霧峰追風者

WTPN21 PGTW 081530
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93W)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
220 NM EITHER SIDE OF A LINE FROM 12.6N 131.9E TO 17.7N 129.9E
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 30 TO 35 KNOTS. METSAT IMAGERY AT
081500Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.6N
131.9E. THE SYSTEM IS MOVING EAST-NORTHEASTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED
NEAR 12.4N 131.3E IS NOW LOCATED NEAR 12.6N 131.9E, APPROXIMATELY
351NM NORTH-NORTHWEST OF PALAU. THIS SYSTEM IS CURRENTLY CLASSIFIED
AS A MONSOON DEPRESSION WITH EXPANSIVE GALE-FORCE WINDS OVER THE
EASTERN PERIPHERY OF THE SYSTEM. THE GALE-FORCE WINDS ARE LOCATED
OVER 300NM FROM THE BROAD, POORLY-DEFINED SYSTEM CENTER. AS IS
TYPICAL WITH MONSOON DEPRESSIONS, ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY AND A 080928Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT
EXTENSIVE AREAS OF INTENSE DEEP CONVECTION OVER THE WESTERN,
SOUTHERN AND EASTERN PERIPHERIES WITH NO CENTRAL CONVECTION OVER THE
BROAD, POORLY-DEFINED LOW-LEVEL CIRCULATION. A 081025Z ASCAT-A
PARTIAL IMAGE REVEALS AN ELONGATED, WEAK CIRCULATION WITH 20-25 KNOT
WESTERLY WINDS OVER THE SOUTHERN SEMICIRCLE AND SHARP TROUGHING
EXTENDING NORTHEASTWARD INTO INVEST 94W, WHICH IS ROTATING AROUND
THE PERIPHERY OF INVEST 93W. UPPER-LEVEL ANALYSIS INDICATES A
MARGINAL ENVIRONMENT WITH CONVERGENT NORTHERLY FLOW OVER THE LLC AND
LOW TO MODERATE (10-20 KTS) VERTICAL WIND SHEAR. GLOBAL MODELS
INDICATE THAT THIS MONSOON DEPRESSION WILL STEADILY STRENGTHEN AS IT
TRACKS NORTHWARD TO NORTHWESTWARD OVER THE NEXT TWO DAYS. THE SYSTEM
IS EXPECTED TO GRADUALLY GAIN TROPICAL CYCLONE (WARM-CORE)
CHARACTERISTICS WITH IMPROVED CENTRAL CONVECTION AND A RADIUS OF
MAXIMUM WINDS LESS THAN 100NM. BASED ON THE PERIPHERAL WINDS IN
RECENT ASCAT IMAGERY, MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED
AT 30 TO 35 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE
NEAR 996 MB. 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
091530Z.//
NNNN

king111807

【別"再"被暴風圈騙了】

季風低壓的經典特性：外強內弱環流大。

把圓規颱風的風場掃描疊圖，

和氣象局與日本氣象廳定義的暴風圈疊在一起。

日本氣象廳定義的暴風半徑有９５０公里，

中央氣象局定義的暴風半徑僅１２０公里，

兩者差異甚大！

-

圖中紅色風標代表風場有達到７級風的區域，

可以發現若以氣象局定義的暴風圈而言，

強風區幾乎遠在暴風圈之外，

氣象局剛好把風速最弱的那圈框起來而已。

(氣象局框的範圍大概只有0~2級風，

真正的7級風離超遠...)

-

因此要特別提醒下週一~下週二，

圓規颱風最接近的時候，

北部、東部、恆春半島、外島、西部沿岸，

都要慎防９～１２級的強陣風(根據歐洲數值預報)，

尤其是北部和台灣海峽

受到地形效應、狹管效應和氣壓梯度影響的緣故，

風速會非常非常非常強。

-

至於能不能放颱風假，

就得看縣市首長們的智慧了，

以科學和風力條件的角度來說，

北部和澎湖應該是最有機會達到放假標準的，

但很可惜颱風假需要在颱風警戒區才有機會放

(↑暴風圈會摸過的地方)

