Rod's Weather Headlines

A strong jet core with 155 mph winds aloft, lifting moisture over a slow crossing cold front produced record rain Monday. New daily rain total Monday for Portland:  1.66" at PDX breaks the old record of .68".  The rain total ends the month of February with 4.29", which is .11" above the monthly average of 4.18".  February 2011 becomes the first February to have above normal precipitation in more than 10 years!  Downtown Portland reported more than 2.30" for the 24 hour period. Salem also set a daily rainfall record with 1.67".   Below are 24 hour rain totals for Monday's storm.

Kelso          1.74"

Scappoose  1.39"

Vancouver  1.55"

Troutdale    1.76"

Hillsboro      1.15"

McMinnville 1.51"

Salem         1.71"

Tualatin      1.70"

Tigard         1.93"

Beaverton   1.54"

Newberg     1.94"

Canby         1.26"

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Here is the most amazing headline regarding snow.  Saddle Mountain, just higher than 3,000' in the Coast Range had 20" of snow on the ground a week ago and the Coast Range snowpack was 46% or normal.  Today the reporting site has 82" of snow on the ground and the Coast Range snowpack is more than 100% of normal.  You do not see the Coast Range receive 60" of snow in one week very often!  The numbers on Mt. Hood are also impressive.  Today's snow survey measured 129" on the ground.   The snow would melt into 41" of water.  The Mt. Hood snowpack is still only 80% of normal.  Remember the snowpack was way down in January and the first two weeks of February.  Average snow water equivalency by May 1st is 65" of water in the snow.  Here is a listing of storm snowfall:

Timberline Lodge:          32"

Government Camp:       22"

Washougal, Wa. 1,400'  21"

Santiam Pass                19"

Sandy                           18"

Scappoose 1,000'          12"

Brush Prairie 1,400'      11"

Wilson River Summit     10"

Estacada 1,000'            10"

Stevenson, Wa.              9"

Forest Grove 1,200'        8"

Hood River                      8"

St. Helens                       4"

Camas, Prune Hill            3"

Forest Grove                   3"

Battle Ground                 2"

Longview                        2"

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The above snow report from Sunday night and Monday represents accumulating snow on average down to 500 feet.  Areas near 500 feet to receive snow were mostly areas near the Cascades foothills and the Coast Range.  Monday's heavy precipitation rates actually pulled down cold air from aloft, lowering the snow levels and dumping heavy snow near 1,000 feet.  If the moisture would have been lighter, Monday's snow level would have likely been closer to 1,200 - 1,500 feet.  A perfect example of how one variable can alter our weather and make a huge difference!

If your plans call for travel in the coming days, please check weather conditions.  Storm fronts Monday, Wednesday and Saturday are expected.  A strong jet core of 150 mph will feed heavy rain and mountain snow Monday.  A vigerous low pressure center depending on it's track, could produce very strong winds at the coast Wednesday.  Here is what to expect this week:

Monday:  2" of rain at the coast with early 65 mph wind gusts.  The valley could see an inch of rain, wind gusts to 45 mph will be possible early morning.  The snow level will lower from 2,000' to 1,200' during the day.  High Coast Range passes will see afternoon snow.  The Cascades will see 14-20" of snow along with possible wind gusts of 100 mph at upper elevations.  40 mph wind gusts at pass levels would produce blizzard conditions and possibly force road closures.

Tuesday:  Calmer day but still very wet.  An inch of rain at the coast,  .50" or more across the valley and another foot plus of snow on Mt. Hood.  The snow level will rise from 1,500' to 4,000 feet.

Wednesday:  Tracking a vigerous low pressure center.  If the low nears the coast, very high winds of 85 mph and higher will be possible and perhaps widespread into the Coast Range.  More rain for the valley.  Gorge east winds could spike 45-55 mph in reponse to the low pressure center.

Rest of the week:  Wet at times, calmer weather.  Snow levels near 1,000' Thursday, 2,000' Friday.

Forecast charts show wet and cooler weather than normal through at least March 15th!

Let me begin by saying, a low pressure area tracking south into our region early Thursday morning does have the potential to dump 1-2" of widespread snow at all elevations.  If that does not happen, will will simply see scattered Thursday snow showers with a trace of snow to scattered dustings and an inch or so in the hills at most.  Morning temperatures will likely be freezing, please watch out for icy spots. 

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I accept my job as a forecaster with a great deal of pride, responsibility and hard work.  My forecast is just that - mine.  My decisions are my own judgements.  It always bothers me when people say - "you guys missed it".  Or when people assume a forecast they heard from a company I work for is also my conclusion.  Forecasting is an individual act.  With that said, assuming we do not get 1-4" of snow Thursday morning, my error was believing we would have .25" of total liquid moisture fall as snow Wednesday overnight and Thursday.  The amount would produce 4" of snow.  The forecast charts have printed out up to .50" of moisture.  It is my job to know what to believe and I chose incorrectly.  Showers Wednesday hit the Coast Range and bounced to the Cascades, leaving little across the I-5 corridor.  I am very surprised at the lack of moisture we had today. I thought we would have 1-4" in the metro hills and similar amounts on the valley floor into Thursday morning.  I believe the odds favor a similar shower pattern Thursday - but as I mentioned a morning snow blitz looks at least possible.  

