Monday, June 30, 2014

One Day Heat Wave

 10:30 AM update:   Temperatures at Sea-Tac and Boeing Field are running 12F ahead of yesterday, 10F ahead of yesterday at Olympia.   The winds aloft are now strongly from the southeast--a very warm direction (see graphic).  A lot of folks, particularly away from the water should see 90F today.

 Make sure your fans are working.

Today, temperatures moved up into the upper 70s in western Washington and the 80s in the Willamette Valley (see graphic), but tomorrow temperatures will surge by around 10F, with highs reaching the upper

80s to low 90s in western Washington and way into the 90s in the western Oregon interior.   In fact, the Portland NWS office has a heat advisory in place for tomorrow!

Today's high resolution WRF forecast for 5 PM tomorrow, shows the high 80s on the eastern side of the Sound and super warmth from Portland south.   It really is a warmer world during summer in the Willamette Valley. And NW Washington, open to the Pacific through the Strait, will be decidedly cooler.

The UW's probcasts system, which makes use of ensembles and lots of statistics, is going for an amazing 92F around the University of Washington on Tuesday (see graphic).  This system is generally most skillful during warm-ups like this one.

This heat wave is associated with high pressure building east of the western Washington/Oregon and the development of offshore flow, which brings warm continental air from the interior and downslope flow on the western slopes of the Cascades (downslope air warms by compression).  

The offshore (easterly) flow has already started aloft. Here is what we call a time-height cross section of winds (blue barbs) and temperature (red lines).  The y-axis is height in pressure (hPa), with 850 (700)  hPa about 5000 (10,000) ft.  Time in GMT/UTC is on the x-axis with time increasing to the left.  Southeasterly flow developed aloft today.   You see the low-level northerlies?  Very typical when the lowest pressure is south of us and the western interior gets warm.

Warm, dry easterly flow produces very good visibility...and the mountains have been very distinct(see Rainier below).  

The forecast surface maps shown below (for 5 PM Monday and Tuesday), indicate that the warming is associated with the northward movement of the "thermal" elongated area of low pressure that extends northward from CA.

That thermal trough will not be sticking around.   Tuesday night it will move east of the Cascades, with cooler air following behind.  Take off 10 degrees on Wednesday.   And, by the way, July 4th should have excellent weather.

Saturday, June 28, 2014

When Puget Sound Convergence Zones Don't Stop in Puget Sound

Many of you are familiar with the Puget Sound Convergence Zone, a band of clouds and precipitation that often forms north of Seattle when the winds approaching the coast are from the west or northwest (see schematic).  The clouds are produced by the low-level converging air flows, which in turn force air upwards.  Upward-moving air cools, saturates, and can produce clouds and precipitation.   Lynnwood and north Seattle are ground zero for precipitation for the typical convergence zone, but the band does shift around.   The convergence is essentially a feature produced by the Olympic Mountains--no Olympics, no convergence zone.

Although the convergence zone location shown in the figure above is quite frequent, it can shift north or south depending on the direction of the coastal winds.  For example, if the incoming flow is more southwesterly, the convergence zone tends to shift north...often positioned from Everett to central Whidbey Island (see graphic).  

The Puget Sound convergence zone is probably the most important local feature of Puget Sound meteorology, typically occurring 10-30 times per year.  

But something that is not as well known is that convergence zone precipitation often extends far eastward of Puget Sound, often intensifying precipitation over the windward slopes of the Cascades, at the Cascade crest, and sometimes a bit on to the eastern slopes.  And such major downwind convergence effects are forecast today.

Here is a high resolution WRF model forecast over western Washington for 11 PM Saturday, showing near-surface (10-m) wind speeds (shaded) and wind bards (which show direction and speed).  Look carefully and you will see the winds along the coast are southwesterly (from the SW), with air splitting around the Olympics and converging into an area of light winds over northern Puget Sound.

Now let's look at the forecast precipitation for the 3-h period ending 11 PM Saturday.   Can you see the  band of precipitation stretching SW-NE from central Puget Sound into the north Cascades?   That band is associated with the convergence zone.  Some folks camping in the north Cascades might get wet tonight.  You will also notice some upslope precipitation on the western sides of the Cascades.

If you really want to get in a wet mood, here is the precipitation forecast for the 24-h period ending 5 AM Sunday.  The western foothills are wet (1/3 to 2/3 inch of rain), but that area of convergence zone influence is really unpleasant (1-2 inches).

