Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 232136
Area Forecast Discussion
National Weather Service Tiyan GU
736 AM ChST Fri Feb 24 2017
Andersen Air Force Base Doppler weather radar shows only a few
showers moving through the Marianas waters. Satellite shows the
remains of an old shear line blowing through, mainly causing an
increase in cloud cover.
Shear line remnants should clear the area today, allowing sunnier
skies for the weekend and perhaps on into next week. GFS is
getting more generous with rainfall amounts, however the ECMWF-
HiRes is still a bit stingy. For now satellite seems to favor the
drier scenario, which is currently the forecast one. Therefore,
only small changes were made, primarily freshening and extending
the wave grids. As the available guidance converges toward one of
the two scenarios, will tweak the forecast if needed later.
The buoys have been creeping upward. They are still under small
craft advisory criteria, but have a notched a couple 9 foot
readings. This is too close for comfort and will have to be
IR satellite animation shows a busier weather pattern this morning
with active convection in clusters across the eastern region.
Showers and thunderstorms are seen south and west of Chuuk,
primarily south of Pohnpei, and across Kosrae to south of Majuro.
Forecast for today brings in a slight chance of thunderstorms to
Chuuk and Pohnpei, and wetter conditions at Kosrae with scattered
showers and isolated thunderstorms there. Also bumped up the winds
at Majuro today to between 15 and 25 knots based on the ASCAT
pass this morning showing stronger winds across the Ratak Chain.
The showery trade wind pattern will push west-southwest with
moderate to fresh, drier trades filtering in from the northeast.
Showery weather will return late in the weekend to the region as
the axis of convergence shifts northward again.
Combined seas and surf are slowly building across the region. A high
surf advisory remains in effect for east facing reefs of Kosrae.
Held off on any surf advisories at Majuro and Pohnpei for now, but
high surf still looks possible over the weekend at both
locations. Went ahead with small craft advisory for seas at all 3
forecast points with seas building to between 9 and 10 feet
across the region tonight. A small craft advisory due to winds is
in effect this morning at Majuro as ASCAT shows winds of 15 to 25
knots there this morning. Additionally, lunar high tides and large
seas and surf could cause some minor inundation during high tides
the next several days at Majuro, particularly at low-lying
The dry pattern over Yap and Palau will slowly erode away as clouds
increase across the region today from east to west. A trade wind
disturbance will move west across Chuuk State toward Yap and Koror
today with showers and thunderstorms expected there tonight. Models
still showing the bulk of the showers keeping near and just south of
Yap. Models maintain a showery pattern in the long-range with an
active trade-wind convergence set up over the region for early next
Combined seas will increase to around 9 feet by Saturday at Yap and
Chuuk. Seas should stay just below small craft advisory here, but
will have to watch closely the next few days. Combined seas are
expected to remain below 9 feet in Palau.