9pm Update: Freezing Rain Stays South of Salem

November 30, 2014

FREEZING RAIN SHOULD BE A NO-SHOW IN THE PORTLAND METRO AREA AND SALEM ON MONDAY

Almost all evening models (except the ECMWF) are in and show rain staying SOUTH OF SALEM tomorrow morning so that’s what we’ll go with.  The are all remarkably similar on the rain band sitting between Salem and Roseburg most of the day.  Note the WRF-GFS shows a big soaking around Eugene, but nothing north of about Albany:

wrf_4pmprecip

There are hints of a few sprinkles far eastside metro area between 4-8am, but at this point (if it occurs at all) it appears to be too little to even produce ice on roads.  Something to keep an eye on for the morning commute out there though.  By far eastside I mean east of Gresham/Damascus/Estacada.  This showed up on the 00z MM5-NAM, HRRR, and our RPM model. Note the colored areas start at .10″

RPM_12KM_Precip_NWOR

Then after 8am or so it’ll should be dry from Salem northward with quite a bit of late afternoon sun.  Actually all day tomorrow looks mainly sunny at Tillamook, Astoria, and Longview!

To reflect the changing forecast, I updated the CHANCE OF FREEZING RAIN graphic for the 10pm show:

MarkFreezingRain_IceDetails2

Chief Meteorologist Mark Nelsen


Freezing Rain Update

November 30, 2014

If you live south of Salem in the Willamette Valley, expect some areas of ice on roads tomorrow morning.  That’s because rain will arrive around daybreak, especially from Albany to Eugene.  It will be cold enough in some spots (not all areas) to allow the liquid rain to freeze into a glaze.

Here are my latest thoughts as of 5pm Sunday…

  1. Most of our models are dry in the Portland Metro area all day Monday, keeping all (or almost all) of the rain even south of Salem.
  2. A couple generate very light sprinkles overhead in the morning hours for us.  It may or may not be below freezing at that time.
  3. Much better chance for brief freezing rain from Albany through Corvallis/Eugene around daybreak.

As a result, the NWS has a Freezing Rain advisory for only the central/southern Willamette Valley, not the metro area, for Monday morning.  Even down there it’s possible the freezing on roadways will be real spotty.

MarkWarnings_FreezingRain_Snow

Right now I’d assign these chances to Freezing Rain (ice glazing on roads) affecting the morning commute:

MarkFreezingRain_IceDetails

There is one more evening run of the models which should help us either totally eliminate any precipitation in the metro area or not.

Chief Meteorologist Mark Nelsen