krichard2011

  中度熱帶風暴  
   編號：07-20142015 ( 97 S → 08 S )    
   名稱：Diamondra



  基本資料   
　擾動編號日期：2015 年 01 月 23 日 14 時
　命名日期　　：2015 年 01 月 27 日 14 時
　轉化日期　　：2015 年 02 月 01 日 14 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
    法國氣象局 (MFR)：  45   kt
    美國海軍 (JTWC)  ：  45   kt  (   TS   )
    海平面最低氣壓　 ： 988 百帕

  過去路徑圖  
暫無
  討論帖圖片  

97S.INVEST.15kts-1010mb-15.5S-79.3E


以上資料來自：MFR、JTWC、颱風論壇整理製作

t02436

Over the far Eastern part of the basin : Geostat imagery shows a low near 15.1S / 82.0E at
1000Z. The 0400Z incomplete ASCAT swath indicates maximum associated winds at 10/15 kt and
locally 20 kt over the Southern semi-circle. Minimal pressure is estimated at 1006 hpa. The
Environmental conditions are expected to be good on Monday and Tuesday with a good low level
inflow, a weak to moderate vertical windshear and a good upper level divergence over the eastern
edge of the low. Therefore, the system should deepen significantly and move slowly Westwards
over the Northern edge of the low level ridge then curve Southwards towards a weakness in the
subtropical hight belt. But, from Wednesday the gradual increase of the Westwards vertical
windshear should limit its development. The last ECMWF ensemble forecast indicates a tropical
storm genesis likelihood higher than 90% from Monday to Wednesday.

The likelihood that this system becomes a Tropical Depression is high Monday and becomes
very high Tuesday.

JTWC提升評級至Medium

B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 15.6S 81.7E
IS NOW LOCATED NEAR 15.8S 81.3E, APPROXIMATELY 725 NM SOUTHEAST OF
DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS
INCREASED CONVECTION WRAPPING INTO A BETTER CONSOLIDATED LOW-LEVEL
CIRCULATION CENTER (LLCC). MICROWAVE IMAGERY FROM A 252055Z SSMIS
AND A 251957Z AMSR2 PASS SHOWS DEEP CURVED BANDING ALONG THE WESTERN
AND NORTHERN PERIPHERIES WRAPPING INTO THE LLCC. UPPER LEVEL
ANALYSIS INDICATES THAT THE SYSTEM IS STILL LOCATED IN A MARGINALLY
FAVORABLE ENVIRONMENT WITH LOW TO MODERATE VERTICAL WIND SHEAR (10
TO 20 KNOTS) OFFSET BY EXCELLENT EQUATORWARD OUTFLOW. THE SYSTEM IS
TRACKING WEST-SOUTHWEST ALONG THE SOUTHEASTERN PERIPHERY OF A LOW-
TO MID-LEVEL NEAR EQUATORIAL RIDGE. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 25 TO 30 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.