The extension of convergence zone precipitation into the Cascades is known to many skiers, who enjoy the snow-enhancing impacts of the convergence zone on Stevens and occasionally Snoqualmie passes.

Finally, our weather has worsened the last two days because we lost the east Pacific high pressure and an unusually strong jet stream is directed east-west across the Northwest.  Here is the upper level (300 hPa, about 30,000 ft) heights (like pressure) and winds at 11 PM Saturday (colors give wind speeds, with yellow being strong). Really strong westerly upper level flow for this time of the year.  I flew from Denver to Seattle this morning and it was an amazingly LONG flight with such headwinds.

Fortunately, the atmosphere will reconfigure on Sunday and Monday, and a warming spell will arrive, with temperatures rising above 80F on Tuesday.

Wednesday, June 25, 2014

Clouds Tell You a Story

Can you tell what clouds are made of by looking at them?   To a considerable degree you can.  There are really just three possibilities:
  1. Clouds made of ice crystals
  2. Clouds made of water droplets
  3. Clouds made of BOTH ice crystal and water droplets.
And there is a major complication you might not be aware of:  clouds can be made of water droplets even when temperatures are below freezing (0 C, 32 F).  This is called supercooled water.  Turns out water droplets don't have to freeze until temperatures get way cold, -40C (-40F), although the amount of supercooled water tends to drop off rapidly as temperatures fall below roughly -15C.

Interpretation rule 1:  Clouds with sharp edges and predominantly made of water droplets.
 Take a look at this picture of a growing and massive cumulus cloud.  Edges are sharp, so mainly liquid water.

Interpretation rule 2:  Clouds with soft, fibrous, and diffuse edges are generally made of ice crystals.

Like this example of a cirrus cloud.

You don't need the cone to know the clouds are made of ice crystals in this picture.  Wispy and diffuse edges.

You can also tell a lot about whether the atmosphere is turbulent or unstable by looking at clouds.

When the atmosphere is relatively stable and laminar (not a lot of vertical mixing), the clouds are layered.  Like this:

By when it is bubbling up with turrets (like this cumulus), the atmosphere is roiled by thermals and mixing.

Or if the clouds look like waves breaking on a beach, looking out for a lot of mixing and turbulence:

And there some clouds you are better off not knowing about:

We deal with such clouds in graduate school.

Monday, June 23, 2014

Almost No Night in the Northwest

The summer solstice was yesterday and there is something that always amazes me during this period:  the almost absence of night.

The official sunset and sunrise are 9:11 PM and 5:12 AM, respectively, for 15 hours, 59 minutes, and 20 seconds of daylight.   But that does not even start to tell the story because light lingers in the sky for hours after dusk and before dawn--as you will experience in a few minutes.

Another definition of the beginning and ending of night is civil twilight.   Before that time after sunset, under good weather conditions, there is enough light for objects to be clearly distinguished without extra illumination.  The same is true between civil twilight and sunrise in the morning. Technically, civil twilight occurs when the sun is below the horizon by 6 degrees.

The past two days, civil twilight times were 9:52 PM and 4:31 AM.  So  there is about 40 minutes on both sides of sunrise and sunset during which you could see what your are doing outside.  Here is an example of the view between sunrise and civil twilight

4:57 AM on June 22, looking north from the Kitsap Peninsula (courtesy of Greg Johnson)

And then there is nautical twilight, until which time the general outlines of objects can be distinguished and the horizon is still visible even on a moonless night.  Technically, the sun is 12 degrees below the horizon at nautical twilight.  The last few days nautical twilight was at 10:48 PM and 3:34 AM, roughly adding 1 hour 40 minutes to the "day" at both ends.  Night is getting mighty short.  Here is an example of the view during the period between civil and nautical twilight:

3:57 AM on June 22nd (picture courtesy of Greg Johnson)

And finally, there is astronomical twilight.  At night, after astronomical twilight there is less scattered light from the sun than from starlight or natural sources.  Dark enough for our astronomer friends to work. Technically, the sun is at 18 degrees below the horizon at astronomical twilight. During the past few days, astronomical twilight times have been 12:19 and 2:03 AM. So as far as astronomers are concerned there is less than two hours of night around here near the solstice.  You have to feel sorry for them.  They have to work fast!  And if you go just a bit further north--like Bellingham--there is NO astronomical twilight.  It never gets completely dark there by this definition.

