C. TWO MORE NOAA 49 G-IV SYNOPTIC SURVEILLANCE MISSIONS AROUND AL94 FOR THE 29/0000Z AND 29/1200Z SYNOPTIC TIMES, DEPARTING KLAL AT 28/1730Z AND 29/0530Z RESPECTIVELY. D. BEGIN 12-HRLY FIXES ON HURRICANE HUMBERTO AT 29/0000Z NEAR 25.3N 65.2W.
Hurricane Humberto Discussion Number 10 NWS National Hurricane Center Miami FL AL082025 1100 PM AST Fri Sep 26 2025 Humberto has continued to intensify rapidly this evening. The eye temperature has increased to 15C and the eyewall white ring (-73C) is nearly closed. A 2137 UTC WSFM-1 HiRes microwave pass indicated that a concentric ring was developing about 65 nm from the eye. The initial intensity is raised to 125 kt and is close to the UW-CIMSS ADT of T6.4 and above the constrained subjective Dvorak intensity estimates from TAFB and SAB. All intensity contributions, low shear, warm waters, and ample mid-level moisture, appear conducive for Humberto to intensify rapidly during the next 12-24 hours. DTOPS guidance indicates a high probability of RI during the next 12-24 hours, and the latest official intensity forecast follows suit, bringing Humberto to a peak intensity of 140 kt Saturday night. By the 36 hour period, however, inner-core fluctuations as a result of eyewall replacement cycles (ERC) are possible, and it's difficult to forecast the exact timing. It's worth mentioning, however, that the UW-CIMSS M-PERC (Microwave-based Probability of Eyewall Replacement Cycle) statistical model is predicting a 61 percent of onset. By mid-next week, increasing vertical shear spreading over Humberto should induce a gradual weakening trend. At the same time, while it passes west of Bermuda, a significant expansion in the surface wind field will likely occur. The NHC intensity forecast is just above the previous forecast through the 36 hour period, and closely follows a blend of the HCCA consensus and the HAFS/HWRF/HMON hurricane models. Humberto has taken a trochoidal jog to the left of the track this evening, likely due to the rapid intensification event. The initial motion is estimated to be slightly south of due west, or 265/6 kt. Humberto is expected to move slowly toward the west or west-northwest during the next day or so in the easterly steering flow provided by mid-tropospheric high pressure located to the north of the cyclone and just east of Bermuda. Around the 48 hour period, or Sunday evening, a northwestward turn with some reduction in forward speed is forecast while the above-mentioned high pressure weakens and shifts eastward. By day 4, Humberto should commence a rather abrupt turn northward and northeastward in response to a major shortwave upper-level trough amplifying and moving out of northeastern Canada and into the northwestern Atlantic. The official track forecast is located just to the left of the previous advisory, primarily due to the initial motion left of track, and lies between the HCCA corrected consensus and the Google DeepMind ensemble model. 今晚 Humberto 继续快速增强。其风眼温度已升至15℃,而眼墙白色环带(-73℃)几乎闭合。2137 UTC 的 WSFM-1 HiRes 微波观测显示,距风眼约65海里处正在形成同心环。初始强度提升至125节,这与 UW-CIMSS 的 ADT T6.4 接近,并且高于 TAFB 和 SAB 的约束性主观 Dvorak 强度估计。 所有有利于增强的条件——低风切变、温暖海水和充足的中层水汽——都显示 Humberto 在未来12-24小时内具备快速增强的条件。DTOPS 指导显示在未来12-24小时内有很高的快速增强概率,最新的官方强度预报也反映了这一趋势,预计 Humberto 在周六晚间将达到140节的峰值强度。然而,到36小时左右,由于眼墙置换循环(ERC),可能会出现内核结构波动,具体时间难以预测。值得一提的是,UW-CIMSS 的 M-PERC(基于微波的眼墙置换循环概率统计模型)预测有61%的发生概率。到下周中期,随 Humberto 上空的垂直风切变增强,预计将出现逐渐减弱的趋势。同时,当它经过百慕大以西时,地表风场也可能显著扩大。NHC 的强度预报在36小时内略高于前一份预报,并大体接近 HCCA 共识以及 HAFS/HWRF/HMON 飓风模式的综合结果。 今晚 Humberto 出现了一个向左的小幅回旋运动,这可能与快速增强事件有关。初始移动方向估计为略偏南的正西,即265°/6节。预计 Humberto 在未来一天左右将缓慢向西或西北偏西移动,其导向气流来自位于气旋北侧并在百慕大以东的中层高压。到48小时(即周日晚间)左右,随着上述高压减弱并东移,Humberto 预计将向西北转向,同时前进速度有所减缓。到第4天,受从加拿大东北部南下并深入西北大西洋的强大短波高空槽影响,Humberto 将开始一个明显的北转和东北转。此次官方路径预报相较于前一份略偏左,主要原因是初始移动轨迹更偏左,同时路径位于 HCCA 修正共识与 Google DeepMind 集合模型之间。