564 FXUS66 KSEW 182123 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 223 PM PDT Sat Apr 18 2026 .SYNOPSIS... Mostly dry and mild conditions will continue into early next week, before chances for precipitation increase across western Washington through the middle of the week. Drying and warming conditions may return by next weekend. && .SHORT TERM /TONIGHT THROUGH MONDAY/... Upper level ridging will continue over western Washington allowing for warmer and drier conditions throughout the rest of the weekend. High temperatures this afternoon have been generally in the upper 60s with some locations closer to the foothills in the low 70s. Some mid to high clouds have been streaming in overhead with a mix of sun. Progressing into Sunday, generally the same set up with temperatures a touch warmer across much of the area with likely the warmest temperatures we`ve seen this year thus far with temps in the mid 70s, even upper 70s for locations in the Cascade foothills. The same weather trend will continue into Monday, with more places seeing low to mid 70s - with areas along the water seeing more upper 60s. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...An upper level low will move inland near Oregon which could allow wrap around moisture through Washington. Precipitation chances start to increase more so Tuesday into Wednesday as the low moves further inland. Temperatures look to return to normal during this time, in the upper 50s to lower 60s. Some ensembles are starting to key into warmer and drier conditions returning near the end of the week and into the weekend, potentially back in the upper 60s to lower 70s. Mazurkiewicz && .AVIATION...High pressure over the region today will shift east on Sunday, while low pressure tracks south offshore. Winds aloft are west to southwest. Overall, mainly a mix of mid and high clouds over the area with VFR conditions. 33 KSEA...VFR conditions will prevail tonight through Sunday. Light winds becoming N/NE by 03Z. 33 && .MARINE...Light winds over the waters with high pressure. Low pressure will track south over the offshore waters on Sunday with offshore flow over western WA. Onshore flow resumes on Tuesday as the low weakens further then shifts inland. Seas will build over 10 ft on Wednesday over the outer coastal waters. 33 && .HYDROLOGY... River flooding is not expected over the next 7 days. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$

429 FXUS66 KPQR 182123 AFDPQR Area Forecast Discussion National Weather Service Portland OR 223 PM PDT Sat Apr 18 2026 .SYNOPSIS...High pressure overhead is keeping northwest Oregon and southwest Washington warm and dry today. Out over the Pacific, a storm system is organizing and is expected to become a slow-moving closed low late this weekend into early next week. That will gradually bring more clouds on Monday, then a better chance for cooler, wetter weather by the middle of the week. Confidence is increasing that showers become more likely late Monday into Tuesday as the system begins to spread moisture inland. Wednesday still looks like the coolest and most showery day overall. && .SHORT TERM...Now through Sunday night...Thin clouds high in the sky have been streaming across the area at times today (most noticeable near the coast and into southwest Washington), but conditions remain dry and temperatures are still warming up nicely inland. Expect inland highs mainly in the lower to mid 70s today, while the coast stays cooler, generally upper 50s to mid 60s. Later today and tonight, a weakening front will approach the coastal waters. Most of the moisture and lift look like they will remain offshore, so for most locations the main change will be increasing clouds this evening and overnight. While light showers will most likely stay over the ocean, there is a small chance a brief shower could brush the immediate north coast late tonight into Sunday morning. No rain is expected for inland areas. Cloud cover tonight will keep temperatures milder than this morning. Lows should be mostly in the mid to upper 40s inland (a few cooler valleys could dip a bit lower), and generally in the 40s near the coast. With clouds and warmer nighttime temperatures, frost is not expected over at least the next couple mornings. Sunday looks similar to today; warm and dry for most areas, with more thin high clouds around. Inland highs should again reach the low to mid 70s. Parts of the Portland/Vancouver metro and nearby communities could still reach 80 degrees if clouds thin enough during the warmest part of the day, but that will depend on how quickly cloud cover thickens (30-60% chance of daytime temperatures exceeding 80 degrees). There is moderate to high confidence that these high clouds will remain thin, allowing for good daytime heating. Coastal highs stay in the upper 50s to mid 60s. Sunday night remains drys inland with lows mainly in the 40s. .LONG TERM...Monday through Friday...On Monday, the offshore low pressure system will start to have more influence on our weather. Expect more cloud cover and slightly cooler temperatures compared to the weekend. Highs should generally be in the upper 60s to near 70 inland, and upper 50s to low 60s along the coast. Rain shower chances increase late Monday into Tuesday as the system begins to move closer and spread moisture inland, with the first steadier showers most likely over the higher terrain and the southern Willamette Valley. Even so, precipitation through Monday looks light overall, generally around 0.05 to 0.15 inch where showers occur. Tuesday is still the trickiest day. While exact timing still needs refinement, confidence is higher that at least scattered showers will reach more of the area sometime late Monday into Tuesday, rather than staying largely