Tropical Storm Emilia Discussion Number 10
Wiki-Hurricanes Forecast Center
8:00 PM PDT Fri Jun 29 2018
To say Emilia is disorganized would be an understatement. As it has for most of its life, Emilia continues to produce a large mass of deep convection cooler than -70C. However, this thunderstorm activity has become increasingly misshapen over the past few hours, and it's being pushed westward by strong easterly shear near 20kt. The low-level circulation, meanwhile, has become fully exposed, and high-resolution visible satellite imagery before the sun set showed multiple vortices rotating within a broader vorticity maximum. Satellite intensity estimates have dropped sharply this evening, ranging from 47kt from SATCON, to T3.0/45kt from TAFB, to T2.1/31kt from UW-CIMSS ADT, to T2.0/30kt from SAB. A blend of these values supports decreasing the initial intensity to 40kt.
Interestingly, upper-level outflow is expanding to the east of Emilia despite the obviously hostile environment. This suggests that wind shear is occurring below the outflow level, an altitude models struggle to accurately assess, and that forecasts of an improving environment may be misleading. Regardless of whether this is the case, sea surface temperatures underneath Emilia have fallen below 27C and should decrease even further over the next 48 hours as the system moves west-northwest. Mid-level relative humidity also continue to fall, and the culmination of these factors lends confidence that Emilia is past peak and well on its way to becoming a remnant low. Degeneration is expected by 72 hours, but it would not be at all surprising if this occurred sooner given the state of the storm. Emilia should bend toward the west, steered by easterly trade winds, after this takes place.
FORECAST POSITIONS AND MAX WINDS
INIT 30/0300Z 40 KT 45 MPH
12H 30/1200Z 40 KT 45 MPH
24H 01/0000Z 35 KT 40 MPH
36H 01/1200Z 30 KT 35 MPH
48H 02/0000Z 25 KT 30 MPH
72H 03/0000Z 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 04/0000Z 15 KT 20 MPH...POST-TROP/REMNT LOW