Cascade Head to Florence OR from 10 to 60 NM Marine Forecast
| Rest Of Today...S Wind To 5 Kt. Wind Waves S 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds. Widespread Dense Fog In The Morning. Areas Of Dense Fog In The Afternoon. |
| Tonight...N Wind To 5 Kt. Wind Waves N 1 Ft At 4 Seconds. Nw Swell 3 Ft At 9 Seconds. Areas Of Dense Fog In The Evening. Patchy Dense Fog After Midnight. |
| Wed...Ne Wind 5 Kt, Backing To Nw To 5 Kt In The Afternoon. Wind Waves Ne 1 Ft At 4 Seconds, Shifting To The Nw At 4 Seconds In The Afternoon. Nw Swell 3 Ft At 9 Seconds. Patchy Dense Fog In The Morning. |
| Wed Night...Nw Wind 5 Kt, Backing To Se After Midnight. Wind Waves Nw 1 Ft At 4 Seconds, Shifting To The Se At 4 Seconds After Midnight. Nw Swell 3 Ft At 9 Seconds. |
| Thu...S Wind 5 Kt. Wind Waves S 1 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds. |
| Thu Night...N Wind 5 To 10 Kt. Wind Waves N 2 Ft At 4 Seconds. Nw Swell 3 Ft At 10 Seconds. |
| Fri...N Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 4 Ft. |
| Sat...Nw Wind 5 To 10 Kt. Wind Waves 2 Ft. Nw Swell 4 Ft. |
| Area Forecast Discussion National Weather Service Portland OR 1108pm PDT Fri April 10 2026 Updated aviation discussion. Synopsis Unsettled conditions continue through today as broad southerly flow and breaks in cloud cover support scattered showers and thunderstorms, especially across the Oregon Cascades and adjacent foothills. Thunderstorm chances return Saturday afternoon and evening, with the greatest coverage over the central Oregon Cascades and foothills. Cooler conditions develop Sunday into early next week as flow turns more westerly to northwesterly. Another system may bring widespread precipitation and Cascade snow by the middle of next week. .SHORT TERM...Now through Sunday Night...As of mid-afternoon, a vertically stacked low remains positioned off the northern California coast, maintaining moist southerly to southeasterly flow across the region. This pattern continues to support increasing instability and a transition to more convective conditions through this afternoon and evening. Recent observations show partial in some areas, allowing for sufficient surface heating to support thunderstorm development where cloud cover has thinned. Earlier today, Storm Prediction Center updated the Day 1 Convective Outlook to include a Marginal Risk for severe weather across portions of the Willamette Valley south of Wilsonville, including the Salem, Corvallis/Albany, and Eugene/Springfield areas. The Cascade foothills from Molalla southward, including Sweet Home, are also included. Within this area, the primary hazards with any strong thunderstorms include damaging winds and large hail of 1 inch or greater in diameter. This corresponds to roughly a 5-15% chance of severe hazards occurring within 25 miles of a point. Areas outside of the Marginal Risk still carry a thunderstorm risk this afternoon and evening, though the probability of severe thunderstorms remains below 5%. Recent model soundings continue to suggest 400-850 J/kg of MUCAPE this afternoon, with effective shear around 20-25 kt. These values are sufficient to support isolated thunderstorms, with the potential for a few multicell structures, mainly south of the Portland metro where instability is greater. Outside of any stronger storms, the primary impacts will be brief heavy rainfall, cloud-to-ground lightning, small hail, and localized gusty outflow winds. In terms of timing, convective initiation is expected to focus initially over Lane County and the central Oregon Cascades, where activity will develop through the mid to late afternoon. Coverage may expand northward along the Cascades and into portions of the I-5 corridor through the late afternoon into early evening. There remains some uncertainty regarding westward extent, which will depend on cloud cover trends, instability, and the exact orientation of flow aloft. Areas that maintain greater breaks in cloud cover will have a higher likelihood of seeing thunderstorms drift west of the Cascades. Thunderstorm probabilities generally range from 15-40% across much of northwest Oregon this afternoon and evening, with the highest chances over the central Oregon Cascades and foothills. Activity should gradually diminish later this evening with the loss of daytime heating, transitioning to scattered showers overnight. By Saturday, ensemble guidance supports continued cyclonic flow and another round of scattered showers and thunderstorms as another low develops to the south. Instability appears somewhat reduced compared to today, with MUCAPE generally in the 300-600 J/kg range, though sufficient for isolated thunderstorms. Thunderstorm probabilities range from 15-30%, highest across the Cascades and foothills. By Sunday, the upper-level low shifts inland, transitioning the region to more westerly flow and effectively ending most thunderstorm potential outside of a slight chance (around 15%) over the far southern portion of the Lane County Cascades. Showers persist under wrap-around moisture, with Probability of Precipitation of 60-90% over the Cascades and foothills and 30-60% elsewhere. Temperatures cool back into the upper 50s to low 60s inland, closer to seasonal normals. Long Term Monday through Thursday...Ensemble guidance indicates a transition to broad west-northwest to northwest flow aloft early next week. A weak embedded shortwave is expected to move through Monday, maintaining a 50-90% chance of showers, highest across the Cascades. Temperatures remain near to slightly below normal. Shower activity decreases Monday night into Tuesday as a transient ridge briefly builds overhead. Attention then turns to the next Pacific frontal system expected between late Tuesday and Wednesday. While timing differences remain, confidence is increasing in a return to widespread precipitation during this period. Cooling temperatures associated with this system will lower snow levels to near or below Cascade pass elevations, raising the potential for travel impacts. Current probabilistic guidance indicates a 60-80% chance of 6+ inches of snowfall at the Cascade passes over 48 hours (between Tuesday and Thursday afternoon). As for 12+ inches of snowfall, there is a 40-60% chance during the aforementioned time. In addition, cooler and potentially clearer conditions behind the system may introduce renewed frost concerns across portions of the interior valleys by mid to late week. Current guidance suggests a 30-60% chance of frost (less than 36 F) in the Upper Hood River Valley Tuesday night into Wednesday morning. As for Wednesday night into Thursday morning, guidance suggests a 30-70% chance of widespread frost across most inland locations. Thursday morning may be much colder, with a 5-30% chance of freezing temperatures across most inland locations, except for a 50-80% chance in the Upper Hood River Valley (chances from Odell to Parkdale). ~12 Marine Overall conditions remain rather benign through the weekend as seas remain in the 4 to 7 foot range with winds below 20 kt. The next several days will see south/southwest winds slowly become more north/northwest by Saturday and these winds are expected to persist through at least Monday night. Looking towards the middle of next week (Tuesday/Wednesday) a decently robust frontal boundary will likely (40-60% chance) result in Small Craft Advisory wind gusts and seas around 7 to 10 feet. It's worth noting that there is a 5-10% chance of thunderstorms this afternoon and Saturday afternoon across all waters from the southeast. Any thunderstorms that do develop could produce lightning, hail, gusty and erratic winds as well as a less than 2% chance for a funnel cloud or waterspout. /42-99 NOAA Portland OR Office: Watches - Warnings - Advisories OR...None. WA...None. PZ...None. |
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