offshore. If showers do begin Tuesday, they would most likely show up first along the coast and in areas farther south and west, then spread inland later. Confidence is higher for Tuesday night into Wednesday: this is the most likely period for a more widespread cooler, and showery pattern across the area. The Coast Range and Cascades will be favored for more persistent showers due to terrain enhancement. While rain amounts remain uncertain, expect around 0.25 to 0.75 inches in the lowlands and around 1 to 1.75 inches in the Coast Range and Cascades from 5 PM Tuesday to 5 PM Wednesday. By Thursday and Friday, the pattern looks like it will trend drier again with temperatures slowly warming back up into the mid 60s and maybe 70s by Friday. A few leftover showers near the mountains are possible early in that period, but overall conditions should improve late week. ~12 && .AVIATION...High pressure will maintain widespread VFR flight conditions through 00Z Monday with scattered to broken high clouds around 20-25 kft. Winds will remain light and variable less than 5 kt, with one exception. Easterly winds at KTTD will remain breezy through at least 22Z Saturday with occasional gusts up to 20-25 kt before east winds gradually decrease in strength between 22-00Z. Expect easterly winds to restrengthen a bit between 12-18Z Sunday. KPDX AND APPROACHES...Scattered to broken high clouds with cigs above 20-25 kft will maintain VFR flight conditions through 00Z Monday. Variable winds around 5 kt or less are expected to become easterly towards 17Z Sunday with sustained wind speeds approaching 10 kt. -23 && .MARINE...Benign conditions continue through the weekend. Southerly to southwesterly winds between 5-15 kt continue today with seas under 5 ft. Winds will weaken and become east to southeast by early Sunday morning. Winds then remain light through early next week with seas increasing by a few feet, but staying under 10 ft. An area of low pressure sitting off the coast will move inland during the middle of next week. This will bring onshore flow, showers, and increasing winds and seas. However, uncertainty remains regarding exact wind speeds and wave heights. The placement of the low will determine what conditions materialize across the waters. The current forecast favors a period of increasing west to northwest winds late Tuesday into Wednesday with wind gusts reaching 20-25 kt or stronger by Wednesday afternoon. In fact, there is a 50-75% chance for max wind gusts over 25 kt. The highest probabilities are beyond 30 NM offshore. Seas are expected to reach at least 10-12 ft by late Wednesday, however there is a 40-70% chance seas will peak over 12 ft over the northern and central outer waters. There is a 1-5% chance seas will peak as high as 15 ft, which represents the worst case scenario. Very strong ebb currents will continue across the Columbia River Bar each morning through Tuesday. With seas expected to build slightly by early next week, a steep ebb chop may necessitate Small Craft Advisories in the hours around peak flow each day. -23 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

181 FXUS66 KMFR 181934 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1234 PM PDT Sat Apr 18 2026 .DISCUSSION (Today through Friday)... Key Points: * Only minor impacts expected the next several days * Warm, above normal temperatures this weekend * Low pressure enters the region Sunday - Precip chances start Sunday and continue through Wednesday - Isolated thunderstorms possible Tuesday and Wednesday * Drying trend towards the end of the week Further Details: The forecast area will be under high pressure today with a transition occuring tomorrow as an upper low strengthens off the coast. This low eventually becomes a cut-off from the main flow and will meander over the ocean/west coast for a couple days before coming inland Tuesday into Wednesday. Initially, we will see precipitation chances increase tomorrow along/near the coast and eventually spreading west to east through midweek. We are not seeing a signal for heavy rain through this stretch, but rather a consistent light rain for a few days. Rainfall totals for 72 hours ending Thursday morning could end up around 1.00"-1.50" for the higher end amounts. Highest amounts are expected along/near the coast and northern California. Cascades could also see the higher amounts of QPF before switching over to snow. Westside valleys and eastside areas will be considerably less with 72 hour totals only around 0.25"-0.50". MUCAPE values on Tuesday are around 200-500 J/kg, so we are expecting at least some isolated thunder. MUCAPE on Wednesday is only around a couple hundred J/kg so likely less chance for lightning. No expecting any severe weather but lightning and occasional strong gusts (30-45 mph) will be possible through this stretch. Snow levels eventually drop low enough Tuesday night for snow accumulation over the Cascades, eastside areas, and northern California. Through Wednesday, snow amounts wont be enough to warrant any hazard products at this time. That said, 48 hour totals through Thursday morning could end up being around 4-8 inches with the higher end amounts over the Cascades, mountains of Siskiyou County, and Warner mountains. By Thursday, upper level low which will bring precipitation through midweek will be absorbed back into the main flow. A dry north/northwesterly flow will become evident over the forecast area. While the NBM holds onto spotty PoPs Thursday onward, we are anticipating precipitation chances to dwindle Thursday through at least parts of next weekend. Models differences in the extended come to fruition around Saturday. For example, the EC wants to develop a weak area of low pressure which could bring precipitation Saturday