And now it is time for a real treat.  Local cam maestro Greg Johnson runs high resolution cams from his home on the Skunk Bay of north Kitsap and below you can view his animations as the sky got dark and then lit up for the last two nights.   Just amazing.   There is perceptible light in the sky until around 11:20 PM and brightening begins about 2:50 AM. (you can stop and start the videos if you like).  We are talking only 3.5 hours of night from a visual perspective.   No wonder the birds start to sing before 4 AM, their visual alarm clock is ringing by then.

Here is the animation for June 21st.

Night Video Of Summer Solstice 2014 from SkunkBayWeather on Vimeo.

And on June 22nd, there were less clouds, so the light in the sky was even more evident.

Night Video of 6/21 into 6/22 from SkunkBayWeather on Vimeo.


Saturday, June 21, 2014

Why do temperatures cool BEFORE summer fronts and AFTER winter fronts?

On Thursday afternoon, a Pacific front approached the Northwest coast.  The image below, for 2 PM, indicates the front was still well out into the Pacific (the front indicated by the red line I have drawn in). Behind the front there was colder air, as indicated by the speckled instability clouds behind.

There was precipitation with the front, viewable from our wonderful coastal radar later . Take a look at the radar image at 7PM; at that time the front precipitation was just reaching the coast.

But major cooling and a big increase in the winds did not wait for the front to reach us!

To show that, here are the observations in Seattle (University of Washington) from 11 AM on Wednesday (18Z 19 June) to 5 PM on Friday (00Z, 21 June).  Times in meteorology is in Greenwich Mean Time (GMT or Z or UTC, 7 hours later than PDT).  On Wednesday, temps hit about 65F between 5 and 7 PM and slowly dropped.  Winds were modest (5-10 kt).

But Thursday was different.  Temps were much higher (around 74), peaked earlier, and then rapidly dropped between 5 and 7 PM.  The winds became quite strong, gusting to 21 knots..  The rain (blue line) and the frontal directional change did not occur until around 07 Z (midnight)

This is a good example of a summer frontal passage here in the Northwest.  Big changes in weather, including major cooling, occur before the front arrives, often by several hours.

And want to know something else amazing?  What time of the year do we get the biggest surface temperature drops with fronts?  Summer or winter?

The answer is summer, when the inherent fronts are weaker!  Here is the proof, from a paper I did with Dan Brees and Mark Albright.  This shows the frequency of  one-day surface  temperature drops by month for various drop magnitudes.   Summer rules!
So why do we get big frontal temperature changes in summer and why do they proceed the front?  Why are temperature changes weaker in winter?

It all has to do with the temperatures of land versus water.

The ocean temperatures are nearly always the same off the Northwest coast: about 50F, give or take a few degrees.   During the winter, our high temperatures drop into the 40s or low 50s and the near-surface air behind the fronts has been over the mild Pacific for thousands of miles and is highly moderated near the surface.  So when the front goes by, the surface air doesn't cool by much.  Interestingly, the cooling is far more profound aloft, where the air is not warmed by the ocean's surface.

But during the summer things are very different.

With strong sun, the land can warm up to a far higher temperature than the cool Pacific.  As it did on Thursday.  The warming is most profound east of the Cascades, where the ocean influence is far less.   As the front approaches and before the frontal cooler air can reach us, the onshore winds pick up, flooding the Northwest with cooler air from off the Pacific.  Temperatures plummet, even before the front gets here. 

But like those famous infomercials:  wait, there's more!   The warm interior causes the pressure to fall (warm air is less dense than cooler air) and that helps pull in the cool ocean air, as that same time the cool ocean air piles up on the coastal mountains, increasing the pressure.  These local pressure differences greatly enhances the landward movement of cool air, producing what we call the onshore or marine push.

I love the marine push.   The winds get my wind chimes sounding in the most wonderful way.

Happy Summer Solstice!

Wednesday, June 18, 2014

KUOW: A Major Public Radio Station Stumbles

KUOW, one of Seattle's public radio stations, is in deep trouble.

KUOW has been transformed into a quasi-commercial, ratings-chasing, eternally fund raising shadow of its former self.  A station that no longer reflects the needs of its listeners or cares whether it deals with the issues of its community.  This needs to change.

The most recent issue has been the sudden resignation of KUOW's star interviewer,  Steve Scher, a situation I will examine in more detail later.  But this resignation is just one sign of a deeper malaise.

What is a public radio station about?

