周子堯@FB

JTWC 風速提升至20kts,評級亦提升至Medium

(1) THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED
NEAR 21.0N 140.5E IS NOW LOCATED NEAR 21.8N 139.3E, APPROXIMATELY
208 NM SOUTHWEST OF IWO TO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY
(MSI) DEPICTS AN AREA OF LOW LEVEL TURNING WITH FLARING CONVECTION
IN THE SOUTHERN AND EASTERN PERIPHERIES. A 032345Z GPM 37 GHZ
MICROWAVE IMAGE REVEALS LIMITED LOW LEVEL FORMATIVE BANDING WITH
MULTIPLE POSSIBLE ROTATION CENTERS EMBEDDED WITHIN AN ELONGATED
TROUGH. INVEST 90W IS LOCATED IN AN ENVIRONMENT CONDUCIVE FOR
FURTHER DEVELOPMENT WITH GOOD EQUATORWARD OUTFLOW, LOW VERTICAL WIND
SHEAR (<15 KTS), AND WARM (29-30C) SEA SURFACE TEMPERATURES. THERE
IS HIGH UNCERTAINTY IN THE TRACK OF 90W, WITH GLOBAL ENSEMBLE MODEL
DEPICTING SIGNIFICANT SPREAD IN TRACK POSSIBILITIES, WITH A
BIFURCATION IN THE ECMWF AND GEFS ENSEMBLES THAT RANGE FROM EAST OF
HONSHU TO NORTHEAST OF TAIWAN. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.

老農民版夜神月

JMA00Z仍維持LPA(低壓帶),但預測今晚即將升格其為TD

megi

看了過去幾天的數值預報演變，基本上幾乎可以確定，明天的這波西風槽東移是不會拉走這個系統了

再來的關注焦點就是當高壓重新增強的脊場分布狀態
若是東邊的高壓較強，系統的移動路徑較偏北，或許到達琉球附近有機會被另一波西風槽帶走影響日本，又或者沒有西風槽加深並且東移直直地向著台灣北部到北部海面過來
若是西邊高壓較強，系統的移動路徑較偏南，有可能登陸台灣東南部或者穿越巴士海峽

我的看法是這個系統應該會是今年颱風對台灣有影響的最後機會了(其實我本來認為今年不會有颱風對台灣有影響了XD)

以上是小弟觀察的淺見，若有錯誤不吝指教，還望鞭小力點XD

蔡秉勳

megi 發表於 2020-10-4 15:08
看了過去幾天的數值預報演變，基本上幾乎可以確定，明天的這波西風槽東移是不會拉走這個系統了

再來的關注 ...

現在GFS和EC的決定性預報有蠻大的落差的，我個人是認為台灣上空的副高西環緯度比較低，不是一個颱風容易親台的配置，
颱風離開鞍型場後北方高壓重新連接的位置很關鍵
若在颱風北邊重新連接，甚至能給颱風一些偏南分量，並讓它持續西行金進台灣(EC)
相反的，若高壓在颱風南邊重新連接，就是往東北掰掰了(GFS)
短時間內颱風偏北少一點，前者就比校容易發生，反之亦然
以上是我個人的淺見

Heigo

JMA TD

Heigo

JTWC TCFA

THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED
NEAR 21.8N 139.3E IS NOW LOCATED NEAR 22.3N 139.1E, APPROXIMATELY
201 NM SOUTHWEST OF IWO TO. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY DEPICTS BUILDING, DEEP CONVECTION THAT HAS CONTINUED TO
CONSOLIDATE AND WRAP INTO AN OBSCURED LOW LEVEL CIRCULATION CENTER.
DESPITE THE CONSOLIDATING CONVECTION, THE LOW LEVELS REMAIN
DISORGANIZED AS EVIDENT IN RECENT MICROWAVE IMAGERY FROM 040404Z
AMSR2 36GHZ AND 040646Z SSMIS 37GHZ RETRIEVALS. FURTHERMORE, DATA
FROM A 032352Z ASCAT-A PASS REVEALS THAT THE LOW LEVEL CIRCULATION
REMAINS BROAD AND ELONGATED ALONG A NORTHEAST TO SOUTHWEST AXIS.
THE SCATTEROMETRY DATA FURTHER DEPICTS 10-15 KT WINDS ALONG THE
PERIPHERY OF THE LOW LEVEL CIRCULATION AND STRONGER, 20-30 KTS WINDS
DISPLACED > 100 NM TO THE SOUTHEAST. INVEST 90W IS TRACKING SLOWLY
NORTHWESTWARD AND THROUGH AN ENVIRONMENT CONDUCIVE FOR FURTHER
DEVELOPMENT WITH LOW (5-10 KT) VERTICAL WIND SHEAR, WARM (29-30
CELSIUS) SEA SURFACE TEMPERATURES AND ROBUST EQUATORWARD OUTFLOW
ALOFT. NUMERICAL MODEL SOLUTIONS ARE IN DISAGREEMENT OVER THE
OVERALL TRACK OF THE SYSTEM CENTER AND THERE IS A SIGNIFICANT
DIVERGENCE IN MODEL TRACK GUIDANCE. NAVGEM AND GFS SOLUTIONS PREDICT
A NORTH TO NORTHWESTWARD TRACK WHILE ECMWF AND UKMET CALCULATE
WESTWARD SOLUTIONS. ENSEMBLE MEMBERS IN BOTH GFS AND ECMWF SOLUTIONS
BIFURCATE, SUGGESTING BOTH MODELS CONSIDER THE DISPARATE
DETERMINISTIC SOLUTIONS. DESPITE THIS DISAGREEMENT IN MODEL
SOLUTIONS, THE SYSTEM IS EXPECTED TO TRACK GENERALLY NORTHWESTWARD
OVER THE NEXT 24 HOURS AS IT CONTINUES TO CONSOLIDATE IN THE
FAVORABLE ENVIRONMENT. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. SEE
REF A (WTPN21 PGTW 040900) FOR FURTHER DETAILS.

老農民版夜神月

最新雲圖及底層掃描,90W的北半側還是稍嫌弱了點
不過整體型態看上去已經有颱風的雛型,JMA晚間或凌晨可能就會發GW