ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM Hurricane Trudy Discussion Number 21 NWS National Hurricane Center Miami FL EP212026 800 AM MST Sun Oct 18 2026 Trudy has changed little in organization during the past few hours. The hurricane has a well-defined central dense overcast with cloud tops colder than -80C, and there have been occasional attempts at eye formation. The various subjective and objective satellite intensity estimates have an unusually large spread from 62-102 kt, but there has been little change in them since the previous advisory. Thus, the initial intensity is held at 90 kt. The initial motion is still northwestward or 325/7 kt. This motion should continue today, followed by a turn toward the west-northwest at a slower forward speed as Trudy shears apart vertically and becomes steered by the lighter low- to mid-level flow. The new forecast track is similar to, but a little west of the previous track. On the forecast track, the hurricane will move away from southwest and west-central Mexico starting this afternoon and then move slowly south of Baja California Sur on Monday and Tuesday. The hurricane is about to encounter increasing southwesterly shear and a drier and more stable airmass. The dynamical intensity guidance forecasts this combination to cause rapid weakening beginning just after 12 h, and the intensity forecast follows the trend of this guidance. The new forecast follows the previous forecast, showing Trudy degenerating to a post-tropical cyclone by 60 hours and dissipating in 3 or 4 days. And as mentioned previously, both of these could occur sooner than currently predicted. KEY MESSAGES: 1. Tropical storm conditions are expected in the tropical storm warning area today. 2. A dangerous storm surge accompanied by damaging waves is likely in areas of onshore winds within the warning areas. 3. Heavy rainfall associated with Trudy will continue to impact the southwest Mexican coast between Colima and Nayarit through today. This rainfall may produce life-threatening flooding and mudslides, especially in areas along steep terrain. 4. Large swells will continue to affect the coast of southwestern Mexico and west-central Mexico during the next few days, causing life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 18/1500Z 19.1N 106.8W 90 KT 105 MPH 12H 19/0000Z 19.7N 107.2W 85 KT 100 MPH 24H 19/1200Z 20.1N 107.8W 70 KT 80 MPH 36H 20/0000Z 20.3N 108.4W 55 KT 65 MPH 48H 20/1200Z 20.6N 109.0W 40 KT 45 MPH 60H 21/0000Z 21.2N 109.6W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 21/1200Z 21.7N 110.0W 20 KT 25 MPH...POST-TROP/REMNT LOW 96H 22/1200Z...DISSIPATED $$ Forecaster Beven NNNN

WDPN32 PGTW 181500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TYPHOON 29W (CHAMPI) WARNING NR 017// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 13.5N 141.4E INITIAL INTENSITY: 120 KTS GEOGRAPHIC REFERENCE: 187 NM WEST OF NAVSTA GUAM MOVEMENT PAST 6 HOURS: WEST-NORTHWESTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: 46 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A COMPACT INNER CORE OF DEEP CONVECTION, FEATURING RAPIDLY DEVELOPING VORTICAL HOT TOWERS (VHTS) DEEPENING CONCENTRICALLY AND INITIATING A NEW EYE FORMATION. THE RECENT SATELLITE CHANGES HAVE DRIVEN THE CIMSS ADT TECHNIQUE TO CHANGE FROM UNIFORM CDO TO AN ACTIVE PINHOLE EYE SCHEME, WITH RAW T-NUMBERS RAPIDLY INCREASING TO T6.5. THERE HAS BEEN A LACK OF MICROWAVE IMAGERY COVERAGE OF 29W SINCE 180621Z; CONSEQUENTLY, THE EXACT PROGRESSION OF THE EYEWALL REPLACEMENT CYCLE (ERC) CANNOT BE RESOLVED BEYOND OBSERVATIONS OF CLOUD CLEARING WITHIN THE CENTRAL CORE. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE, POSITIONED NEAR THE INCIPIENT EYE RESOLVED IN EIR. SIMILARLY, THE ABSENCE OF HIGH-RESOLUTION SURFACE WIND MEASUREMENTS CAPABLE OF SAMPLING THE COMPACT INNER-CORE WIND FIELDS FOR THE PAST 36 HOURS ELEVATES INTENSITY UNCERTAINTY. ACCORDINGLY, INITIAL INTENSITY IS HEDGED CONSERVATIVELY AT 120 KNOTS BASED ON A SYNTHESIS OF MULTI-AGENCY SUBJECTIVE AND CIMSS OBJECTIVE SATELLITE ESTIMATES. IN THE UPPER-LEVELS, THE ANTICYCLONE POSITIONED TO THE NORTHWEST EXHIBITS WEAKENING AND WESTWARD DISPLACEMENT, REDUCING THE NORTHERLY SHEAR THAT WAS INFLUENCING THE SYSTEM EARLIER. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE, WITH LOW VWS, VERY WARM SSTS, HIGH OHC AND ROBUST RADIAL OUTFLOW ALOFT. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEVELOPING SUBTROPICAL RIDGE (STR) CENTER TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.0 - 115 KTS RJTD: T7.0 - 140 KTS RCTP: T6.5 - 127 KTS CIMSS ADT: 117 KTS AT 181130Z CIMSS AIDT: 126 KTS AT 181130Z CIMSS D-MINT: 123 KTS AT 181011Z CIMSS D-PRINT: 123 KTS AT 181200Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 5-10 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG RADIAL ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM INITIAL INTENSITY: LOW INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: THE TRACK OF TYPHOON 29W HAS SHIFTED WEST- NORTHWESTWARD OVER THE PAST SIX HOURS, AS THE DEEP-LAYER RIDGE EXTENSION DRAPED ACROSS THE NORTHERN PACIFIC HAS PINCHED OFF INTO A DISCRETE SECONDARY ANTICYCLONE TO THE NORTHEAST. SIMULTANEOUSLY, THE TRANSLATION SPEED HAS DECREASED SLIGHTLY AS A LOCALIZED COL REGION DEVELOPS NORTH OF THE SYSTEM, RELAXING THE STEERING GRADIENT. THIS WEAKNESS WILL BE SUPPRESSED BY A EASTWARD EXTENSION OF THE PRIMARY STR (CENTERED NEAR HONG KONG) WITHIN 24 TO 36 HOURS. THIS CELL IS PROJECTED TO TRANSLATE RAPIDLY EASTWARD NORTH OF 29W FROM TAU 36 TO TAU 72, REINFORCING THE NORTHWESTWARD TRAJECTORY AND ACCELERATING THE CYCLONE TO APPROXIMATELY 13 KNOTS. BY TAU 72, A PASSING POLAR TROUGH OVER THE KOREAN PENINSULA WILL WEAKEN THE RIDGE, OPENING A STEERING COL ACROSS THE EAST CHINA SEA. THE RESULTANT RELAXATION OF THE STEERING GRADIENT WILL INDUCE GRADUAL DECELERATION THROUGH THE END OF THE FORECAST. REGARDING INTENSITY, THE ERC APPEARS TO HAVE COMPLETED, AND THE SYNOPTIC ENVIRONMENT FAVORS INCIPIENT REINTENSIFICATION. THE SYSTEM WILL TRAVERSE AN EXTENSIVE POOL OF THE WARMEST, HIGHEST OHC WATERS IN THE WESTERN PACIFIC OVER THE NEXT 48 HOURS, PROVIDING ROBUST THERMODYNAMIC ENERGY TO SUPPORT SUSTAINED INTENSIFI…

