Hurricane Fabio Discussion Number 12

Wiki-Hurricanes Forecast Center

9:00 PM MDT Sun Jul 3 2018

Fabio's large size has caught up to its intensification as a large intrusion of dry air this afternoon into the circulation has effectively served as a reset button for the hurricane. This morning's deep convection warmed dramatically this afternoon and largely dispersed, leaving an overall warm cloud top environment. Microwave imagery shows a large expanse of subsident air without any deep convective activity on the center's western flanks, though the storm is trying its best to maintain a microwave eye and a partial eyewall. Some new central convection began around 2200Z around the center and is trying to become more established as Fabio makes a new effort to reintensify. SAB estimated T4.0/65kt again in their subjective Dvorak analysis. However, since that time the system has convectively developed quite appreciably. Final estimates from UW-CIMSS ADT indicate T4.2/70kt, though some of the recent convective developments are throwing raw values a bit upwards without constraints, as high as T5.6/105kt. If we are to hug Dvorak satellite estimates, not much would have to change for technique outputs to rise substantially to be indicative of a Category 2 or Category 3 as the ADT raw indicated. In line with Fabio's inner reworkings, the intensity for Fabio has been set at 80 kt, higher than filtered SATCON and old subjective estimates given the overall convective organization for Fabio. With Dvorak technique alone, Fabio has just made inched its way into T5.0/90kt DT territory by my personal subjective analysis as the infrared eyewall begins to connect, but since this is not a conventional six-hourly analysis and these are recent developments, I have opted to keep the current intensity at 80 kt.

No changes anticipated in forecast track with US subtropical ridging behaving more or less as anticipated. The latest setback in intensification has served to be a sharp blade cutting away at Fabio's ultimate potential as the hurricane is in a race against a diminishing window of opportunity for appreciable intensification. Sea surface temperatures are still favorable but are now beginning to fall with latitude; they will be rather unfavorable after about 36 hours once Fabio reaches a tight temperature gradient. Conditions are moist, but as detailed earlier a negative mode of upper-level velocity potential may be working against the hurricane by creating a general environment of subsidence. Noticeable gravity waves emanating from the system seen in water vapor-optimized wavelengths indicate that the Fabio has now pulled an anticyclone in its grasp, which could perhaps reduce the influx of dry air into the circulation, though whether or not that counteracts an overall subsident environment is unknown. An internally asymmetric structure is not as favorable for rapid intensification, but given generally positive factors Fabio should still strengthen some before beginning to shrivel up after two days. Fabio is in the midst of a new intensification phase it appears that is expected to help propel the system to Category 3 intensity. It should be noted that all statistical and dynamic guidance keeps Fabio at Category 3 and below, a bearish end to some of the aggressive modeling from yesterday and earlier in Fabio's history.


INIT 03/0300Z 80 KT 90 MPH

12H 03/1200Z 95 KT 100 MPH

24H 04/0000Z 105 KT 120 MPH

36H 04/1200Z 110 KT 125 MPH

48H 05/0000Z 95 KT 110 MPH

72H 06/0000Z 60 KT 70 MPH

96H 07/0000Z 35 KT 40 MPH

120H 08/0000Z 25 KT 30 MPH...POST-TROP/REMNT LOW