Area Forecast Discussion
Issued by NWS San Juan, PR
FXCA62 TJSJ 260201
Area Forecast Discussion
National Weather Service San Juan PR
1001 PM AST Sat Feb 25 2017
.UPDATE...Some showers developed across the north central and
northwest sections of Puerto Rico. The heaviest rainfall occured
in the vicinity of Hatillo and Camuy where doppler radar estimated
up to two inches in localized areas. Rest of tonight, some passing
showers are expected, but overall will remain dry. No changes were
made to forecast grids tonight.
.AVIATION...Mainly VFR conditions will prevail across all terminals
through the forecast period. However, SHRA is expected to develop
over western interior sections of PR from 26/18-22z. Impacting
mainly the flying area of TJMZ with MVFR conds. Surface winds light
and variable overnight...increasing 10-15 kts from the ENE after
26/13z with sea breeze variations.
.MARINE...Seas have diminished near 5 feet across the offshore
Atlantic waters. Seas are expected to increase once again Monday
night into Tuesday.
.PREV DISCUSSION... /issued 204 PM AST Sat Feb 25 2017/
SYNOPSIS...Upper level trough is moving across the region today...
however mid levels continues dry and stable. As a result...shallow
convection if any will develop later this afternoon across the
north coastal sections of Puerto Rico. Although...below normal
moisture will prevail the rest of the weekend...passing showers
will reach the local islands at times. Then...high pressure builds
over the Central Atlantic pushing several bands of moisture
across the U.S. Virgin Islands and Puerto Rico next week.
DISCUSSION...An area of low level moisture moved over the U.S.
Virgin Islands...Culebra and Vieques this morning. As a result...
cloudy skies have prevailed over Culebra...Vieques and eastern
Puerto Rico today. A relatively dry and stable conditions were
observed elsewhere. Morning sounding indicated moisture level
below normal and strong subsidence cap at 800mb. The rest of today...
sea breeze convergence will likely induce some showers over the
northern half of Puerto Rico. Conditions will remain fairly stable
the rest of the wek. The winds shift from the east on Sunday...
focusing the afternoon showers over portions of the West Interior
and Western Puerto Rico.
An easterly pertubation will reach the Northeast Caribbean between
Monday and Tuesday...increasing the potential for showers across
the USVI and PR. At the same...surface high pressure is forecast
to build over the Central/Eastern Atlantic resulting in fresh
trade winds over the local area. As a result...a trade wind pattern
will establish across the local islands most of next week. Patches
of low level moisture embedded in the trade winds will bring
passing showers across the local islands from time to time.
AVIATION...VFR conds at all TAF sites through the fcst prd. Few
clds FL025..FL060...SKC abv. Isold -SHRA/SHRA. Prevailing east to
southeast wind flow at 10 knots or less except for local sea breeze
variations along the coastal areas. Wnds fm se 5-15 kts blo FL200...
bcmg fm SW to W and incr w/ht abv. No sig operational or wx impact
MARINE...Marine conditions will gradually improve through Monday
Morning. Surface high pressure will build over the Central/Eastern
Atlantic resulting fresh winds across the region. This will lead
to choppy seas across the local waters from late Monday through
the end of next week. Seas are forecast to build up to 8 feet
across the offshore waters.
.PRELIMINARY POINT TEMPS/POPS...
SJU 74 85 74 85 / 10 20 40 40
STT 73 85 74 86 / 20 20 40 40