Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
046 FXUS66 KSEW 261037 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 337 AM PDT Sun May 26 2024 .SYNOPSIS...
-- Changed Discussion --
Cooler and showery conditions will continue across western Washington today as a frontal system brushes the region. Upper level ridging will then gradually begin to build east of the area Monday, allowing for temperatures to warm a few degrees. Upper level troughing over the northeastern Pacific will continue to influence Washington, however, with the next frontal system slated to move across the region on Tuesday. Drier and warmer conditions will be possible late in the week as upper ridging builds offshore.
-- End Changed Discussion --
&& .SHORT TERM /TODAY THROUGH TUESDAY/...
-- Changed Discussion --
A weak frontal system will brush the region today, bringing showers and cooler temperatures to much of western Washington. Radar shows a few light showers persisting across the central and northern Cascades this morning, but also shows shower activity increasing offshore and moving inland along the North Coast. Expect showers to continue to progress inland through the day today, with overall precipitation amounts remaining rather light for the majority of the interior lowlands. The bulk of precipitation will likely remain along the North Coast, the mountains, and areas generally north of Snohomish county. Showers then look to taper tonight across the majority of the area, with a few persisting along the Pacific coast into Monday. High temperatures will be roughly 5 to 10 degrees below normal, and look to only climb into the mid to upper 50s. An upper level ridge will start to build east of the area on Monday, while troughing offshore continues to influence western Washington. Overall, expect drier conditions for the majority of the forecast area, with only a few showers persisting along the coast. Temperatures will warm closer to normal, with afternoon highs climbing into the mid 60s to near 70 across the interior. The coast will remain cooler, with high temperatures topping out in the low 60s. The next upper level disturbance and associated surface frontal system will then move across the region on Tuesday, bringing another round of showers and cooler temperatures. Showers will move along the coast early Tuesday and gradually make their way into the interior by the afternoon hours. Afternoon high temperatures will fall back to 5 to 10 degrees below normal, topping out in the upper 50s to low 60s for most areas. .LONG TERM /WEDNESDAY THROUGH SATURDAY/...An upper level trough over the northeastern Pacific will push its trough axis onshore on Wednesday. This will maintain chances of showers and below normal temperatures across western Washington midweek. Shower coverage then looks to gradually decrease on Thursday as the trough axis pushes further off to the east and upper level ridging starts to build over the northeastern Pacific. Ensemble guidance remains in in decent agreement in regards to the upper ridge influencing western Washington late in the week, which would mean warmer and drier conditions Friday and heading into next weekend. 14
-- End Changed Discussion --
&& .AVIATION...
-- Changed Discussion --
Westerly flow aloft with a warm front lifting across the region this morning. This will maintain a rather moist air mass and consistent southerly or southwest low-level flow across much of the region with onshore flow through the Strait of Juan de Fuca. Expect widespread MVFR and local IFR ceilings early this morning with light rain showers. Ceilings will be slow to lift, but expect widespread MVFR late morning giving way to VFR after 22z with the front pushing northward into B.C. by late afternoon. Stabilizing air mass likely brings return of low ceilings again Sunday night through Wednesday morning. KSEA...MVFR ceilings continue this morning with around a 15% chance of dipping to IFR for a few hours 12-16z this morning. Light rain showers at times through the morning. Southerly surface wind around 10 kt with some gusts toward 20 kt this afternoon as front lifts north. MVFR ceilings likely return again after 03z through much of overnight period. Cullen
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
A passing warm front lifts north across the waters into southern B.C. later today, but winds likely remain below advisory thresholds across all waters for the next few days. Another front reaches the waters on Tuesday with a stronger west push down the Strait of Juan de Fuca Tuesday night may bring winds again into the 20-25 kt range, with around a 40% chance of reaching advisory speeds. Seas over the coastal waters remain dominated by rather short period waves, which will maintain choppy conditions through much of the week ahead, with seas generally holding in the 5 to 7 ft range. Cullen
-- End Changed Discussion --
&& .SEW WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
WA...None. PZ...None.
-- End Changed Discussion --
&& $$