Rod's Weather Headlines

Forecast Focus On Tuesday Night

By Rod Hill on 2011-01-10

SUNDAY EVENING UPDATE 8:00 P.M. //  One of the main forecast models I use shows the following:  Light snow starts Tuesday afternoon, changes to sleet or freezing rain before midnight and quickly to all rain as early as 5:00 a.m. Wednesday morning.  If true, Portland would see up to 4" of snow before becoming mostly ice and temperatures would be above freezing with rain falling by the Wednesday morning commute!  Snow and ice in the gorge would linger through the day.  I still feel much of what I have written below could come true.  Remember, forecast models often erode the cold air out of the gorge too quickly.  Please keep updated. //

________________________________________________________________________________________

Here is my Sunday noon update:  Light snow becomes likely Tuesday afternoon and becomes heavy into the night.  The north coast, Salem, Portland, Longview will all see snow.  Portland could see 6" of snow in the city by Wednesday morning.  

Wednesday is the possible transition day.  Good chance of snow changing to rain near Salem during the early morning hours. Portland will likely see a slow transition with snow to ice to rain all possible.  Timing for all rain could be anywhere from noon to 5:00 p.m. due to gusty east winds out of the gorge.  

Confidence is high that all of us will see rain with warmer temperatures Thursday.  Again, Wednesday is the day of uncertainty.  The Gorge will see likely winter conditions through the day Wednesday.  I am closely watching the possibility that the cold air boundary will hover near Portland into the day Thursday.  Still lots of questions?

To recap:  Growing confidence of up to 6" of snow Tuesday evening and night.  Wednesday morning could be bad with Portland slow to transition to rain during the day in east wind zones.  Total moisture continues to show 1-2" of liquid Tuesday night - Thursday!

(As a forecaster, it is my job to analyze possible scenarios.  In these situations it is always best to lean toward worst case, so that you will be prepared).

Rod Hill

Read More ...


Watching Wednesday & Thursday

By Rod Hill on 2011-01-09

Colder air arriving Monday will bring gusty east winds and allow metro temperatures in the 20s Tuesday overnight as moisture approaches from the south.  The set up will bring a warm front pushing up from our south with east winds driving cold air into the moisture north of the warm front as it arrives.  The result could be 1-2 days of snow with totals of a foot or more Wednesday through Thursday.  The "natural" snow level will be near 3,000' or higher. Elevations below the snow level will likely see a mix of ice and snow.  If the metro gets a lot of sleet or freezing rain, snow totals may be closer to six inches. Areas south of Salem may see a brief period of winter before warmer air brings rain. Tough to tell how long Salem will stay in the cold zone before warming above freezing.  Again, the heart of the storm will be in the gorge outflow areas. 

I will be watching all charts closely to see if the models back off or change.  If not, Portland could see a foot or more of snow Wednesday and Thursday!  As of Saturday evening, the above still verifies. 

Please keep updated.  

Rod Hill

Read More ...


Daylight March Toward Spring

By Rod Hill on 2011-01-07

This morning, January 6th, became the first day the sun starts to rise earlier each morning! It is true that our sunset has been happening later for a while.  If you go back to December, when the sunrise was 7:43 and the sunset was 4:27, we have to date picked up less than 10 extra minutes of total daylight each day because the sun has been coming up later until this morning.  Starting today, we will begin to make real progress in total minutes of daylight! Here are a few milestone dates to mark our progress as daylight hours grow longer. 

1.  Today, January 6th:  Sunrise 7:50 a.m. / Sunset 4:42 p.m. (1st day of earlier sunrise & later sunset)

2.  January 20th:  Sunset 5:00 pm!

3.  February 1st:   Sunrise 7:32 am / Sunset 5:17 pm

4.  February 23:    Sunrise 7:00 am / Sunset 5:49 pm

5.  March 3:          Sunrise 6:46 am / Sunset 6:00 pm

6.  March 13:        Sunrise 7:27 am / Sunset 7:14 pm   (Daylight Saving Time Begins)

____________________________________________________________________

March 20th:  Spring Begins!!

