Hurricane Fabio Discussion Number 11
Wiki-Hurricanes Forecast Center
3:00 PM MDT Mon Jul 2 2018
Fabio is gradually organizing. Visible satellite imagery shows an eye that is making attempts to clear, while infrared images show that convection is becoming more symmetric about the central dense overcast as opposed to weighted east like this morning. Still, a 1730z ASCAT pass indicated that there is a huge discrepancy in maximum winds by quadrant, with hurricane-force winds in the northeast quadrant and winds just below tropical storm force in the southwest quadrant. Recent satellite intensity estimates were T4.0/65kt from SAB and SATCON, T4.1/67.4kt from UW-CIMSS ADT, and T4.5/77kt from TAFB. A blend of these estimates supports leaving the initial intensity at 70kt.
Although the hurricane is intensifying, it is doing so at a much slower rate than most models expected. Conventional and microwave imagery shows that a substantial amount of mid-level dry air lurks to the west of the storm center. There are two hypotheses for where this dry air is coming from. The first is that it is coming from outside the immediate storm environment, a byproduct of Fabio's large circulation size. The second is that it is originating from a convectively-suppressed kelvin wave that is passing over the storm. These waves are accompanied by upper-level convergence, which causes air to sink, warm, and dry. Whatever the reason, it is clear that previous forecasts has been too bullish. The latest SHIPS now indicates a peak of 103kt, a decrease of 43kt from this time yesterday. The LGEM forecasts 91kt, a decrease of 47kt since 18z yesterday! One model that has stood its ground is the HWRF, which perhaps correctly never bought into the idea of a Category 4 cyclone. While the environment remains favorable for gradual intensification, the prospects of rapid intensification have decreased, and the clock is beginning to tick as Fabio moves on a consistent west-northwest course toward the 26°C isotherm. As such, the forecast peak has been again decreased from 120kt to 110kt. Weakening is expected after 36 hours, and the storm is expected to degenerate to a remnant low by day 5.
FORECAST POSITIONS AND MAX WINDS
INIT 02/2100Z 70 KT 80 MPH
12H 03/0600Z 80 KT 90 MPH
24H 03/1800Z 95 KT 110 MPH
36H 04/0600Z 110 KT 125 MPH
48H 04/1800Z 95 KT 110 MPH
72H 05/1800Z 65 KT 75 MPH
96H 06/1800Z 35 KT 40 MPH
120H 07/1800Z 25 KT 30 MPH...POST-TROP/REMNT LOW