but the Canadian and the GFS both remain dry. At this time, confidence is low on the details after Friday. -Guerrero && .AVIATION (18Z TAFs)... VFR conditions will prevail for the next 24 hours with thickening high clouds and generally light winds. Southerly winds will increase and become gusty in the Shasta Valley and over the East Side Sunday afternoon. Even portions of the Rogue Valley could turn locally breezy. Precipitation chances remain low during Sunday. However, some light rain and lower ceilings could impact the marine waters. Eventually, higher rain chances and lowering ceilings move onto the coast Sunday night. -Spilde && .MARINE...Updated 1230 PM PDT Saturday, April 18, 2026...Southerly winds will increase tonight, but with relatively low seas. Low pressure offshore will bring a return of active weather Sunday into Wednesday, with increasing swell and periods of gusty south winds. Winds are likely to be strongest from Sunday morning through Monday evening with a period of steep seas hazardous to small craft mostly beyond 10 NM from shore. Conditions should improve a bit Tuesday, then increasing NW swell should bring an increase in seas again Wednesday into Thursday. -Spilde && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM Sunday to 8 AM PDT Monday for PZZ370-376. && $$

866 FXUS66 KEKA 182132 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 232 PM PDT Sat Apr 18 2026 .SYNOPSIS...Overnight temperatures moderate as high pressure begins giving way to a trough. Rain chances increase late Sunday and chances will maintain through mid next week. A period of drier weather is then expected to begin late next week. && .DISCUSSION...An upper trough is evident on satellite Saturday afternoon over the NE Pacific. A cold core upper low will cut off from the flow and proceed toward the California coast late Sunday. Rain chances begin to increase late Sunday, along with southerly winds. An increase in moist, southerly flow and some associated upglide instability may coax out some light precipitation tonight. Moderate to some instances of heavy rainfall will arrive Monday, particularly with some smaller scale disturbances which will rotate in around the periphery of the cutoff low. Precipitable water values will be high, rising to 200% of normal, and this increases the chances for some heavier rainfall rates. Southerly winds will turn gusty at times Sunday and Monday, mainly for the ridges. The isolated disturbances that pass through may locally increase winds at times. NBM is struggling to resolve meaningful probabilities for gusts over 25 mph, but there is some upper level wind support in the 925 mb level (around 2000 ft) for some locally gustier winds. A general 1 to 2 inches of rain, with locally 3 inches over some of the ridges on the King Range and southward is likely. Lighter amounts can be expected north of the King Range. NBM chances for over 1.5 inches of rainfall are moderate to high for the King Range and southward (40 to 65 %). Snow levels will drop to around 5000 ft, and some light snow is possible over Scott Mountain pass in far northern Trinity County. The cold core of the low will cross over N CA Tuesday. The steepened lapse rates, broad ascent, and increased instability will bring a chance for thunderstorms (15 to 25%). Soundings are resolving some relatively high CAPE for the region of 300 to over 500 J/kg for the interior, mainly focused over and south of Cape Mendcino. The increased winds around the low will generate effective shear to 30 kts. These conditions will bring a more favorable chance for some stronger storms capable of hail over the southern portion of the region through Mendocino and Lake counties, but the exact placement of the low may nudge the greater threat north or even south out of the area over Sonoma County or the Sacramento Valley. Soundings show more of "skinny" CAPE profiles for the coastal areas north of Cape Mendocino, and thunderstorms coverage for those areas may be more limited to what wraps in from the southeast. Veering flow is also noted south of Cape Mendocino along the Mendocino coast, and this will have to be watched for any potential for weak rotation in any storms. Chances for at least additional showers may linger into Thursday when a weak shortwave moves through behind the departing low. Generally dry weather is likely thereafter, with perhaps a weak disturbance bringing a chance for a shower or two at times. JJW && .AVIATION...VFR conditions are in place this afternoon once the morning stratus cleared out. A frontal boundary is approaching the area and winds are gradually becoming south to southeast. The southeast winds are expected to increase tonight and Sunday morning. The main forecast challenge is when/if the winds will pick up enough to keep the stratus off the coast. Most of the HiRes models are keeping the stratus off the coast. However, it is still possible some low clouds will form at KACV and KCEC this evening before the winds pick up. For now have some MVFR conditions in the TAFS highlighting this. The rain is expected to remain offshore through Sunday evening and finally move over the terminals very early Monday and this will likely bring lower CIGS in the rain. MKK && .MARINE...A frontal boundary ahead of an area of low pressure is approaching the area this afternoon. Winds are starting to turn southerly. These will be completely southerly and start to increase shortly after midnight tonight. Winds are expected to be around 15 to 20 by Sunday afternoon and remain elevated Sunday night. Monday southerly winds are expected to continue, but slowly diminish through the day as the low approaches and weakens. A westerly swell building in is expected to become the dominant wave as it quickly builds to 8 to 