Cloud Bowl of Eastern Washington

While many of you are thinking about the Superbowl, today let's talk about another bowl:  the Cloudbowl of eastern Washington. While a warm, blazing sun is considered the signature condition of eastern Washington by some (see the logo for the TriCities Visitor Bureau below), the truth is that during the middle of the winter the Columbia Basin of eastern Washington is often filled with fog and stratus clouds:  a cloud bowl.

To illustrate, here is a MODIS satellite image from mid-day on Saturday.  Typical cloud bowl conditions.  You can see low clouds in eastern Washington, with fingers westward in the Cascades to the passes.  Such cloud bowl conditions are made worse with high pressure over the region.   Notice the low clouds in the Willamette Valley and Puget Sound.  Two junior bowls.

So that  all of you have the proper sympathy with our brethren in eastern Washington here is a WSDOT cam shot Saturday in Richalnd.  How many ways can you say dismal?  And such low clouds and fog coupled with low temperatures often produces freezing fog on the bridges in the Tri-Cities.  Just wonderful.

The National Weather Service forecast for Richland says it all.  You won't find this on the Tri-Cities convention bureau website.

The key issue is that the Columbia Basin of eastern Washington is a topographic bowl, with very narrow openings (e.g., the Columbia Gorge, Okanogan) .  Cool air can settle into the lower elevations and sit there.  With warmer air frequently overhead, the temperature change with height over the Basin is often characterized by an inversion, with temperature increasing with height. 

Take a look at the temperatures, dew point and winds with height at Spokane on Saturday morning (below).  The right solid line is temperature.  900 hPA is roughly 3000 ft above sea level.  You see that temperature increases with height to above 850 hPA (about 5000 ft) and that temperature and dew point are on top of each other near the surface....that suggests saturation and clouds.    We knew that already!

A weather forecast for 1 PM on Saturday showing pressure (solid lines) and low level temperatures (shaded, at  925 hPA, around 2500 ft up) shows cold temperatures (while and blue colors) and high pressure over eastern Washington.  This makes sense because cold air is dense.

A surface temperature forecast illustrated the cold air in eastern Washington at 2-meters.  Dark blue is the coldest.  Colder near the Tri-Cities than at the surface in the Cascades!

Moving up to 850 hPa (around 5000 ft), there is warm, southwesterly flow.

Let me end with some interesting cloud statistics.   Below you will see a graphical rendition of the cloud cover percentages over Richland and Seattle at various times of the year.  The solid lines are the median cloud cover.  The dark band shows that between 40% and 60% of the observations are in that range.  Light shades, 25th to 75%.

Richland is in clouds more than 90% of the time from roughly Dec. 1 through Feb 1.  Not much different than Seattle.   And Richland's clouds are the worse type:   low or at the surface.  But things improve rapidly in February and by April 6st they are down to 50%.   Midsummer...down to 3%.

Seattle is no worse in mid-winter, but clouds stick around until early summer, slowly decreasing in time  Seattle NEVER hits the 50% mark, but there is an amazingly rapid decline in late June and early July.

Richland cloudiness

Seattle cloudiness

So avoid the Columbia Basin in mid-winter, but starting around March 1st it is a good bet for sun-starved west siders.

PS:  I have been inundated with emails from folks wanting to know the forecast for the SuperBowl--including several bookies and odds-makers.    If the Seahawks win (as we all know they will) I will talk about it in the next blog.  Some research has suggested that the Seahawks do better in bad weather, so a good forecast is worth a lot of $ to some folks.

Seattle Public Schools Math Curriculum Review

As noted in earlier blogs, Seattle Public Schools is now in  the process to review and recommend new math curriculum in K-5, a critical issue considering the poor books now in place (Everyday Math).  Three finalists will be selected.   The question is whether the process will allow parents and others to comment in an effective and convenient way.   Potential books must be available in some public libraries and community centers that are open at night or weekends:  not just in a few schools or the Stanford center  that close at 5 PM on weekdays.  Community members who work need after-hour access.  And it is very important that online commenting on the books is allowed.  A large amount of information about the potential curricula is available online, including extended samples of the material.  Excluding online commenting will limit input, something that works against a fair and representative decision.

Extreme Drought in California

California is now experiencing an extraordinary, historic drought.  2013 was the driest year on record for many California cities, and as the graphic here shows the precipitation averaged over the entire state was the driest for a record going back to 1895.   Oregon was also quite dry (4th most arid on record).  In contrast, wet conditions were observed over much of the central and eastern U.S.

The precipitation totals for all of 2013 were amazing (all in inches).  A few examples

Downtown LA 3.60
Santa Barbara 3.95
Paso Robles 1.92
Santa Cruz 4.78

All are all-time records.  I could give you a dozen more.  The total precipitation for the last three months (see graphic) shows much of California has gotten less than 1.5 inches with large areas not even getting an inch.

Snow pack in the Sierra Nevada is now at alarming levels ranging from 8% of normal in the north to 22% of normal to the south.  

 A plot of the snow water content in the snow pack for the north, central, and southern portions of the state not only show it is very low, but running lower than the worst snow pack year on record 1976-1977:

California has massive reservoir capacity and the state did get a lot of precipitation in late 2012, but the lack of rain has brought most of the reservoirs to far below capacity, particularly the critical large ones in the northern part of the State (see below). 

The big question is whether there will be any precipitation soon over California.  The models are pretty emphatic about this:  nothing during next week.  Here is the probability of getting at least 5 mm (.2 inches) of precipitation during any 24 hr period over the remainder of the month based on one of the best ensemble (many model runs) numerical weather prediction systems (NAEFS, the North American Ensemble Forecasting System).  Very low probability of getting even that modest amount.  It is even very dry over us in the NW.

The February prediction from the Climate Prediction Center (see below) is for a continuation of dry conditions over California.

The only saving grace for California is that that snow pack over Colorado and environs is above normal and thus the Colorado River, a significant water source for CA should be in decent shape.  And the huge capacity of the California's reservoirs might allow them to squeak by this year.

But this lack of  precipitation is bringing major records and is getting very serious.   This pattern of dry conditions over the the entire western U.S/southern BC. is different from the pattern suggested by many climate models for the end of the century:  very dry over southern and central CA, but wetter over the Northwest and British Columbia.

Forecast note:  the inversion over the western interior will strengthen today, but weaken greatly Saturday as clouds from a weak front approaches.   Cold and foggy over lowlands but warm along the coast (60s) and over the Cascade foothills. No rain at all in the near future, with the exception of perhaps a few sprinkles on the coast on Saturday.  No new snow.

Finally, a big thank you to all of you that supported my colleague's  (Becky Alexander) research project to study ozone production associated with gas fracking.   She is in the field now!