This event if it turns out to be nothing is a reminder that unless we have dry weather for a couple of days with strong gorge east winds and high temperatures in the 20s in place as Pacific moisture arrives - snow is never a guarantee.  Any westerly flow makes it very difficult to hold temperatures below 32 degrees and for widespread snow to blanket the valley.  It can happen and I thought this would be one of those times with very cold air arriving Wednesday night and an active enough flow pattern to deliver the moisture.  It looks like I may have been wrong - we will know for sure by late morning.  

Again, I sincerely apologize for altering your plans if it turns out to be not necessary.   I work in a field that no one is right all of the time.  My goal is to be right most of the time. 

Meteorologist, Rod Hill

Here is the National Weather Service snow report.  As of 11:00 this morning, 1" of snow will go in the record book for Portland.  Metro reports averaged 2", with 1-3" across the region.  Areas of elevation received 4" or more in many locations. 

SANTIAM PASS,OR............18.0               
 TIMBERLINE LODGE,OR........16.0         
 SANTIAM JUNCTION,OR........15.0                
 WILLAMETTE PASS,OR.........15.0               
 MT HOOD MEADOWS,OR.........14.0               
 GOVERNMENT CAMP,OR.........11.0                
 BLUE BOX PASS,OR...........10.0          
 VERNONIA,OR................9.0
 HOODOO,OR..................8.0          
 ZIG ZAG,OR.................8.0         
 KM MOUNTAIN,WA.............8.0          
 MCMINNVILLE,OR (7 MI W)....8.0 
 OAKRIDGE,OR................7.2         
 BLODGETT,OR................4.5 TO 6.5          
 WHITE SALMON,WA............6.0          
 PARKDALE,OR................6.0 
 MCKENZIE BRIDGE,OR.........6.0 
 TIMBER,OR..................5.5        
 PHILOMATH,OR...............5.25       
 AMITY,OR...................5.0 
 TILLAMOOK,OR (16 MI ENE)...5.0 
 MILL CITY,OR...............5.0        
 BRUSH PRAIRIE,WA...........2.5 TO 5.0         
 AMITY,OR...................5.0 
 GASTON,OR..................4.2        
 KALAMA,WA..................4.0          
 HOCKINSON,WA...............4.0 
 CASCADE LOCKS,OR...........4.0         
 LONGVIEW,WA................1.0 TO 4.0          
 MCMINNVILLE,OR.............2.0 TO 4.0         
 BRUSH PRAIRIE,WA...........3.5         
 STEVENSON,WA...............3.0          
 CAMAS,WA...................3.0          
 PHILOMATH,OR...............3.0 TO 6.5        
 CORVALLIS,OR...............1.0 TO 4.5          
 ROSBURG,WA.................3.0          
 CLATSKANIE,OR..............3.0         
 LYONS,OR...................3.0          
 HILLSBORO,OR (5 NE)........3.0        
 ORCHARDS,WA................3.0         
 DALLAS,OR..................2.5 TO 3.0 
 MONROE, OR.................3.0         
 CORNELIUS,OR...............2.75         
 VANCOUVER,WA...............1.5 TO 2.75  
 SWEET HOME,OR..............2.7       
 EDDYVILLE,OR...............2.6          
 KELSO,WA...................2.5       
 WILSONVILLE,OR.............2.5          
 LONG BEACH,WA..............2.5 
 SPRINGFIELD,OR.............2.5 
 STAYTON,OR.................2.5        
 OCEAN PARK,WA..............2.0          
 TILLAMOOK,OR...............2.0         
 TIGARD,OR..................2.0          
 NORTH PLAINS,OR............2.0 TO 6.5         
 CAMAS,WA...................2.0         
 OCEAN PARK,WA..............2.0          
 BANKS,OR...................2.0          
 YAMHILL,OR.................2.0 
 ALBANY,OR..................2.0
 COTTAGE GROVE,OR...........2.0 TO 3.0         
 FOREST GROVE,OR............1.5 TO 2.0       
 OREGON CITY,OR.............1.5          
 ALOHA,OR...................1.5          
 ELMIRA,OR..................1.5
 CLACKAMAS,OR...............1.5
 TROUTDALE,OR...............1.5
 EUGENE,OR..................1.2         
 PORTLAND,OR................1.0 TO 1.5          
 ASTORIA,OR.................1.0          
 HILLSBORO HIGH SCHOOL,OR...1.0          
 GRESHAM,OR.................1.0          
 WOODLAND,WA................1.0          
 SALEM,OR...................1.0 TO 2.0
 LINCOLN CITY,OR............0.5
 NEWPORT,OR.................0.5
 

Forecast update Wednesday 8:00 a.m.

