Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
FXPQ60 PGUM 231827

Area Forecast Discussion
National Weather Service Tiyan GU
400 AM ChST Sat Jun 24 2017

.Marianas Synopsis...
An upper-level low is seen on the latest IR and water vapor
satellite images to the north-northeast of Saipan. A weak surface
trough is east of the Marianas. Isolated showers and thunderstorms
are seen over the area this morning with scattered showers and
isolated thunderstorms to the east of Tinian and Saipan and
southeast of Guam.


A TUTT cell is seen north-northeast of Saipan with a weak surface
trough to the east of the Marianas. These features continue to
approach the islands and are producing scattered showers and
isolated thunderstorms to the east of Tinian and Saipan. This area
of convection will move into Tinian and Saipan this morning, with
mostly cloudy skies, scattered showers and isolated thunderstorms
expected over both islands and waters through the day. The
convection will spread southwestward through the day, affecting
Rota and Guam by this evening. Conditions will then improve Monday
as both features move west of the Marianas allowing a drier
trade-wind pattern to return to the islands. Another approaching
disturbance will bring a renewed chance of convection to the area
around the middle of next week. Latest model guidance now shows
the best chance for these showers to be Thursday. Due to the
uncertainty of the changing guidance for the later time period,
decided to keep the forecast as is for now.


.Eastern Micronesia...
A trade-wind trough with patchy showers runs from south of Pohnpei
and Kosrae to near the Date Line east of Majuro. A ridge of high
pressure and fair weather will be over Chuuk State today and Sunday
at least. The trough is moving slowly westward, and will trigger
scattered showers for Majuro by tonight thru Sunday and Kosrae
tonight thru Monday. Patchy showers could arrive at Pohnpei late
Sunday thru Monday and at Chuuk late Sunday perhaps thru Tuesday.
Then, relatively drier trade winds are expected to develop across
the area next week.


.Western Micronesia...
Discussion for the Chuuk forecast can be found under Eastern
Micronesia above.

Satellite shows heavier showers have moved far west of Koror, but a
pattern of surface troughing remains over far Western Micronesia,
and spotty showers persist, especially near Yap. A few showers will
linger near Koror today and near Yap today and perhaps thru tonight.
Then, a broad surface ridge building westward from Chuuk State will
provide drier weather for Yap and Koror from Sunday thru the middle
of next week.


Marianas Waters...None.


Kleeschulte/Simpson is the U.S. government's official web portal to all federal, state and local government web resources and services.