Sunday, November 27, 2011

Olympic Rain Shadow, Again

7:35 AM, Temp 52.1° F, Dew Point 46.1° F, Barometer 29.84 in, Wind 11 mph G/24, Humidity 80%

We speak occasionally here about the Olympic Rain Shadow.  It is also known as the San Juan Sunbelt, Banana Belt and the Blue Hole.  This is what accounts for a surprisingly low annual rainfall in the area of the western Strait of Juan de Fuca, northern Puget Sound and the southern Strait of Georgia.  You can see the rain shadow on the radar map from this morning.  It is literally the hole in the middle of the rain image.  The Olympic Mountain Range sits southwest of the city of Port Angeles.  The clear wedge in the radar image locates the mountains which the radar cannot penetrate.

The red box marks Fidalgo Weather's location.  Despite the large weather system all around us, we were bone dry at that time.  During these events, I can sometimes look southwest and see blue sky over Whidbey Island.  It really is a "blue hole" in an otherwise cloudy sky.  South Fidalgo and North Whidbey Islands receive about 20-22 inches (50-56 cm) of rainfall per year.  By comparison, Seattle receives around 38 inches (97 cm) annually.

As an aside, notice the empty wedges in the radar image north and east of Mount Vernon.  These are probably due to the Cascade foothills in the area.  Bow Hill to the north and Little Mountain southeast of Mount Vernon are probably partially responsible.  I would also venture a guess that Mount Pilchuck is producing the large gap between Mount Vernon and Everett.

A second and more profound rain shadow is created by the Cascade Mountain Range.  Out-of state visitors to eastern Washington and Oregon are often startled to find desert in a region famous for rain.  Some areas over there receive less than 10 inches (25 cm) of rainfall each year.  With deserts, forests, grasslands, mountains, river valleys and alpine snows, we have it all here.

9:15 AM, Temp 50.1° F, Dew Point 47.3° F, Barometer 29.91 in, Wind 10 mph G/22, Humidity 90%

By 9:15 AM, our rain shadow had closed up and it was about to rain very hard.  I drove downtown in a complete downpour.  Also at this time, the barometer reading of atmospheric pressure had begun rising rapidly.  It stopped raining by noon.  We would get a total of 0.13 in (3.3 mm), not that much to speak of.

In typical fashion, the rain was proceeded by wind.  As low pressure systems move inland north of us, southerly winds will roar up the Puget Sound basin, funneling between the Olympics and Cascades.  Once again these mountains are influencing our weather.  The winds will course up Saratoga Passage and Skagit Bay and slam right into South Fidalgo.  The Cliff Mass Weather Blog posted on the subject just in time, and explains it much better than I can.

Peak winds at my station would reach 33 mph (53 kph) at about 5:00 AM.  I woke to the sounds of rumbling and of fir cones and small limbs dropping on the roof.  A similar storm rolled through just three days ago on Thanksgiving Day bringing 35 mph (56 kph) gusts.  We can expect one or two of these wind events each week through December.  This morning, the winds would become calm with the arrival of the rain, which is another typical pattern for us.

Because windstorms are so common here, I have added a widget to the Current Weather page on a trial basis:

The widget shows wind predictions four days out and revealed this morning's event right to the hour.  I always check these widgets out carefully before making them permanent.  It doesn't link to anything nasty that I have found, but it may be disrupting page loads a bit.  I'll be keeping a close eye on it for a while.  I would appreciate hearing feedback about the feature, especially if it seems to be affecting page loads in different browsers.

Thursday, November 24, 2011

Thanksgiving Day

November is our rainiest month, and late November usually means a succession of windstorms rolling through.  At Wild Fidalgo, we discover a lesson in diversity and tolerance at Deception Pass State Park.  Under an approaching windstorm, Black Oystercatchers and Glaucous-winged Gulls take a rest on the Thanksgiving holiday.  Have a great Thanksgiving, everyone.

Saturday, November 19, 2011

Ala Spit

This is a zoomed photo of Ala Spit as seen from my house.  For many years I gazed at it through binoculars and I wondered what it was.  To the naked eye, it looked artificial.  That is Whidbey Island over there and it turns out, the spit is an Island County park.  It is also a natural sand spit built by currents, tidal action and wind.

I have now made two visits to the park.  Ala Spit is a deceptively complicated land form system packed into a narrow strip of sand.  A salt marsh and pocket estuary are sheltered on the leeward side.  Other features include rocky beach, mudflats, a coastal grassland and driftwood field.  It is a popular spot for fishing, clamming, wildlife viewing, browsing and beachcombing.

