000 FXUS66 KSEW 261610 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 910 AM PDT Fri Apr 26 2024 .SYNOPSIS...Additional frontal systems will impact the region through the weekend and into early next week. A trend toward somewhat drier conditions and temperatures closer to normal is expected for the later half of next week. && .SHORT TERM /TODAY THROUGH SUNDAY/...Scattered showers continuing over the region this morning will diminish in coverage later today as upper trough axis gradually shifts east of the region. Most areas will see a brief drying spell tonight before next system poised offshore moves into the area during the day on Saturday. No forecast updates are anticipated this morning. Previous discussion follows with updates to marine and aviation portions. 27 Current surface analysis showers a surface cold/occluded front over Forks draping into the Southwest Interior and into Oregon. An upper level trough sits directly overhead western Washington for Friday as it moves onshore. A surface low is also centered off the coast in the Pacific. The overall stacking of this system indicates weakening as it comes onto land and is slowed down. Radar imagery shows a couple pockets of showers/rain continuing in the Cascades and Olympics this morning, with isolated showers south of Olympia moving north. Some of the moisture is wrapping around the low in the Pacific, aided by southwest/west flow aloft keeping the air at least somewhat moist before dry air aloft intrudes in behind the trough. A couple smaller shortwave troughs will still pass over the region Saturday and Sunday. Long story short, precipitation chances will continue through the weekend. Although not an all day washout, multiple rounds of showers will be possible for the remainder of Friday, Saturday, and Sunday. Convection is not anticipated, but the cool air aloft/warmer surface temperatures may support a graupel shower. The heaviest precipitation from yesterday`s system has mostly concluded, and many areas received anywhere from a half of an inch of QPF to near 2 inches. For the remainder of Friday, lowland areas may see a couple more tenths of an inch of QPF, with close to a half an inch possible in the Cascades/Olympics. Same amounts are expected for Saturday. For Sunday, heavier precipitation may set up over the Cascades, increasing QPF totals to around an inch (potentially just over). Friday will be the warmest day in the short term with highs around 60. This drops into the mid 50s Saturday and Sunday, well below average. Winds remain light out of the south/west at 5 to 10 miles per hour, but a few gusty winds are possible near waterways. .LONG TERM /MONDAY THROUGH THURSDAY/...Additional systems are expected to impact the region next week. The wettest day at this time appears to be Monday, with a strong mid-latitude cyclone/jet streak dropping down from Canada. Some models have hinted convection with this system on Monday, although activity is expected to remain showery and isolated in nature. After Wednesday, there remains disagreement into how strong an additional trough will dig down the west coast. Some models have it staying in Canada, while others have it dropping into northern California. A couple more ensembles members (compared to yesterday) are even showing some ridging over the Pacific Northwest Thursday. Monday/Tuesday remain cool in the 50s, but could see 60s make a return next Wednesday/Thursday. Winds will remain light as well in the forecast. HPR && .AVIATION...Light southwest flow aloft with light south- southwesterly flow at low levels = except northerly flow at the northern Puget Sound terminals after 23Z today. MVFR CIGs will generally trend towards VFR levels this morning, areas/terminals with lingering showers will be slower to improve. MVFR CIGs along the coast will likely hang in there longer into the afternoon before overall improvement there. Widespread CIGs are likely to dip back to MVFR levels early Saturday AM. KSEA...CIGs have improved at the terminal and will continue to trend that way through the afternoon and evening. Scattered showers into the afternoon may result in brief periods of MVFR conditions - 2500 to 3000 ft CIGs and 3-5 sm VSBYs. VFR conditions tonight will trend back to MVFR around 7/8Z as ceilings lower to 2500 to 3000 ft, with improvement as the marine layer lifts Saturday AM. South to southwest winds 4 to 8 kt. && .MARINE...Surface low pressure continues to weaken as it moves further inland this morning. No headlines currently in effect with marginal northerly wind gusts to near 20 kt possible over the far offshore waters through early this evening. The next frontal system is poised to move over the area waters Saturday, as a warm front lifts across the waters, turning flow to the southwest with advisory- level wind gusts likely over the offshore waters late Saturday morning into the afternoon (80-90% chance). Additional frontal systems will cross the area waters through next week as an active weather pattern continues. Seas ranging from 5 to 7 feet, rising to 6 to 9 feet later this afternoon and closer to 10 feet into Saturday night and Sunday, lingering around 8t 10 feet through early next week. Davis && && .HYDROLOGY...No river flooding is anticipated at this time over the next seven days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$
NWS SEW Office Area Forecast Discussion
