Tropical Storm Emilia Discussion Number 9
Wiki-Hurricanes Forecast Center
2:00 PM PDT Fri Jun 29 2018
Not much has changed in association with Emilia since this morning, with a bulbous convective core displaced towards the southwest from the center of circulation. The deep-layer wind shear mean has decreased marginally with outflow pushing radially from the convection, but the lagging low-level circulation suggests that this wind shear is still inhibiting development. Microwave images show a fairly potent band to the southwest driving the dense overcast, but not much else aside from meager banding attempting to form but failing to establish itself in the northwestern quadrant, indicative of stable air in that region as evidenced by the stratocumuli field. SAB estimates continue a steady T3.0/45 kt with more or less the same from automated outputs. Microwave estimates have run a bit higher, at around 50 kt, though an estimate of 60 kt from SSMIS data seems to be an overreaction to the southwestern core band given that the circulation remains poorly stacked. With Emilia appearing to be steady-state for now, the winds for this advisory are maintained at 50 kt.
Driving west-northwest in the tropical easterlies, the track philosophy for Emilia remains unchanged, with the same digging trough providing some northward impetus in the day 2-3 window. The timeframe in which Emilia can strengthen is also diminishing, especially given that Emilia appears to have leveled off for now. SHIPS and LGEM show very little strengthening in the forecast range with sea surface temperatures beginning to gradually fall with moisture thinning out as Emilia progresses westward. The cyclone has about a day or so before it crosses the 26°C isotherm, after which it would be more difficult for convection to continue developing in the manner that it has. Some of the hurricane models depict a sort of conditional oasis Sunday, though this is a tough sell given 24°C sea surface temperatures and mediocre relative humidity values in the 50% range. The current intensity forecast still highlights the current window of opportunity for some gradual strengthening before the storm tapers off, with the general forecast philosophy remaining unchanged.
FORECAST POSITIONS AND MAX WINDS
INIT 29/2100Z 50 KT 60 MPH
12H 30/0600Z 55 KT 65 MPH
24H 30/1800Z 50 KT 65 MPH
36H 01/0600Z 45 KT 50 MPH
48H 01/1800Z 45 KT 60 MPH
72H 02/1800Z 30 KT 45 MPH
96H 03/1800Z 25 KT 35 MPH...POST-TROP/REMNT LOW
120H 04/1800Z 20 KT 30 MPH...POST-TROP/REMNT LOW