Tropical Storm MALOU Advisory 10月26日

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 25W (MALOU) WARNING NR
008//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
   INITIAL POSITION: 19.5N 138.1E
   INITIAL INTENSITY: 40 KTS
   GEOGRAPHIC REFERENCE: 364 NM SOUTH-SOUTHWEST OF IWO TO
   MOVEMENT PAST 6 HOURS: NORTHWARD AT 08 KTS
   SIGNIFICANT WAVE HEIGHT: 18 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A BROAD
CIRCULATION WITH DEEP CONVECTIVE BANDING WRAPPING INTO A LOW LEVEL
CIRCULATION CENTER (LLCC) AND A DEVELOPING OUTFLOW CHANNEL TO THE
NORTH. FURTHER WATER VAPOR ANALYSIS REVEALS RELATIVELY DRY AIR IS
BEING INTRODUCED FROM THE NORTHWEST AND IS WRAPPING INTO THE CENTER.
THE INITIAL POSITION IS BASED ON A PARTIAL 251755Z GMI 37GHZ IMAGE
AND THE PGTW POSITION FIX. THE INITIAL INTENSITY IS BASED ON A BLEND
OF MULTIPLE DVORAK AND OBJECTIVE SATELLITE INTENSITY ESTIMATES.
INITIAL WIND RADII BASIS: SCATTEROMETER DATA
CURRENT STEERING MECHANISM: WESTERN PERIPHERY OF A BUILDING
SUBTROPICAL RIDGE POSITIONED TO THE EAST-NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
   PGTW: T2.5 - 35 KTS
   RJTD: T2.5 - 35 KTS
   KNES: T3.0 - 45 KTS
   CIMSS SATCON: 45 KTS AT 251612Z
   CIMSS ADT: 34 KTS AT 251430Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
   VWS: 10-15 KTS
   SST: 28-29 CELSIUS
   OUTFLOW: MODERATE POLEWARD
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: TROPICAL STORM 25W (MALOU) HAS ROUNDED THE
RIDGE AXIS AND BEGUN ITS TURN TO THE NORTH-NORTHEAST IN THE WAKE OF
A BAROCLINIC LOW PRESSURE SYSTEM LOCATED SOUTH OF HONSHU. TS 25W
WILL REMAIN IN A FAVORABLE ENVIRONMENT UNTIL TAU 72. THE SYSTEM WILL
CONTINUE TO DEEPEN UNTIL REACHING A PEAK INTENSITY OF 80 KTS DUE TO
INCREASING POLEWARD OUTFLOW. SHORTLY AFTERWARD INTERACTING WITH THE
BAROCLINIC ZONE, COOLING SEA SURFACE TEMPERATURES AND INCREASING
VERTICAL WIND SHEAR WILL BEGIN TO WEAKEN THE SYSTEM AS IT UNDERGOES
EXTRATROPICAL TRANSITION (ETT). TS 25W WILL COMPLETE ETT BY TAU 96
AS IT BECOMES FURTHER EMBEDDED IN THE BAROCLINIC ZONE AND WEAKENS IN
INTENSITY.
MODEL DISCUSSION: NUMERICAL MODELS ARE IN GOOD AGREEMENT THAT TS
25W (MALOU) WILL CONTINUE ON A NORTH-NORTHEASTWARD TRACK, FOLLOWED
BY A TURN TO THE NORTHEAST AFTER TAU 36. AT TAU 48, THE MODEL CROSS-
TRACK SPREAD IS 70 NM, GRADUALLY SPREADING TO 170 NM BY TAU 96,
LENDING TO HIGH CONFIDENCE IN THE FORECAST TRACK TO TAU 72, BECOMING
MEDIUM CONFIDENCE BY TAU 96. IN ADDITION, THE MODELS ARE IN BETTER
AGREEMENT IN REGARDS TO TRACK SPEED THAN PREVIOUS RUNS, WITH NAVGEM
BEING THE OUTLIER AS IT APPEARS TO LAG BEHIND THE OTHER CONSENSUS
MEMBERS. NUMERICAL MODELS ARE IN GOOD AGREEMENT IN REGARDS TO THE
INTENSITY GUIDANCE WITH MOST MODELS SHOWING A PERIOD OF STEADY
INTENSIFICATION PEAKING AROUND TAU 72 AT ABOUT 70-85 KTS FOLLOWED
BY A WEAKENING TREND FOR THE REMAINDER OF THE FORECAST PERIOD.
FORECAST CONFIDENCE:
   TRACK 0 - 72 HR: HIGH
   TRACK 72-120 HR: MEDIUM
   INTENSITY 0 - 72 HR: HIGH
   INTENSITY 72-120 HR: MEDIUM//
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