數值看好發展

t02436

MFR 06Z 編號擾動區7號
上望50KT

ZCZC 909
WTIO30 FMEE 260658
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 1/7/20142015
1.A ZONE OF DISTURBED WEATHER  7
2.A POSITION 2015/01/26 AT 0600 UTC:
WITHIN 30 NM RADIUS OF POINT 16.5 S / 79.4 E
(SIXTEEN    DECIMAL FIVE   DEGREES SOUTH AND SEVENTY NINE    DECIMAL
FOUR   DEGREES EAST)
MOVEMENT : WEST-SOUTH-WEST 11 KT
3.A DVORAK ANALYSIS: 1.5/1.5/D 0.5/12 H
4.A CENTRAL PRESSURE: 1003 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT
RADIUS OF MAXIMUM WINDS (RMW) :NIL
6.A EXTENSION OF WIND BY QUADRANTS (KM):
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 600 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : MEDIUM
1.B FORECASTS:
12H: 2015/01/26 18 UTC: 17.0 S / 78.1 E, MAX WIND=025 KT, TROPICAL
DISTURBANCE
24H: 2015/01/27 06 UTC: 17.4 S / 77.7 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
36H: 2015/01/27 18 UTC: 18.1 S / 78.0 E, MAX WIND=040 KT, MODERATE
TROPICAL STORM
48H: 2015/01/28 06 UTC: 18.7 S / 78.7 E, MAX WIND=050 KT, SEVERE
TROPICAL STORM
60H: 2015/01/28 18 UTC: 19.2 S / 79.5 E, MAX WIND=050 KT, SEVERE
TROPICAL STORM
72H: 2015/01/29 06 UTC: 19.8 S / 80.4 E, MAX WIND=040 KT, MODERATE
TROPICAL STORM
2.B LONGER-RANGE OUTLOOK :
96H: 2015/01/30 06 UTC: 21.8 S / 83.0 E, MAX WIND=030 KT, TROPICAL
DEPRESSION
120H: 2015/01/31 06 UTC: 24.0 S / 85.7 E, MAX WIND=025 KT, TROPICAL
DEPRESSION
2.C ADDITIONAL INFORMATIONS:
T=1.5 AND CI=1.5
METEOSAT7 SATELLITE IMAGERY REVEALS AN OBVIOUS IMPROVING CLOUD
PATTERN WITHIN THE LAST 24 HOURS AND DEEP CONVECTIVE ACTIVITY HAS
CONSOLIDATED NEAR THE CENTRE SINCE 25/0930Z.
0434Z ASCAT SWATH SHOWS MAXIMUM WINDS AT 20KT ALL AROUND THE
CIRCULATION AND WINDS UP TO 25KT OVER THE SOUTHERN AND NORTHERN
SECTORS.
ENVIRONMENTAL CONDITIONS ARE CONDUCTIVE FOR FURTHER INTENSIFICATION
ON MONDAY AND TUESDAY EXPERIENCING AN EFFICIENT LOW LEVELS INFLOWS ON
THE BOTH SIDES, A WEAK TO MODERATE VERTICAL WINDSHEAR AND A GOOD
DIVERGENCE EASTWARD UNDER THE UPPER LEVEL RIDGE.
THIS LOW IS EXPECTED TO SLOWLY SHIFT WEST-SOUTH-WESTWARDS UNDER THE
STEERING INFLUENCE OF THE LOW/MID LEVELS SUBTROPICAL RIDGE AND TO
TURN SOUTHWARDS THEN SOUTH-EASTWARDS TOWARDS A WEAKNESS IN THE
SUBTROPICAL BELT.
ON WEDNESDAY, THE GRADUAL WESTERLY VWS INCREASE SHOULD LIMIT THE
DEVELOPMENT.
LAST ECMWF ENSEMBLE COMPUTES 90 PER CENT PROBABILITY TO REACH
TROPICAL STORM STAGE FROM MONDAY TO FRIDAY.
ANOTHER LOW SHOULD DEEPEN MORE WESTERN WITHIN THE MONSOON TROUGH
DURING THE NEXT DAYS AND HIGH LEVELS RESPECTIVE INFLUENCES ONE TO THE
OTHER ONE (INDUCED VWS) REMAIN DIFFICULT TO QUALIFY BY THAT TIME.
CURRENT INTENSITY DOES NOT JUSTIFY ISSUANCE OF REGULAR WARNINGS.=
NNNN

krichard2011

對流爆發 JTWC 率先升格熱帶風暴
從衛星雲圖來看 結構相當不錯
所在風切目前也處於偏弱的情形
稍後命名的機會應該是算滿高的


JTWC初報上看TS上限

krichard2011

MFR命名 Diamondra
不過對流似乎有被切離情形
後期仍上看 STS

krichard2011

從紅外線雲圖看似很有規模
但底層對流切離的情形 依然相當嚴重
這部分還有待改善
幅散方面 南北流出還不錯
不過旁邊垂直風仍則是個阻礙
強度發展暫時受到限制
但GFS最新一報 轉向看好發展到不錯的強度
並且可能有雙強旋共存的機會

krichard2011

MFR稍微上調了Diamondra的強度
不過認為現在就是巔峰了
受限於垂直風切 底層一直無法順利整合起來
未來逐漸越往高緯的途中環境將越來越差
除了風切之外還有乾空氣入侵 不利於這個系統的增強
因此現在這個強度應該就是極限了

