ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Tropical Storm Vance Discussion Number 33 NWS National Hurricane Center Miami FL EP222026 800 AM MST Thu Oct 29 2026 Deep convection near the center yesterday evening produced tropical-storm-force winds in Vance's northern and eastern semicircles. Strong (50 kt) west-southwesterly vertical wind shear has been pushing the deep convection farther and farther away from the center over the past 9 to 12 hours, and now the convection is located more than 90 n mi east and northeast of the center. Recent surface observations from Islas Marias are 20 kt gusting to 30 kt while located underneath some of the deepest convection for the past few hours, so the winds are likely decreasing, but it is still possible that a small area of winds to tropical-storm-force exists in that convection, so Vance will be held at 35 kt for this advisory. Scatterometer passes expected within the next couple of hours should give us a better assessment of Vance's strength. The UW-CIMSS shear analysis and the latest SHIPS guidance are both analyzing about 50 kt of west-southwesterly vertical wind shear currently impacting Vance. The shear is forecast to increase to around 55 kt over the next 6 h or so. Vance is also located within a drier environment than it was yesterday, with mid-level relative humidity values in the 40 to 50 percent range. Therefore, deep convection, which is currently located well east of the center and moving farther away, is unlikely to return, and the GFS and ECMWF simulated satellite products do not forecast any new convection to form near the center. Therefore, the timing of post-tropical transition has been moved up to hour 12 in the official forecast. Most of the models then show the remnant low dissipating in about 18 to 24 hours over the southern Gulf of California. Although gradual weakening is forecast until dissipation, gusts to tropical-storm-force are still likely today within the deep convection well east of the center. Vance has been moving northward, or 350/7 kt. A generally northward motion at about the same speed is expected until Vance degenerates into a trough of low pressure over the southern Gulf of California in about 18 to 24 hours. The new NHC forecast is nudged a bit to the left of the previous one and is near the latest HCCA and GDMI. It should be emphasized that the main threat with Vance is the very heavy rainfall and high rain rates near the areas of very deep convection near the Islas Marias and west-central Mexico. Key Messages: 1. Periods of heavy rainfall associated with Vance will impact portions of western Mexico during the next day or two. This rainfall may produce flooding and mudslides across central and southern Sinaloa, far southwestern Durango, and far northwestern Nayarit, especially in areas along steep terrain. 2. Moisture carried northeastward from Vance will produce heavy rain across portions of the U.S. Southern Plains and New Mexico today into Friday. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 21.6N 108.8W 35 KT 40 MPH 12H 30/0000Z 22.9N 108.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 24H 30/1200Z...DISSIPATED $$ Forecaster Hagen NNNN

