Re: Caribbean - Central America Weather
Posted: Fri Apr 19, 2019 5:13 am
Area Forecast Discussion
National Weather Service San Juan PR
438 AM AST Fri Apr 19 2019
.SYNOPSIS...Large amplitude upper level trough over the central
Atlantic will gradually shift eastward as it deepens into a closed
low. An upper level ridge will build across the central and
eastern Caribbean in response to another trough over the eastern
U.S. At the surface...a frontal boundary will extend from the
closed low southwestward and may have an impact on the local
weather conditions later this week.
&&
.SHORT TERM...High pressure continues to build in the western
Atlantic north of 40 north and between 55 and 50 degrees west. It
will wobble in place during the period. It is forecast to become
a 1038 mb high by late Saturday (21/00Z). This high will gradually
increase the easterly trade wind flow over the area through the
period. Low pressure has cut off of a trough in the mid Atlantic
today near 37.5 degrees north 39 degrees west and will migrate
south and then southwest during the period. The low has adopted
the front associated with the main low and under pressure from the
high in the north its tail will approach Puerto Rico and the U.S.
Virgin Islands, such that by late Sunday it will be about 160
miles northeast of San Juan. Patchy moisture will continue to
yield scattered light showers across the area in the usual diurnal
pattern of night and early morning showers in the eastern portion
of Puerto Rico and mostly around the U.S. Virgin Islands over the
local waters, followed by moderate afternoon showers in western
and interior Puerto Rico. Showers will increase Saturday and
Sunday--mainly in the west--as conditions aloft become more
favorable.
.LONG TERM...Monday through Saturday...A frontal boundary is
forecast to move across the local forecast area on Monday.
This feature will help increase the shower coverage mainly along
the northern half of Puerto Rico and northern USVI in the morning
hours and later on the rest of the CWA. After Tuesday...the low is
forecast lift northward again and the front dissipates. A return
to a mostly easterly flow is expected which will continue to
advect small patches of low level moisture from time to time.
&&
.AVIATION...Iso-sct SHRA cont across the waters surrounding the
north and south coasts of PR with few arriving over land. Sfc winds
are ENE and will incr to 10-23 kt aft 19/14Z with gusts to 28kt psbl
along the N and S coasts of PR. Aft 19/17Z SHRA are to dvlp
downstream from TISX, El Yunque and over wrn PR with lcl MVFR conds
nr TJMZ and mtn obscurations. Tops mostly blo FL150. Conds imprvg
aft 19/22Z. Max winds WNW 50-60 kt btwn FL380-450.
&&
.MARINE...Choppy and breezy conditions are expected to continue
through the weekend. There is a moderate risk of rip currents
across many of the local beaches and even more beaches will have
this moderate risk of rip currents this weekend.Small craft
operators are urged to exercise caution today as seas will be up
to 6 feet and winds will be up to 20 knots.
A low pressure is forecast to develop NE of our local waters on
Saturday and it is expected to move west south west. This feature
will generate a NE swell that will be arriving our local waters
late Tuesday night. Swells are expected to be between 5 to 7 feet
with periods of around 12 seconds.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 87 76 / 30 40 30 30
STT 87 75 87 74 / 30 30 30 40
National Weather Service San Juan PR
438 AM AST Fri Apr 19 2019
.SYNOPSIS...Large amplitude upper level trough over the central
Atlantic will gradually shift eastward as it deepens into a closed
low. An upper level ridge will build across the central and
eastern Caribbean in response to another trough over the eastern
U.S. At the surface...a frontal boundary will extend from the
closed low southwestward and may have an impact on the local
weather conditions later this week.
&&
.SHORT TERM...High pressure continues to build in the western
Atlantic north of 40 north and between 55 and 50 degrees west. It
will wobble in place during the period. It is forecast to become
a 1038 mb high by late Saturday (21/00Z). This high will gradually
increase the easterly trade wind flow over the area through the
period. Low pressure has cut off of a trough in the mid Atlantic
today near 37.5 degrees north 39 degrees west and will migrate
south and then southwest during the period. The low has adopted
the front associated with the main low and under pressure from the
high in the north its tail will approach Puerto Rico and the U.S.
Virgin Islands, such that by late Sunday it will be about 160
miles northeast of San Juan. Patchy moisture will continue to
yield scattered light showers across the area in the usual diurnal
pattern of night and early morning showers in the eastern portion
of Puerto Rico and mostly around the U.S. Virgin Islands over the
local waters, followed by moderate afternoon showers in western
and interior Puerto Rico. Showers will increase Saturday and
Sunday--mainly in the west--as conditions aloft become more
favorable.
.LONG TERM...Monday through Saturday...A frontal boundary is
forecast to move across the local forecast area on Monday.
This feature will help increase the shower coverage mainly along
the northern half of Puerto Rico and northern USVI in the morning
hours and later on the rest of the CWA. After Tuesday...the low is
forecast lift northward again and the front dissipates. A return
to a mostly easterly flow is expected which will continue to
advect small patches of low level moisture from time to time.
&&
.AVIATION...Iso-sct SHRA cont across the waters surrounding the
north and south coasts of PR with few arriving over land. Sfc winds
are ENE and will incr to 10-23 kt aft 19/14Z with gusts to 28kt psbl
along the N and S coasts of PR. Aft 19/17Z SHRA are to dvlp
downstream from TISX, El Yunque and over wrn PR with lcl MVFR conds
nr TJMZ and mtn obscurations. Tops mostly blo FL150. Conds imprvg
aft 19/22Z. Max winds WNW 50-60 kt btwn FL380-450.
&&
.MARINE...Choppy and breezy conditions are expected to continue
through the weekend. There is a moderate risk of rip currents
across many of the local beaches and even more beaches will have
this moderate risk of rip currents this weekend.Small craft
operators are urged to exercise caution today as seas will be up
to 6 feet and winds will be up to 20 knots.
A low pressure is forecast to develop NE of our local waters on
Saturday and it is expected to move west south west. This feature
will generate a NE swell that will be arriving our local waters
late Tuesday night. Swells are expected to be between 5 to 7 feet
with periods of around 12 seconds.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 75 87 76 / 30 40 30 30
STT 87 75 87 74 / 30 30 30 40