Cool Weather & Early October Soaker On The Way

October 3, 2018

9pm Wednesday…

This morning was chilly!  Temperatures dropped well down into the 30s in many parts of the metro area; stopping at 44 right in the city at PDX.

PDX Observed Low Today

This afternoon was “comfortably cool” I suppose with highs just a few notches below normal.  Tomorrow looks dry or mainly dry (just a slight risk of an afternoon sprinkle) as a cool upper-level trough passes overhead.

Friday gives us our first rainy/overcast/chilly day of the season.  A surface low pressure system tracks right into northern Oregon during the afternoon, pushing a large shield of rain/clouds ahead of it.  Here’s the early afternoon view from our RPM model:

RPM Clouds Rain

And total rain forecast…looks like up to 1/2″ or so in the valleys of western Oregon and southwest Washington.  The best news is that this system will finally bring some light rain to those of you east of the Cascades.  Not a lot, but enough to settle the dust in central and north-central Oregon.  These areas haven’t seen any significant rain since spring.

RPM Precipitation Accumulation

Looking ahead, the weekend should be pleasant, but a bit on the cool side with highs remaining in the 60s.  There is no sign of a stormy/rainy season start as a large upper-level high remains over the eastern Pacific the next 7-10 days.  Occasional weak systems will slide down the back side of the ridge (along the west coast of Canada and PACNW) and give us showers at times.  That keeps temperatures near/below average through at least the middle of next week.  I noticed the ECMWF ensembles warm us up around Day 10 as the ridge moves closer to us.

KPDX_2018100312_eps_min_max_15

We’ll see how that works out.  Big picture = a mellow weather pattern over the next week.

JULIE FONG PIC

PIC BY JULIE FONG

By the way, a bunch of you sent in pics of the “ice halo” around the sun this afternoon.  That’s caused when the ice crystals in the high clouds “refract” or bend the light at a 22 degree angle.  You can read more about it here:

http://www.atoptics.co.uk/halo/circular.htm

Chief Meteorologist Mark Nelsen