Public radio is supposed to be a different animal than commercial radio.  Rather than making a maximum amount of money or secure the biggest audience, public radio should serve the community by providing programming of importance to its listeners that commercial outlets would not consider.  Most important is covering issues of local importance and analyzing issues in depth.  Local public radio should act as an aural town commons, where ideas can be discussed and examined.  Call in programs are an important tool for creating such an environment, as is the use of online chats, blogs, and Facebook/Google+ environments.  A university public radio station can go further, by tapping into the vast intellectual reserves (lectures, faculty) of the school.

KUOW Abandons Local Programs for Nationally Syndicated Shows

Three years ago, KUOW had five hours of local programming each day.   This included the station's flagship program, Weekday, in which authors, politicians, and others would be interviewed by Steve Scher at depth (typically 20-30 minutes), with listeners calling to join the conversation.  Today, there is only one hour of local programming for a new show, The Record, that is broadcast at a time when few folks listen (noon). This show is an amorphous,hodge-podge of short local and national stories.  So 80% of KUOW's local programming has been cut.   This is unacceptable.

KUOW seems to think it is a commercial radio station and has begun using a lot of the irritating methods of the worst commercial outlets.   For example, over and over again you hear:
 "This story is one you will only hear on KUOW".  And they love to advertise stories ahead, particularly sexy ones.   "Want to learn about vitamins and health?  Story at 10:35!"
 Why does such hawking seem tone deaf for a public radio station?

The mastermind of the suppression of local programs is KUOW's programming director, Jeff Hansen (see picture below).  Mr. Hansen believes that Seattle listeners do not have the patience for in-depth, long-form segments and holds that we can only tolerate short (5-8 minute) pieces.   The  National Public Radio shows (like Morning Edition and All Things Considered) are like that, as are the national shows he has brought on to replace local content (The Takeaway, BBC Newshour, Here and Now).   The new local show, The Record is also limited to short pieces.

Jeff Hansen, KUOW Programming Director

I believe Jeff Hansen is dead wrong and will undermine KUOW if allowed to continue this policy.  First, it is insulting to Seattle listeners to suggest that we can't deal with long-form shows:  KUOW's successful Weekday program proved him wrong.  Second, some stories require more time than 5-10 minutes to handle properly.  Third, Mr. Hansen's approach excludes listener participation, and I would suggest that acting as a regional aural town square is important.   And finally, his approach makes no sense from a technological standpoint.    Most of the programs that KUOW offers are national/international programs available easily on the web.  You can get them on your browser or smartphone (with wifi or internet) at any time and choose what you want.  Many cars have satellite radio and in five years most cars will have internet.  Listeners won't need KUOW to get these programs and listenership will plummet unless KUOW creates programs that are unique, local, and interesting.  But that is exactly the kind of programs Jeff Hansen is stripping from KUOW's line-up.  An ill-advised approach guaranteed to damage a major local radio station.

If you peruse KUOW's facebook page you will find the overwhelming sentiment of  the comments/reviews is unhappiness with recent programming changes (see below) and KUOW's market share has dropped according to Arbitron (see stats).   KUOW used to be in first or second place in this market, now it is in tenth place.

But Mr. Hansen seems determined to run the KUOW train off the track.

I had some personal experience with Mr. Hansen three years ago.  As many of you know, I was on KUOW for nearly 15 years, but was "fired" by Steve Scher for speaking about a topic other than weather (I defended the UW's admissions policy when I was moved to the Week in Review segment one day).  You heard it right, I was ejected from the UW's public radio station for defending the UW from non-factual attacks by the Seattle Times.    But let me tell you some details not generally known.  On the Monday, following the "firing", Steve Scher called my office, obviously very upset.   He apologized for his email firing and admitted to me that he made a mistake.  He wondered whether he was going to be fired, particularly with the huge public outcry that ensued.  I told him I did not want to see him fired, that he lost his temper as everyone does at time, and that I would come back to the program if he wished.  He said he might be willing to do that and that he would call me back.

The next day, I called Mr. Hansen to see if the situation could be fixed.    By that time, a major signature campaign for my return was ensuring and KUOW had to shut down its call-in lines because they were overwhelmed.  I told Hansen about my conversation with Steve and Hansen replied that I was never coming back to the station.  I asked him whether the massive protests, emails (hundreds of them), petition drives and the like meant anything to him.   He told me he didn't care.  I asked him, what if there were 5000 or 10000 signatures (and there would be).  Again, he told me he didn't care...I was never coming back to KUOW. This tells you something about the guy, doesn't it?  He simply didn't care what listeners wanted and during the last few years he has proven that.

