7.7 Quake West Coast of B.C…No Tsunami Threat

October 27, 2012

And impressive 7.7 magnitude quake struck about 90 minutes ago (sorry, I was Netflixing…) in the Haida Gwaii (Queen Charlotte) islands off the coast of British Columbia.  It was right along a main fault, well to the north of the Cascadia Subduction Zone.  2 aftershocks have followed.  The 7.7 was a 8:04pm, a 5.8 10 minutes later, then a 4.8 at 8:52pm.  The ground is rearranging itself up there!

There is still a Tsunami Warning for extreme SE Alaska and the central coast of British Columbia, but there has not been a threat this far south.  So no warning, watch, or advisory for our coastline.

Chief Meteorologist Mark Nelsen

 


The Super Storm Forecast

October 26, 2012

It is truly going to be a historic wind and rain storm for the East Coast Monday through Wednesday…here’s a snippet from the forecast discussion at the Hydrometeorological Prediction Center (HPC), emphasis added by me:

THE EXTRATROPICAL TRANSITION OF SANDY MAY HAVE ALREADY BEGUN BASED UPON RECENT SATELLITE IMAGERY…A PROCESS EXPECTED TO COMPLETE TUESDAY PER NHC. 

THE DETERMINISTIC GUIDANCE (PARTICULARLY THE 00 UTC ECMWF) SHOW PRESSURE SOLUTIONS WELL BEYOND WHAT HAS EVER BEEN OBSERVED NEAR THE NEW JERSEY/NEW YORK COAST (EVEN EXCEEDING THE 1938 LONG ISLAND EXPRESS HURRICANE) EARLY IN THE MEDIUM RANGE PERIOD.

It’s hard to count that many isobars, but it forecasts a 939 millibar low at that point; far deeper than Hurricane Sandy is right now.  Think of it as a huge hole ripped through the atmosphere that air is rushing into.  Maybe more disturbing is the movement.  Since it has just been caught up in a cold upper-level trough in the Eastern USA, it moves quickly straight west into the New Jersey coastline.  6 hours later it’s on the coast. 

The areas to the north of the low (New Jersey, New York, and Long Island will get assaulted by hurricane force easterly wind and a storm surge.  The low has weakened significantly, up to about 960mb…yeah, only about as deep as our Columbus Day Storm! 

Remember that this is only ONE model, but it IS the ECMWF (European) model; the #1 forecast model on the planet.

Here are maps from the 18z GFS:

18z NAM:

and 12z GEM (Canadian):

These all show a landfall slightly farther north, closer to New York City or Long Island…the drama builds!

The New York Marathon A Washington DC marathon is Sunday, so runners…run fast and get the heck out of there!

Chief Meteorologist Mark Nelsen


18z RPM…A Lot of Rain Ahead!

October 26, 2012

Here’s our 18z RPM model rain output from midday today to midday Monday:

 

Last time I saw numbers this high was back in January when we had some flooding.  The WRF-GFS still is saying 5-8″ rain in the Cascades as well.  We’ll see if we get flooding out of this; the next 5 days sure looks similar to November 2006 to me…

 

 


Wettest October In Years; Much More On The Way

October 25, 2012

We’ve seen about 18 hours of dry weather now, and I don’t expect much rain in the next 24 hours.  But after that the firehose of warm subtropical rain turns back on in the Pacific Northwest.

We are just a few tenths of an inch of rain away having the wettest October since 1997; shouldn’t be hard to reach that by Saturday.  We’ve been in a cool and wet airmass for the last 6 days but that’s about to change.  Through the foreseeable future (the next 7-10 days) an upper level ridge, or at least higher than normal upper level heights, will be centered on or just off the West Coast.  This says warm and wet most of the time.  And models are responding by generating a LOT of rain.

Here’s the 72 hour rain forecast from Saturday to Tuesday afternoon from the 00z WRF-GFS, showing 5″+ just in that period in the Cascades.  Even the driest parts of the valley get maybe 1.50″

And the 12z ECMWF 7 Day rain forecast:

Both models are extremely wet.  You don’t get much detail on ECMWF because it’s a global model, but you get the idea.

