Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 042114
Area Forecast Discussion
National Weather Service Tiyan GU
639 AM ChST Mon Dec 5 2016
.Synopsis... East to northeast trade-winds and isolated showers
prevail across the local area this morning.
Only a few minor changes made to the forecast. Nixed scattered
showers in today`s forecast. Satellite and radar imagery did show
a few showers over the local area, but not enough coverage to be
Breezy east winds of 15 to 25 mph will prevail across the Marianas
today. Winds will decrease slightly to 15 to 20 tonight and Tuesday.
Models show an increased chance of showers Tuesday night through
Wednesday night. These showers will be the result of trade-wind
convergence. Deep layer moisture is not predicted to be high so
just expect mostly cloudy skies while keeping shower coverage
Radar 2kft VAD wind speeds from this morning averaged in the
upper 20 knot range. Expect winds between 20 and 25 knots through
the day before decreasing in the late afternoon.
Buoy data show seas between 8 to 10 feet this morning. Ritidian
buoy did recorded a maximum sea height of 15 feet, although feel
the average will be between 9 to 11 feet today. A Small Craft
Advisory remains in effect because of winds and seas. Winds and
seas will decrease below Small Craft criteria by tonight.
An east swell will prevail through the forecast. Models keep a
north swell in the forecast through tonight...although buoy data
hints that it may have already ended. Surf will be hazardous on
east and north facing reefs with surf on east facing reefs between
10 to 12 feet and 7 TO 9 feet on north facing reefs. The hazardous
conditions will prevail through this afternoon decreasing below
Showers and thunderstorms are seen near and south of Chuuk and
Pohnpei near the southern end of a surface trough. Convection has
decreased near Kosrae and Majuro but models suggest showers will
increase at Kosrae later today as trade-wind convergence increases
once again. In the long run, models maintain a narrow band of
showers and thunderstorms across the region within the zone of
trade- wind convergence. This will periodically bring showers and
thunderstorms to most areas from Chuuk to Majuro this week. Fresh
to strong trade winds will be the most notable aspect of the
forecast the next couple of days. Winds will weaken overall during
the latter half of the week.
Fresh to strong trade winds and swell will maintain hazardous surf
and sea conditions from Chuuk eastward to Majuro the next day or two
before winds and then seas slowly decrease from east to west. Some
coastal inundation is possible due to the astronomical high tide and
large trade wind swell. Tide levels continue to fall and inundation
risk will diminish by tonight.
Reasoning for the Chuuk forecast can be found under the Eastern
Micronesia discussion above.
A broad disturbance is seen south of Koror and Yap along a near-
equatorial trough. Showers and thunderstorms continue to simmer to
the south of both locations. Both GFS and ECMWF show the trough axis
lifting north, keeping stronger trades north of 10N. The northward
shift will also bring isolated thunderstorms to both areas for much
of the week.
GU...High Surf Advisory until 3 PM CHST this afternoon for GUZ001>004.
Marianas Waters...Small Craft Advisory until 3 PM CHST this afternoon for