10 feet at 12 seconds through the day Monday. Eventually on Tuesday the low will start to move over the area and off to the east, but confidence is low on how quickly this will happen. Once the low moves past the waters winds begin to turn northerly once again. Winds will likely remain fairly light on Wednesday. Thursday and Friday high pressure builds back in and northerly winds are expected to increase again. MKK && .COASTAL FLOODING...A new moon cycle is bringing higher than usual tidal swings. A near 1 foot positive tidal anomaly is also contributing to higher tides. Slackening northerly winds and increasing southerly winds may further increase the anomaly. The high tide plus anomaly may yield a high tide near 8.8 ft at the North Spit gauge near 1 AM Sunday morning. A coastal flood advisory has been issued to highlight this. High tides will likely near this value again near 2 AM Monday morning. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Coastal Flood Advisory from midnight tonight to 3 AM PDT Sunday for CAZ103. NORTHWEST CALIFORNIA COASTAL WATERS... Coastal Flood Advisory from midnight tonight to 3 AM PDT Sunday for PZZ415. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png

331 FXUS66 KMTR 181904 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1204 PM PDT Sat Apr 18 2026 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 1201 PM PDT Sat Apr 18 2026 - Seasonably warm temperatures expected through the remainder of the weekend - Cooler temperatures and beneficial rain for the beginning of the upcoming week && .SHORT TERM... Issued at 1201 PM PDT Sat Apr 18 2026 (This evening through Sunday) High clouds continue to stream in from the west, yet will have very little impact on high temperatures this afternoon. We are forecasting mid 60s to lower 70s in the northwest facing locations and low-to-upper 70s elsewhere. There is a greater than 50% probability for Concord, San Jose, Gilroy, Hollister, and King City to exceed 80 degrees F on this afternoon (but less than 10% of exceeding 85 degrees F). Tonight and into Sunday morning, expecting low clouds to return to the coast and coastal adjacent valleys as moisture increases ahead of an approaching mid/upper level low. This low will also cool temperatures slightly as clouds increase, most notability in the North Bay and San Francisco Bay Area. Meanwhile, the Central Coast will remain quite warm across the interior Sunday afternoon. && .LONG TERM... Issued at 1201 PM PDT Sat Apr 18 2026 (Sunday night through next Friday) The progression of the anticipated cold front has slowed down by about 12-18 hours. However, we still expect pre-frontal rain showers to begin Monday morning across the North Bay and then spread southward across the Bay Area. Outside of the coastal ranges of the Central Coast, we may see very little rainfall on during the day Monday. The main cold front is now expected to move across the Bay Area and Central Coast on Tuesday morning. By Tuesday afternoon and evening, we have the greatest potential for thunderstorms with up to 30% across much of the region as up to 500 J/kg of surface based CAPE is forecast. We are mostly forecasting this rainfall to be beneficial, but urban and poorly drained areas may experience flooding concerns during periods of heavy rain showers and/or thunderstorms. The WPC has a Marginal Risk of Excessive Rainfall (at least 5%) from the Santa Cruz Mountains northward on Day 3 (5 AM Monday - 5 AM Tuesday). However, we are not expecting any major river flooding with this event. Post-frontal rain showers and possible thunderstorms (generally less than 15%) linger into Wednesday afternoon as a colder air mass settles in behind the cold front. Drier conditions look to return to the region for the latter half of the week with troughing forecast by the clusters. && .AVIATION... (18Z TAFS) Issued at 1100 AM PDT Sat Apr 18 2026 High clouds are building across the area with moderate winds building into the afternoon. Winds become light into the evening and into the night with low clouds building along the coast. IFR CIGs look to affect HAF and and the Monterey Bay terminals overnight and through much of Sunday morning. Winds stay light for most areas through Sunday morning, but moderate southwest winds begin to build that afternoon. Vicinity of SFO...VFR through the TAF period. High clouds will build through the day and into Sunday. Expect west-northwest winds to build through the afternoon but ease into the late night. Winds stay light through early Sunday afternoon before moderate west-southwest winds build. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR lasts into the the night. Expect moderate northwest winds to build into the afternoon and ease into the late evening. IFR CIGs build at MRY and around the Monterey Bay coastline into the night, but don`t reach SNS until the late night. Winds will stay light through Sunday morning, but CIGs will erode in the mid to late morning. && .MARINE... (Today through Thursday) Issued at 1100 AM PDT Sat Apr 18 2026 Light winds and seas last through the rest of the weekend. Northerly winds shift and become southerly Sunday ahead of an incoming low pressure system and cold front. Winds will strengthen ahead of the cold front Monday through Tuesday with localized strong gusts expected. Expect moderate seas, rain and a slight chance to chance of thunderstorms Monday night and Tuesday. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ SHORT TERM...RGass LONG TERM....RGass AVIATION...Murdock MARINE...Murdock Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea

