Hurricane Season runs from June 1-November 30
[10/10]
959
FXCA62 TJSJ 250827
AFDSJU
Area Forecast Discussion
National Weather Service San Juan PR
427 AM AST Wed Dec 25 2024
.SYNOPSIS...
Showers and isolated thunderstorms are expected for Christmas Day
across portions of the islands. An old frontal boundary north of
the region will continue to promote showery weather conditions
through the weekend under light to moderate northeasterly winds. A
strong pulse of Saharan dust has reached the region, promoting
hazy skies and reduced visibilities. Marine and coastal conditions
will continue deteriorated due to breezy conditions and a pulse
of northeasterly swell across the Atlantic waters and the Mona
Channel.
&&
.SHORT TERM...Today through Friday...
Clear to partly cloudy skies prevailed during the early morning
hours across Puerto Rico and the U.S. Virgin Islands. Quick passing
showers were noted along the northern and eastern sections of the
islands. The Doppler radar estimated between 0.25-0.50 inches of
rain with this activity. Minimum temperatures were from upper 60s to
low 70s across the higher elevations to the mid and upper 70s across
the lower elevations. The wind was from the northeast around 10 mph
with land breeze variations.
An old frontal boundary north of the region will continue to bring
shallow moisture content through the short-term period under light
to moderate east to northeast winds. At mid-levels, an atypical
Saharan Air Layer with suspended Saharan dust will continue to
promote hazy skies across the islands today. Although drier air
aloft will be present across the area, the 500 mb temps are forecast
to remain around minus 7/7.5 degrees C and PWAT content should
fluctuate between 1.6-1.8 inches. This will aid in the development
of locally induced afternoon showers with possible isolated
thunderstorms over the SW quadrant of PR each afternoon. Meanwhile,
colder air moving over warmer waters under the ENE winds will bring
passing showers across the USVI and northern/eastern sections of PR
during the nighttime and early morning hours thru the period.
.LONG TERM...Saturday through Wednesday...
The latest model guidances continues to suggest a very dry and
cooler pattern for most of the long-term period. Moisture associated
with a cold front north of the region is anticipated to cross the
islands by Saturday into Sunday. As the front moves over the region,
isolated to scattered showers are likely mostly over the
northeastern municipalities of Puerto Rico and the US Virgin
Islands during the morning hours. Then, in the afternoon hours
the southern and southwestern portions of Puerto Rico will observe
the development of more shower activity over the area. A drop in
precipitable water content is expected by Monday with values
around 1.35 inches. Therefore, limited shower activity and stable
weather conditions are anticipated for the New Year`s
festivities. At the surface levels a building strong high
pressure moving-off the eastern coast of the Continental United
States and a strong low in the central Atlantic will promote a
moderate to locally fresh wind flow from the north across the
region. As both of the systems builds up over the waters, cooler
and dry air will filter into the region promoting temperatures to
drop during the overnight hours.
&&
.AVIATION...
(06Z TAFS)
Mainly VFR conditions are expected to prevail across all terminals
during the next 24 hours. However, trade wind SHRA could persist
through 25/13z across the USVI and eastern PR terminals, causing
brief MVFR cigs. Also, SHRA/TSRA expected to develop near TJPS btw
25/17z-21z. Mtn tops obscd expected along the Cordillera. HZ due to
Saharan dust will continue but VSBY should remain P6SM. Winds mostly
ENE at 10-15 kt with stronger gusts at times.
&&
.MARINE...
A building surface high pressure over the Western Atlantic will
yield moderate to locally fresh east to northeast winds, creating
choppy conditions for small craft. Confused seas will create
hazardous marine conditions across the Atlantic waters. In the
meantime, the remnants of an old frontal will continue to generate
scattered showers and isolated thunderstorm. Saharan dust will
maintain hazy skies for the next several weeks.
&&
.BEACH FORECAST...
Strong winds will continue to enhance the risk of life-
threatening rip currents along the north coast of Puerto Rico.
Elsewhere, the risk is moderate.
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...High Rip Current Risk through this afternoon for PRZ001-002-005-
008-010.
VI...None.
AM...Small Craft Advisory until noon AST today for AMZ711-741.
Small Craft Advisory until 6 AM AST early this morning for
AMZ712-742.
&&
$$
SHORT TERM...DSR
LONG TERM....GRS
