zjk369

GFS估計梅莎強度達強烈颱風

04W FOUR
As of 18:00 UTC Mar 26, 2015:


Location: 6.7°N 158.8°E
Maximum Winds: 20 kt
Minimum Central Pressure: 1008 mb

Meow

啼吸誒腐誒來了



WTPN21 PGTW 261030
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
200 NM EITHER SIDE OF A LINE FROM 5.8N 162.3E TO 8.0N 155.4E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 260900Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 6.2N 160.9E. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 06
KNOTS.
2. REMARKS: THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 6.2N
160.9E IS NOW LOCATED NEAR 6.5N 160.1E, APPROXIMATELY 115 NM EAST OF
POHNPEI. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A
LARGE AREA OF CONVECTION WITH FORMATIVE BANDING OVER THE NORTHERN
SEMI-CIRCLE WRAPPING INTO A SLOWLY-DEVELOPING LOW-LEVEL CIRCULATION
CENTER (LLCC). A 260853Z SSMIS MICROWAVE IMAGE REVEALS DEEPENED
CENTRAL CONVECTION WITH BROKEN CONVECTIVE BANDS WRAPPING INTO THE
LLCC. UPPER-LEVEL ANALYSIS INDICATES THE DISTURBANCE IS LOCATED IN
AN AREA OF LOW TO MODERATE (10 TO 20 KNOT) VERTICAL WIND SHEAR
OFFSET BY GOOD POLEWARD OUTFLOW. ADDITIONALLY, WARM SEA SURFACE
TEMPERATURES ARE CONDUCIVE FOR DEVELOPMENT. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL
PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. DUE TO INCREASED
CONVECTION AND IMPROVED ORGANIZATION, 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
271030Z.//
NNNN

丹尼兒

zjk369 發表於 2015-3-26 15:56
GFS預測4月8日5號海神和6號紅霞同時生成

EC倒是預測繼梅莎生成後 4/4~4/5間海神颱風有機會誕生 有機會成雙颱的局面

zjk369

GFS預測4月8日5號海神和6號紅霞同時生成

ben811018

日本氣象廳已升格為熱帶性低氣壓，不過以最新資料來看，９８Ｗ低層環流結構仍差，組織依舊散亂，雖然環流中心有逐漸建立趨勢，不過尚無穩定的深層對流發展，還需時間持續整理。


９８Ｗ目前位於遠洋低緯度海域，繼續沿著高壓邊緣偏西進行，將在下週靠近菲律賓東南方海域，後期路徑變數仍高，有待觀察。

t02436

JMA升格熱帶低壓

TROPICAL DEPRESSION 1010 HPA AT 06N 161E WEST 10 KT.

krichard2011

LLCC 目前似乎有裸露的情形
風切的影響目前應該算是有的
環境暫時有待改善

krichard2011

---這篇可能有點離題---
對於GFS是否為1分鐘平均 對此我趕到疑惑
氣壓與風速之間的對應則說不過去
理論上一分鐘平均風速 100 KT 氣壓應該會落在 948~944百帕之間
但GFS預測卻達到 930 百帕左右

長期觀察GFS數值模式發現
無論熱帶氣旋是 C5 以上
GFS的初始場 並不會達到140 KT 以上
對此我調了前幾個星期 Pam 3月13日00Z 的GFS初始場為例
此時JTWC將Pam 評價140KT
為了方便說明 我將 57.6 m/s 區間用呈白色
由此可知 此初始場所預測的最大風速約為 57.6 m/s ≒ 110 KT


再調3月9日18Z +102小時的GFS預測圖
圖中所預測最大風速122KT 然而中心氣壓卻低達866hPa
然而換算為 CI 的話 約在 7.5 ~ 8 之間
CI = 8 以舊式得法的話 對應氣壓 859 百帕 一分鐘風速理應 160~170 KT
相較之下 CI 8 十分鐘風速 125 KT 相對合理


以上我的淺見