Area Forecast Discussion
Issued by NWS
FXPQ60 PGUM 271952
Area Forecast Discussion
National Weather Service Tiyan GU
540 AM ChST Tue Jun 28 2016
.Synopsis...East trade-winds and a few showers could be found
across the Marianas this morning.
No change made to the forecast. Expect east winds of between
10 to 15 mph today and tonight.
Models are in agreement with a circulation developing near Pohnpei
by Wednesday. A surface trough will extend from the circulation
northward. The development of the surface trough will cause winds
to become northeast across the Marianas Wednesday. Models keep the
circulation weak and move it west-northwest passing south of Guam
by Saturday. The surface trough moving along with the circulation
will pass across the local area around Friday night. The northeast
winds will become southerly by Friday after the passage of the
Models keep showers spotty and while there could be periods of
showers the predominate coverage will be isolated through the
The southerly winds Friday night will persist through part of
the weekend. The winds will be light at that time which will be
favorable for island thunderstorms Friday through Sunday night.
Upper-level winds will also be slightly favorable for
thunderstorms during that time.
Ritidian, Ipan and Tanapag buoy data show combined seas of between
4 to 5 feet this morning. The same data showed a east to northeast
swell with a period of 10 to 11 seconds. The east trade- wind
swell is expected through Wednesday night. The swell will become
more northeasterly the second half of the week. The swell of 4 to
5 feet tonight will decrease tonight. Winds will be 10 to 15 knots
today decreasing tonight.
Pockets of scattered showers and a few thunderstorms are seen
across the region from Chuuk to the date line. Most active weather
this morning is seen near and just north of Chuuk...near and east
of Pohnpei and northeast of Majuro. Near-term forecast adjusts
weather at Pohnpei and Chuuk today...mainly due to the location of
nearby weather. Improved conditions today for Chuuk with showers
passing north...and increased showers at Pohnpei. Models show a
weak circulation just southeast of Pohnpei that will be the focus
of showers as it heads slowly west-northwest the next few days.
Current pattern across Micronesia with the light...and at times...
variable winds will persist through the week. Weak troughing could
generate showers the next few days but models show no discernible
Discussion for the Chuuk forecast is combined with the Eastern
Micronesia section above.
A weak monsoon trough remains near Yap and Koror. 12Z Ascat pass
shows the trough to be just south of Koror...passing through a weak
circulation centered southeast of Koror at 6N136E. Scattered showers
and isolated thunderstorms will persist at Yap and Koror the next
few days as this trough slowly lifts north. Winds across both
locations will become variable mid to late week...possibly shifting
to the south or southwest. This would be a result of the monsoon
trough linking up to a weak circulation near Chuuk and Pohnpei
around Thursday. Unsettled weather conditions are expected the next
few days as the trough remains nearby. Expect gentle winds through