Midnight Special: Saturday Storm Looking Stronger!

October 12, 2016

11:50pm Wednesday…

If you are looking for info about Storm #1 coming Thursday evening, read the previous post down below.  This post refers to Storm #2 for Saturday…

Quick update…finally got a chance to look at all evening models.  A few thoughts:

  • The evening ECMWF run is now the 3rd in a row to bring a severe windstorm to the I-5 corridor Saturday afternoon/evening
  • The NAM model has now joined it, and the GEM (Canadian) is moving the low much closer to us as well.
  • Only the GFS is stubbornly hanging on to a position farther offshore.

That means 3 out of 4 major models are producing either a significant or (in the case of the ECMWF & NAM models) severe windstorm for the populated areas between the Coast and Cascade ranges.  That includes the Portland Metro Area.  By “severe” I mean the strongest storm we’ve seen since the December 1995 event for many of us.

Here is a comparison of those 4 models at either 5pm or 10pm Saturday evening.  Notice how the low is much closer to us except for the GFS

As a result the threat for a significant windstorm for all areas west of the Cascades is higher now than it was 24 hours ago.

IF it does appear in the next 48 hours that a big storm is coming, you will have Friday to prep for it…just lots of showers and regular breezy conditions.  I’ll keep you updated!

Chief Meteorologist Mark Nelsen


Thursday Storm Update

October 12, 2016

9pm Wednesday…

Playing catch up a bit this evening since I had half a day off for my son’s 16th birthday.  But in full storm mode now!

For those of you that just want the basics:

HIGHLIGHTS FOR STORM #1

  • Rain is beginning now, and we have a good 1.50″ coming up in the next 24 hours…get ready for localized flooding (not creeks or rivers) where drains clog up with leaves.
  • But we do not expect river flooding at this time, at least in the next two days.
  • HIGH WIND WARNING COAST/COAST RANGE: South wind gusts reach 65-80 mph along the coastline 4pm-10pm tomorrow.  Unusually strong for October.
  • South wind gusts 40-50 mph in the metro area 4pm-10pm tomorrow.  Not especially strong, but that’s a lot for October.  Leaves on trees mean more trees break/fall.
  • Expect power outages scattered about in the evening.  We saw these speeds two years ago in the metro area in late October and had something like 50,000 outages!
  • The wind remains breezy through much of Friday too…gusts 30-35 mph inland

By the way, WE DO NOT SEE A REPEAT OF THE COLUMBUS DAY STORM for Saturday at this point.  I saw a Facebook posting with that info and had an email about it today I figure I should squash that rumor right away!

markwarnings_wind_coast_valleys

 

markwarnings_wind_coast_valleys2

 

Let’s not forget the rain:

rpm_rain_nworegon

 

Often our RPM model overdoes the rain, but I think 2-3″ is a safe bet from now through late Saturday.  That is not enough for widespread river flooding, especially since we’re just now getting into the wet season.  I’m sure we will get a river flood warning somewhere (likely along the coast), but for now I think WIND is the big story the next 3 days.

WIND:

This first storm is a surface low pressure system tracking offshore during the 2nd half of Thursday.  By late tomorrow evening it likely ends up as a 980mb low pressure center near the NW tip of Washington as seen in this evening’s GFS model:

gfs_10pmthurspm

A 980 millibar low moving relatively far offshore and ending up well north of us is not a HUGE wind producer inland typically.  Hopefully we don’t get a surprise.  Nevertheless for October this is quite a start to the stormy season.

Friday will be the in-between day, by that I mean we’ll be between the Thursday night storm and Saturday’s monster storm.  More on that either later (when I get time) or for sure tomorrow morning.  I’ve got a 10pm show to get ready for.

Chief Meteorologist Mark Nelsen