1. Shower activity associated with a trough of low pressure located a
few hundred miles south of the southern tip of the Baja California
peninsula has decreased during the past several hours. The
disturbance is moving northwestward toward colder water, but it
could still briefly become a tropical depression if showers and
thunderstorms redevelop on Monday.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.
Tropical Depression Four-E Discussion Number 1
NWS National Hurricane Center Miami FL EP042020
900 PM MDT Mon Jun 29 2020
The circulation associated with the area of low pressure located
southwest of the southern tip of the Baja California peninsula has
become better defined over the past 24 hours, and the system has
maintained convection for much of the past 12 hours. Although the
convection has not been particularly well organized at times today,
a new burst of convection developed just northeast of the low-level
center late this afternoon and has been persistent over the past
several hours. Based on these observations and Dvorak T-number of
1.5 from TAFB and 2.0 from SAB, the system is being designated as a
30-kt tropical depression. The system is expected to be a short-
lived tropical cyclone as it will be moving into an area of
increasing southwesterly vertical wind shear and over SSTs of around
24 degrees Celsius by Tuesday morning. As a result, the depression
is forecast to degenerate into a remnant low on Tuesday. The NHC
wind speed prediction follows the trend of the intensity guidance
and also calls for the remnant low to dissipate in 2 to 3 days.
The depression is moving slowly northwestward around the western
portion of a mid-level ridge that extends westward over central
Mexico. The cyclone should continue moving on the same general
heading with some reduction in forward speed as it weakens and is
steered by the weaker low-level flow. The NHC track forecast is
near the middle of the guidance envelope in best agreement
with the HFIP corrected consensus model.
Tropical Depression Four-E Discussion Number 3
NWS National Hurricane Center Miami FL EP042020
900 AM MDT Tue Jun 30 2020
The depression's center remains exposed, with any limited convection
displaced more than 90 n mi northeast of the center. Effectively,
the system is on its way to becoming a remnant low this afternoon
if convection does not re-form closer to the center. The initial
wind speed remains 25 kt. The low should gradually spin down
during the next day or two over cool waters while it moves slowly
northwestward. Only a small northeastward shift was made to
the track forecast, and the low should degenerate into a trough of
low pressure in a couple of days.
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