642
FXUS66 KSEW 121049
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
349 AM PDT Fri Jul 12 2024

.SYNOPSIS...Upper level ridge remaining over Western Washington
through the weekend into next week with continued low level
onshore flow. This will maintain above normal temperatures, but
still notably cooler than the start of this week. No rain expected
with only subtle variations in the strength of the marine pushes
each night.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...Satellite imagery shows low
clouds along the coast and over the Lower Chehalis Valley. Clear
skies over the remainder of the area. Temperatures at 3 am/10z
were in the lower 50s to lower 60s.

Will your alarm go off this morning with I got you Babe playing on
the radio? It would be fitting for the weather the next few days.
Flat upper level ridge over Western Washington through Sunday with
onshore flow in the lower levels. 500 mb heights staying in the
mid to upper 580 dms with 850 mb temperatures in the plus 16C to
20C each day. Varying degrees of onshore flow with a shallow marine
layer keeping the morning stratus confined to the coast and
Lower Chehalis Valley for the most part. The stratus will retreat
to the coastline each day by midday. Highs in the mid 70s to mid
80s inland with mid 60s to lower 70s along the coast. Lows in the
50s and lower 60s.

.LONG TERM /MONDAY THROUGH THURSDAY/...Very little change in the
pattern through the extended period. Weak trofiness developing
well offshore late in the period changing the flow aloft from
westerly to southwesterly. If the trough deepens enough to turn
the flow aloft southerly the threat of convection over the
Southern Cascades could develop Thursday afternoon. That`s a big
if right now. In the lower levels varying degrees of onshore flow
continuing through Thursday. Highs remaining in the mid 70s to mid
80s for the interior and mid 60s to lower 70s for the coast. Lows
in the 50s and lower 60s. Felton

&&

.AVIATION...Westerly winds aloft through the period as we`re locked
in zonal flow. Currently, marine stratus is hugging the coast and
pushing into SW WA. IFR to MVFR cigs will persist at HQM before
conditions improve around 18-20z. A 30-40% chance of MVFR cigs
reaching KOLM and KPWT this morning as well which should burn off by
16-18z if it makes it to the terminals. Elsewhere, VFR cigs are in
store for much of the upcoming TAF period with the exception of
coastal airfields (KHQM, KUIL, etc.).


KSEA...VFR for the upcoming TAF period. Light winds this morning
increasing out of the NW between 5-10 kt becoming lighter again
tonight into Saturday morning.

McMillian

&&

.MARINE...Stout surface high pressure remains offshore pushing
low-level onshore winds across area waters. SCA advisory remains
over the outer coastal waters, however, they`ve been allowed to
expire over the inner coastal waters and the central and eastern
strait. Diurnal westerlies will persist into early next week with
additional headlines possible for the Strait. Will have to monitor
winds for this area this afternoon as well.

Seas 6 to 10 ft for the coastal waters with the highest waves over
the outer waters. Seas will then gradually decrease to around 4 to 6
feet into the weekend.

McMillian

&&

.CLIMATE...Some streaks so far this month in Seattle. The 4 days
in a row of 90 degrees plus tied for the 4th longest consecutive
days of 90 degrees plus streak. The three longer streaks 6 days (
July 26-31, 2022 ) and 5 days ( July 1-5, 2015 and August 7-11,
1981 ). The high of 83 degrees yesterday ended the streak of 85
degree plus days at 6. This tied for the 7th longest streak. The
longer streaks, 9 days ( July 22-30, 2018, August 5-13, 1977 and
August 12-20, 1967 ) and 7 days ( July 25-31, 2022, June 30-July
6, 2015 and August 6-12, 1981 ).

The current streak of 80 degree plus days in a row in Seattle is
at 8 days. The 7 day forecast has highs 80 degrees plus every day.
If this verifies it will tie the record for the longest streak of
80 degree plus days in Seattle which is 15 days ( June 25-July 9,
2015 and July 30-August 13, 1977 ). Felton

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory until 5 AM PDT early this morning for
     Central U.S. Waters Strait Of Juan De Fuca-East Entrance
     U.S. Waters Strait Of Juan De Fuca.

     Small Craft Advisory until 6 PM PDT this evening for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm.

&&

$$