Beyond the spit to the east is Skagit Island (left) and Kiket Island on the right.  Skagit is a state park offering boat moorage, camping and diving.  It is accessible only by boat.  We have visited Kiket and its little companion Flagstaff Island before.

Ala Spit has just undergone a restoration project aimed at returning it to a more natural state (.pdf).  Rip-rap revetments have been removed and it is anticipated that some reshaping of the spit can be expected.  One goal of the project was to revitalize the pocket estuary north of the parking lot.  These sheltered lagoons are important elements of wild salmon habitat.  Salmon fry will spend time here protected from predatory fish.  They must become accustomed to salt water before venturing out into the ocean.

The small coastal grassland has now entered its winter dormancy.  There were some remnants of wildflowers still blooming in October.  I plan to return in the spring to see what else this garden has in store.  Beyond the spit in the photo is home on South Fidalgo Island.

A diverse and healthy ecosystem naturally attracts wildlife.  Canada Geese embark on a morning swim.  The old pilings provide perches for Double-crested Cormorants.

The pilings may reveal the site of an old ferry landing.  There are similar ruins across the bay on both ends of Dewey Beach.  Before the Deception Pass Bridge opened in 1935, small ferries were the only means of travel between Fidalgo and Whidbey Islands.  I would be interested to hear from anyone who knows the history behind these old posts.

After diving, Cormorants will strike this "angel" pose to dry their wings.  Captive birds will do the same after feeding, even if they are not wet.

A Northwestern Crow has claimed ownership of someone's driftwood fort.

I always struggle identifying gulls, but I think this is a Western Gull x Glaucous-winged Gull hybrid bird.  The mottled winter coloring of the head and neck, pink legs, black wing tips, dark eye, large yellow beak and red beak spot are the clues.  I could be dead wrong.  Herring Gulls and Thayer's Gulls have similar markings as do Glaucous-winged x Herring hybrids.  See the problem?

On the east side looking towards Hope Island, a low tide terrace of sand is visible during minus tides.  This is the windward side of the spit during storms.

The driftwood field is also concentrated on the windward shore (foreground), again because of the direction of storms.  Always keep in mind that driftwood in natural places should not be collected or disturbed.  It stabilizes beach erosion and provides habitat for wildlife.  On the left, Hoypus Point on Whidbey marks the entrance to Deception Pass.  Across Skagit Bay beyond Hoypus is Dewey Beach on South Fidalgo.

Thursday, November 17, 2011

Skywatch Friday:  Sunrise Season

Sunrise season has returned to South Fidalgo Island and Skagit Bay.  The best morning light shows here always occur during fall and winter months. This is probably because our most interesting weather also happens at this time.  Skagit Bay is the northern-most eastern reach of Puget Sound in Washington State.  This is a view looking south towards cloudier Seattle.

Sunday, November 6, 2011

The Snow Geese of Fir Island

At Wild Fidalgo, check out the Snow Geese of Fir Island, Washington.

Tuesday, November 1, 2011

Autumn in the Garden

I have discovered a fascination with macro photography.  This is when you take pictures of small things up close.  Instead of photographing a tree, a macro shot might focus on one of its leaves.  While fall is a season of decline, it does not express itself with a lessening of intensity.  Above is one of our Pacific Northwest natives, the Vine Maple (Acer circinatum).  Enjoy this album of some of the autumn colors in my garden.

Eastern Dogwood (Cornus florida)

Giant Feather Grass (Stipa gigantea)

Vine Maple (Acer circinatum)

Coral Bark Japanese Maple 'Sango Kaku' (Acer palmatum)

Japanese Maple 'Osakazuki' (Acer palmatum)

For shade-loving Hostas, this time of year means "Hosta la vista."  They die back and disappear completely.  We won't see them again until around April.

Japanese Maple 'Katsura' (Acer palmatum)

Japanese Maple 'Emperor I' (Acer palmatum)

Vine Maple (Acer circinatum)

Eastern Dogwood (Cornus florida)

Coral Bark Japanese Maple 'Sango Kaku' (Acer palmatum)

Japanese Maple 'Katsura' (Acer palmatum)

Weather Statistics for October, 2011

TemperatureHigh 65.2° FLow 38.5° FMean 50.4° F
Rainfall1.66 inches
WindHigh 25 mphAverage 1.2 mphDom Dir SW

Observed at South Fidalgo Island (See Climate page for complete climatological data)