Modified Arctic Air and Low Elevation Snow Later on Monday and Tuesday

There is a saying about waiting until you see the whites of their eyes before firing.... and a similar thing is true about forecasting cold and snow over the Northwest lowlands.    The situation is so rare, the atmospheric configuration needed is so difficult to achieve, and the uncertainties in getting the ingredients together so uncertain, that a wise forecaster waits until the event is within 3-4 days before alarming the public.

"Don't forecast Puget Sound snow until less than four days out or 
you see the white of the flakes"

Well, our meteorological foe is now cresting the hill and running towards us, so I need to make a call.  Here it is.

During the weekend we will have a weak ridge of high pressure over us, bringing cool, sunny conditions:  perfect for outdoor activities or catching up in your yard.
Or hit the slopes at Mt. Baker, Crystal, or Mount Hood Meadows.

But by Monday morning at 4 AM, a sharp upper level trough will approach us (see upper level map at that time  at 500 hPa (about 18,000 ft), below), a trough that will bring upward motion, clouds, and precipitation.  A trough that will drive cool air southward out of Canada.

The surface map (sea level isobars, surface winds, and temperatures near the surface)  at 4 AM on Monday shows the vanguard of the cold air, moved along by northerly flow.  Blue is cold air, white is intermediate air and yellows and greens are warmer.

Twenty four hours (4 AM Tuesday) later the change is stark and sobering.  Cold, modified arctic air has now pushed over our region, although the primo arctic cold is still over the interior of BC...the purple color.  Can you see the packing of the solid lines (isobars) over British Columbia?  That is that famous ARCTIC FRONT.

 The upper trough at this time has amplified and extended down over our region (see map), a pattern quite close to the canonical lowland snow configuration.  Perhaps not quite deep and west enough.  HUGE ridge to the west in the eastern Pacific.  When I see this pattern I worry about snow in Seattle.

The passage of the cold front and associated upper level trough brings precipitation to our area...here is the 24 totals ending 4 AM Tuesday. Light and moderate amounts over the region, particularly over Oregon and the north Cascades and BC interior.

But you want to know...what about snow?  Here is the model snow forecast for the same 24 h.  Lots of snow over the Cascades.  Plenty over British Columbia.   And if you look closely, some very light snow extends over the Puget Sound and NW Washington lowlands.  Not a lot....but something.  The problem is temperature....the air coming off the mild ocean has been warmed at low levels.  No snow on the coast for that reason.

During the next 24 h (through Wednesday at 4 AM) even colder air pushes southward, with precipitation ending from the north (see map at 4 AM Wednesday).   Wow...the coldest air we have seen for a long time--even gets to California.  THIS IS NOT AN EL NINO PATTERN!  The trouble for snow lovers is that by the time the really cold air is in place, precipitation is ending.   The classic lowland snow situation.

Snow during that next 24 will far over southern Oregon and northern CA as well as Montana.

So at this point, cold air (lows around western Washington into the low 20s) is pretty certain, as is mountain snow.  A lot of uncertainty with lowland snow, but it looks light at this time.  But keep tuned ... if the trough changes position by only a few hundred miles, you could have a snowy Turkey season.

All local mayors, and particularly Seattle's, should begin preparations for potential snow.   You know what happened to Ex-Mayor Greg Nickels...

I will update the snow situation on Sunday or Monday after I talk about attempts to kill the loved KPLU NPR station by UW and PLU administrators.

How can we be in a drought if there is flooding?

*See update at the end!

The current official US Government Drought Monitor graphic for Washington State is shown below.  According to our government, the entire state is in at least moderate drought, with NW Washington and eastern Washington being in severe or extreme drought.

Many state and local entities using the US Drought Monitor, such as Washington State and the Dept of Ecology Drought Page, which features the Drought Monitor information at the top of their webpage! (see below)

As I will demonstrate, the NOAA Drought Monitor information is unscientific and subjective.  More of a political and motivational tool than reliable guidance to make key decisions.

First, it is ridiculous to claim that our entire state is in moderate or more severe drought.  There are stronger words I could have used, but this is is a family friendly blog.

