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. //

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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