|Hurricane Erick||Winds: 105 kt|
|Pressure: 955 mbar|
|Advisory 15 / 8:00 PM PDT Wednesday, July 30, 2019|
After peaking as a Category 4 hurricane this afternoon, Erick has begun a downward trend. Convection has warmed in the central dense overcast, and this has been mirrored by a cooling of the hurricane's eye. A combination of SHIPS diagnostics and water vapor imagery indicates that upper-level winds are beginning to increase, and this is likely the cause for Erick's strife, especially given its small stature. Satellite intensity estimates were a consensus T5.5/102kt from SAB, PHFO, and PGTW, while current intensity values range from T6.0/115kt to T6.5/127kt. It is hard to reconcile those latter numbers given a just-released microwave pass which shows a fragile-looking inner core. Therefore, the initial intensity has been decreased to 105kt, a little above satellite estimates.
After enjoying life in literally zero shear, Erick is beginning to feel the effects of increasing upper-level winds. This wind shear should remain marginal for the next 24 hours or so, but it is expected to become downright destructive thereafter, with SHIPS indicating values near 45kt by the end of the period. Coupled with marginal mid-level relative humidity values, these two factors are expected to prompt rapid weakening of the hurricane, despite the fact that ocean temperatures should remain generally favorable over the next 5 days. For this advisory package, I have sped up Erick's rate of weakening.
Erick is moving west-northwest on the southern side of a large mid-level ridge. This motion will continue for the next 36 hours, but turn more westerly on days 2 through 4 as Erick loses vertical depth and becomes steered by low-level trades. By day 5, though, a weak mid-level trough will weaken the ridge to Erick's north, allowing it to move back west-northwest.
FORECAST MAX WINDS
INIT 31/0300Z 105 KT 120 MPH
12H 31/1200Z 95 KT 110 MPH
24H 01/0000Z 85 KT 100 MPH
36H 01/1200Z 65 KT 75 MPH
48H 02/0000Z 50 KT 65 MPH
72H 03/0000Z 35 KT 40 MPH
96H 04/0000Z 30 KT 35 MPH...POST-TROP/REMNT LOW120H 05/0000Z 25 KT 30 MPH...POST-TROP/REMNT LOW