WDPN31 PGTW 291500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 30W (IN-FA) WARNING NR 025// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 16.6N 151.3E INITIAL INTENSITY: 130 KTS GEOGRAPHIC REFERENCE: 328 NM EAST-NORTHEAST OF SAIPAN MOVEMENT PAST 6 HOURS: WESTWARD AT 16 KTS SIGNIFICANT WAVE HEIGHT: 60 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: IN-FA IS LIKELY AT OR VERY NEAR SUPER TYPHOON (STY) STRENGTH. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS CONTINUED COOLING OF CLOUD-TOP TEMPERATURES AND WARMING OF THE 40-NM WIDE EYE. THE EYE HAS WARMED TO +21.8 DEGREES CELSIUS FROM +17 DEGREES CELSIUS SIX HOURS AGO. THE DISTRIBUTION OF CLOUD-TOP TEMPERATURES IS VERY UNIFORM. AT 291200Z, THE NARROWEST WIDTHS OF THE BD-CURVE BLACK AND WHITE SHADES MEASURED APPROXIMATELY 60 NM AND 30 NM, RESPECTIVELY. A 291013Z METOP-B MHS PASS REVEALED A THICK RING SURROUNDING THE CENTER THAT LACKED DISTINCT BANDING FEATURES, SUPPORTING THE ASSESSMENT THAT THE SYSTEM HAS SOME ANNULAR CHARACTERISTICS. THE ACCOMPANYING ASCAT-B IMAGE INDICATED THAT THE CORE OF STORM- AND TYPHOON-FORCE WINDS IS RATHER LARGE WITH RESPECT TO THE EXTENT OF GALE-FORCE WINDS. A 290755Z SENTINEL-1C SAR PASS ESTIMATED SIMILAR WIND RADII WITH MAXIMUM WINDS NEAR 120 KTS. SINCE THAT TIME, THE STORM'S SATELLITE APPEARANCE HAS CONTINUED TO IMPROVE. THE DVORAK EIR EYE TECHNIQUE YIELDED A DATA T-NUMBER OF 7.0 BY 291300Z. HOWEVER, GIVEN THE EYE SIZE, THE ACTUAL INTENSITY WOULD LIKELY BE LOWER THAN 140 KTS. THEREFORE, THE INITIAL INTENSITY HAS BEEN RAISED TO 130 KTS WITH MEDIUM CONFIDENCE, WHICH IS CLOSEST TO D-MINT AND D-PRINT. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WELL-DEFINED EYE IN SHORTWAVE IR IMAGERY. THE ENVIRONMENT REMAINS FAVORABLE, WITH LOW VERTICAL WIND SHEAR (VWS) AND HIGH OCEAN HEAT CONTENT (OHC). INITIAL WIND RADII BASIS: SCATTEROMETER AND SAR DATA CURRENT STEERING MECHANISM: SOUTHWESTERN FLANK OF A DEEP-LAYER SUBTROPICAL RIDGE (STR) CENTERED NEAR 28N 165E AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T6.0 - 115 KTS RJTD: T6.5 - 127 KTS RCTP: T6.0 - 115 KTS CIMSS SATCON: 120 KTS AT 290510Z CIMSS ADT: 112 KTS AT 291130Z CIMSS AIDT: 124 KTS AT 291130Z CIMSS D-MINT: 129 KTS AT 291329Z CIMSS D-PRINT: 129 KTS AT 291130Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: MODERATE RADIAL 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: STY 30W WILL CONTINUE WEST-NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STR THROUGH TAU 36. A BROAD, LONGWAVE TROUGH PASSING OVER HONSHU WILL INDUCE A LARGE WEAKNESS IN THE STR, ALLOWING STY 30W TO TURN POLEWARD AND SLOW DOWN. THE PROGRESSIVE TROUGH WILL RACE DOWNSTREAM, AND A SEPARATE DEEP-LAYER STR TO THE WEST WILL BUILD EASTWARD, CLOSING OFF THE WEAKNESS AND CAUSING THE SYSTEM TO DEFLECT WESTWARD. BY THE END OF THE FORECAST PERIOD, ANOTHER TROUGH PASSING TO THE NORTH MAY CREATE ANOTHER OPENING, AND THE SYSTEM SHOULD SLOW DOWN AND TURN POLEWARD ONCE AGAIN. THERE REMAINS A GREAT DEAL OF UNCERTAINTY IN THE TRACK BEYOND TAU 36. THE INTERACTION OF THE LONGWAVE TROUGH WITH BOTH RIDGES WILL INFLUENCE THE POLEWARD EXTENT OF THE TRACK PRIOR TO THE WESTWARD DEFLECTION AND THE TIMING OF THE WESTWARD TURN. IF THE TROUGH PASSES MORE SLOWLY OR THE STR TO THE EAST CLOSES THE WEAKNESS MORE SLOWLY, STY 30W COULD TURN NORTHEASTWARD PRIOR TO DEFLECTING WESTWARD. AN ADDITIONAL SCENARIO EMERGES BY TAU 120. IF THE SECOND TROUGH IS WEAKER THAN PREDICTED OR THE WESTERN RIDGE BUILDS MORE STRONGLY, THE SYSTEM COULD CO…