陳約禮@FB

  三級強烈熱帶氣旋  
編號：17 F ( 20 P )
名稱：Amos


  基本資料  
擾動編號日期：2016 年 04 月 15 日 14 時
JTWC升格日期:2016 年 04 月 20 日 08 時
命名日期　　：2016 年 04 月 20 日 21 時
撤編日期　　：2016 年 04 月 26 日 08 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速 / 海平面最低氣壓
斐濟氣象局 (FMS)：80 kt
聯合颱風警報中心(JTWC)：90 kt ( CAT.2 )
海平面最低氣壓   ：965 百帕

  過去路徑圖  


  討論帖圖片  
90P.INVEST.20kts.1007mb.13.9S.174.3E



以上資料來自：FMS、JTWC、颱風論壇整理製作

t02436

FMS編號17F

TROPICAL DISTURBANCE 17F CENTRE [1005HPA] WAS LOCATED NEAR 14.05S
176.0E AT 150600UTC. TD17F SLOW MOVING. POSITION POOR. ORGANISATION
REMAINS POOR. CONVECTION CONTINUE TO FLUCTUATE OVER SUPPOSE LLCC.
SYSTEM LIES UNDER AN UPPER ANTICYCLONIC CIRCULATION IN A LOW SHEARED
ENVIRONMENT. SST IS AROUND 29 DEGREES CELSIUS. GLOBAL MODELS HAVE
PICKED UP THE SYSTEM AND MOVE IT WESTWARD THAN SOUTHWARDS WITH
GRADUAL INTENSIFICATION.

POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 24 TO 48 HOURS IS MODERATE.

JTWC直接評級Medium

B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION HAS PERSISTED NEAR 14.5S 175.0E,
APPROXIMATELY 240 NM NORTHWEST OF NADI, FIJI. ANIMATED ENHANCED
INFRARED SATELLITE IMAGERY DEPICTS A BROAD LOW-LEVEL CIRCULATION
CENTER WITH FRAGMENTED BANDING. A 151011Z METOP-B 89GHZ IMAGE SHOWS
FRAGMENTED, CURVED BANDING WRAPPING BROADLY INTO AN ILL-DEFINED
CENTER. UPPER-LEVEL ANALYSIS INDICATES A MARGINALLY-FAVORABLE
ENVIRONMENT WITH MODERATE VERTICAL WIND SHEAR OFFSET BY ENHANCED
POLEWARD OUTFLOW. DYNAMIC MODEL GUIDANCE INDICATES A GENERALLY
SOUTHEASTWARD TRACK TOWARD FIJI WITH GRADUAL INTENSIFICATION.
MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS.
MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS MEDIUM.

陳約禮@FB

04Z JTWC對90P發布TCFA

WTPS21 PGTW 180400
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
150 NM EITHER SIDE OF A LINE FROM 16.7S 176.9W TO 11.6S 175.5W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 27 TO 32 KNOTS. METSAT
IMAGERY AT 180000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 16.1S 176.9W. THE SYSTEM IS MOVING EAST-NORTHEASTWARD AT 07
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 17.4S
179.5E, IS NOW LOCATED NEAR 16.1S 176.9W, APPROXIMATELY 375 NM WEST-
SOUTHWEST OF PAGO PAGO, AMERICAN SAMOA. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS A CONSOLIDATING LOW LEVEL CIRCULATION
CENTER (LLCC) WITH LIMITED CENTRAL CONVECTION. A 162125Z AMSU-B
MICROWAVE IMAGE SHOWED A WELL DEFINED LLCC WITH THE ASSOCIATED
CONVECTION SHEARED JUST SOUTHEAST. A 162037Z ASCAT PASS FURTHER
ILLUSTRATED THE LLCC WITH 30 KNOT WINDS WRAPPING AROUND THE
SYMMETRIC LLCC AND ISOLATED 35 KNOT WINDS LOCATED WITHIN THE
CONVECTION TO THE SOUTHEAST. ENVIRONMENTAL ANALYSIS INDICATES A
MARGINAL BUT IMPROVING ENVIRONMENT WITH 15 TO 20 KNOT VERTICAL WIND
SHEAR AND STRONG POLEWARD DIVERGENCE. DYNAMIC MODEL GUIDANCE SHOWS
THE DISTURBANCE TRACKING NORTHEASTWARD INTO A LOW VWS ENVIRONMENT
WITH WEAK DEVELOPMENT. SEA SURFACE TEMPERATURES NEAR 30 CELSIUS ARE
CONDUCIVE FOR FURTHER DEVELOPMENT. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 27 TO 32 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1000 MB. BASED ON THE CURRENT STRUCTURE AND
IMPROVING ENVIRONMENT, THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
190400Z.//
NNNN