We could end up with another 2-3″ rain before the month is up; if so, that would get us up in the 5-7″ range.  So much for a developing drought!

Chief Meteorologist Mark Nelsen


Hail & Thunder In Tillamook This Evening

October 24, 2012

Several thunderstorms developed over Tillamook between 9 & 10:30 this evening, producing a dozen or more lightning strikes, and apparently some hail!  Take a look at this pic from Ken Myers:

 


Snow Gate Closes Thursday On Larch Mountain

October 24, 2012

Thursday morning the highest paved road in Multnomah County will be closed for the winter.  Each Fall, road crews close the “Snow Gate” at the 2,600′ elevation on Larch Mountain.  This keeps people from driving higher up into deep snow and getting stuck.  I’ve always wished they would plow it and make a nice snow park up there.  It would be nice to have a snow play area only 45 minutes from downtown Portland.  On the other hand that would cost a lot to maintain/plow, plus I doubt locals would want hordes of visitors jamming the narrow roads leading up to it each weekend all winter long.  Okay, bad idea, nevermind.  More details here:  http://corbettoregon.com/forum/index.php?topic=651.0

That reminds me.  When you are on a road with 3 signs in one mile that say ROAD CLOSED AHEAD,   then ROAD CLOSED 1000′ AHEAD,  then ROAD CLOSED 500′ AHEAD?  Please don’t stop where it is actually closed and sit in the middle of the road wondering where to drive next.  Especially if there is another road veering off to the right at the same spot.  That’s really annoying…I’ve had that happen to me a bunch of times in the last few weeks.  Just pull off to the side and let other traffic go by.

Chief Meteorologist Mark Nelsen


Rain Keeps Adding Up; Was It Really Dry?

October 23, 2012

Seems like just a dream, was this really our 7 Day Forecast 3 weeks ago?

It’s just a memory now and we sure DID need the rain.  But considering the first 1/3 of October was dry, it’s amazing that we are now ABOVE AVERAGE for October rainfall.  We are at about 3.45″ at PDX, which is well above the 2.88″ we typically get in the month of October.  Add in more showers tomorrow, plus some heavier rain likely sometime between Sunday and next Wednesday, and I think it’s quite possible we get 5″ for the month.  If we get more than 4″ (very likely) it’ll be our wettest October in 15 years!

The wetter west side of the Mt. Hood National Forest has seen 7-13″ totals, and I see some totals close to 16″ up around Mt. St. Helens.  These are precipitation (rain and melted snow), not snow totals…the wet season has arrived with a vengeance!

The sad part for the mountains is that a decent chunk of the fresh snowpack on the ground below 6,000′ is going to melt at some point in the next week; snow levels will soar starting Friday. 

And heavy rain is the biggest enemy of snow cover, far more than warm sunshine and clear skies.

Speaking of heavy and mild rain; models show our cold and wet atmosphere departing after one more day of showers and sunbreaks tomorrow.  It’ll be replaced by a weak upper-level ridge along the West Coast Friday through Sunday.  A warm front rides over the ridge Friday, bringing a classic drippy, gray, cool day.  Southerly wind should kick in Saturday and/or Sunday for warmer temps. 

Models have been in some disagreement on the amount and placement of heavier rain for early week (Sunday-Tuesday).   ECMWF was real bullish on heavy rain later Sunday and Monday.  New 00z GFS isn’t too dramatic…just MORE rain.

Right now I don’t see any real strong wind events or flooding rain in the next 7 days, just more slop.

And for that person that wrote me a nasty email three weeks ago claiming I was “ignoring the drought”?  THIS is why I didn’t get real excited about the early Fall dry weather.

By the way, FOX12 has the World Series again this year.  First game around 5pm tomorrow at San Francisco.  Could be a few showers, but more likely dry.

Chief Meteorologist Mark Nelsen