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JTWC/01W/#19/01-19 06Z Prognostic Reasoning
WDPN31 PGTW 190900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 01W (NOKAEN) WARNING NR
019//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 16.7N 126.6E
INITIAL INTENSITY: 35 KTS
GEOGRAPHIC REFERENCE: 347 NM EAST-NORTHEAST OF MANILA,
PHILIPPINES
MOVEMENT PAST 6 HOURS: NORTHEASTWARD AT 01 KTS
SIGNIFICANT WAVE HEIGHT: 17 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS TROPICAL
STORM (TS) 01W (NOKAEN) WITH PERSISTENT FLARING CONVECTION
PARTIALLY OBSCURING THE LOW-LEVEL CIRCULATION CENTER (LLCC) WITH AN
ASSOCIATED CONVECTIVE BAND EXTENDING WESTWARD THROUGH THE NORTHERN
SEMICIRCLE. VERY DRY AIR HAS REMAINED EVIDENT SINCE THE PREVIOUS
WARNING, PRIMARILY THROUGHOUT THE WESTERN AND SOUTHERN QUADRANTS,
RESULTING LIMITED CONVECTION THROUGHOUT THE ENTIRE WESTERN
SEMICIRCLE. ALOFT, UPPER-LEVEL OUTFLOW HAS BECOME RELATIVELY WEAK
OVER THE LAST FEW HOURS, WITH A FRAGMENTED NORTHEASTWARD CHANNEL. THE
ENVIRONMENT HAS REMAINED MARGINALLY FAVORABLE, WITH WARM SEA
SURFACE TEMPERATURES (SST) OF 26-27 C, LOW VERTICAL WIND SHEAR
(VWS) BELOW 15 KTS, AND THE AFOREMENTIONED PRESENCE OF LARGE SWATHS
OF DRY AIR ENCIRCLING TS 01W. THE INITIAL POSITION HAS BEEN PLACED
WITH HIGH CONFIDENCE, BASED ON THE OBSERVABLE PARTIALLY OBSCURED
LLCC ON ANIMATED MSI. THE INITIAL INTENSITY HAS BEEN ASSESSED WITH
MEDIUM CONFIDENCE BASED ON AGENCY SUBJECTIVE INTENSITY ESTIMATES
RANGING FROM 25-35 KTS, AND CIMSS OBJECTIVE INTENSITY ESTIMATES
LISTED BELOW.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: SUBTROPICAL RIDGE (STR) CENTERED TO THE
EAST
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T2.0 - 30 KTS
RJTD: T1.5 - 25 KTS
RCTP: T1.5 - 25 KTS
KNES: T2.5 - 35 KTS
CIMSS SATCON: 35 KTS AT 190501Z
CIMSS ADT: 41 KTS AT 190530Z
CIMSS AIDT: 38 KTS AT 190530Z
CIMSS D-MINT: 26 KTS AT 190511Z
CIMSS D-PRINT: 28 KTS AT 190630Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 10-15 KTS
SST: 26-27 CELSIUS
OUTFLOW: WEAK 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: TS 01W IS FORECASTED TO CONTINUE NORTHEASTWARD
OVER THE NEXT 24 HOURS, ALONG THE NORTHWESTERN EXTENT OF THE STR
LOCATED DIRECTLY TO THE EAST AND SOUTHEAST. FOLLOWING TAU 24, THE
STR CENTERED OVER CAMBODIA AND VIETNAM WILL CONTINUE BUILDING
WESTWARD, BECOMING THE PRIMARY STEERING DRIVER FOR TS 01W. WHEN
THIS OCCURS, THE TRACK FOR TS NOKAEN WILL BECOME LARGELY SOUTHWARD
BETWEEN TAU 36 AND TAU 72 ALONG THE EASTERN PERIPHERY OF THE STR NOW
CENTERED DIRECTLY TO THE WEST. REGARDING INTENSITY, SLIGHT
INTENSIFICATION IS FORECASTED OVER THE NEXT 12 HOURS, AS TS 01W
ATTEMPTS TO MAINTAIN A MOIST CORE IN AN INCREASINGLY DRY
ENVIRONMENT. BETWEEN TAU 12 AND TAU 24, VWS IS FORECASTED TO
INCREASE TO MORE THAN 20 KTS, INITIATING A GRADUAL WEAKENING TREND.
FOLLOWING TAU 36, DRY AIR AND PERSISTENT UNFAVORABLE VWS
GREATER THAN 25 KTS WILL ERODE THE SYSTEMS CENTRAL VORTEX,
EXACERBATING THE TERMINAL WEAKENING PHASE TOWARD 25 KTS BY TAU 72.
BY TAU 72, TS 01W IS FORECASTED TO DISSIPATE AS A SIGNIFICANT
TROPICAL CYCLONE OVER WATER, FROM OVERWHELMING NON-CONDUCIVE
ENVIRONMENTAL INFLUENCES, INCLUDING VWS OVER 30 KTS, INCREASING DRY
AIR, AND LIMITED OUTFLOW ALOFT.
MODEL DISCUSSION: NUMERICAL MODEL TRACK GUIDANCE CONTINUES IN FAIR
AGREEMENT THROUGH THE INITIAL 12 HOURS OF THE FORECAST PERIOD,
WITH AN ASSOCIATED 37 NM CROSS-TRACK SPREAD. FOLLOWING TAU 12, JTWC
CONSENSUS MEMBERS BEGIN TO DIVERGE SIGNIFICANTLY DURING THE
EXPECTED APPROACH TOWARD THE RE-CURVE TRACK SOUTHWARD. THE
CROSS-TRACK SPREAD INCREASES TO 96 NM BY TAU 24, AND EVENTUALLY
TOWARD 451 NM BY THE END OF THE FORECAST PERIOD. ALTHOUGH THE
MAJORITY OF JTWC CONSENSUS SOLUTIONS ILLUSTRATE A SOUTHWARD TURN
FOLLOWING TAU 24, NAVGEM CONTINUES TO CHARACTERIZE THE TIGHTER
RECURVE SOLUTION, HOLDING THE WESTERN MOST TRACK, WHILE THE ECMWF
ENSEMBLE MEAN EXPECTS A COMPLETE DISSIPATION FARTHER NORTHWARD.
THEREFORE, THE JTWC TRACK FORECAST HAS BEEN PLACED WITH LOW
CONFIDENCE THROUGHOUT THE 72 FORECAST PERIOD DUE TO THE INCREASING
CROSS-TRACK SPREAD NEAR DISSIPATION. REGARDING INTENSITY, ALL
AVAILABLE INTENSITY MEMBERS SHOW A STEADY OR SLIGHT INTENSIFICATION
PHASE OVER THE NEXT 24 HOURS, WITH GRADUAL WEAKENING THEREAFTER.
DUE TO THE TIMING OF DISSIPATION NEAR TAU 72, THE JTWC INTENSITY
FORECAST WAS ASSESSED WITH MEDIUM CONFIDENCE.
FORECAST CONFIDENCE:
TRACK 00-72 HR: LOW
INTENSITY 00-72 HR: MEDIUM//
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楼主: 红豆棒冰冰
发表于 2026-1-19 14:40
发表于 2026-1-19 15:16
