Tropical Storm Fabio Discussion Number 6

Wiki-Hurricanes Forecast Center

10:00 AM CDT Mon Jul 1 2018

Fabio has continued to gradually organize this morning, with the central dense overcast becoming a bit more aligned with the center of circulation and the equatorward outflow channel becoming more well-defined. All favorables that Fabio possessed earlier—vigorous convection, organized banding, and a strong poleward outflow channel—are all still present. However, microwave imagery shows that the low-level center of circulation is still displaced to the northeast of the circulation, with the main convective core mostly limited to the system's southwest. Mesoscale-sector visible imagery also confirms the displacement, with the cloud-lines of the circulation somewhat visible under a thin cirrus canopy, but convection is surging back. SAB subjective estimates had T3.0/45kt with a similar T3.1/47kt from the automated CIMSS-ADT. SATCON consensus is at 42 kt with CIMSS-AMSU in agreement with infrared techniques by giving a 43 kt estimate. Based on this information, the intensity for Fabio has been raised to 45 kt.

Subtropical ridging is keeping Fabio on a west-northwesterly path with the dominant high-pressure area now centered over Beaumont, Texas. There are not a whole lot of surprises regarding steering over the next few days as Fabio slowly rounds the ridge's periphery, which will eventually allow for more latitudinal gains late in the forecast window. A more westerly path for Fabio would keep it over warmer sea surface temperatures for longer, while a more northerly path would more quickly intercept the cooler Pacific subtropical waters. Model guidance has shifted slightly westward, which is a good development for Fabio's future.

The road ahead for Fabio is favorable for substantial intensification, especially within the short range. The current upper-anticyclone associated with Fabio is currently displaced but should center itself over time as the tropical storm continues to convectively develop, allowing the storm to develop in its own crafted environment with even wind flow throughout the vertical air column. Sea surface temperatures will be highly conducive and in excess of 28°C for the storm for at least two days, turning unfavorable after day 4; humidity values are also favorable and well-aligned with sea surface temperatures. Within the short-range, Fabio has a very high ceiling, and its ultimate strength will hinge on how well Fabio manages its internal affairs and repairs incidental setbacks to its structure. Intensity guidance has grown increasingly aggressive as tracks shift west. SHIPS statistical guidance yields a Category 5 in around two days, with LGEM depicting a solid Category 4 in that timeframe. HWRF and HMON show a threshold major hurricane. Global models are more in disagreement: GFS has joined the ranks of SHIPS with a Category 5, but ECMWF-IFS shows just a Category 1; UKMO-G has shallowed a bit but still has a major hurricane as it aligns with the model track consensus. The current forecast intensity shows a solid Category 4 hurricane at peak before cooler waters curtail development after day 4.


INIT 01/1500Z 45 KT 50 MPH

12H 02/0000Z 55 KT 65 MPH

24H 02/1200Z 75 KT 85 MPH

36H 03/0000Z 95 KT 105 MPH

48H 03/1200Z 115 KT 130 MPH

72H 04/1200Z 115 KT 130 MPH

96H 05/1200Z 90 KT 105 MPH

120H 06/1200Z 50 KT 60 MPH