然而以這次圓規颱風的個案來看，

除了氣象局定義的暴風圈大小值得討論外，

颱風的風場也會因為多種因素而有增強或減弱的狀況，

可能會發生警戒區外的風比警戒區還大的狀況，

用暴風圈來作為陸上警戒的依據是否合適呢？

如果比照日本氣象廳，

分別針對風力和雨量各有一套警戒標準，會不會更好呢？

發布時間｜2021.10.08 17:04

圖資來源｜ASCAT、中央氣象局、日本氣象廳

king111807

JTWC發布TCFA

WTPN22 PGTW 081930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94W)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/081521Z OCT 21//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 081530)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 17.1N 134.1E TO 19.2N 129.2E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 081800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.2N 133.5E. THE SYSTEM IS MOVING WESTWARD AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 15.6N 137.1E IS NOW LOCATED NEAR 17.2N 133.5E, APPROXIMATELY
680 NM EAST OF APARRI, PHILIPPINES. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC) WITH CONVECTION DISPLACED >90NM TO THE EAST, EXTENDING
EQUATORWARD. A 081657Z AMSR2 89GHZ SATELLITE IMAGE REVEALS LOW LEVEL
CLOUD LINES WRAPPING INTO THE LLCC, AND AN OVERALL ABSENCE OF
ORGANIZATION TO THE DEEP CONVECTION ASSOCIATED WITH THE SYSTEM.
INVEST 94W IS CURRENTLY EMBEDDED IN A BROAD MONSOON DEPRESSION WITH
LIGHT (<15 KNOTS) WINDS NEAR THE CENTER, AND A LARGE SWATH OF 25-30
KT WINDS DISPLACED >60 NM TO THE EAST. UPPER-LEVEL ANALYSIS
INDICATES A MARGINAL ENVIRONMENT WITH ROBUST POLEWARD OUTFLOW ALOFT
OVER THE MAIN CONVECTION, AND MODERATE TO HIGH (20-30 KTS) VERTICAL
WIND SHEAR. SEA SURFACE TEMPERATURES (SST) ARE FAVORABLE WITH WARM
(30-31C) AND HIGH OCEAN HEAT CONTENT (>100 KJ PER SQUARE CM). GLOBAL
MODELS INDICATE THAT THE TWO DOMINANT VORTEX CENTERS EMBEDDED IN THE
MONSOON DEPRESSION (INVESTS 93W AND 94W) WILL STEADILY ORBIT ONE
ANOTHER AND MERGE DUE TO THEIR CLOSE PROXIMITY (ABOUT 250 NM).
DURING THIS CONSOLIDATION PHASE, THE SYSTEM IS EXPECTED TO GRADUALLY
GAIN TROPICAL CYCLONE (WARM-CORE) CHARACTERISTICS WITH IMPROVED
CENTRAL CONVECTION AND A RADIUS OF MAXIMUM WINDS LESS THAN 100NM.
NUMERICAL MODELS FURTHER AGREE ON A SLOW, GENERALLY NORTHWESTWARD
TRACK OVER THE NEXT 24 TO 48 HOURS. IT REMAINS UNCLEAR WHICH STORM
WILL GAIN THE DOMINANT CENTER. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1000 MB. 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
091930Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 12.6N 131.9E.//
NNNN

霧峰追風者

WTPN22 PGTW 081930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 94W)//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/081521Z OCT 21//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 081530)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
140 NM EITHER SIDE OF A LINE FROM 17.1N 134.1E TO 19.2N 129.2E
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 081800Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 17.2N 133.5E. THE SYSTEM IS MOVING WESTWARD AT 12 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED
NEAR 15.6N 137.1E IS NOW LOCATED NEAR 17.2N 133.5E, APPROXIMATELY
680 NM EAST OF APARRI, PHILIPPINES. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION
CENTER (LLCC) WITH CONVECTION DISPLACED >90NM TO THE EAST, EXTENDING
EQUATORWARD. A 081657Z AMSR2 89GHZ SATELLITE IMAGE REVEALS LOW LEVEL
CLOUD LINES WRAPPING INTO THE LLCC, AND AN OVERALL ABSENCE OF
ORGANIZATION TO THE DEEP CONVECTION ASSOCIATED WITH THE SYSTEM.
INVEST 94W IS CURRENTLY EMBEDDED IN A BROAD MONSOON DEPRESSION WITH
LIGHT (<15 KNOTS) WINDS NEAR THE CENTER, AND A LARGE SWATH OF 25-30
KT WINDS DISPLACED >60 NM TO THE EAST. UPPER-LEVEL ANALYSIS
INDICATES A MARGINAL ENVIRONMENT WITH ROBUST POLEWARD OUTFLOW ALOFT
OVER THE MAIN CONVECTION, AND MODERATE TO HIGH (20-30 KTS) VERTICAL
WIND SHEAR. SEA SURFACE TEMPERATURES (SST) ARE FAVORABLE WITH WARM
(30-31C) AND HIGH OCEAN HEAT CONTENT (>100 KJ PER SQUARE CM). GLOBAL
MODELS INDICATE THAT THE TWO DOMINANT VORTEX CENTERS EMBEDDED IN THE
MONSOON DEPRESSION (INVESTS 93W AND 94W) WILL STEADILY ORBIT ONE
ANOTHER AND MERGE DUE TO THEIR CLOSE PROXIMITY (ABOUT 250 NM).
DURING THIS CONSOLIDATION PHASE, THE SYSTEM IS EXPECTED TO GRADUALLY
GAIN TROPICAL CYCLONE (WARM-CORE) CHARACTERISTICS WITH IMPROVED
CENTRAL CONVECTION AND A RADIUS OF MAXIMUM WINDS LESS THAN 100NM.
NUMERICAL MODELS FURTHER AGREE ON A SLOW, GENERALLY NORTHWESTWARD
TRACK OVER THE NEXT 24 TO 48 HOURS. IT REMAINS UNCLEAR WHICH STORM
WILL GAIN THE DOMINANT CENTER. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 1000 MB. 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
091930Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 12.6N 131.9E.//
NNNN

