Marine Weather and Tide Forecast for Raymond, WA

SHORT TERM
Now through Thursday...There are two concerns today: heat and increasing convective potential. Upper ridging remains in place today, and warm overnight temperatures have once again left much of the interior with poor overnight cooling heading into the new day. That sets the stage for another hot afternoon, although the temperature forecast is more complicated due to increasing mid and high level moisture advancing northward.

For the heat portion of the forecast, inland locations remain on track to climb well into the 90s again today, with the warmest interior valleys having at least some chance to reach the upper 90s to near 100 degrees (notably around the Portland/Vancouver metro). The exact high temperature today will depend in part on how quickly cloud cover increases and how much sunshine can be maintained into the afternoon. Even if highs end up a few degrees lower than peak potential, the added humidity will make conditions feel more oppressive than on previous days. A Heat Advisory remains in effect through this evening for much of the interior lowlands, including the Portland/Vancouver Metro, the Columbia River Gorge including Hood River County, Kelso/Longview, and portions of the south Washington Cascades. Major HeatRisk remains a concern for much of the Willamette Valley, especially where overnight temperatures stay elevated and afternoon heat builds before storms develop.

The more active part of the forecast arrives later today as monsoonal moisture and an offshore low work together to destabilize the atmosphere. Guidance continues to suggest that at least isolated convection could begin as early as 11 AM this morning in a few locations, but confidence is notably greater in development from 1 PM this afternoon to 7 PM this evening when daytime heating can maximize instability. The favored area for thunderstorm development continues to be the Lane and Linn County Cascades and nearby Willamette National Forest, though a few storms could develop farther west as well if sufficient breaks in cloud cover allow instability to build. This is reflected in the latest SPC convective outlook, which depicts a general thunderstorm risk across much of southwest Washington and northwest Oregon, with a marginal risk focused over the Oregon Cascades. It is critical that if you hear thunder or see lightning that you take cover immediately inside of a sturdy structure, get off of the water, and limit outdoor activities.

Forecast soundings and convective guidance continue to support an environment capable of thunderstorms, with elevated instability in place and precipitable water (PWAT) values around 1.2 to 1.5 inches. While that amount of moisture could support pockets of locally heavier rainfall, relatively dry air in the lower levels may reduce rainfall efficiency in some locations. While lightning remains the primary concern, locally gusty and erratic winds may accompany any stronger storms, especially near the Cascades. A more scattered thunderstorm scenario cannot be ruled out this afternoon and evening, particularly over the higher terrain.

Showers and thunderstorms may linger into tonight, though coverage and intensity should gradually diminish after sunset as surface-based instability weakens. A few showers could persist into Thursday morning before the broader pattern begins to shift.

LONG TERM
Thursday Night through Tuesday...By late Thursday into Friday, upper ridging will weaken while a broader trough moves toward the Pacific Northwest. This will allow onshore flow to re-establish itself and bring a more noticeable cooling trend late this week, along with a return to more marine influence and night/morning cloud cover. Confidence is moderate to high in the overall cooling trend, though lower in the exact day-to-day temperatures. Temperatures should remain somewhat above seasonal averages Thursday and Friday, but well below the temperatures reached earlier in the week, with improved overnight recovery as well. Looking into the weekend and early next week, temperatures appear likely to settle back into the upper 70s to lower 80s inland, with no strong signal for meaningful precipitation after Friday, though light shower chances may linger Saturday along the north Oregon coast and south Washington coast.
~12

AVIATION
Through 12Z Thursday...VFR conditions with sct/bkn high clouds inland will continue through most of the TAF period, with the exception of marine stratus potentially pushing inland late Wednesday, bringing a 20-30% chance of MVFR conditions after 06Z Thu. Periods of haze from elevated smoke may restrict vis to 5-6 SM in the afternoon at inland terminals. As for coastal terminals, current LIFR conditions will likely improve back to VFR conditions by 16-18Z Wed. Marine stratus will then likely creep back in from south to north, returning KONP to LIFR/IFR conditions around 00Z Thu, then to KTMK around 06Z Thu, and to KAST by 09Z Thu. There is less confidence for these conditions at KAST compared to KONP, with a 30-40% chance of IFR at KAST but a 80-90% chance at KONP. Additionally, there is a 20-40% chance of LIFR at KAST but 50-70% chance at KONP.

Otherwise, winds will be calm to light and variable early this morning, building out of the west to northwest at 5-10 kt inland and 9-14 kt along the coast after 18-21Z Wed. KEUG and KSLE are an exception, with winds around 9-14 kt expected.
Coastal terminals and KEUG/KSLE may see gusts up to 20 kt during the afternoon. Winds will begin to shift more west to southwesterly after 03Z Thu.

Afternoon temperatures are forecast to approach 100 degrees at many inland terminals this afternoon; be aware of high density altitude which may reduce aircraft performance. Showers and isolated thunderstorms are expected to develop this afternoon, tracking northward through the remainder of the period.
Confidence in the occurrence of thunder is too low to include in TAFs at this time, but heavy showers may briefly result in MVFR/IFR vis if they pass over a terminal. Showers may also produce gusty or erratic winds nearby. Late in the period, winds will begin to turn out of the southwest to south as showers wane.

KPDX AND APPROACHES...VFR conditions and sct/bkn high clouds through most of the TAF period. There is a 20-30% chance of MVFR CIGs after 06Z Thu. Smoke aloft may yield surface vis of 5-6 SM this afternoon, although vis aloft can often be lower. Chances for showers or an isolated thunderstorm increase after 00z Thu; the most likely terminal impacts are gusty/erratic winds and locally heavy downpours which may briefly restrict vis to IFR/MVFR levels. Northwest winds continue through the period at 5 kt or less overnight, building to 5-10 kt by this afternoon.
Winds will shift more west to southwesterly after 03Z Thu.
~12/36

MARINE
North to northwest winds over the coastal waters will shift to west to southwesterly late today and through the weekend as weak low pressure develops over the waters. Winds will remain light less than 10-15 kts. Seas will be 3-6 ft at 8-9 seconds through the weekend.

Today, there is a chance for showers and thunderstorms across all of the waters through the majority of the day and overnight hours. There could be frequent lightning and gusty and erratic winds with any thunderstorm that forms. ~12/03

CLIMATE
Daily record high minimum temperatures for July 22 Astoria 62 (2007)
Vancouver, WA 74 (2006)
Portland Int'l 74 (2006)
Hillsboro 73 (2006)
McMinnville 73 (2006)
Salem 74 (2006)
Eugene 71 (2006)

Daily record high maximum temperatures for July 22 Astoria 88 (1891)
Vancouver, WA 98 (1928)
Portland Int'l 98 (1978, 2004)
Hillsboro 103 (1938)
McMinnville 102 (1928)
Salem 102 (1928, 1978)
Eugene 101 (2006)

PQR WATCHES/WARNINGS/ADVISORIES
OR...Heat Advisory until 11 PM PDT this evening for ORZ108>115- 120>122.
WA...Heat Advisory until 11 PM PDT this evening for WAZ204>210.
PZ...None.