|Tropical Storm Erick||Winds: 40 kt|
|Pressure: 1004 mbar|
|Advisory 6 / 2:00 PM PDT Sunday, July 28, 2019|
Erick has changed little in organization since the last advisory. Visible imagery indicates that deep convection continues to form over the circulation center, with multiple accompanying spiral bands in the southern semicircle. Despite this, microwave imagery does not indicate the development or even the start of an inner core. Satellite intensity estimates are T2.5/35kt from TAFB, T2.8/41kt from UW CIMSS ADT, and T3.0/45kt from SAB. A blend of these values supports leaving the initial intensity at 40kt.
Erick has organized slower than anticipated today, despite warm ocean temperatures, low wind shear, and an adequately moist environment. One potential cause for this is the storm's fast forward motion, though brisk westerly winds on the south side of Erick's circulation via the recent ASCAT pass would argue against this. Like yesterday, there continues to be a wide range in intensity forecasts. Neither the SHIPS nor the LGEM forecast Erick to become a hurricane, while the ECMWF depicts a Category 1 and the GFS forecasts a Category 2. Even the HWRF, which depict a cyclone close to Category 4 intensity yesterday afternoon, has risen about 10mb in forecast peak since this time 24 hours ago. This is not a huge surprise given the presence of a convectively-suppressed kelvin wave that is traversing the eastern Pacific. All told, Erick has about 60 to 72 hours left before upper-level winds begin to increase, ocean temperatures cool, and the air becomes drier. SHIPS rapid intensification indices are elevated, especially in the short term, but not at values that support explicitly forecasting an RI event. Given the culmination of everything discussed above, the new forecast is slower in initial points but about the same after 48 hours.
Broad mid-level ridging to the north of Erick is responsible for the storm's brisk west-northwest motion, and little deviation is expected over the next 4 to 5 days. By the end of the period, as Erick loses vertical depth, it may turn west via the low-level easterly trade wind flow across the eastern and central Pacific. On this track, Erick is expected to remain south of the Hawaiian Islands.
FORECAST MAX WINDS
INIT 28/2100Z 40 KT 45 MPH
12H 29/0600Z 45 KT 50 MPH
24H 29/1800Z 55 KT 65 MPH
36H 30/0600Z 65 KT 75 MPH
48H 30/1800Z 80 KT 90 MPH
72H 31/1800Z 90 KT 105 MPH
96H 01/1800Z 50 KT 60 MPH120H 02/1800Z 35 KT 40 MPH