|
|
楼主 |
发表于 2025-11-29 05:26
|
显示全部楼层
JTWC/33W/#17/11-28 18Z Prognostic Reasoning
WDPN31 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 33W (KOTO) WARNING NR
017//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
SUMMARY:
INITIAL POSITION: 12.9N 112.5E
INITIAL INTENSITY: 50 KTS
GEOGRAPHIC REFERENCE: 307 NM SOUTHEAST OF DA NANG, VIETNAM
MOVEMENT PAST 6 HOURS: NORTHWARD AT 02 KTS
SIGNIFICANT WAVE HEIGHT: 19 FEET
SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION:
TROPICAL STORM (TS) 33W CONTINUES TO DRIFT SLOWLY NORTHWARD, CAUGHT
IN A WEAK AND COMPETING STEERING PATTERN. THE PRIMARY DRIVER
PUSHING THE SYSTEM NORTHWARD IS THE RELATIVELY STRONGER STR TO THE
PRODUCING A SLIGHTLY ENHANCED STEERING GRADIENT ALONG THE EASTERN
SIDE OF THE SYSTEM, AND THE MODERATE MONSOONAL SOUTHWESTERLIES TO
THE EASTERN FLANK OF THE SYSTEM. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY INDICATES THAT OVER THE PAST 6-12 HOURS, THE
PREVIOUSLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) HAS TUCKED
BACK UP UNDER THE SOUTHERN EDGE OF A RECENTLY DEVELOPED CENTRAL
DENSE OVERCAST (CDO) FEATURE. HOWEVER, A 281749Z AMSR2 36GHZ
MICROWAVE IMAGE REVEALED THE WELL-DEFINED LLCC TO BE FURTHER SOUTH
THAN PREVIOUSLY ANALYZED, REQUIRING A LAST-MINUTE ADJUSTMENT IN THE
BEST TRACK POSITION. THE MICROWAVE IMAGE ALSO REVEALED WELL-DEFINED
CONVECTIVE BANDING FEATURES ALONG THE WESTERN PERIPHERY OF THE
CIRCULATION, WRAPPING INTO THE SOUTHERN PORTION OF THE INNER CORE,
THOUGH THE EASTERN SIDE IS MUCH WEAKER DUE TO THE PRESENCE OF
MID-LEVEL DRY AIR IN THAT PORTION OF THE CIRCULATION. THE INITIAL
POSITION IS ASSESSED WITH CONFIDENCE BASED ON THE ARCHER ANALYSIS
OF THE AMSR2 IMAGE. THE INITIAL INTENSITY IS ASSESSED WITH MEDIUM
CONFIDENCE, CONSISTENT WITH THE HIGHER AGENCY DVORAK CURRENT
INTENSITY ESIMATES NOTED BELOW. ENVIRONMENTAL CONDITIONS HAVE IN
GENERAL IMPROVED, WITH SHEAR DROPPING BELOW 10 KNOTS, HOWEVER
DEEP-LAYER OUTFLOW HAS WEAKENED AND SIGNIFICANT UPWELLING HAS
RESULTED IN MUCH COOLER SSTS IN VICINITY OF THE SLOW-MOVING SYSTEM.
INITIAL WIND RADII BASIS: PERSISTENCE
CURRENT STEERING MECHANISM: COMPETING STEERING PATTERN, CAUGHT
BETWEEN A SUBTROPICAL RIDGE (STR) OVER THE PHILIPPINE SEA AND AN
STR OVER SOUTHERN MYANMAR.
AGENCY DVORAK AND AUTOMATED FIXES:
PGTW: T3.0 - 45 KTS
RJTD: T3.5 - 55 KTS
RCTP: T3.0 - 45 KTS
KNES: T3.0 - 45 KTS
DEMS: T3.0 - 45 KTS
CIMSS SATCON: 50 KTS AT 281758Z
CIMSS ADT: 41 KTS AT 281730Z
CIMSS AIDT: 33 KTS AT 281730Z
CIMSS D-MINT: 37 KTS AT 281758Z
CIMSS D-PRINT: 37 KTS AT 281900Z
FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE
VWS: 5-10 KTS
SST: 25-26 CELSIUS
OUTFLOW: WEAK POLEWARD AND EQUATORWARD
OTHER FACTORS: DRY AIR ENTRAINMENT, PARTICULARLY ALONG THE
EASTERN FLANK.
