Tropical Depression Eight-E Discussion Number 1
Wiki-Hurricanes Forecast Center
2:00 PM PDT Fri Jul 26 2018
An area of low pressure associated with a tropical wave roughly 650 miles southwest of Socorro Island has become sufficiently organized to be classified as a tropical depression. Visible and infrared satellite imagery reveal two elongated spiral bands about a small area of central convection. An ASCAT pass from 1734Z showed at least half of a well-organized circulation with 30 kt winds in the northern semicircle, though a closed circulation encapsulated by westerly winds was unclear from the data due to suspect values towards the south. However, an OSCAT pass from 1723Z revealed a closed circulation with winds of 30 kt concentrated to the system's west. Based on this information, the low has been designated Tropical Depression Eight-E with winds of 30 kt, and the scatterometer data is more or less in agreement with subjective satellite intensity estimates from SAB and TAFB.
Ridging over the southwestern United States is keeping Eight-E on a westerly track which should continue throughout the forecast period. Some west-northwesterly motion could occur towards day 4 and day 5 as Eight-E rounds the southwestern periphery of the ridge and interacts somewhat with lower heights west of the high pressure zone. Conditions are modestly favorable for intensification as Eight-E currently finds itself in an area of low shear, slightly warm waters and sufficiently moist air. Such conditions should allow for some slow strengthening over the next three or so days, after which an upper-level trough over the northern Pacific should begin to impart hightened shear which will also provide an injection of drier subtropical air southeastwards towards the tropical cyclone. Weakening is shown after 72 hours with dissipation following afterwards in five days.
FORECAST POSITIONS AND MAX WINDS
INIT 26/2100Z 30 KT 35 MPH
12H 27/0600Z 30 KT 35 MPH
24H 27/1800Z 35 KT 40 MPH
36H 28/0600Z 35 KT 40 MPH
48H 28/1800Z 40 KT 45 MPH
72H 29/1800Z 35 KT 40 MPH
96H 30/1800Z 30 KT 35 MPH...REMNANT LOW
120H 31/1800Z...DISSIPATED