Forecast Discussion for SEW NWS Office
000
FXUS66 KSEW 060249
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
749 PM PDT Wed Oct 5 2022

.UPDATE...Mainly clear across the area this evening with low
stratus along the coast. Stratus will spread inland tonight into
Thursday morning with patchy fog possible. Clouds will clear
quicker on Thursday for dry, mostly sunny conditions later in the
afternoon and evening.

&&

.SYNOPSIS...An upper ridge will be over the area through the
weekend for warm, dry weather. An upper low may bring
precipitation potential and cooler temperatures early next week.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...Still some lingering marine
stratus in the East and South Sound areas as well as along the
coast, otherwise the remainder of W WA has cleared up for the most
part. Inherited forecast remains on track as temps throughout the
area are in the 60s...although some just barely.

Another weaker push is expected tonight, but with the change over to
offshore flow expected tomorrow, both easterly extent and duration
will be limited. On the larger scale, the upper level ridge will
retrograde and rebuild over WA on Thursday. The combination of this
ridge and the easterly flow will make for warmer conditions. Highs
Thursday will be in the 60s at the beaches and 70s inland with a few
low 80s in the interior.

The ridge axis retrogrades farther west and offshore on Friday
before gradually diminishing throughout the day Saturday. This will
still be enough to keep dry and unusually warm weather in the short
term forecast. Highs for both days will generally run in the mid to
upper 70s for the interior lowlands with mid 60s to near 70 for
along the coast and near water. 18

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...Sunday will continue this
warm and dry trend for one more day as the ridge breaks down
further. Deterministic models finally in agreement in bringing a
system in for the start of next week, although details are still not
in line...the GFS opting for a Monday passing while the ECMWF is
leaning more toward a late Monday/early Tuesday event. Ensemble
members seem to be voting for the earlier timing but a high degree
of uncertainty is present in most members both on said timing as
well as if the area will see any precip at all. Current forecast
retains slight chance wording until a clearer picture can emerge.
Dry conditions return Wednesday.

Sunday will see temps more in line with Friday and Saturday, while
if the incoming early week system brings nothing else, it will bring
more seasonable temperatures. Highs Monday will fall into the mid to
upper 60s while Tuesday will only be a couple of degrees above
seasonal normals with highs in the lower to mid 60s. Temps get a
little bit of a bump on Wednesday with highs very close to what is
expected Monday. 18

&&

.AVIATION...West to southwest flow aloft, with north winds turning
to light northeasterlies later this evening. Low clouds and fog are
expected to develop once again tonight into Thursday morning, but
will clear out much quicker than previous days, and will be less
widespread due to drier air. Likely IFR/LIFR conditions once again
for inland terminals through the morning, clearing out by early
afternoon.

KSEA...FEW to SCT clouds around 1500 feet this evening. Northerly
winds will transition to light northeasterlies tonight and into
Thursday morning. Low clouds and fog developing near the terminal
once again Thursday morning, but will scatter out earlier than
previous days, likely around 18-19z. VFR conditions will then return
with just some high passing clouds overhead.

Mazurkiewicz/Kristell

&&

.MARINE...Ridging will amplify in the next couple of
days, which will increase N/NE winds over Puget Sound and over the
Coastal Waters, but will remain below Small Craft Advisory levels.

As we look ahead into the beginning of next week, there are some
indicators of a stronger weather system crossing into the coastal
waters. There is disagreement between model consensus on the
timing of this weather system, so at this time confidence is low.
Regardless, if this weather system holds up, we could see
potential for some headlines in our coastal waters, within Small
Craft Advisory levels (possibly even higher).

Seas generally around 3 to 5 feet throughout the rest of this
week. With the aforementioned weather system potentially crossing
into our region early next week, could possibly see seas building
up to at least 7 to 10 feet.

Mazurkiewicz/Kristell

&&

.HYDROLOGY...The daily hydrology discussion has ended until the
start of the next rainy season; it will only be updated as needed.

&&

.FIRE WEATHER...Dry and warm conditions will remain in place over
the entire forecast period. While RH recoveries in the lowlands will
be good to moderate, there are some concerns about mid-slope RH
recoveries throughout the period. Easterly winds Thursday and into
this weekend may hinder recoveries even further. While no widespread
critical fire weather thresholds are expected to be met throughout
the forecast period, will need to keep an eye on wind forecasts as
new models come in. There are some hints at getting close to Red
Flag criteria for Thursday although current forecast keeps speeds
below criteria. Additionally, regardless of wind, the aforementioned
RH issues may allow for more active fire activity, even at night,
for active incidents within the CWA. 18

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...None.
&&

$$

NWS SEW Office Area Forecast Discussion