375 FXUS66 KOTX 182111 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 211 PM PDT Sat Apr 18 2026 .KEY MESSAGES... - Dry, with warming temperatures through Monday. - Increasing risk for showers and thunderstorms Tuesday. - Light to moderate rains Wednesday, with a chance for thunderstorms. && .SYNOPSIS... Dry, warm conditions through Monday. Unsettled weather returns Tuesday into Wednesday next week, with potential for some moderate rains. && .DISCUSSION... Tonight to Tuesday morning: A ridge of high pressure will continue building over the region in response to low pressure dropping south along the Pacific coast. This set-up will continue to favor dry weather and warming temperatures. Through Monday look for transient, variable high clouds and a few afternoon cumulus build-ups. Heading into Tuesday clouds start to increase over the region and the first shower chances reach into the Cascade crest. Tonight, lows will be in the 30s to mid-40s. Highs warm into the 70s Sunday through Tuesday, with some low 80s in the deeper basin, while lows are forecast to be in the 40s to low 50s. Tuesday afternoon to Saturday: The area has a moderate to high chance of moving into period of wet weather midweek, before trending drier. Ensembles are in good agreement with the depiction of the low pressure off the coast shifting east-northeast toward the northern Rockies/Great Basin area, before a ridge starts to flop back in toward the latter part of next week. This will mean increasing precipitation chances starting to emerge over the Cascades and southeast CWA Tuesday afternoon into Tuesday evening, expanding over most of the area Tuesday overnight and especially into Wednesday when PoPs peak around 60-90% over the east third of WA and ID and 30-50% over central WA, up to near 60-70% at the Cascade crest. This will be mainly rain and high elevation snow, with snow levels around 7.5-8.5kft Tuesday dropping to around 4.5-5kft by Thursday. Additionally, the chance for thunderstorms continues to increase for Tuesday and Wednesday. With the leading edge of the upper trough bringing some modest diffluent flow, the milder air ahead of it and a front moving in, a risk for t-storms is reasonable. This includes a chance for some nocturnal t-storms overnight Tuesday into Wednesday morning. How widespread these are will be linked to how much the best lift and instability can sync up. If the lift does not quite get here before the best instability before sunset, then the risk would be somewhat lower. Either way this will be something we will watch. The main risk will be gusty winds and hail. The deformation axis that lifts in later Tuesday night into Wednesday will be a focal point for the potential for moderate to locally heavy rainfall. Rain amounts between 0.75" to 1.0" are in the forecast for Tuesday night into Wednesday night around southeast WA and the ID Panhandle, locally between 1.0" to 1.50" near the higher Palouse into the Panhandle mountains. South-central and northeast WA could seen between 0.25" to 0.75"; the Cascades through the Okanogan Valley could see between 0.05" to 0.25", highest in the mountains. With milder temperatures ahead of this and then the rain, this comes with some rises in area rivers, though most mainstem river remain below action stage. Stehekin is an exception which is expected to see rises early in the new work week. So that will be monitored. Additionally the NWRFC also shows that Kootenai River at Bonners Ferry may push above action stage after midweek. Streams and creeks and poor drainage areas and fields will be monitored for flooding as well, with areas such as southeast WA including the Palouse prone to potential issues, as it has had this spring. The best risk will be around Wednesday, receding into Thursday. From Thursday to Saturday the precipitation potential wanes. The risk remains modest on Thursday, with a secondary shortwave dropping south behind the exiting trough. There are differences in the precise track of that secondary shortwave, depending on how quickly the parent trough shifts east. The highest potential for precipitation remains around the ID Panhandle and secondarily over the eastern third of WA. By this time the potential for significant precipitation will be waning, For Friday and Saturday some shower chances linger around mountain zones for the afternoon hours. Otherwise it looks drier. As for temperatures, highs drop about 15 degrees heading into Wednesday (compared to Tuesday) with readings in the upper 50s and 60s. Lows will be the 40s to low 50s Wednesday morning, then upper 30s and 40s Thursday through Saturday morning. With the dropping temperatures look for some breezy conditions, especially Wednesday and Thursday with gusts in the 15 to 25 mph range, highest near the Cascades to Upper Columbia Basin. Locally higher winds are forecast around the higher terrain near the Cascades and Blues, with gusts near 40 mph possible, especially Wednesday. /Solveig && .AVIATION... 00Z TAFS: VFR conditions expected. Variable middle to high clouds pass over the region, thinning tonight into Sunday as high pressure builds. Some fair weather cumulus build-ups in the afternoon, particularly closer to the mountains. Winds generally light this period, save for near KPUW with some breezy easterly winds in the morning hours. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports,please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 38 69 44 75 48 75 / 0 0 0 0 0 0 Coeur d`Alene 37 69 44 75 48 75 / 0 0 0 0 0 0 Pullman 39 68 46 75 49 72 / 0 0 0 0 0 10 Lewiston 41 73 47 78 51 75 / 0 0 0 0 0 10 Colville 35 72 41 78 46 80 / 0 0 0 0 0 10 Sandpoint 36 67 43 72 46 74 / 0 0 0 0 0 0 Kellogg 38 69 46 75 50 77 / 0 0 0 0 0 0 Moses Lake 39 77 45 81 49 80 / 0 0 0 0 0 0 Wenatchee 43 72 51 77 54 77 / 0 0 0 0 0 10 Omak 41 73 47 79 51 79 / 0 0 0 0 0 10 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