Read More ...


Mountain Snow & Valley Rain On Wet Pace

By Rod Hill on 2010-12-31

December 2010 at PDX will finish with 8.35" of precipitation, including a trace of snow.  Normal for the month is 5.71".  Our water year total ( since Oct. 1st) is 18.85", which is +4.60" above normal to date.  

Timberline reports 307" of total snowfall this season.  Last season, the lodge did not receive 300" of snow until March 1st!  The first snow survey taken yesterday, measured a snow depth of 92" at 5,400 feet on Mt. Hood.  The snow would melt into 26.8" of water.  The amount is 6% above normal to date - not as much as you may have thought.  

All precipitation outlooks continue to call for above normal moisture through the month of March.  December became the 4th consecutive month of above normal precipitation for PDX.

Daily Mt. Hood resort snow reports can be found on the Ski Forecast Page.

Read More ...


Valley, Metro Hills Snow

By Rod Hill on 2010-12-28

Snow levels will sharply fall by early Wednesday.  A westerly flow will keep metro temperatures above freezing until lighter winds develop by early Thursday.  Wednesday will see temperatures bounce between 34 & 40 degrees with passing showers.  Low elevations will see anything from mostly rain showers to a hail and or snow mix.  Best chance of a grassy dusting of snow showers will begin at 500 feet.  Best chance for roadway snow accumulation of an inch or two will be near and above 1,000 feet.  Hill elevations above 1,000' could see 1-4" of snow, such as Sandy!

If we get a push of moisture early Thursday, all areas could see a dusting of snow.  During the day Thursday, low elevations will be mostly above freezing with a showery mix possible.  However, not much if any precipitation looks possible - we could be dry.  Cold east winds will develop through the gorge late Thursday and last through the weekend as Arctic air spills into eastern Oregon and Washington.  The metro will likely be dry and cold.  

Read More ...


Forecast Not As Wet

By Rod Hill on 2010-12-23

Cool water temperatures in the equatorial Pacific continue to be 1.4 to 1.7 degrees centigrade cooler than normal, which is classified as a moderate to strong La Nina.  About ten days ago, I mentioned Portland would enter a period of heavy rain and would likely see 10.00" this month.  We know now, the rain I was talking about moved into California.  In fact, the dominate jet stream pattern over the past 30 days or so has been to our south.  Not only have we not been seeing heavy rain, but only a few storm centers have pushed inland into the Northwest, most have stayed offshore and dropped south.  

Heaviest moisture in terms of season averages have been mostly across California, Nevada, Idaho, Wyoming and Montana. This area is representative of a jet entrance into California and the leading trough northeast into Montana.  This pattern is not what you would expect with La Nina.  A typical El Nino flow would enter California, but would stay more south and run across Colorado or New Mexico, Missouri or farther south into dixie.  

So, the point is, the flow pattern has not been what was expected.  It is true, that our total rainfall has been above normal each month since September and is expected to continue into March, but the surplus will likely not be as high as predicted.  To date, PDX has a water year total (since Oct. 1st) of 16.37".  The total is above normal by 3.80 inches. 

THE UPDATED FORECAST:  Near normal to slightly cooler temperatures will continue into March.  Precipitation will continue to be above normal, but not significantly so.  I do expect a stretch of wet weather much of next week.  I remind you that the Willamette valley is due for a strong windstorm.  I continue to believe we will not see a heightened chance of valley snow.  

Wettest weather through March is expected to be to our north, across northern Washington, Idaho and Montana. I am sure the folks in California are glad to hear this!  As I always say....we'll see.

Rod Hill

Read More ...


Fall Headlines of 2010

By Rod Hill on 2010-12-22

Here are the headlines of our La Nina Fall 2010:

1.  September, October, November & December all above normal rainfall.  This becomes only the 3rd time since 1999, that PDX has had four consecutive months of above normal rainfall.  The water year total, beginning Oct. 1st, is 16.34".  The rain surplus to date is:  +4.07".

