Freezing Rain Tonight? No, But Close

January 8, 2016

5pm Friday…

I’ve been busy this afternoon so a little slow getting the info, but here are my quick thoughts on freezing rain west of the Cascades.

  • Wherever the east wind is blowing it’ll stay above freezing tonight, that includes the western Gorge below about 1,000′ and all of the east metro area.  That means no freezing rain in these areas.  The cold airmass in the Gorge is too “warm” and too moist now (almost no evaporative cooling).
  • Some outlying areas in the valleys (mainly Washington and/or Clark Counties) will drop to freezing before midnight, but the increasing cloud cover should bring those spots back up to or above freezing when the precipitation arrives.  As a result if there is some sort of freezing rain it would be only in an isolated spot or two.
  • As a result, 95% of us won’t see any freezing precipitation in the next 24 hours.

In the Gorge, assuming more than a few hundredths of precipitation make it there, it should fall as snow since the cold layer is deep enough east of Bonneville.

Sunday looks very nice…like today, because the cool Gorge wind will keep fog & low clouds down in the central/southern valley.

Chief Meteorologist Mark Nelsen

ECMWF Weekly Maps

January 8, 2016

For the geeks only…

Sorry, forgot to post these yesterday.  4 weekly maps of average 500 millibar height and anomaly from the ECMWF monthly run.  This is always all the ensembles averaged together.  Model seems to prefer some sort of ridging just to our north and northeast through early February.  Below normal heights to the south over the southern USA most of the time too.  This is somewhat similar to the current pattern with weak systems and lots of offshore flow.  Keep in mind that at one point in late November it looked like this for December too; just the usual disclaimer.