El Nino Returns?

June 8, 2009
CPC Ensemble Mean Shows El Nino Developing by Fall

CPC Ensemble Mean Shows El Nino Developing by Fall

Some news today out of the Pacific Ocean that should prompt a bit of debate.  The Climate Prediction Center says El Nino conditions should develop in the Equatorial Pacific over the next 3 months, possibly leading to a full blown El Nino event this Fall and Winter.  The image to the left shows the various long range models used to predict ENSO events.  Notice the heavy blue line shows we are now in Neutral conditions with the death of La Nina last Spring.  Actually that sounds a bit morbid, but you know what I mean…La Nina conditions disappeared during the northern Spring this year.

Now you can discuss amongst yourselves for the next 4-6 months.  Typically we have mild and drier than normal winters here in the Pacific Northwest during these conditions.  Now some would (or will) say that neutral or weak El Nino winters have given us some great storms (January 1998 Snow).    Some even believe that a neutral year is great for snow in Portland, and then real crazies say “what about the lack of sunspots PLUS an El Nino year???  Could that mean the four horsemen of the apocalypse are close?”.    Okay, now I’m way off track so as I said, you have plenty of time to discuss.

The full report is at this site: http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

Mark Nelsen


Storm Wrap Up

June 5, 2009

A nice line of storms made for a crazy (and quick!) 2 hours.  If you were in a movie theater you probably missed it.  Here are the highs and lows.  Let me know if I’ve missed something important.

Highs:

1.  Wind:  The storm was really about the wind here in town.  Peak gust of 49 mph at PDX is the highest since December 2006.  It’s been even longer since Hillsboro has been up to that 55 mph gust.  Although both sensors had a different calculation for peak gust during the December 2006 storm.  So most likely with today’s current peak gust calculation they both would have been above 60 mph during that storm.  A little bit of “apples to oranges” on the comparison, but they were both very impressive speeds.   Around 6:30pm I pulled up the radar loop and notice the very obvious outflow line had quickly moved north on I-5 to Longview.  Do you think there may have been a bunch of dust helping out the reflectivity on the radar?

2. Scary looking clouds: Even I started to freak out briefly at home.

3.  Tornado warning in Marion County:  I can only think of maybe 1 other times in my career when the Portland NWS put out a tornado warning based on rotation detected on radar.  Usually our crappy radar coverage shoots right over the top of our generally weak storms and/or a warning has come out after a tornado is already on the ground (or maybe has already dissipated).

4.  Great job by the weather team at KPTV and models: I saw Drew once and heard him on the radio while driving.  And Rob Martin came in close to “bedtime” to help out and keep things under control.  And it definitely was not a “surprise” storm.  I made a point on the air (10pm Wednesday) and in the previous blog post about the good chance for evening thunderstorms farther north Thursday evening.  Models did very well showing some sort of big blowup of storms somewhere between Salem and Longview.  SPC issued the severe thunderstorm watch for the Metro area in the early afternoon and the NWS followed through with severe thunderstorm warnings.  Anyone paying attention to any sort of media wouldn’t have been surprised.

Lows:

1.  Lightning:  I saw very little.  We’ve seen far better and more frequent lightning out of storms just in the last year (May 2008 and July 2008).

2.  Rainfall:  In the Metro area amounts were relatively light.  No flooding here.

3.  Hail:  As far as I know we didn’t get significant hail in the Metro area either.

4.  Mark is Missing!:  This is the first thunderstorm outbreak in the last 8 years in which I haven’t been at the station.  It was a scheduled day off with family.  I sure missed being there, but considering it only lasted 1-2 hours, it would have been too late to go into work anyway.  I don’t have any days off scheduled in the next 2 weeks, so the weather should stay quiet.

Mark Nelsen


Severe Thunderstorms

June 4, 2009

The Mark Nelsen vacation curse has struck again!  I have one day off (today) and a line of severe thunderstorms is moving northwestward out of the Cascades and across the North Willamette Valley.  I’m at home right now, hearing the first rumble or two.  Everyone stay safe and have a good time watching the storms.