2.  Temperatures within a degree of climate average.  An early Arctic front arrives Nov. 22nd and produces a scattered dusting of snow across the metro.  PDX reports total snow of:  .3".

3.  Early ski season.  Resorts open in October and later sustain consistent snowpack before Thanksgiving weekend.

4.  The Aumsville EF-2 tornado strikes Dec. 14th.  No serious injuries,  10 homes badly damaged. 

5.  Dec. 18th,  strong east winds out of the gorge gust to 50 mph and higher.  Tree damage and power outages reported.  

6.  What I think is the number one headline to date:  No Big Storms Yet!  The past days have seen an active jet stream produce flooding rains in California.  It is the type of weather expected here this winter, not to our south.  Lucky Us!

Read More ...


A Typical Northwest Christmas!

By Rod Hill on 2010-12-19

Here is an early look at Christmas Day.  All forecasts can change, but the following seems to be a good bet:

A strong southerly jet stream will push occasional rain north into Oregon and Washington Thursday, Friday and Christmas day.  Snow levels will rise to near 4,000 feet Thursday and 5,000' or higher Friday.  This means Christmas Eve travel over Government Camp and Santiam will find wet roadways.  The Coast Range will be warm and wet.  A cold front Christmas day will bring likely rain at times.  The snow level will lower by evening below Cascade passes and sit below 2,000' Sunday.  

Travel south over the Siskiyou will find possible snow at night Thursday and Friday, but mostly rain with above freezing temperatures during the day.  Snow levels will be near 4,000' or higher at night and 5,000' (above the pass) Friday and Christmas morning.  (Very similar to the  Cascades.)

I don't see any big issues on I-84 through the gorge.  

Read More ...


Monday Evening Sky Show, Winter Begins.

By Rod Hill on 2010-12-19

A 50-50% chance of partly cloudy skies Monday night to see at least a glimpse of the total LUNAR ECLIPSE.  The moon will move through the dark shadow of the Earth and for 73 minutes, the only light hitting the moon will be the reddish glow from the Earth's sunrises and sunsets.  The Eclipse will begin at 9:29 p.m., totality will start at 11:40.  The next Lunar Eclipse for the Northwest will be December 10, 2011. 

A star party, weather permitting will be held in the parking lot of OMSI.  You are invited to look through the big telescopes - it's lots of fun!  It is safe to view a Lunar Eclipse with the naked eye.

The Winter Solstice will take place local time, Tuesday afternoon at 3:38 p.m.  The next few days will see the longest sunrise and sunsets of the year.  Daylight hours will be nearly 8.5 hours.  After the Solstice, daylight hours will start to increase!  Areas north of the Arctic circle will be in total darkness for 24 hours the day of the Solstice.

Happy Winter!

Read More ...


Monday Evening Sky Show, Winter Begins.

By Rod Hill on 2010-12-19

A 50-50% chance of partly cloudy skies Monday night to see at least a glimpse of the total LUNAR ECLIPSE.  The moon will move through the dark shadow of the Earth and for 73 minutes, the only light hitting the moon will be the reddish glow from the Earth's sunrises and sunsets.  The Eclipse will begin at 9:29 p.m., totality will start at 11:40.  The next Lunar Eclipse for the Northwest will be December 10, 2011. 

A star party, weather permitting will be held in the parking lot of OMSI.  You are invited to look through the big telescopes - it's lots of fun!  It is safe to view a Lunar Eclipse with the naked eye.

The Winter Solstice will take place local time, Tuesday afternoon at 3:38 p.m.  The next few days will see the longest sunrise and sunsets of the year.  Daylight hours will be nearly 8.5 hours.  After the Solstice, daylight hours will start to increase!  Areas north of the Arctic circle will be in total darkness for 24 hours the day of the Solstice.

Happy Winter!

Read More ...