243 FXUS66 KPDT 182013 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 113 PM PDT Sat Apr 18 2026 .KEY MESSAGES... - Warming trend through Monday, followed by cooler air moving in midweek via a cold frontal boundary. - Chances of showers and thunderstorms increase Tuesday through Wednesday. - Breezy conditions going into Wednesday as the frontal boundary passes through. && .DISCUSSION... More mild overnight temperatures are expected as the airmass modifies and thicker cloud cover overspreads the Interior NW Tonight. Lows in the upper 30s and low 40s will warm efficiently Sunday morning, reaching highs in the upper 60s to 70s across all non mountain zones. An amplifying upper level ridge and sw boundary layer flow will continue to modify the airmass by Monday with even warmer lows in the 40s and low 50s, reaching highs approaching 80 degrees in the Eastern Columbia River Gorge, central Oregon, Lower Columbia Basin and John Day Basin. The days 4 and 5 LREF, centered on Tuesday seem to indicate slightly slower and southward (offshore) solutions shared by the clusters 1 through 4. By Wednesday general agreement in the clusters show the low moving inland as an open 500 mb trough. ESAT suggests about a +2 to 3 standard deviation of specific humidity as compared to model climatology at 500 mb but only normal to about 1 SD at 700 mb. A marginal increase in confidence in thunderstorm chances is with respect to timing as the NBM ensemble continues to focus and initial 10% chance of Thunderstorms across the Oregon Cascades late afternoon and early evening Monday followed by more broad chances Tuesday afternoon, with less than 10% chances across the lowlands, about 10-15% chances across the Cascades and Northern Blues, and a maximum of 25% chances across the rest of the eastern mountains, with sbcape values between 150-400 J/kg. Increasing expectations of wetting rains with the current ensembles, as chances for 0.10 or higher rainfall by Tuesday evening range from 60 to 80% for the Oregon Cascades and central Oregon (Bend/Redmond) and across the John Day Basin and southern Blues. The wetting rain chances become widespread at 60 to 80% chances by Wednesday morning with the expectation of the Columbia river Gorge and Lower Columbia basin and Yakima Kittitas valleys where probability is around 50-60% for wetting rains. && .AVIATION /18Z TAFS THROUGH 18Z SUNDAY/... VFR conditions with winds less than 10 kts will prevail through Sunday. && .Preliminary Point Temps/PoPs... PDT 68 41 74 45 / 0 0 0 0 ALW 68 45 74 51 / 0 0 0 0 PSC 71 40 77 46 / 0 0 0 0 YKM 67 40 74 47 / 0 0 0 0 HRI 70 39 76 45 / 0 0 0 0 ELN 63 38 71 44 / 0 0 0 0 RDM 70 36 74 41 / 0 0 0 0 LGD 61 36 69 41 / 0 0 0 0 GCD 64 38 72 44 / 0 0 0 0 DLS 72 45 75 51 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...71 AVIATION...77

416 FXUS65 KREV 182132 AFDREV Area Forecast Discussion National Weather Service Reno NV 232 PM PDT Sat Apr 18 2026 .KEY MESSAGES... * Dry and mild weather prevails this weekend with increased afternoon breezes on Sunday. * Periods of gusty winds, rain, and mountain snow are expected between Monday and Wednesday. * Warmer and drier weather late next week, but with lingering shower chances. && .DISCUSSION... Seasonably warm and dry conditions will largely characterize this weekend`s weather as weak high pressure passes through the western states. Abundant sunshine will allow temperatures to warm into the 60s and 70s this afternoon for Sierra and NE CA/W NV valleys, respectively. Much of the same is in store for Sunday, but with greater cloud cover and breezier afternoon winds. Our next storm is slowly churning in the eastern Pacific per latest moisture-channel imagery, and is projected to impact the region during the first half of the upcoming week. Gusty winds and mountain snow -- and their attendant impacts to recreation and travel -- are the primary concerns with this storm passage between Monday and Wednesday. Strongest winds are favored Monday and Tuesday when there is a moderate to high (50-90%) likelihood of gusts exceeding 40 mph across much of the region. A more southerly orientation of the wind field suggests that areas prone to south winds (e.g. along US-395/I- 580, US-95, etc) may see locally stronger gusts up to 60-65 mph at times. Winds will be gusty/strong on Tuesday, but intensity and duration will depend on the timing of a cold frontal passage. However, there is higher confidence in strongest winds materializing from Mono County to Pershing County closer to a deepening surface low in W central Nevada. Rain and mountain snow begins to overspread the region Tuesday in concert with the advancing cold front. Snow levels start at 6500- 7500 ft across the eastern Sierra before falling to around 5000-5500 ft Wednesday morning. This will allow snowfall down to Sierra passes during this timeframe when there is ~30% chance of 12" or more by Thursday morning. The higher sun angle does introduce uncertainty in how much snow can stick to roadways, but in any case, be prepared for travel disruptions in and across the Sierra next week. A few lightning strikes also cannot be ruled out as increasing instability will bring a 10-20% of thunderstorms Tuesday and Wednesday afternoons. We`ll begin to warm-up and dry out Thursday into the weekend, but a persistent troughing pattern will maintain lower end shower chances each day through next Saturday. -Salas && .AVIATION... Widespread VFR conditions and light breezes prevail today under weak high pressure. Similar conditions are expected Sunday with breezy S/SW winds in the afternoon. Flight conditions are expected to deteriorate Monday through Wednesday as a late season storm brings gusty winds, rain, mountain snow, and low chances (10-20%) chance of lightning. -Salas && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