Mark Nelsen


Another Wild Day…To the South

June 3, 2009

A Severe Storm Moving Into the Sweet Home Area This Afternoon

A Severe Storm Moving Into the Sweet Home Area This Afternoon

This must have been a nice storm (maybe not if you were right under it I suppose) to watch moving through Linn County this afternoon.  Can anyone count the 15 minutes worth of cloud to ground lightning strikes?  Must have been at least 50.

The storms were located slightly farther north today and mesoscale models look even better for tomorrow. 

I didn’t work yesterday, so it’s nice to not have to explain the mostly cloudy forecast that turned sunny, hot, and 90 degrees.  But it was a tough forecast, that’s for sure.  We did hit 90 at PDX today, the first of the year.  I was out running errands this afternoon and can attest to the warmth.  So why so warm?  Well, look at the observations.  The offshore flow surfaced across most of the Metro area today.  Notice the easterly breezes at PDX, TTD, and HIO.  And cloud cover remained to the south today.

For Tonight:  The big storms should die down, but I notice our RPM shows some weak instability drifting up over us late (like 2-5am) and generates a few light showers.  Then skies clear out around daybreak.  If we get incredibly lucky maybe some flashes of lightning late tonight.

Tomorrow:  There is good news for convection tomorrow.  Looks to me like tomorrow COULD be the big day with several things lining up for a good outbreak right here in the city.  It appears the offshore flow will continue until late afternoon, promising another very warm day.  Then a sudden southwesterly marine surge arrives in the Metro Area in the evening at about the same time CAPE values reach 1500-2000.  Lifted index of -2 to -4 along with precipitable water well above 1″ too.  I think it’s the WRF-GFS that generates over 1″ of rainfall close by in the 5-10pm timeperiod.  Our RPM model shows something similar except down closer to Salem.    Can’t wait for the 00z data.  Forecasting thunderstorms is even harder than snow in some ways, but I have a feeling someone between Salem and Longview in the valleys could get nailed tomorrow afternoon/evening.

Friday and Beyond:  Our 2+ week spell of unusual warmth is going to come to an end with a big marine push pushing lots of low clouds inland Friday and the weekend.  Not much chance for rain, but much more typical temps (highs 70-75) .

Mark Nelsen


Weather Action Picks Up

June 1, 2009
First Thunderstorm Approaching Estacada Today

First Thunderstorm Approaching Estacada Today

Hoping for some good weather action during the evening shows…we’ll see.  More later.

4:30PM:  Obviously plenty of cloud to cloud lightning in the last hour and a half because there were no strikes on detection any closer than east of Estacada (in the image).  Thanks for the blog comments letting me know when you hear thunder.  I’m also timelapsing the nice group of towers up around Mt. St. Helens.  Should make a nice movie for the later shows!

10:15pm: Things sure died down quickly after 7pm tonight.  In fact all the action from 9pm to now has been 50 miles offshore of Newport and Lincoln City.   Low level atmosphere is moist this evening…whew!  Sweaty out there.  Looks like a good afternoon for scattered storms again tomorrow with easterly flow developing at all levels below 5,000′ helping out our surface heating as well.  Models continue to put most of the main action to our south tomorrow and Wednesday.  Generally this pattern is very good for storms west of the Cascades.  But no model shows a good trigger for a wild afternoon or evening of storms.  We’ll see. 

The bizarre unseasonably warm, but not hot, weather is going to continue for 2 more days.  There are signs of some sort of significant change coming up over the weekend.  No more of the real warm weather with high temps coming back down close to seasonal norms.  This time of year that would be near 70 or so.


You’re in the Wrong Place

June 1, 2009

As of April 2009, this weather blog has moved to a different place.  We are still working on moving some of the older content to the new site.

Go here: https://fox12weather.wordpress.com/