JTWC指出其LLCC已逐漸鞏固，極向流出持續優良，ASCAT在底層也掃出30KT的風速，是發佈TCFA的主因。




ITCZ輻合槽發展出來的低壓向來有環流過大，整合費時的弊病。不過經過將近一周的整合，LLCC已略有雛形。

環流依舊十分廣泛

比起FANTALA，90P所處的南太平洋季風槽十分活躍，水氣充足

目前風切雖不弱，但未來隨著90P朝向東北移動，風切有減弱趨勢，海溫也會上升到30度

陳約禮@FB

20日03Z，JTWC升格為20P

WTPS31 PGTW 200300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE WARNING//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI//180351ZAPR2016//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. TROPICAL CYCLONE 20P (TWENTY) WARNING NR 001   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   200000Z --- NEAR 13.1S 178.2W
     MOVEMENT PAST SIX HOURS - 285 DEGREES AT 10 KTS
     POSITION ACCURATE TO WITHIN 060 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   REPEAT POSIT: 13.1S 178.2W
    ---
   FORECASTS:
   12 HRS, VALID AT:
   201200Z --- 12.9S 179.0W
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 24 HR POSIT: 295 DEG/ 03 KTS
    ---
   24 HRS, VALID AT:
   210000Z --- 12.6S 179.6W
   MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 060 DEG/ 04 KTS
    ---
   36 HRS, VALID AT:
   211200Z --- 12.2S 178.9W
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT
                            045 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 080 DEG/ 06 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   220000Z --- 12.0S 177.6W
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 015 NM NORTHEAST QUADRANT
                            015 NM SOUTHEAST QUADRANT
                            015 NM SOUTHWEST QUADRANT
                            015 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
                            055 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            065 NM NORTHWEST QUADRANT
   VECTOR TO 72 HR POSIT: 100 DEG/ 06 KTS
    ---
   72 HRS, VALID AT:
   230000Z --- 12.4S 175.2W
   MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 025 NM NORTHEAST QUADRANT
                            030 NM SOUTHEAST QUADRANT
                            025 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
                            065 NM SOUTHEAST QUADRANT
                            060 NM SOUTHWEST QUADRANT
                            070 NM NORTHWEST QUADRANT
   VECTOR TO 96 HR POSIT: 125 DEG/ 08 KTS
    ---
   LONG RANGE OUTLOOK:
    ---
   96 HRS, VALID AT:
   240000Z --- 14.2S 172.6W
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   VECTOR TO 120 HR POSIT: 125 DEG/ 07 KTS
    ---
   120 HRS, VALID AT:
   250000Z --- 15.8S 170.1W
   MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
REMARKS:
200300Z POSITION NEAR 13.0S 178.4W. TROPICAL CYCLONE 20P (TWENTY),
LOCATED APPROXIMATELY 316 NM WEST OF AVATA SAMOA, HAS TRACKED WEST-
NORTHWESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. ANIMATED
MULTISPECTRAL SATELLITE IMAGERY DEPICTS DEEP CONVECTION
CONSOLIDATING AROUND A LOW-LEVEL CIRCULATION CENTER (LLCC) WHICH IS
CURRENTLY COVERED BY A CENTRAL DENSE OVERCAST (CDO). A 192043Z AMSU-
B 89GHZ IMAGE SHOWS THAT THE DEEP CONVECTION IS RESTRICTED TO THE
NORTHEASTERN QUADRANT OF THE SYSTEM WITH SOME MODERATE CONVECTIVE
BANDS BEGINNING TO FORM TO THE SOUTHEAST OF THE LLCC. THE
CORRESPONDING 192043Z ASCAT-B PASS INDICATES BROAD AREAS OF 20-25
KNOT WINDS BOTH NORTH AND SOUTH OF THE LLCC, WHILE AN EARLIER
191747Z WINDSAT PASS SHOWED A FEW 30-35 KNOT UNFLAGGED PLOTS. THE
INITIAL INTENSITY IS ASSESSED AT 30 KNOTS BASED ON DVORAK ESTIMATES
BETWEEN 30 AND 35 KNOTS FROM KNES AND PGTW RESPECTIVELY. UPPER-LEVEL
ANALYSIS INDICATES TC 20P IS CURRENTLY IN A MARGINALLY FAVORABLE
ENVIRONMENT WITH LOW-MODERATE (10 TO 20 KNOTS) VERTICAL WIND SHEAR
(VWS), MODERATE POLEWARD OUTFLOW AND SEA SURFACE TEMPERATURES (SSTS)
OF 30 DEG CELSIUS. TC 18P IS CURRENTLY TRACKING WEST-NORTHWESTWARD
UNDER THE INFLUENCE A TRANSIENT RIDGE TO THE SOUTH. BY TAU 24, THIS
RIDGE WILL WEAKEN AND SHIFT EASTWARD, ALLOWING THE NEAR EQUATORIAL
RIDGE (NER) TO BECOME THE DOMINATE STEERING MECHANISM, RESULTING IN
A TURN OF TC 20P BACK TO AN EASTWARD TRACK BY TAU 36. THROUGH THE
REMAINDER OF THE FORECAST PERIOD THE SYSTEM IS FORECAST TO TRACK
EAST THEN SOUTHEASTWARD UNDER THE INFLUENCE OF THE NER. TC 20P IS
FORECAST TO SLOWLY INTENSIFY OVER THE NEXT 24 HOURS, AS THE UPPER-
LEVEL ENVIRONMENT REMAINS MARGINAL DUE TO MODERATE VWS AND THE
ENTRAINMENT OF RELATIVELY DRY AIR FROM THE WEST. AFTER TAU 24, THE
MOISTURE ENVELOPE WILL IMPROVE, VWS WILL DECREASE AND OUTFLOW WILL
IMPROVE AS THE SYSTEM TAPS INTO THE UPPER-LEVEL WESTERLIES, ALLOWING
FURTHER INTENSIFICATION, BEFORE PEAKING AT 60 KNOTS BY TAU 72.
THROUGH THE REMAINDER OF THE FORECAST PERIOD, TC 20P WILL SLOWLY
WEAKEN AS IT ENCOUNTERS HIGHER VWS. DYNAMIC MODEL GUIDANCE IS IN
FAIRLY TIGHT AGREEMENT IN THE OVERALL TRACK BUT THERE IS HIGH
UNCERTAINTY IN THE TIMING AND LOCATION OF THE TURN BACK TOWARDS THE
EAST, THEREFORE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 200000Z IS 8 FEET. NEXT WARNINGS
AT 200900Z, 201500Z, 202100Z AND 210300Z. THIS CANCELS AND
SUPERSEDES REF A (WTPS22 PGTW 190400).//
NNNN

