本帖最後由 krichard2011 於 2014-10-1 23:16 編輯 雖然發展的還算不錯 只是風眼沒有開得很成功 現在已近乎消散 也被NHC撤掉了 可惜沒什麼人關心她 就這樣默默退場了 覺得它有點可憐 ˇˇ 最後還是來發一下VIRRS的衛星影像吧... 不過老實說 從可見光來看的話 她這副模樣還挺美的 有另一種美感... |
上到75kts了 小鋼炮一隻: |
經過了一段時間的整合 結構終於像樣多了 連底層風眼都快要轉出來了 為OHC以經不是很高 加上西北側的乾空氣 要增強倒多強應該是多少受到限制了... 不過如果真的開眼說不定能挑戰一下 C1~C2左右的強度 |
本帖最後由 krichard2011 於 2014-9-25 23:04 編輯 相較於昨天深層對流 沒有完全覆蓋於中心附近的問題 最近幾張可見光雲圖 大致可以看出結構已有明顯改善 強度稍早NHC也提升至45KT 上看TS上限 路徑上處於低風切海溫也還算支持 不過北方的乾空氣也算是一個變數... TROPICAL STORM RACHEL DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL EP182014 800 AM PDT THU SEP 25 2014 The northeasterly shear that has been affecting the cyclone during the past day or so appears to be decreasing, with the center of Rachel now located beneath the cold cloud tops. Dvorak intensity estimates from both TAFB and SAB support an initial wind speed of 45 kt for this advisory. The shear is expected to further decrease over the next 24 to 36 hours and additional strengthening is likely during this period. The new NHC intensity forecast is above the previous forecast and close to the SHIPS/LGEM guidance. After 48 hours, Rachel will be moving over slightly cooler water and into a drier airmass, which should cause steady weakening late in the forecast period. A recent SSMIS overpass was very helpful in locating the center this morning. The fixes indicate an initial motion of 295 degrees at about 11 kt. Rachel should continue moving west-northwestward to the south of a mid-level ridge over Mexico during the next 24 to 36 hours. After that time, a trough approaching the west coast of the United States will create a break in the ridge which should cause Rachel to turn northwestward. During the 3 to 5 day period, there continues to be large differences in the model solutions. The GFS, GFDL, and HWRF take the cyclone northward, then northeastward, while the ECMWF and UKMET show a weaker cyclone becoming nearly stationary well southwest of the Baja peninsula. The NHC track leans toward the more northward solution, but it is not nearly as fast or as far east as the GFS and GFDL models at days 4 and 5. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 16.3N 109.6W 45 KT 50 MPH 12H 26/0000Z 17.1N 111.0W 50 KT 60 MPH 24H 26/1200Z 18.2N 112.9W 55 KT 65 MPH 36H 27/0000Z 19.0N 114.2W 55 KT 65 MPH 48H 27/1200Z 19.8N 115.0W 60 KT 70 MPH 72H 28/1200Z 21.5N 115.8W 55 KT 65 MPH 96H 29/1200Z 22.7N 115.5W 45 KT 50 MPH 120H 30/1200Z 23.5N 115.0W 30 KT 35 MPH |
NHC 稍早命名 Rachel 不過強度方面仍不是很看好... ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM RACHEL DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP182014 800 PM PDT WED SEP 24 2014 Vigorous deep convection has expanded in association with the tropical cyclone this evening, primarily in the southwestern semicircle. The asymmetric distribution of thunderstorms around the system is due to about 25 kt of northeasterly vertical shear being caused by a strong upper-level anticyclone to its north. The current intensity is based upon 35 kt estimates from both the Satellite Analysis Branch and the Advanced Dvorak Technique, though the Tropical Analysis and Forecast Branch suggests a slightly stronger system. Thus the cyclone is now named Tropical Storm Rachel. The system may gradually intensify during the next two to three days as the shear diminishes some. However, Rachel should also encounter cooler sea surface temperatures and drier low-level air as it moves toward the west-northwest. The system is expected to peak in intensity as a moderate tropical storm around day 2 or 3, followed by a gradual weakening. The NHC official intensity forecast is based upon the tightly clustered IVCN multi-model ensemble and is about the same as the previous advisory. The earlier ASCAT scatterometer pass suggested a radius of maximum wind of around 40 nm, which helped to define the tropical-storm- force wind radii now that the cyclone has strengthened. The global and regional hurricane models suggest that Rachel will remain rather small in size. A blend of these models with the climatology- persistence technique is the basis for the NHC wind radii predictions. A 2333Z SSMIS microwave image assisted in locating the center of Rachel, as the low-level swirl has remain tucked just under the convective overcast. Rachel is moving toward the west at about 10 kt. The tropical storm should turn toward the west-northwest during the next two days as it moves around the periphery of the mid-level subtropical ridge. In about three days, a strong short wave trough will be passing north of Rachel over California. The new 18Z GFS and the hurricane models run from it respond by turning Rachel northeastward toward Baja California, while the older 12Z ECMWF and UK Met Office global models continue moving a weaker Rachel west-northwestward. The NHC official track splits the difference and is slightly eastward from that of the previous advisory, but not as far eastward as the TVCE multi-model ensemble. FORECAST POSITIONS AND MAX WINDS INIT 25/0300Z 15.3N 107.4W 35 KT 40 MPH 12H 25/1200Z 15.8N 108.8W 35 KT 40 MPH 24H 26/0000Z 16.9N 110.7W 40 KT 45 MPH 36H 26/1200Z 17.9N 112.5W 40 KT 45 MPH 48H 27/0000Z 18.6N 113.9W 45 KT 50 MPH 72H 28/0000Z 19.7N 115.5W 45 KT 50 MPH 96H 29/0000Z 20.5N 116.0W 40 KT 45 MPH 120H 30/0000Z 21.5N 116.0W 30 KT 35 MPH |