EPAC: FOUR-E - Remnants

[cycloneye]

Tropical Depression Four-E Discussion Number 5
NWS National Hurricane Center Miami FL EP042019
300 PM MDT Sat Jul 13 2019

The depression consists of a small low-level swirl, exposed to the
east of a shrinking area of convection. The initial winds have been
maintained at 30 kt based on the latest Dvorak CI numbers from TAFB
and SAB. For the moment, the system appears to be on its way to
becoming a remnant low with convection gradually decreasing, just as
most of the dynamical models predicted during the last day or so.
There has been no important change in the guidance, and the cyclone
is still forecast to gradually weaken during the next couple of days
and could become a remnant low as early as tomorrow afternoon. The
remnant low could then last for another day or so after that, but
should open into a trough and dissipate early next week.

The depression is moving west-northwestward, or 290/13 kt, but is
forecast to turn toward the west tonight as it weakens and loses its
convection. While there is still some spread in the models,
especially regarding how far westward the remnant low will make it
before it dissipates, they all generally agree on this forecast. The
NHC forecast is near the mean of the GFS and ECMWF models, and is
largely unchanged from the previous forecast.

FORECAST POSITIONS AND MAX WINDS

INIT 13/2100Z 17.5N 112.4W 30 KT 35 MPH
12H 14/0600Z 17.8N 114.5W 30 KT 35 MPH
24H 14/1800Z 18.1N 116.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 15/0600Z 18.4N 119.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 15/1800Z 18.0N 120.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 16/1800Z...DISSIPATED

$$
Forecaster Zelinsky

[cycloneye]

Tropical Depression Four-E Discussion Number 6
NWS National Hurricane Center Miami FL EP042019
900 PM MDT Sat Jul 13 2019

The depression lost essentially all of its deep convection a few
hours ago, as strong easterly shear has continued to disrupt the
system. Recently, a few cells have formed near the center. Since
the cyclone is over marginally warm sea surface temperatures,
additional new convection could still re-develop in the
circulation overnight. However, it seems likely that the system
will degenerate into a remnant low within 24 hours.

The motion continues west-northwestward, or 290/13 kt. A low- to
mid-level ridge to the north of the cyclone should cause a turn
toward the west tomorrow, and eventually a west-southwestward
motion is likely as the shallow circulation follows the low-level
tradewind flow. The official track forecast is somewhat south of
the dynamical model consensus, and close to the previous NHC track.

FORECAST POSITIONS AND MAX WINDS

INIT 14/0300Z 17.7N 113.7W 30 KT 35 MPH
12H 14/1200Z 18.1N 115.7W 30 KT 35 MPH
24H 15/0000Z 18.5N 117.9W 25 KT 30 MPH...POST-TROP/REMNT LOW
36H 15/1200Z 18.6N 119.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 16/0000Z 18.0N 121.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
72H 17/0000Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

Tropical Depression Four-E Discussion Number 7
NWS National Hurricane Center Miami FL EP042019
300 AM MDT Sun Jul 14 2019

The depression has been devoid of significant convection since early
Saturday evening. Even in the convective maximum period, the system
has only been able to muster intermittent individual cells producing
anvils that are being subsequently blown west of the circulation by
about 20 kt of easterly shear. A recent scatterometer pass showed
peak winds of around 25 kt in the northeastern quadrant, and this is
the initial advisory intensity. The stable environment ahead of the
cyclone is not conducive for its longevity and it will likely become
a remnant low later today. The remnant low should dissipate within a
couple of days.

The motion continues west-northwestward, or 290/12 kt. A low- to
mid-level ridge to the north of the cyclone should cause a turn
toward the west later today or tonight. The official track forecast
is essentially the same as the previous one.

FORECAST POSITIONS AND MAX WINDS

INIT 14/0900Z 18.2N 114.8W 25 KT 30 MPH
12H 14/1800Z 18.5N 116.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
24H 15/0600Z 18.8N 118.6W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 15/1800Z 18.8N 120.2W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 16/0600Z...DISSIPATED

$$
Forecaster Latto/Cangialosi

[cycloneye]

Zayonara.

Post-Tropical Cyclone Four-E Discussion Number 8
NWS National Hurricane Center Miami FL EP042019
800 AM PDT Sun Jul 14 2019

Former Tropical Depression Four-E has been producing only small
bursts of convection for the past 18 h or so. The system is moving
over progressively cooler water and into a more stable air mass, so
re-development of organized convection appears unlikely. Thus, the
system is being downgraded to a remnant low pressure area. The
global models indicate that the remnant low should dissipate by
36 h at the latest, and the NHC forecast follows this scenario.

The motion is west-northwestward, or 285/11 kt. A low- to mid-level
ridge to the north of the cyclone should cause a turn toward the
west later today, with this general motion continuing until
dissipation.

This is the last advisory issued by the National Hurricane Center
on this system. For additional information on the remnant low
please see High Seas Forecasts issued by the National Weather
Service, under AWIPS header NFDHSFEPI, WMO header FZPN02 KWBC, and
on the web at ocean.weather.gov/shtml/NFDHSFEPI.php


FORECAST POSITIONS AND MAX WINDS

INIT 14/1500Z 18.4N 115.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
12H 15/0000Z 18.6N 117.7W 20 KT 25 MPH...POST-TROP/REMNT LOW
24H 15/1200Z 18.6N 119.4W 20 KT 25 MPH...POST-TROP/REMNT LOW
36H 16/0000Z 18.5N 121.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 16/1200Z...DISSIPATED

$$
Forecaster Beven