首報巔峰上望60KT，路徑方面，36小時後，將受近赤道脊影響被帶往東南，但老J也指出路徑的不確定性仍高，可信度低。


深層對流鞏固而CDO漸漸成形並覆蓋LLCC，部分區域WINDSAT更掃出了30-35KT的風域。目前環境尚優良，風切10-20KT，極向流出中等，海溫約30度。


環流已經緊縮

流出中等


強度方面，24小時內受中等風切及西側乾空氣影響而增強緩慢，隨後風切、濕度、流出改善，巔峰可上望60KT，直到朝向東南方遇上較強風切才緩慢減弱。

t02436

13Z命名Amos

TROPICAL DISTURBANCE ADVISORY NUMBER A5 ISSUED FROM RSMC NADI
Apr 201349 UTC.

TROPICAL CYCLONE AMOS CENTRE 995HPA WAS LOCATED NEAR 12.8S 179.8W AT
201200UTC. POSITION FAIR BASED ON HIMAWARI-8 IMAGERY AND PERIPHERAL
SURFACE REPORTS. AMOS MOVING WEST-SOUTHWEST AT ABOUT 04 KNOTS.
MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35
KNOTS.EXPECT SUSTAINED WINDS OF 35 KNOTS CLOSE TO THE CENTRE.

DEEP CONVECTION REMAINS PERSISTENT WITH BAND TRYING TO WRAP AROUND
LLCC. ORGANISATION HAS IMPROVED IN LAST 24 HOURS. CYCLONIC
CIRCULATION EXTENDS UP TO 500HPA. SYSTEM LIES IN A MODERATE UPPER
DIVERGENCE REIGION AND IN A LOW SHEARED ENVIRONMENT. SST AROUND 30
DEGREE CELCIUS.OUTFLOW GOOD TO THE SOUTH. DVORAK ANALYSIS BASED ON
0.55-0.6 WRAP YIELDS DT=3.0, MET AND PT AGREE. FT BASED ON DT. THUS,
YIELDING T3.0/3.0/D1.5/24HRS.

FORECASTS :
AT 12 HRS VALID AT 210000 UTC 12.8S 179.9E MOV W AT 02KT WITH 40 KT
CLOSE TO CENTRE
AT 24 HRS VALID AT 211200 UTC 12.6S 179.7W MOV ENE AT 02KT WITH 50 KT
CLOSE TO CENTRE.

OUTLOOK:
AT 36 HRS VALID AT 220000 UTC 12.3S 178.8W MOV ENE AT 05KT WITH 55 KT
CLOSE TO CENTRE
AT 48 HRS VALID AT 221200 UTC 12.3S 177.4W MOV E AT 06KT WITH 60 KT
CLOSE TO CENTRE.

THE NEXT TOPICAL DISTURBANCE ADVISORY ON AMOS WILL BE ISSUED AROUND
202000UTC.

tpm630

00z升評價65kts 升格cat1 底層畫質奇差都看的出已經建立





目前環境各方面還不錯 幅散 海溫都良
但南方風切非常強 發展時間估計還剩一天多

tpm630

JTWC 09Z分析T4.5 評價75節 巔峰上望Cat.3 (105kts)




高層風眼建立中 趁南落以前 藉良好高空幅散有爆發增強的機會

陳約禮@FB

底層風眼已經相當明顯

高層風眼也即將開啟