10pm: Stormy Weather Update


Evening models are in and just about all of them show the same thing now; a surface low tracking up the coastline just offshore.  Nice to see them finally agree 18-24 hours out.  Here are the quick highlights:

  • Strong wind arrives at the central coastline midday to early afternoon, moving north it’ll reach the Columbia River (Astoria) around 4pm.
  • In the valleys this WILL NOT be a HUGE windstorm like Dec. 1995, but it’ll probably be a bit stronger than what we saw in October.  Strong wind arrives sometime after 3pm.  Most action will be during the evening commute.
  • There will be plenty of power outages and trees down by this time tomorrow evening.
  • Peak gusts at metro area airport locations will likely be in the 45-55 mph range.  Somebody somewhere in the metro area will probably record a gust 60-65 mph on a hill-top.

For some reason I’ve been having trouble forecast-wise with this storm the past 24 hours.  All in my head of course.  I think I figured it out this evening.  The forecast train a couple of days ago started out with the possibility of a BIG storm.  But models have ever so gradually weakened things a bit so now we’re back to a “normal” strong winter storm instead of something possibly “epic”. Here is my forecast I’m using at 10pm:



Note I lowered my forecast for the valleys slightly, down to speeds similar to October’s storm.  There are two reasons for that:

1. All models are showing the low pressure system filling significantly after it reaches the southern Oregon Coast.  The ECMWF fills it a full 10 millibars from 10am to 10pm!   That would reduce the pressure gradient from south to north.

ecm_10am ecm_10pm

2.  The strong WRF-GFS has gradually been lowering its gradients the past 4 runs too.  Yesterday morning it showed a peak Eugene to Portland gradient of 8mb, now it’s 6.  The change from North Bend to Astoria is more significant.  It had shown 19mb, now just 13!  That makes me think the 70-90 mph gust forecast out there could be too high.  65-80 seems more likely.

I see there are schools cancelling on the northern Oregon and southern Washington coast.  Most likely those locations won’t see gusty wind until AFTER school gets out anyway, but I guess they are being extra cautious.

There is actually one more run of models tomorrow morning, so I’ll post once more around 10am.  As of 11:30pm I’ve turned off comments for the night.  I’ll turn them back on tomorrow morning after I post again.  Good time to go to bed anyway!

Chief Meteorologist Mark Nelsen

14 Responses to 10pm: Stormy Weather Update

  1. Dave in SW PDX (235') says:

    Talk about the calm before the storm – I was just outside and it’s completely clear and still. The Moon & Jupiter are nice & bright above the eastern horizon.

  2. Thanks for the update, Mark. 00z ECMWF was even closer to the Coast and deeper than the GFS/WRF. Upgrading to 45-55mph makes sense… Could be widespread 50mph+….

    Check this out
    10:00 PM Water Vapor Imagery update
    For the first time in many years we have a rapidly developing area of low pressure that now appears to likely cross over the critical 130 W, 40 N territory or a touch south of there for classic Pacific Northwest Windstorms. I don’t remember the last time we saw this, perhaps someone can chime in below. Really impressive and good potential for at least a moderate Wind Storm, but don’t yet rule out the possibility of something more significant.

  3. runrain says:

    School’s closed in the Bay Area as well. They’re looking at a ton of rain and wind. Should be an interesting p.m. Commute around here tomorrow.

  4. lilfoot123 says:

    I’m in! Thank you for the timing clarity! As this will make my evening job fun!! Especially if the power goes out as it probably will here Kelso Longview area!

    • Muxpux (Castle Rock 175') says:

      I’ve lived in various areas in LVK my whole life and it’s been a long time since I’ve experienced a power outage

  5. High Desert Mat says:

    Thanks for the update Mark. We appreciate it. Nice to hear it may be stronger than octobers event tho.

  6. moosieman says:

    Thanks for the informative update Mark much appreciated by all. Keep posting Paul and Rob got a feeling this could be special…

  7. High Desert Mat says:

    First! Know bout it.

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