|Tropical Storm Erick||Winds: 35 kt|
|Pressure: 1006 mbar|
|Advisory 1 / 8:00 AM PDT Saturday, July 27, 2019|
Overnight satellite imagery suggests that the low-pressure area located 1200 miles southwest of the southern tip of the Baja California has organized into a tropical cyclone. An ASCAT-C scatterometer pass at 0430z showed winds of 35 kt on the northeastern part of the circulation, so on this basis the storm is designated as Tropical Storm Erick with the intensity prescribed.
Both TAFB and SAB were constrained to T2.0/30kt this morning but would have gone higher otherwise, so the current intensity appears legitimate. Although a ScatSat-1 pass at 0452z suggested that the circulation was still elongated and attached to the monsoon trough, the emergence of early banding features around a developing circulation on SSMI microwave imagery at 1126z indicates that the circulation's structure has changed substantially. Infrared imagery and nighttime microphysics have not been as clear with regards to the wind field, but show a robust -70C area of central convection with pronounced outflow throughout the Erick's circulation.
Erick's positioning at around 11N and shallow west-northwest track are providing the storm long-term access to warm sea surface temperatures above 28C for the next three days. Although the storm does not have a well-positioned anticyclone to lower shear, favorable divergence aloft courtesy of an exceptional convectively-coupled Kelvin should support well-established outflow and maintain low shear values below 10 kt for at least three days, and the HFIP ensemble shear guidance indicates this. However, mid-level relative humidity values are analyzed to be decreasing quite markedly over the next two days, and this along with present entanglement with the monsoon trough appear to be the main inhibitors for Erick to intensify in the short-term. The global models tend to suggest Erick gets into a groove after day 3, but statistical guidance including the TVCN support intensification starting right away. Based on the latest satellite data I'm led to believe that the global models aren't accurately sniffing out Erick's current intensity or organization, so I'd bet on intensification starting a bit earlier. The current intensity forecast calls for slower strengthening early on but is above most guidance beginning at day 2, and I think rapid intensification is possible at some point during the forecast period.
Current track solutions across both ensemble and deterministic guidance forecast a straightforward track towards the west-northwest as a result of building subtropical ridging across the northern Pacific. However, there is a broad upper-level low that is expected to set up north of Hawaii after day 2 and influence the steering flow some, perhaps providing a slight northward tug on Erick's motion before being squelched by expanding ridging around day 5 as depicted on both the GFS and ECMWF-IFS. Ensemble spreads tentatively suggest a possibility of Erick reaching Hawaii, though this is outside the present forecast timeframe.
FORECAST MAX WINDS
INIT 27/1500Z 35 KT 40 MPH
12H 28/0000Z 35 KT 40 MPH
24H 28/1200Z 40 KT 45 MPH
36H 29/0000Z 45 KT 50 MPH
48H 29/1200Z 60 KT 70 MPH
72H 30/1200Z 70 KT 80 MPH
96H 31/1200Z 80 KT 90 MPH120H 01/1200Z 70 KT 80 MPH