813 FXUS66 KSTO 182031 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 131 PM PDT Sat Apr 18 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Dry weather with near to slightly above normal temperatures over the weekend - Storm system brings renewed precipitation chances in rain, mountain snow and thunderstorms Monday through Wednesday, along with cooler temperatures and breezy winds && .DISCUSSION... ...Today through Sunday... Current GOES-West satellite imagery illustrates some high clouds starting to move into California on this Saturday afternoon. Temperatures are currently trending approximately 5 to 10 degrees warmer than this time yesterday, valid at 115 PM PDT. The upper level pattern features ridging, bringing warm and dry conditions today the forecast area. Forecast highs this weekend will be in the 70s to low 80s in the Valley and foothills, and in the 50s to 60s in the mountains. These temperatures will be trending near to slightly above normal for this time of year. Generally light winds are prevailing across the area and will gradually increase out of the south on Sunday ahead of an approaching storm system. ...Next Week... An upper low will approach California and move inland early to mid next week, bringing along cooler temperatures, breezy southerly winds, rain, thunderstorms and mountain snow Monday through Wednesday. The latest forecast precipitation amounts have not changed much, with 1 to 2 inches of rain in the Valley and 1.5 to 3 inches of rain in the foothills, with 1 to 2 feet of snow in the mountains. Snow levels will initially be high on Monday, around 6000 to 7000+ feet, and will lower down to the passes Tuesday, and down to 5000 to 6000 feet late Tuesday into Wednesday. Moderate impacts from mountain snow are forecast, with chain controls, travel delays and reduced visibilities at times. The threat for thunderstorms will have the highest chances on Tuesday, which will bring the potential for strong to severe thunderstorms on this day. There are also be some lingering thunderstorm chances into Wednesday as well. Check back frequently for updates on this storm and always check the forecast and road conditions before traveling! && .AVIATION... General VFR conditions at TAF sites over the next 24 hours. Increasing cloud cover around 00z Monday as a weather system moves into the area, but no changes in flight categories in the next 24 hours. Winds generally less than 12 kts everywhere until 18z Sunday. Then, southerly winds gradually increase with gusts up to 25 kts in the northern Sacramento Valley and foothills, and up to 30 kts in the mountains through 06z Monday. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

034 FXUS65 KMSO 181840 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1240 PM MDT Sat Apr 18 2026 .DISCUSSION... KEY MESSAGES: - Warming and drying trend with the weather pattern during weekend that lasts through early next week. - Showers and isolated thunderstorms possible Tuesday evening, with gusty outflow winds possible. - Widespread rain and much cooler temperatures arrive Wednesday through Friday. A robust ridge of high pressure will amplify over the Northern Rockies this weekend, initiating a significant warming trend through early next week. Regional temperatures will peak on Tuesday, with valley highs reaching the 70s and 80s approximately 20 degrees above seasonal norms. Record breaking daily highs are probable for several locations. By Tuesday afternoon, increasing instability and mid-level moisture will support the development of high-based thunderstorms, primarily across north- central Idaho. The primary hazards with these cells will be frequent lightning and gusty outflow winds. A cold front will cross the region Wednesday ahead of an approaching broad upper-level trough, ushering in widespread precipitation and breezy conditions. While the precise track of the subsequent closed low remains uncertain for late next week, high confidence exists for a transition to much cooler and more unsettled weather. Moderate to heavy rainfall is expected Wednesday through Thursday, with the highest probabilities for >1.00" of liquid accumulation focused over the Clearwater Mountains and the Continental Divide. Ensemble clusters highlight a 30% secondary scenario where a deep moisture plume wraps into the circulation, potentially yielding 2.00" to 3.00" of liquid along the Divide. Impacts will include rises on area waterways, though flooding is currently not anticipated. Forecast users should remain alert for ponding in poor drainage areas and localized rock or debris fall on steep terrain. Additionally, snow potential increases by Thursday for the higher valleys and mountain passes of southwest Montana, including the Butte area and Homestake/MacDonald passes. The degree of winter impacts remains highly sensitive to the eventual track of the closed low. && .AVIATION...VFR conditions will prevail throughout the period as a strengthening ridge of high pressure maintains clear skies and light, terrain-driven winds. Some patchy fog is possible near river bottoms Sunday morning, but impacts to airfields are not anticipated. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

