ,  ,  , 1,  max. wind is 10 minute sustained                    

 

WDPN32 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 18W (NARRA) WARNING NR 
015//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 19.9N 107.3E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 103 NM SOUTHEAST OF HANOI, VIETNAM
   MOVEMENT PAST 6 HOURS: SOUTHWESTWARD AT 05 KTS
   SIGNIFICANT WAVE HEIGHT: 13 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL STORM 
18W (NARRA) WITH VIGOROUS BURSTS OF DEEP CONVECTION OFFSET TO THE WEST 
OF A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). STRONG 
NORTHEASTERLY SHEAR CONTINUES TO IMPACT THE VORTEX, CAUSING A 
SOUTHWESTWARD TILT WITH HEIGHT AND PREVENTING CONVECTION FROM BUILDING 
OVER THE CENTER. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE 
BASED ON A COMBINATION OF THE ANIMATED MSI AND RADAR IMAGERY SHOWING A 
DEFINED CIRCULATION. THE INITIAL INTENSITY OF 40 KTS IS ASSESSED WITH 
MEDIUM CONFIDENCE BASED ON THE AGENCY DVORAK FIXES AND CIMSS INTENSITY 
ESTIMATES LISTED BELOW. ENVIRONMENTAL ANALYSIS INDICATES THAT 18W IS 
IN A MARGINALLY FAVORABLE ENVIRONMENT CHARACTERIZED BY STRONG 
EQUATORWARD OUTFLOW ALOFT AND VERY WARM (30-31 C) SEA SURFACE 
TEMPERATURES OFFSET BY MODERATE TO HIGH (20-25 KTS) NORTHEASTERLY 
SHEAR AND DRY AIR ENTRAINMENT.

INITIAL WIND RADII BASIS: 240215Z METOP-C ASCAT SCATTEROMETER DATA. 

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

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T2.0 - 30 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T2.5 - 35 KTS
   DEMS: T2.5 - 35 KTS
   CIMSS ADT: 35 KTS AT 240610Z
   CIMSS AIDT: 40 KTS AT 240610Z
   CIMSS D-MINT: 43 KTS AT 240625Z
   CIMSS D-PRINT: 36 KTS AT 240710Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
   VWS: 20-25 KTS
   SST: 30-31 CELSIUS
   OUTFLOW: STRONG EQUATORWARD
   OTHER FACTORS: SLIGHT DRY AIR ENTRAINMENT FROM THE SOUTH AND
EAST

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 18W IS FORECAST TO BEGIN TRACKING SLOWLY 
EASTWARD OVER THE NEXT 24 HOURS AS THE STR RIDGE TO THE NORTH WEAKENS 
AND THE NER TO THE SOUTH BECOMES THE PRIMARY STEERING MECHANISM. AFTER 
TAU 24, 18W IS EXPECTED TO TURN POLEWARD, USHERED BY THE NER BUILDING 
TO THE SOUTHEAST OF THE SYSTEM. LANDFALL WITHIN SOUTHERN CHINA IS 
FORECAST TO OCCUR AROUND TAU 48 NEAR THE LEIZHOU PENINSULA. REGARDING 
INTENSITY, 18W IS FORECAST TO MAINTAIN ITS CURRENT INTENSITY THROUGH 
TAU 12 AS THE SHEAR REMAINS MODERATE. AFTER TAU 12, EASTERLY SHEAR AND 
DRY AIR ENTRAINMENT IS EXPECTED TO INCREASE, CAUSING THE SYSTEM TO 
WEAKEN AS IT APPROACHES THE COAST. AFTER LANDFALL, TERRAIN INTERACTION 
WILL QUICKLY WEAKEN THE VORTEX WITH DISSIPATION ANTICIPATED TO OCCUR 
BY TAU 60. 

MODEL DISCUSSION: MODEL TRACK GUIDANCE CONTINUES TO BE IN BETTER 
AGREEMENT THIS MODEL RUN WITH A CROSS-TRACK SPREAD OF ABOUT 70 NM AT 
TAU 48. THE JTWC TRACK FORECAST IS PLACED CLOSE TO THE MULTI-MODEL 
CONSENSUS WITH MEDIUM CONFIDENCE. INTENSITY GUIDANCE AGREES ON STEADY 
WEAKENING THROUGHOUT THE FORECAST PERIOD WITH NO NOTABLE OUTLIERS 
PRESENT. AS A RESULT, THE JTWC INTENSITY FORECAST IS ALSO PLACED NEAR 
THE CONSENSUS WITH MEDIUM CONFIDENCE.

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

 

WDPN33 PGTW 240900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL DEPRESSION 19W (ATSANI) WARNING 
NR 008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.

