National Weather Service Raw Text Product

300 
FXPQ50 PGUM 042021
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
621 AM ChST Tue May 5 2020

.Marianas Synopsis...
Satellite shows a weak trade-wind disturbance moving through the
Marianas with scattered showers. Moderate trades continue, along
with 4-6 ft seas.

&&

.Discussion...
Previous forecast is still on track, with scattered showers moving
through this morning, followed by isolated showers in the afternoon.
The rest of the week looks drier again, with variations in moisture
reflected by forecast variations in cloud cover. GFS shows a possible
disturbance next Monday, but the ECMWF is very weak with it.

&&

.Marine...
Moderate trades will persist through the next 5 days, and seas will
change very little, with a slight decrease in seas the second half
of this week followed by a slow increase early next week.

&&

.Eastern Micronesia...
Convergent trade-wind flow and embedded surface troughs are 
generating batches of showers and thunderstorms between 3N and 6N. 
Most deep convection is south of Pohnpei and Majuro this morning. 

Trade-wind convergence currently south and east of Majuro will push 
north and west tonight, bringing scattered showers to Majuro and 
Kosrae on Wednesday and Pohnpei Thursday. Shower coverage may end 
up being more isolated at Kosrae by Thursday as convection lifts 
farther north. A weak surface ridge develops south of Pohnpei and 
Kosrae late this week. This should lead to a brief break in showers
for the region. Another impulse of showery weather is slated to 
reach Majuro early next week from the east. Convection next week 
looks to establish between 6N and 9N, allowing Kosrae to dry out a
bit while more showers spread across Kwajalein and nearby atolls.

Overnight ASCAT indicating fresh to strong trades just east of 
Pohnpei prompted a headline for hazardous marine conditions today.
Surf along east reefs of Kosrae should fall below hazardous levels
tonight as upstream trades ease a bit. Winds and seas have subsided
slightly across the Marshalls but remain elevated due to a broad 
area of fresh trade winds upstream. This should persist through the
week before dropping another notch early next week.

&&

.Western Micronesia...
A broad and weak disturbance centered near 3N142E is generating 
patchy showers and thunderstorms across eastern Yap state. A surface 
trough and convergent trade flow are triggering showers and 
thunderstorms across Chuuk state. 

Scattered showers are expected to linger through tonight at Chuuk. 
Weather should remain unsettled through the week for Chuuk as 
convergent flow remains overhead and subtle surface troughs 
encourage pulses of deep convection. Bouts of scattered showers are 
likely, but had a difficult time pinning down when they would 
develop as guidance has been "noisy" with placement of low-level 
convergence and convection. Relatively quiet weather is expected 
at Yap and Palau the next day or so before the western fringes of 
the disturbance introduce more showers and clouds. This week's 
disturbance/circulation should bring more showers to Yap than the 
feature from last week. This is due to a series of surface troughs
that will slide through Yap well north of the circulation itself.
Scattered showers are also on the table for Palau late this week.

Maintained hazardous seas at Chuuk based on convection streaming in 
from the east. This decision may be a bit overdone based on ASCAT 
but felt there was enough support from observations and guidance. 
Winds and seas relax late this week for Chuuk while a rather steady-
state pattern prevails at Yap and Palau due to the weak disturbance.

&&

.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
Marianas Waters...None.

&&

$$

Middlebrooke/Bukunt