GRAF made a big move. Uh oh. We still do not yet know how this is going to play out. Everything is still on the table from just a breezy system, to a high impact damaging wind storm. Stay tuned!

And suddenly there it is. National Weather Service 2.webloc

It AIN'T

18z GRAF

Forecast confidence decreases notably beginning Wednesday as the larger-scale pattern becomes more amplified and complex. Guidance depicts the parent trough evolving into a closed low while dropping southward, allowing additional shortwave energy to rotate northward toward the Pacific Northwest. This pattern introduces a wide range of possible outcomes, particularly with regard to wind impacts. Ensemble guidance has pivoted with the most recent update, where the EPS now has the meso-low tracking inland rather than along the coast, resulting in a weak pressure gradient and less impactful winds. However, the GEFS still suggests that this low will track northward along the coast, which would allow for stronger winds. Additionally, high-res model guidance (WRF and NAMnest) still suggest the possibility for strong and impactful winds. To give more detail on this scenario, winds will initially come out of the east (due to the pressure gradient from the low on the coast) and then shift southerly to southwesterly as the low tracks north. The window for potential damaging winds (45 to 65+ mph) remains between 6 AM to 2 PM Wednesday across most of western Oregon and southwest Washington, including the I-5 corridor (most locations will only observe peak wind gusts for 1-2 hours). Such winds would likely result in widespread tree damage and power outages. While this remains a lower-probability outcome relative to the full ensemble envelope, the increasing consistency within higher-resolution and select ensemble guidance warrants close monitoring. Should upcoming model runs continue to trend in this direction, wind-related headlines may become necessary.