SUMMARY:
   INITIAL POSITION: 16.1N 138.1E
   INITIAL INTENSITY: 30 KTS
   GEOGRAPHIC REFERENCE: 552 NM SOUTH-SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 12 KTS
   SIGNIFICANT WAVE HEIGHT: 12 FEET

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A FULLY EXPOSED 
LOW-LEVEL CIRCULATION CENTER (LLCC) ASSOCIATED WITH TROPICAL 
DEPRESSION (TD) 19W (ATSANI). THE LLCC PROPAGATED RAPIDLY 
NORTHEASTWARD OVER THE LAST 06 HOURS, STEERED BY THE COMBINED EFFECTS 
OF LOW- TO MID-LEVEL SOUTHWESTERLIES ASSOCIATED WITH A NEAR-EQUATORIAL 
RIDGE (NER) TO THE EAST-SOUTHEAST, IN TANDEM WITH THE SOUTHEASTWARD 
FLANK OF A SUBTROPICAL RIDGE CENTERED TO THE NORTHEAST - WHICH, IN 
TURN, SERVES AS THE PRIMARY STEERING MECHANISM FOR TYPHOON 17W. 
ADDITIONALLY, THE TWO SYSTEMS ARE WITHIN THE BINARY INTERACTION 
DISTANCE THRESHOLD. THE INITIAL POSITION IS ASSESSED WITH HIGH 
CONFIDENCE BASED ON THE CLEAR LLCC OBSERVED IN THE VISIBLE SATELLITE 
IMAGERY LOOP. ENVIRONMENTAL ANALYSIS INDICATES MARGINALLY UNFAVORABLE 
DEVELOPMENT CONDITIONS. ALTHOUGH SEA SURFACE TEMPERATURES (SST) REMAIN 
CONDUCIVE AT 29-30C AND UPPER-LEVEL DYNAMICS BENEFIT FROM AN 
EQUATORWARD OUTFLOW PATTERN, SEVERE NORTHEASTERLY VERTICAL WIND SHEAR 
(VWS) OF 30+ KTS LIMITS ANY INTENSIFICATION. FURTHERMORE, WHILE 
TROPOSPHERIC MOISTURE IS RELATIVELY HIGH ALONG THE WESTERN PERIPHERY, 
SIGNIFICANT MID-LEVEL DRY-AIR INTRUSION IS INCREASING, DUE TO THE 
SURROUNDING DRY AIR MASS ENVELOPING AND CONSTRAINING THE CORE. THE 
INITIAL INTENSITY OF 30 KTS IS ASSESSED WITH MEDIUM CONFIDENCE, AS NO 
NEW WIND SPEED DATA IS AVAILABLE, WHILE OBJECTIVE AIDS AND SUBJECTIVE 
AGENCY FIXES PRESENT A SLIGHTLY INCREASED VARIABILITY.

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

CURRENT STEERING MECHANISM: LOW- TO MID-LEVEL SOUTHWESTERLIES DRIVEN 
BY SOUTHEASTWARD EXTENSION OF A SUBTROPICAL RIDGE CENTERED TO THE 
NORTHEAST, WHICH IS THE PRIMARY STEERING MECHANISM FOR TYPHOON 17W.

AGENCY DVORAK AND AUTOMATED FIXES: 
   PGTW: T2.5 - 35 KTS
   RJTD: T1.5 - 25 KTS
   RCTP: T2.5 - 35 KTS
   KNES: T2.0 - 30 KTS
   CIMSS SATCON: 38 KTS AT 240540Z
   CIMSS ADT: 35 KTS AT 240610Z
   CIMSS AIDT: 33 KTS AT 240610Z
   CIMSS D-MINT: 32 KTS AT 240442Z
   CIMSS D-PRINT: 27 KTS AT 240610Z

FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE
   VWS: 30+ KTS
   SST: 29-30 CELSIUS
   OUTFLOW: MODERATE EQUATORWARD
   OTHER FACTORS: PERSISTENT DRY AIR ENTRAINMENT