And then for the remainder of the week after my firing,  KUOW began a massive misinformation campaign about what happened, claiming that I demanded to talk about math education.   This was simply untrue.   I not only was not talking about math on KUOW (provable by listening to their archives), but had agreed with Steve  a few years before that I would avoid that topic (after the UW Colllege of Education complained about my talking about math in public schools).  Jeff Hansen played a major role in spreading information that was not correct.

Mr. Hansen has also played a major role in the loss of major KUOW talent such as Ken Vincent and it is clear that Steve Scher's sudden departure was related to the loss of Weekday and the move toward short-segment radio.

KUOW:  Fund Raising Gone Wild

KUOW management is fixated on money and in acquiring funds well beyond their needs.  The aggressive money gathering includes extended two-week pledge drives, in contrast to far shorter drives on other public radio stations like KPLU (always less than a week).  During recent years, KUOW's hawking for cash has extended outside of the pledge weeks.  For example, this week the KUOW web page is dominated by money asks, including irritating pop up windows (see below).

While pleading poverty and begging for money, KUOW is running large surpluses each year, occasionally running well over a million dollars (see below).  862,000 in 2010 and over TWO MILLION dollars in 2011. Then a decline in 2012 to 819,000 (could this be due to KUOW's firing of a certain weatherman???), and then up to 1.8 million in 2013.

KUOW has acquired huge stockpiles of money.  Its fiscal report in June 2013 noted 3.3 million in cash, 6.4 million in investments, and 1.6 million in endowed investments.   Fundraising encompasses 24% of KUOW expenses.

Compare KUOW to KPLU, whose expenses are about 75% of KUOW's.    KPLU lost $65,000 last year (nearly break even) and has only $470,217 in investments. KPLU folks are frugal.

KUOW's pledge drives are often deceptive.   How many times do they tell you that they are radically short of the goal a few minutes before the deadline and then magically they always reach the goal in the nick of time.  Right...

KUOW management is often less than careful stewards of its supporter's money.   Every year the station throws a big holiday party in the UW faculty club with a substantial buffet (yes, including a properly attired chef cutting roast beef) and only TWO free drinks per attendee.  Fifteen years ago, KUOW moved from the UW Communications Bldg. to a very large complex in commercial property off campus, far larger than the station needed.  The costs of this excessive facility was so high that KUOW management was forced to reduce listener's access to expensive national programs.

Finally, KUOW claims to be commercial free, but that is really a joke.  Dozens of times a day you hear something like this:  "This program is supported by Joe's Auto Repair, located at 1533 Spokane St, and offering a sale this month on Acme Water Pumps.  For more information call 206-548-3493 or the"  If this is not a commercial, what is?

Lack of Oversight

Although the UW is KUOW's license holder, it has little to do with management or policy at KUOW.  The Board of Director's just rubber stamp KUOW management's decisions, no matter what the listener's want.  I learned this first hand.   Before I was "fired" from KUOW, I was sent a threatening email from Steve Scher's producer;  the Chair of the KUOW's Board had no interest in even talking about it. Neither were any of the members.  And they have not intervened to stop the wholesale loss of local programming or the excessive fund raising.  Basically, KUOW management has a free hand to do what it wants and a source of virtually unlimited funds from pledge drives that get longer and longer or web-based begging.

Take Listener Money But Don't Give Them a Voice

KUOW management believes that its listeners should pledge but not be heard.   Ten years ago, KUOW had lots of call in shows, where listeners could interact with KUOW hosts and guests.  Today that is history. When KUOW hosts began experimenting with using blogs to interact with audiences, KUOW management nixed it.   When I was "fired" from KUOW, KUOW management cancelled all call in opportunities for days. I could give you other examples, but you get the point.  The folks who run KUOW believe communications should be a one-way street.  You don't have an information public commons that way.

What need to be done to turn KUOW around?

You will notice that this blog has provided no criticism of the current president and general manager, Caryn Mathes.  This is appropriate since she has only been at the station a few months and bears little responsibility for what has gone down.  But if the current situation continues through the end of the year, it will be her problem.

