Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
537 FXUS66 KSEW 292200 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 300 PM PDT Sun Jun 29 2025 .SYNOPSIS...
-- Changed Discussion --
Ridging over the Western US will keep the start of the week warm and dry. Temperatures will trend cooler midweek into the holiday weekend, near or a bit warmer than normal. Conditions also look to remain generally dry for most areas other than the periods of light rain along the north coast Saturday and North Cascades Sunday.
-- End Changed Discussion --
&& .SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
High temperatures warming well into the upper 70s and low 80s as the upper level ridge moves onshore this afternoon. With the ridge axis overhead and light low level offshore flow Monday continues to look to be the warmest day of the stretch for many areas. This will bring temperatures into the mid to upper 80s with a few spots expected to reach the 90 degree mark. This will result in a corridor of Moderate (Orange) HeatRisk for the interior from the Central Puget Sound southward and and some of the foothills and Cascade Valleys. Developing onshore flow Tuesday will result in a cooldown for areas west of Puget Sound, leaving another warm day for the urban corridor from Seattle to Tacoma as well as in the Cascades foothills and valleys. This will yield a second Moderate HeatRisk day for these areas on Tuesday.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A more fully developed onshore push will return Wednesday bringing a return or morning clouds and temperatures closer to seasonal normals Wednesday and Thursday. The most likely forecast remains generally dry through the period for most areas. The zonal pattern does leave the door open for the potential for the odd weak shortwave trough to brush the region. The NBM has backed of the potential for showers into Saturday and Sunday - mostly along the north coast and North Cascades, with most locations remaining otherwise dry.
-- End Changed Discussion --
&& .AVIATION...
-- Changed Discussion --
High pressure over the region for dry and stable conditions. Low level stratus clouds will impact the coast tonight and Monday morning with VFR conditions elsewhere. N winds in the interior, gusting to 20 kt this evening. KSEA...VFR with N winds gusting to 20 kt this evening. 33
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
A thermal trough along the coast will lead to strong NW winds over the coastal waters - a Small Craft Advisory remains in effect. Onshore flow will increase Monday and Tuesday as the thermal trough moves inland. Gales are likely through the Strait of Juan de Fuca Tuesday night. A weak front will cross the waters on Wednesday. 33
-- End Changed Discussion --
&& .FIRE WEATHER...
-- Changed Discussion --
Warm and dry conditions are expected to persist today through Tuesday as high pressure remains overhead. With these temperatures, relative humidity values during the day Monday will be as low as 25% in some of the southern Cascade Valleys (portions of zones 658 and 659), with remaining Cascade and Puget Sound/South Interior areas seeing RH`s as low as 30-40%. This will elevate fire weather concerns due to the dry conditions through Tuesday, as RH`s in some of these areas may not fully recover. The pattern trends cooler by Wednesday, which will improve RH`s across western WA and will lessen fire concerns. Winds are expected to remain light through the week, with light north to northeast and variable winds. HPR
-- End Changed Discussion --
&& && .SEW WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
WA...None. PZ...Small Craft Advisory until 5 AM PDT Monday 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 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.
-- End Changed Discussion --
&& $$