Brier Weather Station
Latitude N 47° 46' 49" Longitude W 122° 16' 48" Elevation 341 ft
529
FXUS66 KSEW 022114
AFDSEW
Area Forecast Discussion
National Weather Service Seattle WA
214 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/...
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...
A frontal system will continue to push showers across the coast,
and the central/northern terminals this afternoon and evening.
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
&&
.MARINE...
A frontal system with weak low pressure will continue to move
across the waters this afternoon through tonight with showers
over the waters. Some low ceilings with areas of mist are likely
in the coastal waters tonight/Friday morning. While another weak
front will move across the waters late Friday, high pressure
will in large 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
&&
.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