WDPS31 PGTW 180900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 01P (WATI) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.1S 162.4W INITIAL INTENSITY: 65 KTS GEOGRAPHIC REFERENCE: 340 NM NORTH-NORTHWEST OF RAROTONGA MOVEMENT PAST 6 HOURS: SOUTHEASTWARD AT 06 KTS SIGNIFICANT WAVE HEIGHT: 24 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BALL OF ROUGHLY SYMMETRICAL CONVECTION WITH ISOLATED OVERSHOOTING TOPS. AN 180450Z SSMIS 91GHZ MICROWAVE IMAGE REVEALED AN UPPER-LEVEL MICROWAVE EYE-LIKE FEATURE, SURROUNDED BY CURVED CONVECTION. HOWEVER, A CLOSE INSPECTION OF THE MICROWAVE IMAGE SUGGESTS THE SYSTEM IS IN THE EARLY PHASES OF VORTEX DECOUPLING, WITH SPIRAL BAND ANALYSIS SUGGESTING THE LOW LEVEL CIRCULATION CENTER (LLCC) IS NOT ALIGNED WITH THE UPPER-LEVEL CENTER. ANALYSIS OF HAFS-A CROSS-SECTIONS SUPPORTS THIS ANALYSIS. THE INITIAL POSITION IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON THE AFOREMENTIONED SPIRAL BAND ANALYSIS OF THE LOW-LEVEL BANDING FEATURES EVIDENT IN THE MICROWAVE IMAGERY. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM CONFIDENCE BASED ON A BLEND OF THE SUBJECTIVE AND OBJECTIVE INTENSITY ESTIMATES OUTLINED BELOW. ENVIRONMENTAL CONDITIONS ARE MARGINALLY UNFAVORABLE, WITH RAPIDLY INCREASING SHEAR, DECREASING SSTS AND STRONG POLEWARD OUTFLOW ALOFT. INITIAL WIND RADII BASIS: PERSISTENCE CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T4.0 - 65 KTS PHFO: T2.5 - 35 KTS NFFN: T3.5 - 55 KTS CIMSS SATCON: 62 KTS AT 180720Z CIMSS ADT: 74 KTS AT 180540Z CIMSS AIDT: 72 KTS AT 180540Z CIMSS D-MINT: 48 KTS AT 180326Z CIMSS D-PRINT: 58 KTS AT 180720Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY UNFAVORABLE VWS: 10-15 KTS SST: 26-27 CELSIUS OUTFLOW: STRONG POLEWARD OTHER FACTORS: VORTEX DECOUPLING. ANALYSIS CONFIDENCE: INITIAL POSITION: MEDIUM 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: TROPICAL CYCLONE (TC) 01P WILL TRACK SOUTHEASTWARD ALONG THE SOUTHWESTERN FLANK OF THE STR FOR THE DURATION OF THE FORECAST PERIOD. REGARDING INTENSITY, THE SYSTEM HAS VERY LIKELY BEGUN THE VORTEX DECOUPLING PROCESS UNDER GRADUALLY INCREASING VWS. HAFS-A CROSS-SECTIONS AND STATISTICAL GUIDANCE DEPICT A SHARP INCREASE IN VWS COMMENCING IN THE NEXT 12 HOURS, COINCIDENT WITH THE SYSTEM CROSSING POLEWARD OF THE 26C ISOTHERM. FULL VORTEX DECOUPLING SHOULD OCCUR BY TAU 36, AS THE SYSTEM RACES SOUTHEASTWARD. 01P COMMENCES EXTRATROPICAL TRANSITION (ETT) BY TAU 24, AS IT BEGINS TO INTERACT WITH THE STRONG JET STREAM TO THE SOUTH, AND A 500MB MAJOR SHORTWAVE TROUGH. BETWEEN TAU 36 AND TAU 48, 01P WILL MOVE INTO PHASE WITH THE 500MB TROUGH, MOVE UNDER THE JET STREAM AND MERGE INTO THE LOW-LEVEL BAROCLINIC ZONE, AND TRANSITION TO A STRONG GALE-FORCE LOW PRESSURE AREA. MODEL DISCUSSION: TRACK GUIDANCE IS IN GOOD AGREEMENT, WITH ALL MEMBERS OF THE CONSENSUS SUPPORTING A SOUTHEASTWARD TRACK THROUGH THE DURATION OF THE FORECAST. CROSS-TRACK SPREAD INCREASES TO 155NM BY TAU 48, WITH ECMWF MARKING THE WESTERN EDGE OF THE GUIDANCE ENVELOPE AND THE GEFS AND ECEPS MEAN MARKING THE EASTERN SIDE. THE JTWC FORECAST IS POSITIONED NEAR THE OPERATIONAL GOOGLE DEEPMIND TRACKER WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS ALSO IN STRONG AGREEMENT, WITH ALL MEMBERS OF THE CONSENSUS INDICATING STEADY WEAKENING THROUGH THE FORECAST PERIOD. FORECAST CONFIDENCE: TRACK 00-72 HR: HIGH INTENSITY 00-72 HR: HIGH// NNNN