No Frost Yet In Portland

November 28, 2017

7pm Tuesday

If you are a gardener like me there’s a decent chance you are staring out the window at a relatively green garden as we head toward December 1st.  I have only had a low temperature of 30 degrees at my home and the banana trees barely look touched by frost and the annuals are rotting, but still alive due to no significant freezing action.  See the lows so far this fall around the metro area.

Mark Low So Far This Winter

The temperature needs to drop down into the upper 20s to really kill off many annuals and very few of us have seen that.  Not on the map is downtown Portland which has only seen a 37 degree temperature.  This is a bit late, but not too unusual.

Mark First Frost Last Few Years

And having a first frost in early December sure is not indicative of the winter to come.  Last year it didn’t happen until December 6th and we know how winter (brrr!) turned out.  It’s more an indication of the weather pattern from Halloween into December.  For frost we need clear nights and a relatively dry airmass to allow temps to drop.  When we have constant rain that doesn’t happen.

But fear not, I expect frost for almost all of us at some point next week.  An east wind pattern is coming much of next week (after Monday).  The result should be widespread freezing for just about all of us west of the Cascades.  Dry offshore flow in December means fog and/or frost west of the Cascades.  It’s likely downtown Portland and a few windy spots in the western Gorge still won’t drop to freezing.

Speaking of dry, the big change is still on for next week.  Bad news for ski areas that are only going to pick up a maximum of 2 feet new snow the next few days, then dry out.

Snow MtHood Outlook

But it’s good news in the lowlands, a chance to hang your Christmas Lights and not get soaked maybe?

Chief Meteorologist Mark Nelsen