742 FXUS65 KBOI 182052 AFDBOI Area Forecast Discussion National Weather Service Boise ID 252 PM MDT Sat Apr 18 2026 .KEY MESSAGES... - Dry and warm through Tuesday. - Showers and thunderstorms and turning cooler Wednesday as a cold front moves inland. && .SHORT TERM /Through Monday Night/... A ridge of high pressure will continue to build into the area over the next several days with a warming trend through Monday. Temperatures will warm an additional 10 degrees on Sunday and around 5 degrees on Monday. As the ridge strengthens, the surface winds shift to south-southeast aiding in the warming as well with breezy conditions during the afternoons through Monday. && .LONG TERM /Tuesday through Saturday/... Tuesday will continue the trend of well-above average temperatures across the region, with the upper-level ridge over the Rockies and a cutoff low moving into the Western U.S. coast. With this sharp pressure gradient over the region, breezy southerly winds are forecast Tuesday afternoon. Beginning Tuesday evening into Wednesday, this cold-core Pacific low will bring cold air (behind a west-to-east cold front), widespread showers, and a slight chance of thunderstorms. Wednesday will become the wettest day, with the probability of precip climbing to 60-90% for the morning and afternoon. Snow levels will also lower to 5000-6500 ft MSL at that time as the low center moves overhead, allowing snow accumulation over the higher terrain. Maximum daily temperatures are forecast to drop as much as 20-30 degrees from Tuesday to Wednesday. Showers and below normal temperatures will persist into Thursday as the upper low becomes ingested into the parent Canadian trough to the north. This will solidify cool and unsettled northerly flow across the N Rockies as the low progresses east, with lingering mountain showers expected into Fri. Winds will be gusty Wednesday and breezy on Thursday behind the cold front and as the trough moves east. The upper-level pattern becomes quite disorganized and variable across the long range models Friday onwards. What can be said at this time is that the clusters agree on below-normal upper-level heights, indicating an active pattern remaining. && .AVIATION /18Z Saturday through Sunday/... Issued 1209 PM MDT SAT APR 18 2026 VFR under high clouds. Surface winds: E-SE 5-15 kt. Gusts to 20 kt in the lower Snake Plain into KBKE. Winds aloft at 10kft MSL:SW-S 5-15 kt. KBOI...VFR. Surface winds: SE 7-14 kt. Gusts around 20 kt through the afternoon. Sunday Outlook...Continued dry with periods of high cloud cover. Surface winds E-SE 10-20 kt with gusts to 25 kt, strongest in Snake Plain east of KBOI. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...KA LONG TERM....CH AVIATION.....CH

184 FXUS65 KLKN 182013 AFDLKN Area Forecast Discussion National Weather Service Elko NV 113 PM PDT Sat Apr 18 2026 .KEY MESSAGES... * Generally fair weather in place through Monday, though breezes will be present Sunday * Next weather system moves in over Nevada Tuesday and Wednesday with periods of rain and mountain snow * Strong gusty winds over central Nevada Monday and especially Tuesday * Temperatures will be cooler than normal Wednesday through the weekend && .DISCUSSION... (This afternoon through next Saturday) WEATHER PATTERN OVERVIEW: A few mid and high-level clouds are streaming across northern and central Nevada this afternoon with plenty of sunshine peaking through. This is all due to a ridge of high pressure that will be affecting the area`s weather for the next several days. Quiet and dry weather will continue tonight under mostly clear skies with lows in the 20s and 30s. The upper ridge axis will move overhead and then head east of the area on Sunday. The flow will become more southwesterly in nature with afternoon highs warming into the 60s and 70s by the afternoon. A few afternoon breezes will develop during this time, especially across central Nevada where wind gusts to 30 mph are possible. No precipitation is expected. Dry and quiet weather will continue Sunday night into Monday with lows warmer than the previous morning with readings into the 30s and light winds. By Monday, a large closed upper low will be wobbling towards the west coast of the United States. Southwest flow will continue over the forecast area and additional warming is expected. This will result in afternoon highs about four to seven degrees warmer than on Sunday. Even with this warming, only one climate site will be near its record. Elko Airport`s current record of 82 degrees was set back in 1994 while the forecast high will be 79 degrees on Monday. All other locations will be in the 70s to near 80 degrees for highs. Winds will also develop on Monday with southwest winds of 15 to 25 mph with wind gusts of 35 to 45 mph. Clouds are expected to increase due to the slow forward progression of the incoming cutoff trough. Overnight lows will be in the 40s. The main upper low center is forecast to remain off the coast, though precipitation is expected to move into portions of California and western Nevada. Conditions are expected to remain dry during the morning but moisture will be increasing during the day. Strong winds will be developing during the late morning and afternoon. The strongest winds are forecast to be in central Nevada where speeds gusting to 50 mph are possible. In addition, high temperatures will remain above normal levels with readings in the 70s. Snow levels are expected to remain high during the overnight with lows in the 40s. By Wednesday and Thursday, the upper low is expected to fill though cool and showery, wet conditions will remain. Highs will be in the 50s with lows in the 30s. Light showers are possible through Saturday with temperatures remaining near normal. FORECAST CONFIDENCE & DEVIATIONS: No changes were made to the forecast. High confidence continues through the short term with respect to the warming and dry conditions. Confidence has risen to around low to moderate with regards to the incoming cutoff system early next week. && .AVIATION...Look for VFR conditions through the next 24 hours. Winds will be breezy across the central TAF sites of KTPH and KELY with gusts to 30KT. Other locations in northern Nevada will see winds less than 15KT. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...86 AVIATION...86