ANALYSIS CONFIDENCE:
   INITIAL POSITION: HIGH
   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 19W IS FORECAST TO CONTINUE TRACKING 
NORTHEASTWARD OVER THE NEXT 06-12 HOURS BEFORE GRADUALLY VEERING 
NORTHWARD AND FOLLOWING IN THE WAKE OF TY 17W ALONG THE SOUTHWESTERN 
PERIPHERY OF A STR ANCHORED TO THE NORTHEAST. THE SYSTEM IS BEGINNING 
ITS TERMINAL WEAKENING PHASE, DRIVEN PRIMARILY BY HOSTILE VWS AND 
INCREASING DRY-AIR ENTRAINMENT. AS SUCH, IT IS EXPECTED TO RETAIN 30 
KTS INTENSITY FOR A SHORT PERIOD OF TIME. IT WILL LIKELY STRUGGLE TO 
RETAIN SYMMETRY AND WILL BEGIN TO OPEN UP, PARTICULARLY OVER THE 
WESTERN SEMICIRCLE. THESE DESTRUCTIVE DYNAMIC AND THERMODYNAMIC 
IMPEDIMENTS WILL PERSIST, LEADING TO THE STEADY DECAY OF TD ATSANI. 
INTENSITY IS EXPECTED TO DEPRESS TO 25 KTS BY TAU 24, CULMINATING IN 
COMPLETE DISSIPATION OVER OPEN WATER WITHIN THE NEXT 36 HOURS.

MODEL DISCUSSION: NUMERICAL WEATHER PREDICTION SPREAD EXHIBITS HIGH 
TRACK CONSISTENCY, DEPICTING A TIGHT 90-NM CROSS-TRACK DISPERSION 
ENVELOPE THROUGH TAU 36. ALONG-TRACK UNCERTAINTY IS MODERATE,   
CONSTRAINED TO APPROXIMATELY 200 NM SPREAD BETWEEN THE MAJORITY OF THE 
TRACKERS AND THE SLOWEST ECMWF AND UKMET GUIDANCE. THE OFFICIAL JTWC 
TRACK IS POSITIONED ON THE EASTERN SIDE OF THE MULTI-MODEL CONSENSUS 
WITH HIGH CONFIDENCE, OFFSETTING THE MUCH SLOWER AND TIGHTER-TURNING 
UKMET TRACKER. IN TERMS OF INTENSITY, ALL AVAILABLE GUIDANCE MEMBERS 
PROJECT TERMINAL WEAKENING, WITH DISSIPATION ESTIMATED BETWEEN TAUS 24 
AND 36. WHILE PREVIOUS RUNS FROM COAMPS-TC RECENTLY ACTED AS OUTLIERS 
PROGNOSTICATING PEAK SPEEDS OF 50-55 KTS, CURRENT CONSENSUS MEMBERS 
HAVE FULLY REALIGNED WITH A STEADY WEAKENING SCENARIO, SECURING HIGH 
CONFIDENCE IN THE DISSIPATION OUTLOOK.

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

 

WTPN21 PGTW 240200
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INEVEST 98W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
035 NM EITHER SIDE OF A LINE FROM 24.4N 119.2E TO 26.4N 119.0E
WITHIN THE NEXT 12 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 18 TO 23 KNOTS. METSAT
IMAGERY AT 240200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 24.6N 119.2E. THE SYSTEM IS MOVING NORTHWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 98W) IS LOCATED NEAR 24.6N 
119.2E, APPROXIMATELY 127 NM WEST-SOUTHWEST OF TAIPEI, TAIWAN. 
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS AN EXPOSED LOW-
LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION ALONG THE 
EAST-SOUTHEAST PERIPHERY OF THE CIRCULATION. ANIMATED RADAR DATA SHOWS 
A WELL-DEFINED CIRCULATION WITH MODERATE CONVECTIVE BANDS WRAPPING 
INTO THE LLCC AND MORE CONCENTRATED CONVECTION TO THE SOUTHEAST NEAR 
THE WEST COAST OF TAIWAN. RECENT OBSERVATIONS FROM ACROSS THE REGION 
DEPICT GENERALLY SOUTHERN WINDS OF 15-20KTS WITH GUSTS AS HIGH AS 
35KTS, PARTICULARLY FROM THE PENGHU ISLANDS. ENVIRONMENTAL ANALYSIS 
REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW VERTICAL WIND 
SHEAR (10 TO 15KTS), WARM SEA SURFACE TEMPERATURES (27 TO 28 C), AND 
GOOD UPPER-LEVEL OUTFLOW. GLOBAL DETERMINISTIC AND ENSEMBLE MODELS ARE 
IN POOR AGREEMENT ON A SHORT WINDOW FOR DEVELOPMENT OF INVEST 98W. GFS 
STALLS THE SYSTEM OVER WATER FOR ABOUT 24 HOURS, ALLOWING FOR A BRIEF 
PERIOD OF DEVELOPMENT, WHILE THE ECMWF MOVES THE CIRCULATION OVER LAND 
MORE QUICKLY, DENYING TIME FOR THE SYSTEM TO DEVELOP FURTHER. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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 
250200Z.//
NNNN