Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 230058 CCA
Area Forecast Discussion...Corrected
National Weather Service Tiyan GU
530 AM ChST Sun Apr 23 2017
Corrected day for decreasing showers
Mostly cloudy skies and moderate winds prevail across the Marianas.
A tropical disturbance is seen on the latest IR satellite data to the
south of Guam. Isolated showers and a few thunderstorms were seen
over night across the southern Mariana coastal waters.
Model guidance is in good agreement with the tracking and development
of the tropical disturbance to the south of Guam. All of the models
show an abundance of showers over the Marianas for the next few days,
with scattered showers developing initially over Guam, then spreading
northward to Saipan. A few lightning strikes were detected over night
over the western Guam waters and as the instability increases, expect
to see more thunderstorms develop over the area. Although shower
coverage is expected to decrease to isolated by Tuesday morning, an
overall unsettled pattern is likely through most of the week. Coastal
waters will see combined seas remaining around 4 to 6 feet the next
couple of days, then a slow fall beginning around midweek.
An active ITCZ will maintain showers and thunderstorms across much of
the region between 2N and 7N from Pohnpei to the southern Marshalls.
At Pohnpei, showers will increase early this morning before tapering
off around midday. At Kosrae and Majuro, showers will gradually
increase this evening, becoming scattered the next day or two.
Unsettled weather will persist for the next several days over eastern
Micronesia with showers and thunderstorms periodically increasing
before tapering off. Later in the week, models continue to show the
band of convection stretched east to west, but just south of Pohnpei
A broad, but weak, circulation east of Yap near 8N143E, continues to
be the main weather feature in the region. Scattered to numerous
showers and isolated thunderstorms between Yap and Chuuk, and just
south of Guam, will slowly move WNW the next couple of days. Models
show the circulation maintaining a WNW motion, with some slow
development, keeping the bulk of showers closer to Yap the next
couple of days. Decided to reduce showers at Koror later in the week
with the expectation that most showers and thunderstorms will be
found closer to the circulation center and along the northern and
eastern sides. Isolated showers this morning at Chuuk will increase
around midday and will continue into midweek as the ITCZ stretches
into Chuuk State from eastern Micronesia. Slightly drier weather is
expected by late week, but models continue to indicate disturbed
weather south of 5N.