Atlantic/2019/05L/Archive/8

Dorian has changed little today. Convection has been on a gradual decline, coincident with the approach of the diurnal minimum, except in most recent frames when another large convective burst is taking shape. Microwave imagery from this morning and early afternoon indicates that Dorian is well organized structurally, with a partial inner core that continues to struggle fully consolidating thanks to occasional mid-level dry air entrainment. Satellite intensity estimates range from 45kt to 61kt, so the initial intensity remains 55kt, which is above an average of estimates since Dvorak does not react kindly to waning convection. An Air Force reconnaissance plane will survey Dorian later and assess its strength.
The tropical cyclone continues its west-northwest trek this afternoon, steered on the southwest side of a mid-level ridge north and east of the Greater Antilles. This ridge will weaken some more over the coming days, allowing Dorian to take on a northwest trajectory late tomorrow or Wednesday. Given the current forecast philosophy, the storm should enter the Windward Islands early tomorrow morning and approach either eastern Hispaniola or Puerto Rico about 48 to 60 hours from now. Statistical guidance nudged ever so slightly eastward this afternoon, and it continues to look like Dorian will only skirt the Dominican Republic or Puerto Rico before entering the southwestern Atlantic. Between days 4 and 5, mid-level ridging should reestablish itself north of Dorian, forcing the cyclone to curve west-northwest or even westward.
The intensity forecast remains complicated, although one big question does have increased clarity this advisory. Dropsondes from an upper-air plane and observations from Caribbean islands indicate that the air around Dorian remains extremely dry. Given warm ocean temperatures and light wind shear, this dry air is only being entrained into the storm intermittently, albeit at a pace that has thus far prevented Dorian from developing a consolidated eyewall. Until an inner core takes shape, it is hard to envision significant strengthening, and so slow development continues to appear likely as the storm enters the eastern Caribbean. Between 36 and 60 hours from now, Dorian should interact with a cut-off low, increasing shear over the cyclone that may result in little change or perhaps some weakening. This will be attenuated by some degree of land interaction. Global models have undergone some changes today, with the ECMWF, UKMET, and GFS legacy all maintaining Dorian through its track across the Caribbean, followed by reorganization in the Bahamas. This is a solution generally supported by the HWRF too, leaving the new GFS on its island in terms of degeneration in the short term. Water temperatures will remain more than sufficient over the Bahamas, and upper-level winds should become light again, setting the stage for redevelopment at the end of the forecast period provided interaction with Hispaniola does not destroy the system. This is an unlikely but still theoretically possible solution.
FORECAST MAX WINDS
INIT 26/2100Z 55 KT 65 MPH
12H 27/0600Z 55 KT 65 MPH...MOVING THROUGH LEEWARD ISLANDS
24H 27/1800Z 60 KT 70 MPH
36H 28/0600Z 65 KT 75 MPH
48H 28/1800Z 70 KT 80 MPH
72H 29/1800Z 45 KT 50 MPH...INLAND
96H 30/1800Z 50 KT 60 MPH...OVER WATER