Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
397
FXUS66 KSEW 030344
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
844 PM PDT Thu Jul 2 2026
.SYNOPSIS...A band of showers will continue to move inland
across the region this afternoon into tonight ahead of a
weakening frontal system. The pattern begins to dry out going
into the 4th of July weekend, with cooler temperatures and
clouds transitioning to some sunshine and warmer temperatures.
HeatRisk remains at the minor or yellow level as onshore flow
will continue into next week. The next best chance of moisture
is on Tuesday and Wednesday with a weak disturbance, with
portions of the coast and mountains having the best chance of a
shower or two.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...Showers mainly
over the North Interior and North/Central Cascades tonight, then
taping down early Friday morning. KBLI is up to 0.57" so far
today with a trace to a few hundredths elsewhere in the
interior lowlands. 33
Previous discussion...Upper level and surface analysis has a
shortwave trough driving a weak frontal system into western WA
this afternoon. The front will continue to occlude as it comes
onshore. Radar and satellite continue to remain active with this
system, as bands of showers move inland from the coast across
the central and north interior this afternoon. The initial
showers are encountering some drier air (which combined with
higher cloud bases may result in some of the moisture
evaporating before it reaches the surface, a.k.a. virga).
Amounts so far have been light, but a few heavier bands will
move inland. There`s not much of a signal of a convergence zone
behind the front, but a couple showers may linger post- front in
northern King County up into the northern Cascades
tonight/early Friday. Otherwise amounts will generally remain
very light, with a few hundredths or a tenth for inland areas,
and a tenth or two of an inch for the coast.
The onshore/low level moisture behind the showers moving through
tonight will produce significant low-level cloud coverage for
Friday morning, which will only partially scatter out going into
the afternoon for areas east of the Olympics. Another push
Friday night into Saturday with a dry frontal system will again
bring in extra clouds the morning of the 4th of July. However
as the front collapses and the jet streak of the trough moves
out, the flow will become more zonal and some high pressure
trying to build in behind the front should be enough to create
some clearing Saturday afternoon for the entire region.
High temperatures through this period remain cool, with 60s
today increasing into the low to mid 70s for the interior. Lows
remain in the 50s. HeatRisk remains minor (yellow) for those
extremely sensitive to heat. Winds will generally remain out of
the southwest, with brief north winds in Puget Sound Friday
evening at 5 to 10 mph. A few gusts near the Strait of Juan de
Fuca to 20 mph are possible next couple of afternoons with
diurnal pushes. A couple gusts in Puget Sound to 20 mph are also
possible with showers this afternoon, as well as along the
Cascade Crest over the weekend.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...Ensembles have the zonal
flow move out Sunday in favor of a more meridional pattern
between a ridge Monday/Tuesday, and a trough midweek. With
higher heights building under the ridge early next week, expect
temperatures across the interior to climb into the upper 70s to
low 80s, with Monday being the warmest day. Given the onshore
gradients remain in place, the coast will remain cooler with
highs around 60. Combined with lows dropping into the 50s, the
HeatRisk remains largely minor (yellow) with only a 10-20%
chance of the Seattle metro seeing cases of moderate (orange)
HeatRisk. A trough will bring a weak front across the region
around midweek, with clouds increasing and temperatures in the
interior cooling into the 70s. The best chance of showers with
this front is going to be portions of the north coast, northeast
Olympics, and north Cascades, with minimal precipitation
expected at this time. Winds in the period overall remain light
at 5 to 10 mph, but again portions of the Cascades (especially
along the crest) may see gusts up to 20-25 mph.
HPR
&&
.AVIATION...The last few bands of showers are moving east from
Snohomish county north and will bring some showers to terminals
in that area over the next few hours. Convergence zone potential
remains concentrated from northern King County into the
Cascades, and will likely not drift towards any of the major
terminals. Ceilings will gradually lower as the showers progress
inland, with the coast dropping to MVFR already behind the
leading line. MVFR remains likely for the interior tonight
beginning at 06-09Z and lasting through 18-21Z Friday afternoon
before partially clearing. IFR potential for the interior stays
at around 30% for a brief period Friday morning, but becomes
more certain west of Puget Sound in the Olympics and coast,
where a 40-60% chance of LIFR conditions remain for Friday
morning. Winds will remain out of the southwest through Friday
morning at 5-10 kt (couple gusts to 20 kt possible in the
interior), then transitioning to the west/northwest Friday
afternoon for areas along and south of the Strait of Juan de
Fuca.
KSEA...Off and on showers through tonight, with the convergence
zone remaining away from the terminal to the north/east.
Ceilings likely to lower to MVFR by as early as 06Z, and through
18- 21Z Friday afternoon before scattering out. There remains a
30% chance of IFR from 12Z-16Z in the morning. Winds out of the
southwest 5-10 kt with a couple gusts to 20 kt possible this
afternoon/evening. Expect a turn to the north tomorrow afternoon
around 00Z.
HPR/21
&&
.MARINE...A frontal system will continue to move across the
waters through tonight with showers over the waters. While
another weak front will move across the waters late Friday, high
pressure will begin to build back over the waters going into
this weekend into the first part of next week. As such, onshore
pushes will begin to affect the Strait of Juan de Fuca Friday
night, and continuing off and on through next week. The
strongest push is expected Saturday night, although the threat
of gale-force gusts remains only 10%. A couple periods of strong
northwest winds are also possible for the southern coastal
waters this weekend and early next week, where there is a 40-
60% chance of gusts over 20 kt. Another front may try to squeeze
through the waters midweek next week.
Seas remain at 4-6 ft or 6-8 ft through the forecast, with the
highest seas Sunday and Monday.
HPR/21
&&
.FIRE WEATHER...A front with some showers will continue to move
across the region tonight through Friday morning. Despite the
pattern becoming warmer and drier during the holiday weekend and
early next week. The onshore pattern will remain intact largely
during this warmup, so overnight relative humidity recoveries
will provide relief for any drier air during the period as highs
climb into the upper 70s and low 80s. Another front midweek may
bring the chance of a few showers for portions of the mountains
and the coast.
HPR
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&
$$
NWS SEW Office Area Forecast Discussion