96W
http://www.metoc.navy.mil/jtwc/products/wp9618web.txt
http://www.metoc.navy.mil/jtwc/products/wp9618.gif
WTPN22 PGTW 211300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/210721Z JUL 18//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN21 PGTW 210730)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
240 NM EITHER SIDE OF A LINE FROM 11.6N 140.8E TO 17.2N 137.9E
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 18 TO 23 KNOTS. METSAT
IMAGERY AT 211200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 11.6N 140.5E. THE SYSTEM IS MOVING WESTWARD AT 07 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED
NEAR 11.4N 141.1E, IS NOW LOCATED NEAR 11.6N 140.5E, APPROXIMATELY
190 NM NORTHEAST OF YAP. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS A LOW LEVEL CIRCULATION WITH PERSISTENT CONVECTION AND
LOW LEVEL BANDING BEGINNING TO WRAP INTO THE CENTER. A 210837Z 91GHZ
SSMIS MICROWAVE IMAGE DEPICTS A LOW LEVEL CIRCULATION WITH
PERSISTENT DEEP CONVECTION LOCATED OVER THE CENTER AND SHALLOW
CONVECTION PRIMARILY TO THE SOUTH AND SOUTHEAST. THE DISTURBANCE IS
CURRENTLY LOCATED IN AN AREA OF EXCELLENT EQUATORWARD DIVERGENCE,
LOW (5-10 KNOTS) VERTICAL WIND SHEAR, AND WARM SEA SURFACE
TEMPERATURES (29-30 CELSIUS). GLOBAL MODELS ARE IN AGREEMENT THAT
THE SYSTEM WILL TRACK IN A NORTHERLY DIRECTION AND INTENSIFY OVER
THE NEXT FEW DAYS. SOME MODELS ARE NOT IN AGREEMENT AS TO THE EXACT
TRACK THE SYSTEM WILL TAKE, SHOWING A NORTH-NORTHWESTERN OR
NORTHWESTERN TRACK, WITH A FEW OUTLIERS TAKING THE SYSTEM TO THE
NORTHEAST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 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
221300Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 20.9N 105.6E.//
NNNN
过去的图像显示系统开始有深层对流卷入中心，
此外，系统身处的环境有着极优秀的赤向流出，
极低的垂直风切和29~30度的炎热海温，是促使系统继续发展进而发布TCFA的依据。
全球模式认为系统数天内会向北移动，但其余部分模式仍不明朗，
呈现北北西至西北预测的同时，亦出现朝向东北移动的少数预测路径。
==============================================================================
97W
http://www.metoc.navy.mil/jtwc/products/wp9718web.txt
http://www.metoc.navy.mil/jtwc/products/wp9718.gif
WTPN21 PGTW 211700
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/JOINT TYPHOON WRNCEN PEARL HARBOR HI/211251Z JUL 18//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTPN22 PGTW 211300)//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
160 NM EITHER SIDE OF A LINE FROM 20.9N 159.4E TO 26.0N 159.4E
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 211200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 21.2N 159.3E. THE SYSTEM IS MOVING NORTHEASTWARD AT 06 KNOTS.
2. REMARKS: THE AREA OF CONVECTION (INVEST 97W) PREVIOUSLY LOCATED
NEAR 20.3N 159.8E IS NOW LOCATED NEAR 21.2N 153.3E, APPROXIMATELY
430NM WEST-NORTHWEST OF WAKE ISLAND. ANIMATED ENHANCED INFRARED
SATELLITE IMAGERY AND A 211050Z 89GHZ AMSU MICROWAVE IMAGE DEPICT A
PARTIALLY EXPOSED LLCC WITH A LARGE MASS OF PERSISTENT DEEP
CONVECTION NORTH AND EAST OF THE CENTER. THE LLCC IS CURRENTLY UNDER
A REGION OF LOW (5-10 KNOT) VWS WITH INCREASING SHEAR VALUES TO THE
NORTHEAST. A POLEWARD OUTFLOW CHANNEL IS CREATING STRONG DIVERGENCE
ALOFT, HOWEVER SOME UL INFLOW FROM THE SOUTHWEST IS STIFLING
CONVECTION ALONG THE SOUTHWEST OF THE SYSTEM. SSTS ARE VERY WARM (28-
30 CELSIUS) IN THE NORTHWEST PACIFIC AND WILL SUPPORT FURTHER
DEVELOPMENT. GLOBAL MODELS ARE IN STRONG AGREEMENT ON TRACK, KEEPING
THE SYSTEM TRAVELLING NORTH OVER THE NEXT FEW DAYS AND REACHING
TROPICAL DEPRESSION STRENGTH BY TAU 24. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1005 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
221700Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 11.6N 140.5E.//
NNNN
AMSU显示LLCC虽呈现局部外露，但系统北侧与东侧已经有深对流发展，
系统所处环境垂直风切微弱，惟东北侧有加强趋势，
系统有优秀的极地方向流出，不过西南方向的辐合有些受阻。
大范围高达28~30度的海表面温度供应系统持续发展的能量，
全球模式具有高度信心认为系统会向北移动并于7/24前增强为热带性低气压，
综合这些资讯而发布TCFA。
==============================================================================
整理一下目前的系统和观察重点
11W&12W&13W
11W（山神）︰
JTWC-TD JMA-TD CWB-TD
似乎受到季风槽带动的影响，目前已从越南出海返回北部湾再次增强
虽然一度减弱至LPA（低压区），
但从各机构目前的预报资讯应该仍会继续判定为同一系统
路径方面虽然不受到安比直接影响，但可能受到安比改变驶流配置再度出现大回转。
12W（安比）︰
各机构皆评价相当于TS上限至STS下限之强度
路径已经明朗，做为11W&12W&13W间交互作用的主导者，
接下来的速度是关键，近期有加速趋势。
13W（可能的悟空）︰
JTWC-TD JMA-TD（发GW） CWB-TD（有发展轻台趋势）
系统距离台湾的远近取决于安比的速度，安比速度越快13W将离台湾越近北上，
以贴近石垣岛北上为主流，而老J的第3报仍有比前2报西修的趋势。
96W&97W
数值目前认为此两系统发生藤原的机率不大，
但若96W往东北跑，似乎会和下一个从菲东季风槽诞生的产物藤原。
有类似和安比一样从东北到西北大回转带动后续发展的系统跟随的可能。