Wednesday:  Rain, snow mix with above freezing temperatures at sea level. (It is possible most of the precipitation in the air will be snow).  Possible snow accumulations begin at 500 feet.  The west hills and elevations near 1,000 feet could see 4" of snow.  Look for heavier moisture by noon and a wet afternoon. // Late afternoon or early evening will see an increasing chance of sticking snow at 200 feet.  The chance of snowy roads at sea level will increase into the evening hours.  It is possible, downtown Portland and Salem will have an icy commute home, odds favor wet roads below 200 feet until later in the evening or overnight.  

Thursday:  Snow all elevations.  Likely waking up to snow on the ground all metro areas.  Portland and Salem could see 4" or more of snow accumulate.  Heaviest snowfall may be early morning, producing a horrible early commute.  High metro hills could have 6-8" on the ground through Thursday night. (Notice low level temperatures may be above freezing at times, meaning I-5 from Portland to Salem could be mostly slushy & not bad.  Temperatures Thursday night in the 20s will turn all areas to solid ice).

Friday:  Light snow showers or flurries expected to end during the day. Gusty east winds will keep temperatures near freezing & roads likely icy. 

Saturday:  Dry, still cold with snow on the ground.  Gusty east winds may show signs of easing during the day. 

Sunday:  Approaching Pacific weather front.  Will have to watch for possible snowy start before rain transition. 

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I will continue to update the above each day as needed.  Rod Hill

With the talk of snow and up to 4" in the city of Portland this Thursday (if the forecast holds), here are a few snow facts for PDX.  Records date back to 1940:

Heaviest 24 hour Feb. snowfall:  6.4" of snow, Feb. 18-19, 1993

Greatest Feb. depth:  14" on the ground, Feb. 1, 1950

Latest big snow:  7.7" March 7-8, 1951

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If we get the 4" of snow in Portland Thursday, it will become the largest Feb. winter event in more than 10 years!

By the way, forecast charts continue to show periods of cold weather through the first week of March. 

Many areas reported large, beautiful silver dollar size snowflakes this morning.  The large flakes are possible when the surface temperatures are near and above freezing.  This morning, temperatures around the area were mostly 31 -35 degrees when the snow was falling.  What we saw were not individual flakes, but numerous snowflakes bonded together.  When snowflakes fall into near and above freezing temperatures, they melt, coating themselves with liquid.  This process allows multiple snowflakes to stick or bond together, creating what looks to be a single silver dollar size perfect snowflake!  As temperatures get colder, falling flakes become small and granular in appearance.  Remember, drier air temperatures hold less water and warmer temperatures hold larger quantities of water vapor.  The warm temperatures today, also allowed rapid accumulation of 1-2" in higher elevations near and above 500 feet.  Temperatures through Friday morning will be near freezing at times, meaning we could see more large flakes falling from the sky.

I am tracking the potential of much colder air next Monday - Wednesday.  Forecast charts are not in agreement, so forecast confidence is low.  Also, I am wathcing the potential of valley snow this coming Sunday morning.  Please keep updated. 

Active weather returns to the Northwest!  Here are the headlines I am tracking:

Monday:  Rain increases ahead of the strongest front of the period.  Coast could see high winds of 60 mph develop.  Heavy snow in the Cascades develop.  Snow totals through Tuesday could reach 20 inches!

Tuesday:  Much colder, snow levels drop to 2,000 feet.  Rain in the valley, possible T-Storms & hail. 

Wednesday:  Precipitation becomes more sparse.  Snow level:  1,500'

Thursday:  Showers, snow level near 1,000'.  

Salem and Portland could see a mix of snow showers at times Wednesday - Friday morning. 

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Extended forecast charts into March, starting to show less active weather in the coming weeks. 

Climate data continues to show an adjustment in seasons.  The western and northern United States are leading the country in the expansion of the growing season.  (The growing season is the period usually from spring to fall with no freezing temperatures.) Here in the Northwest, the growing season has grown 14-20 days over the past 20 years.  Perhaps more impressive here at home is a trend toward an earlier final spring freeze.

The 30-year climate average for Portland says the average last spring freeze is March 30th.  Colder areas such as Salem and Hillsboro average a final freeze closer to April 30th.  If you look at the records for PDX dating back to the year 2000, the average final freeze is March 16th.  If the trend holds, the average last spring freeze will occur two weeks earlier than past years!  Of course, I am talking averages only.  Some years will likely continue to see freezes all the way towards May 1st.  

Also of interest to me, is the fact that the last 10 plus years have seen no large winter storms past the middle of January. Remember the last 10 Februarys here in Portland, have all been below normal in terms of precipitation.  Lots of data supports a 10 year trend of harsh winter weather ending earlier than past decades.  

No matter where you look, climate shift or change seems to be happening.  No matter what the reason, this is an interesting time.