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Area Forecast Discussion (AFD)

Issued by Seattle/Tacoma, WA (SEW)

                            
000
FXUS66 KSEW 222134
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
234 PM PDT Fri Mar 22 2019

.SYNOPSIS...A weak front will bring a little rain this evening. 
Showers will become isolated behind the front tonight and Saturday
then end Saturday evening. Another front will reach the area on 
Monday. No organized weather systems are expected for the rest of 
next week but weak upper troughs will bring a chance of showers at
times. 

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...A skinny front will bring 
a few hours of light rain late this afternoon/early this evening 
as it moves from southwest to northeast across the area. It will 
get a little breezy with the front for a few hours but nothing 
too exciting. 

Showers look pretty limited behind the front and most areas will 
be dry later tonight into Saturday morning. Some showers should
bubble up later Saturday with daytime heating and a weak upper 
trough moving into the area providing some lift. An isolated 
thunderstorm is possible in the afternoon near the coast and over
the Southwest Interior where it will be more unstable but the
chances look to low to mention in the forecast. 

Showers will pretty much end after Saturday evening as weak high 
pressure aloft moves over the area. Low level flow will turn 
offshore on Sunday which should help dry things further with 
clouds decreasing during the day. Another front will move into the
area from the southwest on Monday for an increasing chance of 
rain. Highs will be near to slightly above normal the next few 
days. Schneider

.LONG TERM /TUESDAY THROUGH FRIDAY/...Some showers will linger 
into Tuesday behind the Monday front but the trend will be for 
drying. It looks like an upper level blocking pattern will 
develop Wednesday and probably continue into Thursday and Friday. 
This should keep any fronts or organized weather systems out of 
the area but it also makes for a rather squirrely pattern with low
confidence in the details. There will likely be some dry periods 
mixed with times when there is a chance of showers. Schneider

&&

.AVIATION...A cold front will spread rain inland this evening
across Western Washington. The flow aloft is southerly. The air 
mass will remain moist overnight with onshore flow and additional 
showers. MVFR ceilings are likely. Drier conditions are expected
Saturday morning as the flow turns offshore. 33

KSEA...VFR conditions this evening. Rain spreading to the 
terminal by 22-01Z. S winds at the surface increasing to 10-15kt.
MVFR cigs likely overnight with additional showers. 33

&&

.MARINE...Winds will increase over the waters tonight as a cold 
front moves inland - Small Craft Advisories are in effect for all 
waters. Meanwhile, seas will also build to 10-14 feet at the
Coastal Waters and West Entrance. Winds and seas will ease on 
Saturday. The flow will turn offshore on Sunday. The next frontal 
system will arrive on Monday, likely bringing another round of
Small Craft Advisories.  33

&&

.HYDROLOGY...River flooding is not expected for the next 7 days.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT Sunday for Coastal Waters 
     From Cape Flattery To James Island 10 To 60 Nm-Coastal 
     Waters From Cape Flattery To James Island Out 10 Nm-Coastal 
     Waters From James Island To Point Grenville 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville Out 10 
     Nm-Coastal Waters From Point Grenville To Cape Shoalwater 
     10 To 60 Nm-Coastal Waters From Point Grenville To Cape 
     Shoalwater Out 10 Nm.

     Small Craft Advisory for rough bar until 5 AM PDT Sunday for 
     Grays Harbor Bar.

     Small Craft Advisory until 5 AM PDT Saturday for Central U.S. 
     Waters Strait Of Juan De Fuca-East Entrance U.S. Waters 
     Strait Of Juan De Fuca-Northern Inland Waters Including The 
     San Juan Islands.

     Small Craft Advisory for hazardous seas until 5 AM PDT Sunday 
     for West Entrance U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until midnight PDT tonight for Admiralty 
     Inlet.

     Small Craft Advisory until 3 AM PDT Saturday for Puget Sound and 
     Hood Canal.

&&

$$

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