Cold Temps = Icy AM Commute For Many

February 2, 2017

11pm Thursday…

Temperatures have cooled off quite a bit this evening and now we have that liquid rain coming in the next few hours.  It’s pretty obvious that we’re going to see some ice on roads in much of the metro area for the Friday AM commute.  That’s because temps have cooled off more than I expected.  Still, with temps only dropping to right around freezing overnight for much of the metro area, we should be able to get that ice off the roads relatively quickly midday with more rain arriving.

If you live east of I-205 near the Gorge of course the ice is going to be slower to melt, as we see in just about every freezing rain event.  The east wind will finally end tomorrow night and then a warming south wind pushes us above freezing Saturday.

marksnow_pdx_2periods

More tomorrow!

Chief Meteorologist Mark Nelsen


Evening Commute All Clear, Friday Looking Better!

February 2, 2017

11am Thursday

I just checked out all the maps/models/observations…

It’s looking much better if you don’t want to deal with snow/ice again.

  • Forecast-wise, we are getting very close to that point where we would call it a “non-event” tonight and tomorrow morning for most areas west of the Cascades.
  • THIS EVENING:  At most we’ll see flurries/sprinkles this evening.  School kids will be fine getting home and roads should remain bare through at least midnight.
  • LATE TONIGHT & FRIDAY AM: Most likely there will only be a few spots with ice on the roads tomorrow morning,  MANY OF US WILL ONLY SEE WET ROADS AT SUNRISE, ESPECIALLY AWAY FROM THE EAST SIDE OF THE METRO AREA.  Just check in on FOX12 before you head out to see if there are any trouble spots.  We’ll have the latest 4:30-10am of course, like any other frosty/ice winter morning.
  • By midday tomorrow all of us except those living right at the mouth of the Gorge will be done with any freezing rain threat.

 

I’m not totally pulling the plug and saying any chance for snow/ice is gone for the western valleys, that would be a bit irresponsible with a Winter Storm Watch still up for the metro area and north Coast Range.  Remember a WATCH means conditions are possible.  But most likely the NWS will change that to a Winter Weather Advisory, which just means areas of (in this case) freezing rain later tonight and Friday AM.

My suspicions last night of it being a bit too warm for a widespread ice event may be right.  Temperatures have remained well above freezing, and the cold air flowing through the Gorge isn’t nearly as cold as previous events this winter.  At 1,000′ near Crown Point, it’s 33 degrees at my home.  You need mid/upper 20s  at the west end of the Gorge at the start of an event to even think about freezing rain in the bulk of the metro area.  There will be plenty of evaporational cooling (precip falling into dry air = temp drops) later tonight, but at best that will bring many of us only down TO freezing, not below.  As a result I’d be very surprised to see any large part of the metro area (or valley) drop below 30-32 degrees tonight.  If we don’t get below 30-31 = roads don’t ice up.  You may remember that from previous events.  If it doesn’t get below 30 with freezing rain then we don’t get widespread road icing...Save that new salt for the next event PBOT & ODOT! 

For this evening, all models are even a bit drier now with the precipitation, keeping almost everything west of the Coast Range.  So we’ll likely just see flurries or sprinkles that won’t freeze on roads anyway because it’ll be above freezing through midnight.

 

IN THE GORGE:

Through Friday evening (10pm), we’ll probably see up to .50″ precipitation, which means west of Multnomah Falls up to 1/2″ ice could stick to powerlines/trees.  Most likely not a big deal after 3 heavier ice storms earlier this winter.  From Multnomah Falls east, in the central/eastern Gorge, this event will be mainly snow with 3-8″ likely by Saturday AM.  Lighter snow will be farther east at The Dalles where it’ll be drier.  After that time temps should go above freezing…barely.

wrf_4pmsnowfriday

I’ll be on the air tonight at 5pm, 6pm, 8pm (KPDX), 9pm (KPDX), 10pm, & 11pm.  I shouldn’t be hard to find!

Chief Meteorologist Mark Nelsen