Atlantic/2019/05L/Archive/5

Dorian has continued to organize this evening. The cyclone has sported a generally persistent and symmetrical central dense overcast, with signs of a formative eyewall in a microwave pass around 21z. This convection weakened temporarily 1-2 hours ago, but it has come back vigorously since that time. Satellite intensity estimates range from T3.0/45kt from TAFB to T3.2/49kt from UW-CIMSS ADT and finally T3.5/55kt from SAB. An average of these values supports raising the intensity to 50kt.
Dropsondes around Dorian courtesy of an upper-air recon plane indicate that the storm is experiencing light wind shear, helping to inject dry mid-level air into the core. These intrusions should occur intermittently over the coming days, which may result in uneven strengthening during that time, focused mainly around the diurnal maximum when instability is maximized and helps promote central convective bursts. The SHIPS text output yields wind shear between 10-15kt around day 3, which is not destructive but should result in some weakening of this unusually tiny system. It is worth noting that, despite nagging upper-level winds and expectations of continued dry air intrusions, the SHIPS now gives a 1-in-2 chance of 25kt rapid intensification over the next day. That model depicts a high-end Category 1 hurricane, while the LGEM posted its most bullish run yet with a storm of Category 2 intensity. The HWRF, quite the contrarian this cycle, shows significant strengthening around the time upper-level winds are expected to be the highest, ending its run with a major hurricane ravaging the Bahamas. Global models, by comparison, show little further development followed by dissipation in the eastern Caribbean Sea. Like past runs, the best course of action appears to be to call for gradual development over the next few days, followed by some weakening as Dorian approaches Hispaniola or Puerto Rico. One change for this advisory is to show re-strengthening on day 5, the byproduct of an eastward shift in the track as well as Dorian reemerging over the southwestern Atlantic.
Dorian continues its swift westward track today. This trajectory should continue for the next few hours before a more west-northwest track takes over. On days 2 through 4, Dorian should curve even more poleward as the mid-level ridge northeast of the Leeward Islands weakens and a more broad subtropical ridge positioned east of Bermuda takes over; this will be aided by the presence of a mid-level trough north of the Greater Antilles as well. On that trajectory, Dorian should cross the Leeward Islands into the Caribbean in about 36 hours and approach either Hispaniola or Puerto Rico about 4 days from now. Statistical and dynamical guidance shifted quite a ways east this cycle, suggesting that Dorian may only skirt the northeastern coastline of Hispaniola. This would have significant implications for the storm's strength in the latter stages of the forecast period.
FORECAST MAX WINDS
INIT 26/0300Z 50 KT 60 MPH
12H 26/1200Z 55 KT 65 MPH
24H 27/0000Z 55 KT 65 MPH
36H 27/1200Z 60 KT 70 MPH...MOVING THROUGH LEEWARD ISLANDS
48H 28/0000Z 65 KT 75 MPH
72H 29/0000Z 70 KT 80 MPH
96H 30/0000Z 45 KT 50 MPH...INLAND