Marine Weather and Tide Forecast for Springfield, OR

MORNING UPDATE
The Cold Weather Advisory has been allowed to expire at 10 AM as temperatures west of the Cascades have risen above 25 degrees. The previous discussion continues below.

SHORT TERM
Now through Friday...Continued high pressure is leading to light onshore flow and clear skies. Overnight temperatures continue to be several degrees below normal, with little fluctuation. Tonight, temperatures have been a few degrees warmer than previous nights. Due to apparent temperatures (what it "feels like") below 1000 feet reaching lows below 25 deg F, a Cold Weather Advisory has been issued until 10 AM Wednesday for all locations west of the high Cascades. Will note though that temperatures are hovering right along the upper end of the threshold for most urban areas and within the Willamette Valley. Frost also continues to be a possibility, especially on exposed metal surfaces and shaded areas. Similar conditions expected for Wednesday though overnight temperatures are running a tad warmer. Have noted that models are running a few degrees warmer than what is being observed - especially in the southern Willamette Valley.
Therefore have nudged towards a persistence forecast.

The next pattern shift arrives late Thursday into Friday morning as a trough aloft drops down from the Northeast Pacific. This frontal timing has varied significantly over the last several days likely due to the intensity of the ridge currently in place. The impacts from this front, a winds and potential precipitation, have lessened overtime. Confidence in breezy easterly winds is increasing though as the NAM shows the pressure gradient between Troutdale and the Dalles lowering to around -6 mb, and North Bend (OR) and Spokane around -13 mb.
These types of pressure gradients support gustier winds through the east-west aligned gaps like the Columbia River Gorge and downsloping off of the Cascades. Wind concerns are low at this point, but weakened trees could see downed branches around these areas. Precipitation probabilities have stayed fairly consistent with 24 hour measurable rainfall totals (greater than a trace) is around 20% in the lowlands and up to 50% along the Cascades. The probability for 0.1 inch of rain though is less than 20% and concentrated only over the mountains.
Ultimately, even with the incoming precipitation and lingering cold air, no winter precipitation concerns. -Muessle


LONG TERM
Friday night through Tuesday...The shortwave trough will drop southward and out of the area early Saturday morning causing winds aloft to return to the east and surface winds to the north. There is another hint of breezy easterly winds on Saturday during this transition but confidence is low. Rinse and repeat of this week is expected Saturday night through Sunday.
Will see a steady decline in temperatures as high pressure once again builds. Coldest overnight temperatures expected Sunday morning with lows ranging from near freezing along the Coast, to near 25 degrees F in the Willamette Valley. Ultimately, these temperatures are similar to what we have seen over the last week. Minimal change through early in the week. -Muessle



AVIATION
Widespread VFR conditions persist as high pressure remains anchored over the Pacific Northwest. Clear skies, along with sub-freezing temperatures during the overnight hours will likely result in frost developing on exposed surfaces. Currently, not expecting significant frost accretion at this time. There could be some very isolated areas of freezing fog, but am not expecting any to impact the terminals.

PDX AND APPROACHES...VFR conditions to persist with light and variable winds. Clear skies, along with sub-freezing temperatures during the overnight hours will likely result in frost developing on exposed surfaces. Minimal frost accumulation expected at this time. /42

MARINE
A ridge of high pressure overhead will maintain calm conditions and produce northeasterly winds today with gusts up to 20-21 knots across the outer waters before gradually becoming more northerly again on Thursday. Expect those winds to increase to 20-25 knots after that northerly switch Thursday into Friday due to a weak weather disturbance clipping the region riding southward from British Columbia. Until then, seas should stay around 4-6 ft before increasing slightly on Friday to 8-10 ft; highest over the outer waters. It appears both seas and winds will stay below small craft advisory criteria until Thursday night/Friday. Seas likely ease back into the 4-6 ft range for the upcoming weekend as the ridge of high pressure strengthens.
However, expect breezy north to northeast winds to continue on Saturday into Sunday morning, especially over the southern outer waters where small craft wind gusts to 25 kt are likely to occur (55-75% chance). Wind gusts will not be as strong over the northern waters and the inner waters comparatively. Overall it appears this rather benign winter-time weather pattern likely persists into at least the early to middle portion of next week.
-Schuldt

PQR WATCHES/WARNINGS/ADVISORIES

OR...None.
WA...None.
PZ...None.