637
FXCA62 TJSJ 122118 CCA
AFDSJU

Area Forecast Discussion...CORRECTED
National Weather Service San Juan PR
518 PM AST Mon Aug 12 2024

.SYNOPSIS...
A Tropical Storm Warning is in effect for Puerto Rico and the
Virgin Islands. The recently developed Tropical Storm Ernesto will
approach the region late Tuesday, bringing strong gusty winds and
heavy rainfall to the region. The areas most impacted will be the
Virgin Islands, Vieques, Culebra, and eastern Puerto Rico. A
significant risk of flooding is expected, with mudslides likely in
areas of steep terrain. Marine and coastal conditions will
deteriorate as well.

&&

.SHORT TERM...Tonight through Wednesday...

A Tropical Storm Warning has been issued for the Puerto Rico and the
U.S. Virgin Islands. At this time the former Potential Tropical
Cyclone Five has become Tropical Storm Ernesto, now located about
590 MI ESE of San Juan, Puerto Rico. This system is expected to
move near or over the area by early Wednesday morning, bringing
tropical storm force winds and periods of heavy rain, with the
potential for flash flooding and mudslides. Marine and coastal
conditions will become hazardous by Tuesday evening.

At 500 PM AST (2100 UTC), the center of Tropical Storm Ernesto was
located near latitude 16.0 North, longitude 57.5 West. Ernesto is
moving toward the west-northwest near 28 mph (44 km/h). A westward
to west-northwestward motion with some decrease in forward speed is
expected during the next couple of days. On the forecast track,
Ernesto is expected to move across portions of the Leeward Islands
late tonight or Tuesday and near or over the U.S. and British Virgin
Islands and Puerto Rico by Tuesday evening.

By Tuesday through Wednesday, a gradual increase in rainfall and
winds will be observed as Tropical Storm Ernesto moves closer to the
islands. The latest National Hurricane Center forecast track has
this system moving just to the northeast of Puerto Rico and over the
island of Saint Croix. Therefore, there is a high potential for
flooding rains across the region. Tropical force winds and/or wind
gusts will also be likely beginning on Tuesday through Wednesday
through the region.

Residents and visitors should continue to monitor the progress of
this system and review their tropical emergency plans.Please refer
to the latest Tropical Cyclone Bulletin (TCPAT5) issued by National
Hurricane Center and Hurricane Local Statements (HLSSJU) issued by
WFO San Juan PR for the most up to date information.

.LONG TERM...Thursday through Sunday.../prev discussion/

For the beginning of the long-term forecast, hazards will continue
to depend on the potential impacts from the now Potential Tropical
Cyclone Five, which is forecast to move west-northwestward across
or near the region as a tropical storm. The main threats
associated with this system are flooding rains, landslides, windy
or possible tropical storm conditions and hazardous coastal and
marine conditions. PTC Five should start to move away from the
area on Thursday generating southerly winds. Residual moisture
will continue to be driven by the wind flow into our region
causing additional rain. Heavy rainfall may result in locally
considerable flash flooding and mudslides in portions of the U.S.
Virgin Islands Tuesday and Wednesday, and into Puerto Rico
Wednesday through early Thursday. Weather conditions are expected
to quickly improve at the end of the week as a drier-than-normal
air mass, with pockets of low-level moisture, moves into the area
and we switch to a more typical pattern.


&&

.AVIATION...
(18Z TAFS)

Mostly VFR conds can be expcd for most of the pd. Although VCTS/SHRA
could at times impact TJBQ through 22z. Winds will drop aft 22z btwn
8-12 kts mostly from the E but incrg up to 20 kts and hier gsts and
shifting out of the NE aft 13/14z as the Potential Trpcl Cyclone 5
approaches. PROB30 groups were introduced for the USVI TAF sites
after 13/17z as psbl rainbands could start filtering in promoting
low VIS and CIG.

&&

.MARINE...
Tropical Storm Ernesto, located 590 miles ESE of San Juan, is
expected to move into the local waters by Tuesday evening into
Wednesday as a tropical cyclone. However, marine conditions in our
eastern Atlantic waters and the Anegada Passage could deteriorate
as early as Tuesday morning. Further deterioration in marine and
weather conditions is expected Wednesday through Thursday.

&&

.BEACH FORECAST...
Beach conditions will deteriorate as Tropical Storm Ernesto
approaches the region. Large breaking waves are expected to impact
the Virgin Islands and Puerto Rico from late Tuesday into early
Thursday.

&&

.HYDROLOGY...
Tropical Storm Ernesto will bring rainfall accumulation of 6 to 8
inches for portions of the Virgin Islands, eastern and southern
Puerto Rico, as well as the interior. The risk of flooding will be
significant, with rapid river rises, and mudslides likely.

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...Tropical Storm Warning for PRZ001>013.

     Flood Watch from Tuesday evening through Thursday morning for
     PRZ001>013.

VI...Tropical Storm Warning for VIZ001-002.

     Flood Watch from Tuesday evening through Thursday morning for
     VIZ001-002.

AM...Tropical Storm Warning for AMZ711-712-716-723-726-733-735-741-
     742-745.

&&

$$

RADAR/HLS...ERG
IDSS...MRR/CAM
SHORT TERM DISCUSSION...GRS