As I write this blog, many of our local rivers are flooding with nearly all Washington rivers running above normal.    For example, here is the latest USGS streamflow map.  Nearly the entire state has streamflows that are well above normal (green, blue, and black), with some of the largest flows over the eastern slopes of the Cascades.

Only a handful of small, unimportant rivers in eastern WA are below normal.  The latest NW River Forecast Center summaries show many rivers in serious flood stage over our state from the Yakima River in eastern Washington, to the Snoqualmie, to the Chehalis, and more.   Doesn't look like drought there.

Well, what about precipitation?   Here is the precipitation difference from normal for the 30 days ending on Tuesday.  Most of the state is above normal (greens and blues), including all of western Washington, the Cascades, including the eastern slopes, and most of far eastern Washington.  And where it is low (Columbia Basin), it is only a bit below normal.  And those folks generally get their water from the Columbia River, which is at normal levels.

How about the official crop moisture index?  Way above normal in western WA and normal in the east.

I know what you are thinking, what about snowpack?  Surely, that is well below normal!  Well, we don't hide anything on this blog...here are the latest % of normal for the date of snow water content for the U.S. Government SNOTEL sites.  In general, we are close to normal, with sites ranging from 42 to 205%.   And many of our ski areas will be opening early for Thanksgiving (e.g., Baker, Whistler).

But what about our reservoirs?  Surely, they are way below normal due to the drought!  The truth is that many of our reservoirs are well above normal from recent rains.  Take Seattle.  Here is the total storage of the Tolt and Chester Morse reservoirs.  Levels have jumped to WAY ABOVE normal and are about 80% full.  No problems with having enough water for next summer at this rate.

But what about the reservoirs on the eastern slopes that feed the critical Yakima River?  How about Lake Keechulus near Snoqualmie Pass? (see below).  Now well above normal (red asterisks).  And rising.  We are on track to completely fill the Yakima reservoirs earlier than normal.

I could show you more, but you get the point.  It is silly to suggest that we are in a drought.  We are not.   And typical precipitation during even strong El Nino years is generally at or slightly below normal, so there is no reason to expect a drought ahead.

Now, I know what you are wondering.  If it is evident that there is no drought, why is the Drought Monitor saying we are NOW in a serious drought?

The Drought-affected Snoqualmie Valley

Now we get to the embarrassing part of the blog.   The Drought Monitor  is produced through a partnership between the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. 

And now the key point:  it is a SUBJECTIVE, QUALITATIVE BLEND of  all kinds of information, including subjective appraisals of impacts.  It is not a strictly objective index based on precipitation, soil moisture, and the like.  And the folks that make this index tend to seriously exaggerate drought, as should be obvious to anyone who read the early part of my blog.  I will let you speculate why they are producing an unreliable product.

The Drought Monitor is unscientific, subjective and is doing the nation and our region a disservice by providing unreliable information that will lead authorities and governments to make the wrong decisions.   It is also being used by some to hype the current impacts of climate change produced by anthropogenic greenhouse gases.

Our society needs to plan and make adaptations for upcoming climate change.   Products like the Drought Monitor will hinder efforts to do so in a rational, robust fashion.  It should be ended and replaced by a rational, completely objective product.

Update on Thursday

Today an updated Drought Monitor Graphic was released (see below, with the previous week's version below that for each reference).  They have moved western Washington from moderate drought to abnormally dry, but left the Cascades and eastern Washington the same. 

THIS IS RIDICULOUS!  There is absolutely no objective measure showing that western Washington is abnormally dry.  And their changes do not recognize the HUGE amount of moisture that has fallen on the Cascades--on both sides.  I found it hard to understand how NOAA and other groups can allow such a subjective and obviously wrong measure to become the NATION'S MAIN DROUGHT INDEX.   And let me assure you, I can point out equally problematic drought appraisals in other parts of the country.

The total reservoir storage for the Yakima Basin is now at normal:

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Recommended reading in Crosscut.com on KUOW's purchase of KPLU

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