ANALYSIS CONFIDENCE:
INITIAL POSITION: HIGH
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: AS IT IS SITUATED IN A WEAK AND COMPETING
STEERING PATTERN, THE TRACK FORECAST FOR TS 33W IS FRAUGHT WITH
UNCERTAINTY AND ERRATIC AND UNEXPECTED MOTION IS LIKELY OVER THE
NEXT DAY OR TWO. OVERALL, GLOBAL MODELS ARE IN AGREEMENT THAT OVER
THE NEXT DAY OR TWO, RIDGING WILL BUILD OVER LUZON AND ULTIMATELY
EXTEND ALONG A NORTHEAST-SOUTHWEST AXIS FROM BORNEO TO LUZON. A
LARGER BUT SLIGHTLY WEAKER RIDGE IS EXPECTED TO PERSIST OVER
SOUTHERN MYANMAR AT THE SAME TIME. THE NET RESULT IS THAT TS 33W
WILL TRACK VERY SLOWLY NORTHWARD AS THE STRONGEST STEERING GRADIENT
WILL FACE THE RIDGE TO THE EAST. AFTER TAU 48, THE RIDGE OVER LUZON
WILL SHIFT NORTHWESTWARD AND PUSH OUT INTO THE NORTHERN REACHES OF
THE SOUTH CHINA SEA, WHICH WILL BLOCK TS 33W FROM ANY FURTHER
NORTHWARD PROGRESSION AFTER TAU 48. AFTER REACHING AN INFLECTION
POINT AROUND TAU 48, THE RIDGING TO THE WEST OVER MYANMAR WILL COME
TO DOMINATE THE STEERING PATTERN, WITH THE PRIMARY AND STRONGEST
STEERING GRADIENT SHIFTING TO THE WEST SIDE OF TS 33W. THE SYSTEM
THEN RAPIDLY TURNS SOUTHWESTWARD, ACCELERATING THROUGH THE
REMAINDER OF THE FORECAST PERIOD. LANDFALL IS EXPECTED ALONG THE
COAST OF SOUTHERN VIETNAM BETWEEN TAU 96 AND TAU 120. IN TERMS OF
INTENSITY, UPPER-LEVEL CONDITIONS ARE SET TO IMPROVE SLOWLY OVER
THE NEXT 24 HOURS, WITH DECREASING SHEAR, IMPROVED OUTFLOW ALOFT
AND INCREASING MOISTURE. HOWEVER, THE SLOW MOVEMENT OF TS 33W AND
THE RESULTANT UPWELLING HAVE ROBBED IT OF AN ENERGY SOURCE, AND
UNTIL IT MOVES FAR ENOUGH AWAY FROM THIS UPWELLED COLD POOL, THE
LACK OF SUFFICIENT ENERGY WILL KEEP THE SYSTEM FROM INTENSIFYING TO
ANY SIGNIFICANT DEGREE. BY TAU 48, THE SYSTEM SHOULD HAVE MOVED
INTO SLIGHTLY WARMER WATERS, WHICH WILL ALLOW IT TO INTENSIFY
BRIEFLY. AS IT TURNS SOUTHWESTWARD HOWEVER, TS 33W WILL SUCCUMB TO
A SIGNIFICANT INFLUX OF DRY AIR AND INCREASINGLY EASTERLY SHEAR,
WHICH WILL WEAKEN IT THROUGH AND AFTER LANDFALL.
MODEL DISCUSSION: TRACK GUIDANCE IS WIDELY DISPERSED, ESPECIALLY
AFTER TAU 48 AS THE SYSTEM REACHES THE INFLECTION POINT IN ITS
TRACK. UP THROUGH TAU 48, ALL MODELS AGREE ON A SLOW NORTHWARD
TRACK. THE NAVGEM IS SITUATED ON THE FAR WESTERN AND NORTHERN EDGE
OF THE ENVELOPE, TRACKING THE LLCC ALL THE WAY INTO THE GULF OF
THAILAND BY THE END OF THE FORECAST. THE ECMWF-AIFS MEANWHILE TURNS
THE SYSTEM TO THE EAST, THEN SOUTHWESTWARD, POSITIONING IT ON THE
FAR EASTERN EDGE OF THE GUIDANCE PACKAGE. THE RESULTING SPREAD
BETWEEN OUTLIERS IS 550NM. THE REMAINDER OF THE CONSENSUS MEMBERS
ARE RELATIVELY EVENLY SPACED BETWEEN THE TWO OUTLIERS, GENERATING A
HIGH UNCERTAINTY IN THE FORECAST. THE JTWC FORECAST IS POSITIONED
NEAR THE CONSENSUS MEAN AND HEDGED SLIGHTLY TOWARDS THE ECMWF
DETERMINISTIC TRACKER. INTENSITY GUIDANCE IS SPLIT, WITH THE HAFS-A
AND HWRF DEPICTING WEAKENING FROM THE START OF THE FORECAST, WHILE
THE COAMPS-TC (BOTH VERSIONS) AND THE GFS SHOW INTENSIFICATION
AFTER TAU 24, UP TO 65 KNOTS AT TAU 48. THE JTWC FORECAST IS PLACED
NEAR OR SLIGHTLY ABOVE THE CONSENSUS MEAN THROUGH THE FORECAST
PERIOD.
FORECAST CONFIDENCE:
TRACK 00-72 HR: MEDIUM
TRACK 72-120 HR: LOW
INTENSITY 00-72 HR: MEDIUM
INTENSITY 72-120 HR: LOW//
NNNN
|
本帖子中包含更多资源
您需要 登录 才可以下载或查看，没有账号？立即注册
×
|
楼主: ygsj24
发表于 2025-11-29 04:13
发表于 2025-11-29 05:42
