Marine Weather Net

Cape Flattery to James Island WA out 10 NM Marine Forecast


5 - 10


5 - 10


10 - 15


5 - 10

The Marine Weather Forecast In Detail:
PZZ150 Forecast Issued: 251 PM PDT Wed Jul 17 2024

Today...S Wind 5 To 10 Kt, Rising To 10 To 15 Kt Late This Morning And Early Afternoon, Easing To 5 To 10 Kt Late. Seas 4 To 5 Ft. Wave Detail: W 5 Ft At 11 Seconds And Sw 2 Ft At 18 Seconds.
Tonight...S Wind 5 To 10 Kt. Seas 4 To 5 Ft. Wave Detail: S 2 Ft At 4 Seconds, W 4 Ft At 10 Seconds And Sw 2 Ft At 17 Seconds.
Thu...S Wind 10 To 15 Kt. Seas 4 To 5 Ft. Wave Detail: S 3 Ft At 5 Seconds, W 3 Ft At 10 Seconds And Sw 2 Ft At 17 Seconds.
Thu Night...S Wind 5 To 10 Kt. Seas 3 To 5 Ft. Wave Detail: S 2 Ft At 5 Seconds, W 3 Ft At 9 Seconds And Sw 2 Ft At 16 Seconds.
Fri...S Wind Around 5 Kt. Seas 3 To 4 Ft. Wave Detail: W 2 Ft At 9 Seconds And Sw 2 Ft At 15 Seconds.
Fri Night...Nw Wind Around 5 Kt. Seas 3 To 4 Ft. Wave Detail: Sw 2 Ft At 7 Seconds, W 2 Ft At 10 Seconds And Sw 2 Ft At 15 Seconds.
Sat...Nw Wind 5 To 10 Kt. Seas 3 To 4 Ft. Wave Detail: Nw 2 Ft At 4 Seconds, Sw 2 Ft At 7 Seconds And W 3 Ft At 9 Seconds.
Sat Night...Nw Wind Around 10 Kt. Seas 4 To 5 Ft. Wave Detail: W 4 Ft At 8 Seconds And Sw 2 Ft At 14 Seconds.
Sun...Nw Wind 5 To 10 Kt. Seas 4 To 5 Ft. Wave Detail: W 5 Ft At 10 Seconds And Sw 2 Ft At 14 Seconds.
Sun Night...Nw Wind 10 To 15 Kt. Seas 5 To 6 Ft. Wave Detail: W 5 Ft At 10 Seconds And Sw 2 Ft At 14 Seconds.
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Area Forecast Discussion
National Weather Service Seattle WA
258pm PDT Wednesday July 17 2024

A trough of low pressure in eastern Washington will trigger isolated to scattered thunderstorms across the Cascades this afternoon, with a lesser chance in the Olympics of storms. The fire danger continues in these areas through tonight due to the threat of lightning and gusty winds from these storms. Remaining areas will see partly sunny skies through the afternoon. High pressure will build back in through the end of the week, with Saturday being the warmest day with south Puget Sound areas reaching 90 degrees. Onshore flow will strengthen early next week, cooling temperatures down.

Short Term - Tonight Through Saturday
Upper analysis shows southwesterly flow aloft between a ridge over Montana, and a trough to the west over the Pacific Ocean. There is a cutoff upper level low feature over western Washington this afternoon which has been dipping in some vorticity advection into the region (hence the cloud cover over much of the state this morning and afternoon). Instability remains in place over much of the region this afternoon (particularly in the Cascades and Olympics), thanks to a thermal trough still position on the west side of the state. CAPE values still remain sufficient for convection going to the afternoon (especially as daytime heating takes out some of the capping - temperatures already in the 80s this afternoon).

Radar has been most active this morning/afternoon south of Lewis County, where and area of scattered thunderstorms continue to move in a northerly direction up the Cascade Mountains. These thunderstorms are expected to continue their journey north through the remainder of the Cascades this afternoon and evening. Precipitation amounts are rather lackluster with this activity, with only a few hundredths of Quantitative Precipitation Forecast expected in total. Lightning and gusty winds are expected to be the primary concerns with the storms. This will keep critical fire danger in the Cascades and Olympics through tonight (see fire discussion for more details).

The low perturbation feature will move out of Washington by Thursday, with flow aloft remaining southwesterly. Cloud coverage should burn off quickly Thursday morning with light southwest winds, and highs in the low to mid 80s along the I-5 corridor (60-70 along the coast). Patchy fog is possible in a couple low lying areas during the morning hours, but will burn off quickly. Friday is very similar to Thursday. There is a weak upper level trough that will move through B.C. and northern Washington, but as of now will pass through dry. Winds will be lighter and more northerly on Friday.

Saturday is expected to the warmest day in the forecast, with a ridge over the western states building up well into Canada. Southerly flow aloft will increase which will bring warmer air into the region. Highs as of right now are most likely to top out in the upper 80s to 90 degrees (hottest temperatures in south Puget Sound). NBM gives a 25 percent chance of temperatures being 4 to 5 degrees warmer (low to mid 90s). Heat risk at this time is minor to moderate (with the moderates being in urban areas). Lows Saturday morning and Sunday morning may only drop to 60 in urban areas.

Long Term - Sunday Through Wednesday
Pattern remains largely dry in the extended forecast. A small shortwave trough tracking up the west coast of Washington Sunday may trigger a few showers, but confidence is too low at this time to include in the forecast. With an upper level low tracking towards the region first part of next week, the return of some onshore flow will cool high temperatures down into the upper 70s to low 80s.


Onshore flow increasing this evening as surface high pressure builds over area waters. High pressure centered over the offshore waters Thursday through the weekend with varying degrees of onshore flow. A SCA (Small Craft Advisory) is posted for the central and eastern Strait of Juan de Fuca lasting into early Thursday morning. An additional push is in the cards for Thursday evening and again over the weekend with the potential for more headlines.

Seas 3 to 5 ft increasing to 6 ft over the weekend.


Fire Weather
A few clusters of thunderstorms near the Cascades have developed this afternoon. Expect this to continue with the threat area lifting north through the evening hours. The risk is slightly lower for the Olympics, but will maintain the collection of red flag warnings unchanged at this point in time. We'll see a return of warmer and dry conditions through the end of the week, with afternoon minimum RHs again dipping closer to critical thresholds by Friday and Saturday in the Cascades. At this point, there's not an overwhelming signal for significantly increased winds or instability, so just something to monitor for now. Another disturbance may again bring some renewed threat for thunderstorms by late in the weekend across some portion of the mountains, but confidence isn't particularly high for now. Finally, expect a somewhat cooler and more humid pattern to emerge into early next week.

.CLIMATE...In 80 years of records at Seattle-Tacoma airport this was the warmest first half of July. The average temperature of 72.0 degrees was fractionally warmer than the previous warmest in 2015. The average high temperature of 85.3 degrees was two degrees warmer than the previous mark also set in 2015. The average low temperature of 58.7 degrees was 4th warmest ( 60.6 2015, 58.9

NOAA Seattle WA Office: Watches - Warnings - Advisories
WA...Red Flag Warning until 11pm PDT this evening for East Portion of the Olympic Mountains-West Portion of the Olympic Mountains-West Slopes of the Central Cascades Generally above 1500 Feet-West Slopes of the North Cascades Generally above 1500 Feet.

PZ...Small Craft Advisory until 5am PDT Thursday for
Central U.S. Waters Strait Of Juan De Fuca-
East Entrance U.S. Waters Strait Of Juan De Fuca.