WTIO30 FMEE 280708
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 9/7/20142015
1.A MODERATE TROPICAL STORM 7 (DIAMONDRA)
2.A POSITION 2015/01/28 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 18.6 S / 79.3 E
(EIGHTEEN DECIMAL SIX DEGREES SOUTH AND SEVENTY NINE DECIMAL THREE
DEGREES EAST)
MOVEMENT : EAST-SOUTH-EAST 8 KT
3.A DVORAK ANALYSIS: 3.0/3.0/D 0.5/24 H
4.A CENTRAL PRESSURE: 988 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 45 KT
RADIUS OF MAXIMUM WINDS (RMW) :83 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 440 SE: 460 SW: 490 NW: 180
34 KT NE: 290 SE: 290 SW: 260 NW: 110
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1007 HPA / 900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION : UNKNOWN
1.B FORECASTS:
12H: 2015/01/28 18 UTC: 19.2 S / 80.0 E, MAX WIND=045 KT, MODERATE TROPICAL
STORM
24H: 2015/01/29 06 UTC: 20.0 S / 80.9 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
36H: 2015/01/29 18 UTC: 21.0 S / 81.9 E, MAX WIND=040 KT, MODERATE TROPICAL
STORM
48H: 2015/01/30 06 UTC: 22.2 S / 83.1 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
60H: 2015/01/30 18 UTC: 23.5 S / 84.6 E, MAX WIND=035 KT, MODERATE TROPICAL
STORM
72H: 2015/01/31 06 UTC: 24.9 S / 86.2 E, MAX WIND=035 KT, POST-TROPICAL
DEPRESSION
2.B LONGER-RANGE OUTLOOK :
96H: 2015/02/01 06 UTC: 27.7 S / 89.2 E, MAX WIND=050 KT, POST-TROPICAL
DEPRESSION
120H: 2015/02/02 06 UTC: 34.3 S / 91.6 E, MAX WIND=050 KT, EXTRATROPICAL SYSTEM 2.C ADDITIONAL INFORMATIONS:
T=3.0 AND CI=3.0

Meow

JTWC 發佈最後警報了，因為判定轉化為副熱帶氣旋。



WTXS31 PGTW 290900
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 08S (DIAMONDRA) WARNING NR 006//
RMKS/
1. TROPICAL CYCLONE 08S (DIAMONDRA) WARNING NR 006   
   02 ACTIVE TROPICAL CYCLONES IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   290600Z --- NEAR 20.8S 80.2E
     MOVEMENT PAST SIX HOURS - 160 DEGREES AT 05 KTS
     POSITION ACCURATE TO WITHIN 020 NM
     POSITION BASED ON CENTER LOCATED BY A COMBINATION OF
     SATELLITE AND SYNOPTIC DATA
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
   RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT
                            125 NM SOUTHEAST QUADRANT
                            140 NM SOUTHWEST QUADRANT
                            110 NM NORTHWEST QUADRANT
   REPEAT POSIT: 20.8S 80.2E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   291800Z --- 22.0S 81.0E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   SUBTROPICAL
    ---
REMARKS:
290900Z POSITION NEAR 21.1S 80.4E.
TROPICAL CYCLONE (TC) 08S (DIAMONDRA), LOCATED APPROXIMATELY 936 NM
SOUTH-SOUTHEAST OF DIEGO GARCIA, HAS TRACKED SOUTH-SOUTHEASTWARD
AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY DEPICTS DEMINISHING DEEP CONVECTION SHEARED
SOUTH-SOUTHEASTWARD OF A FULLY-EXPOSED LOW-LEVEL CIRCULATION
CENTER. A 290334Z ASCAT PASS REVEALS A 20 TO 25 KNOT CIRCULATION
WITH GALE FORCE WINDS EXTENDED ASYMMETRICALLY TO 100 NM FROM THE
CENTER AND STRONGER (UP TO 45 KNOTS) OVER THE SOUTHWESTERN QUADRANT.
BASED ON THE CURRENT ASSESSMENT, TC 08 IS CLASSIFIED AS A SUBTROPICAL
CYCLONE AND ASSUMES THE SUBTROPICAL CYCLONE CHARACTERISTICS.
THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON
WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z
IS 13 FEET. REFER TO TROPICAL CYCLONE 09S (EUNICE) WARNINGS
(WTXS32 PGTW) FOR TWELVE-HOURLY UPDATES.//
NNNN