A few suggestions include:

1.  Replace the current programming director with someone with a different vision
2.  Restore substantial local programming.  Some ideas include:

  • Start by bring back Weekday in the old form with extended interviews and audience participation.
  • Take advantage of the enormous intellectual resources of the University of Washington.   Include a daily, one hour show that could include rebroadcasts of interesting lectures or in-depth discussion with faculty experts.
  • KUOW has several talented reporters ( such as Ann Dornfeld and Ashley Ahearn).  Dedicate one hour per day to their reports on important regional topics.

3.  Reduce the excessive fundraising by limiting pledge drives to one week and reducing web fundraising.

4.  The UW needs to take a far more active role in overseeing its radio station.

5.  KUOW needs to be more effective using social media, such as blogs.

If KUOW management does not deal with the growing crisis and the clear unhappiness of its listeners, there is one tool that would facilitate change: listeners should withhold their pledges until things change.  That would get their attention.

Monday, June 16, 2014

Snow in Paradise

Wrong paradise.   I am talking about Paradise on Mt. Rainer at around 5500 ft in the Washington Cascades.  Yesterday and this morning they actually had some snow up there, as illustrated by the cam shots below:

The reason?   A cold, upper-level trough has moved over the Northwest:  here is a very short forecast for 8 AM this morning at 500 hPa (about 18,000 ft) showing heights (like pressure), winds and temperatures (color shading).  Blue is cold.

The upper level chart at 850 hPa (about 5000 ft) this morning at 5 AM show temperatures at both the Quillayute and Salem radiosonde stations of 1C at this level under cold northwesterly flow.

Although global warming will have serious impacts here in the Northwest later in the century, the snowpack in our mountains has remained healthy--particularly at higher-elevation locations like Paradise.   To show this, here is plot of the amount of water in the snow (snow water equivalent or SWE) on June 1 at Paradise (at a unit called a snotel) for the last thirty years (the red line is a five-year running average).  If anything, the snow pack at this level is increasing.
Information gather by Mark Albright, UW.

The 83.2 inches of snow water at the Paradise Mt Rainier snotel on June 1 marks the 6th greatest June 1 snowpack out of the past 31 years at Paradise Mt Rainier.  The median snowpack is 63.6 over the past 31 years, with the past 7 years (2008-2014) have all been above the median June 1 snowpack. 

And what about the date of snow melt out?  We have a 97-year record at Paradise and the mean melt-out date is 11 July.  From 2000-2009 the mean melt out date was 10 July.  From 2010-2013 the mean melt out date has been 30 July!  Bottom line:  snow is not melting out earlier at this location.

Before I get harangued by those worried about global warming, it is important to stress that global warming from human-enhanced greenhouse gases will cause the Cascade snowpack to lessen later in the century.  But not yet, since the cooling effects of the ocean and natural variability are still dominant around here.

Friday, June 13, 2014

Cool, Moist Weather and Happy Seeds

After a warm/dry start to June, we have transitioned to a cooler, wetter pattern.  Here is the precipitation from Seattle Rainwatch, which is only valid around the Puget Sound region.  Lots of folks had .2 to .5 inches, with greater amounts in the foothills.
The large-scale atmospheric pattern has shifted so that we are now getting a series of troughs over the eastern Pacific, in contrast to the persistent ridge of the previous period.  A very sharp trough, with a hurricane-looking radar signature came through on Thursday (see upper level map and radar image below).

The precipitation forecast was too wet on Thursday over Seattle, since the rain held off until evening at which time the low center had passed east of us.

Saturday will be the best day of the weekend as a weak ridge is established over the Northwest:  plenty of clouds and temperatures only reaching the lower to mid-60s.  Here is the upper-level map for 8 AM Saturday:  you can see the weak ridge and a moderate trough looming offshore.

Unfortunately, that trough will reach us on Sunday, substantially increasing the change of showers (see upper level map for 11 AM Sunday):
Sorry.  I would not go on a hike that day over the western slopes of crest of the Cascades.  Eastern Washington will be drier--but even there a few showers are possible.

But now the good news for gardeners.  Soil temperatures have substantially warmed and virtually all seeds should germinate fine if they are watered.  Here are the latest soil temperatures (8 inches down) from the WSU AgWeatherNet:.  Mid-60s at Puget Sound locations and 70s east of the Cascades.

To see how far we have come, here are the soil temps in Seattle since April 1st.   From lower 50s to upper 60s.

As you can see from the following table, most seeds should germinate now, even those who like warm conditions (such as eggplant)

Soil temperatures an inch down should be warmer than the above during the day and cooler at night.