Area Forecast Discussion
Issued by NWS San Juan, PR

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FXCA62 TJSJ 251529

Area Forecast Discussion
National Weather Service San Juan PR
1129 AM AST Sat Feb 25 2017

Mostly sunny skies with no rainfall activity prevailed
across the half west portion of Puerto Rico. The U.S. Virgin
Islands and the east half portion of Puerto Rico observed variably
cloudy skies with a few passing showers as a surge of surface
moisture moved this morning. San Juan, St Thomas and St Croix
airports reported temperatures in the low 80s. Under the
prevailing southerly wind flow, maximum temperatures across
northern Puerto Rico could reach the upper 80s and low 90s this
afternoon. However, satellite imagery have a group of clouds
moving toward the islands, which could keep the local maximum
temperatures around the mid 80s this afternoon. Afternoon
convection is expected mainly across the western interior and
Northwest Puerto Rico, as well as in the vicinity of the San Juan
Metro area. Elsewhere, expect clouds and little or no shower


In general, VFR conds are expected to prevail through the fcst
prd. Although little or no SHRA/-SHRA are expected, a patch of
clouds with ceilings btwn FL025-FL060 are expected between
25/15-21z. SHRA expected across the interior and NW PR btwn
25/16-22z and VCSH at TIST/TISX/TNCM/TKPK. Wnds fm s-se btwn 5-15
kts with sea breeze variations til 25/22z, then calm to light and
variable winds.


Local buoy network indicated seas below 5 feet across the nearshore
waters. Mariners can expect seas up to 6 feet across the Atlantic
Offshore waters, but will continue to subside through the
afternoon hours. Beach goers should exercise caution due to a
high risk of rip currents for the northwest to northeast facing
beaches of Puerto Rico and for the northern facing beaches of
Culebra and the northern USVI


.PREV DISCUSSION... /issued 418 AM AST Sat Feb 25 2017/

SYNOPSIS...A surface low pressure and associated frontal boundary
across the western Atlantic in combination with a surface high
pressure across the central Atlantic will continue to produce a
southeasterly wind flow across the region until at least Sunday. A
strong surface high pressure will move over the southwestern
Atlantic on Sunday. As this happens, the local wind is expected to
shift from the east on Sunday and from the East to east-northeast
on Monday.

DISCUSSION...Under a southeast wind flow, Doppler weather radar
detected isolated showers moving northwestward across the U.S.
Virgin Islands and eastern sections of Puerto Rico overnight and
early this morning. Under an stable weather pattern, only small
patches of moisture associated with the southeasterly wind flow
are expected to affect the eastern and southeastern sections of
Puerto Rico during the rest of the morning hours, but mostly sunny
skies are expected across most of the region. The limited moisture
in combination with daytime heating, sea breeze convergence and
other local effect are still expected to produce some cloudiness
and showers across interior and northwest Puerto Rico this
afternoon, but not widespread or significant precipitation is
expected. Under an east southeast low level wind flow, warmer
than normal temperatures are expected this afternoon mostly across
the northern coastal areas of Puerto Rico.

As the low pressure center an associated frontal boundary moves
northeastward toward the northwest Atlantic, a strong surface high
pressure is expected to move across the southwestern Atlantic.
This feature will induce an easterly low level wind flow across
the region on Sunday and an east to east-northeast wind flow by
Monday. An increase in wind speed is also expected as the surface
high pressure strengthens north of the region. Dry and generally
stable conditions are expected to continue over the region today
and Sunday. By early next week, a prefrontal trough will move back
across the region, increasing the frequency of trade wind showers
across the local islands.

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...Mariners can expect seas between 5 and 7 feet across
the offshore Atlantic Waters early this morning. Seas are expected
to decrease to 4 to 6 feet by mid morning and will continue to
slowly subside today. Beach goers should exercise caution due to a
high risk of rip currents for the northwest to northeast facing
beaches of Puerto Rico and for the northern facing beaches of
Culebra and the northern USVI. Small Craft Advisory is in effect
until early this morning for the offshore Atlantic waters.


SJU  87  74  85  74 /  20  10  20  40
STT  83  73  85  74 /  20  20  20  40


PR...High Rip Current Risk until 6 PM AST this evening for Culebra-
     Mayaguez and Vicinity-North Central-Northeast-Northwest-San
     Juan and Vicinity-Southeast-Western Interior.

VI...High Rip Current Risk until 6 PM AST this evening for
     St.Thomas...St. John.. and Adjacent Islands.

AM...High Rip Current Risk until 6 PM AST this evening for Coastal
     Waters of Northern USVI and Culebra out 10 NM-Coastal
     Waters of Southern USVI Vieques and Eastern Puerto Rico out
     10 NM.



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