|
|
楼主 |
发表于 2025-7-3 16:40
|
显示全部楼层
JTWC/04W/#07/07-03 06Z Prognostic Reasoning
WDPN31 PGTW 030900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 04W (MUN) WARNING NR
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 27.6N 145.4E
INITIAL INTENSITY: 50 KTS
GEOGRAPHIC REFERENCE: 173 NM EAST OF CHICHI JIMA
MOVEMENT PAST 6 HOURS: NORTHWARD AT 06 KTS
SIGNIFICANT WAVE HEIGHT: 20 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 04W HAS MAINTAINED A COMPLEX UPPER-LEVEL OUTFLOW
PATTERN, WITH AN UPPER-LEVEL CYCLONE POSITIONED OVER THE CENTER AND
STRONG EASTWARD, DIFFLUENT OUTFLOW ENHANCED BY A JET TO THE NORTHEAST.
THE PRESENCE OF THE UPPER-LEVEL LOW AND DRY AIR ENTRAINMENT WITHIN THE
CORE OF THE SYSTEM IS HINDERING CONVECTIVE DEVELOPMENT. DESPITE THIS
LIMITATION, ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS TIGHTLY
WRAPPED LOW-LEVEL BANDING AND A WELL-DEFINED LOW-LEVEL CIRCULATION
CENTER SUPPORTING THE INITIAL POSITION WITH HIGH CONFIDENCE. THE
INITIAL INTENSITY IS ASSESSED AT 50 KNOTS BASED ON THE PGTW AND KNES
DVORAK ESTIMATES, WHICH ARE CONSISTENT WITH RECENT ASCAT UHR DATA
SHOWING A PATCH OF 50-55 KNOT WINDS. CIMSS OBJECTIVE ESTIMATES REMAIN
TOO LOW, RANGING FROM 33-39 KNOTS. AS INDICATED IN THE DYNAMIC MODELS,
THE CORE IS EXPECTED TO MOISTEN AND CONSOLIDATE WITHIN THE NEXT 12
HOURS, WHICH IS EXPECTED TO LEAD TO A SHARPER INTENSIFICATION RATE.
OVER THE PAST FEW HOURS, THERE APPEARS TO BE SOME EVIDENCE THAT THIS
IS COMMENCING, WITH ANIMATED INFRARED SATELLITE IMAGERY REVEALING
BETTER ORGANIZED CORE CONVECTION, WITH CLOUD TOP TEMPERATURES NEAR
-59C.
INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK
CURRENT STEERING MECHANISM: EXTENSIVE DEEP-LAYERED SUBTROPICAL RIDGE
(STR) PATTERN TO THE SOUTH, EXTENDING NORTHEASTWARD OVER THE EASTERN
PERIPHERY OF THE SYSTEM, WITH A WEAK STR EXTENSION TO THE NORTHEAST.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T2.0 - 30 KTS
RCTP: T2.5 - 35 KTS
KNES: T3.5 - 55 KTS
CIMSS ADT: 33 KTS AT 030530Z
CIMSS AIDT: 37 KTS AT 030530Z
CIMSS D-MINT: 38 KTS AT 030348Z
CIMSS D-PRINT: 39 KTS AT 030530Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE
VWS: 5-10 KTS
SST: 27-28 CELSIUS
OUTFLOW: STRONG EASTWARD
OTHER FACTORS: DRY AIR ENTRAINMENT OVER THE WESTERN SEMICIRCLE
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 04W IS FORECAST TO TRACK NORTHWARD THROUGH
TAU 24 ALONG THE WESTERN PERIPHERY OF THE STR. AFTER TAU 24, THE
SYSTEM IS EXPECTED TO TURN SHARPLY NORTHEASTWARD AS THE STR REORIENTS
IN RESPONSE TO AN APPROACHING SHORTWAVE TROUGH OVER NORTHERN JAPAN.
THE SHORTWAVE TROUGH WILL RAPIDLY PROPAGATE EASTWARD ALLOWING THE STR
TO REBUILD, WHICH WILL DRIVE THE SYSTEM ON A MORE POLEWARD TRAJECTORY
THROUGH TAU 120. AS ALLUDED TO EARLIER, ENVIRONMENTAL CONDITIONS ARE
EXPECTED TO IMPROVE, WHICH SHOULD SUPPORT A SHORT PERIOD OF
INTENSIFICATION, DRIVEN LARGELY BY THE ROBUST EASTWARD OUTFLOW, WITH A
PEAK INTENSITY OF 70 KNOTS FORECAST BY TAU 48. SST VALUES WILL COOL
STEADILY FROM TAU 36 TO TAU 120, WITH VALUES DECREASING TO ABOUT 25C
BY TAU 48 THEN STEADILY DOWN TO 20-21C BY TAU 120. THEREFORE, THE
TIMING OF THE PEAK INTENSITY MAY OCCUR EARLIER. AFTER TAU 72,
ENVIRONMENTAL CONDITIONS WILL DEGRADE QUICKLY, WITH INCREASING
VERTICAL WIND SHEAR (VWS) OF 25-30 KNOTS AFTER TAU 96, WHICH WILL LEAD
TO RAPID WEAKENING. THE SYSTEM IS EXPECTED TO TRANSITION TO A
SUBTROPICAL SYSTEM NEAR TAU 120.
MODEL DISCUSSION: DUE TO THE COMPLEX STEERING ENVIRONMENT AND RUN-TO-
RUN INCONSISTENCIES, THERE IS MEDIUM CONFIDENCE IN THE JTWC TRACK
FORECAST THROUGH TAU 72. THERE IS A 150NM CROSS-TRACK SPREAD IN THE
GUIDANCE AT TAU 72, HOWEVER, THERE ARE SIGNIFICANT DIFFERENCES IN THE
ALONG-TRACK SPEEDS. THE 030000Z GEFS RUN, IN PARTICULAR, INDICATES
A WIDE SWATH OF SOLUTIONS FROM CENTRAL JAPAN TO 160E. THE GFS
DETERMINISTIC MODEL HAS JUMPED AROUND ERRATICALLY THE PAST TWO RUNS,
AND NOW SHOWS A DISSIPATING, WEAK SYSTEM TRACKING TOWARD MAINLAND
JAPAN. ALTHOUGH THERE ARE ROUGHLY SIX ECENS SOLUTIONS TRACKING TOWARD
MAINLAND JAPAN, THE BULK OF THE ECENS GUIDANCE SUPPORTS A MORE
POLEWARD ORIENTED TRACK. RELIABLE INTENSITY GUIDANCE IS MORE COHESIVE,
WITH THE BULK OF THE GUIDANCE SHOWING A BRIEF INTENSIFICATION PERIOD
FROM TAU 24 TO TAU 60. HAFS-A INDICATES A PEAK INTENSITY OF 88 KNOTS
BY TAU 60 WHILE COAMPS-TC (GFS) SHOWS A PEAK OF 80 KNOTS BY TAU 84.
DUE TO HIGH UNCERTAINTY AFTER TAU 72, THERE IS LOW CONFIDENCE IN THE
EXTENDED JTWC FORECAST TRACK.
FORECAST CONFIDENCE:
TRACK 0 - 72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 0 - 72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN |
|
楼主: ygsj24