king111807

【圓規動態】

圓規颱風內戰持續中，

可以分為93W及94W兩個部分，

各自環流都很龐大，

颱風中心部分反而沒什麼雲系～

預計今天持續整合，

如果順利，明天就會逐步成一個系統，

就看誰比較厲害，取得主導權！

也因為圓規成長歷程較為特殊，

實際強風區域會比氣象局定義的７級風圈「大很多」，

即便沒有發布陸上颱風警報，

全台灣的大家還是要注意強風的威脅。

宜蘭、花蓮、臺東、基隆北海岸、台北東側、屏東，

將是本次強降雨熱區，做好防汛準備囉！

發布時間｜2021.10.09 13:09

圖資來源｜RAMMB、EC、GFS、JMA、CWB

t02436

15Z降評Medium

WTPN21 PGTW 091500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93W) CANCELLATION//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/081521ZOCT 21//
REF/B/JOINT TYPHOON WRNCEN PEARL HARBOR HI/081921ZOCT21//
REF/C/JOINT TYPHOON WRNCEN PEARL HARBOR HI/091353ZOCT21//
AMPN/REFS A, B, AND C ARE TROPICAL CYCLONE FORMATION ALERTS//
RMKS/
1. REMARKS: THE AREA OF CONVECTION (INVEST 93W) PREVIOUSLY LOCATED
NEAR 11.6N 129.0E, IS NOW LOCATED NEAR 13.3N 132.3E, APPROXIMATELY
382 NM NORTH-NORTHWEST OF PALAU. ENHANCED INFRARED IMAGERY DEPICTS
BROAD CONVECTION OBSCURING ANY SIGN OF A LOW LEVEL CIRCULATION. A
091302Z DIRECT ASCAT PASS SHOWS THE CIRCULATION HAS UNRAVELED AND
BECOME EMBEDDED IN A BROADER AND ELONGATED CIRCULATION ASSOCIATED
WITH 94W. ENVIRONMENTAL ANALYSIS INDICATES MARGINAL CONDITIONS FOR
DEVELOPMENT WITH GOOD EQUATORWARD OUTFLOW AND WARM (30C) SEA SURFACE
TEMPERATURES, OFFSET BY STRONG (25-30KT) VERTICAL WIND SHEAR. GLOBAL
MODELS ARE IN GOOD AGREEMENT THAT 93W WILL DIMINISH AS INVEST 94W
(REF B) BECOMES THE DOMINANT CYCLONE. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 15 TO 20 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 DOWNGRADED
TO MEDIUM. THIS CANCELS REF A.
2. SEE REF B FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 17.2N 133.5E. SEE REF C FOR DETAILS ON A TROPICAL
CYCLONE FORMATION ALERT LOCATED NEAR 16.6N 162.0E.//
NNNN

king111807

【颱風不直撲，影響反而更大】

圓規內部持續低壓混戰中，

但無論整合結果如何，強度已不是重點。

.

重點在於：

1.圓規颱風超大的環流範圍。

2.「內弱外強」的季風低壓特徵。

.

這直接導致了，

即使暴風圈預測不會碰到(或摸到恆春)，

但颱風最強的部份，卻會侵襲台灣！

-

最新的歐美模式預報，

即便，在最近台的確切時點上有差異，

但大致都落在「週一晚～週二早(11~12)」。

-

要特別提醒，週一～週二，

北部、東半部，受外圍環流影響，

風雨可能會相當有感，

尤其北北基，地形偏東風預測相當強，

目前看很可能吹到７～１０級陣風，

但因為很難有陸警，所以要提醒，

週二早上，台北人頂著風雨上班的機會可能不小...

.

另外台灣海峽上、西部沿海，

氣流受狹管效應加成，風力預測也強勁，

目前陣風預測更上看９～１２級，

提醒大家要小心。

-

這次僅西南部平地是感受小的地方，

不管怎樣，颱風在週三(13)就會快速遠離，

不會久待，這算是好消息囉～

霧峰追風者

JTWC 06Z升格，風力已達35kts。