SLOW Weather

February 19, 2008

SnapshotWe just had one last August, but another lunar eclipse is on the way Wednesday evening.  We may get a break in the cloud cover tomorrow during the eclipse, so it’s still possible we’ll see it.  I found a great web site that has animations showing eclipses, comets and other neat astronomical events.  You’ll find the information here. 

What a weak weather system today…in fact I was surprised how little rain fell this evening.  Of course I missed the forecast high by 5 degrees as well…disappointing.

A real lackluster weather pattern the next 5-7 days too.  Quite a split in the jet stream so we don’t get any strong weather systems as we head into the last week of February.  Spring can’t be too far away right?  On the other hand I notice the 00z GEM (Canadian) brings arctic air across the border into Washington around the 1st of March.  I’ll believe that when I see it.  Last time that happened was March 1st of 1989.  Mark Nelsen


Nice Spring Weather

February 18, 2008

SnapshotThe last two days were perfect early April days with high temps in the 60-65 degree range across the metro area.  It’s only the latter half of February, so you know it can’t stay this warm for too long.  Of course I think it was 3 years ago when we had almost a 3 week long stretch like this from late February through early March.  So maybe the warm weather will return in a week or so.  I had a great time this weekend ignoring the T.V. and actually most internet and weather maps.  Got my property all ready and de-blackberried to plant more trees (douglas firs), threw the dead grouse over the hill, planted some bulbs, and did some bush-wacking down to a waterfall with the kids.  Basically I tried to be outside as much as possible knowing that cool and rainy weather would return.  I hope many of you got the chance to do the same.

But now it’s "back to the usual programming" weatherwise.  Two separate systems are approaching from the southwest.  The first arrives overhead tomorrow afternoon.  A strong negative tilt to this system might give us thunderstorms tomorrow if it was May…but it’s not.  The 2nd moves in late tomorrow night, and it’s quite weak like the first one.  I notice there will be little to no rainfall Wednesday behind these two systems.

A wetter and more typical system for this time of year moves inland Thursday for a cloudier and rainy day.   

Beyond that, there are 3 things I notice in general:

1. No outbreak of cold air or snow chance…we are probably done with both (La Nina = No Snow at PDX???)
2. Very weak and splitty weather systems through early next week (a dry February in a La Nina ???)
3. Generally some sort of longwave ridging over the West Coast through the end of the month (March better be wet or this doesn’t fit our winter pattern so far).

Mark Nelsen


Sunnier Weekend

February 15, 2008

Dscf0005 SnapshotToday’s weak front sure got closer models showed.  In fact a trace of precipitation fell at PDX and TTD late this afternoon or early evening.  Latest look at radar shows we’re back into the dry weather.  That should be the case until Tuesday. 

The upper level ridge over us has been "dented" a bit this evening by the trough passing by to the north.  It then sharpens strongly and moves over the West Coast tomorrow through Monday.  As it does so, surface wind turns northerly tomorrow.  This should be enough to clear out low level moisture by afternoon (morning if we get lucky!).  Tomorrow night through midday Monday strong easterly flow develops and we get the usual Gorge easterly wind.  As I mentioned last night, we are just about to the transition season with east wind.  It’s definitely not a real cold east wind Sunday and Monday, but it’s not like early-mid March when we get some good downslope warming in this sort of event.  So 60-62 still seem like good numbers for Sunday and Monday.  We’ll know by Monday afternoon eh?  We ARE guaranteed perfectly sunny skies both days though…so get off the computer and enjoy the bright days!  That is my plan…Mark Nelsen

The picture of the kid with the bird?  That was the grouse that flew through the Nelsen home’s front window like a baseball this morning.  AFTER going through the window, it went another 15′ or so!  Obviously it didn’t make it…but my son call in the report!


Friday Evening Extra

February 15, 2008

Photo9Something different this evening…this post is a big thank you to all of you posters out there.

Cherie P. from Vernonia, who has been a "regular" on this site for quite a long time (maybe two years?), has gone through a very rough week or so.  Her husband passed away late last week very unexpectedly. 

Cherie & I conversed via e-mail a bit this evening and she wanted to make sure you all know how helpful your calls and emails have been.  Several of you have been in regular contact over the last week.  Cherie pointed out how this "blog family" HAS been just like a real family to her during this very challenging period of time.

If you’d like to get in touch with her (other than through comments here), send me a note at mark.nelsen@kptv.com and I can help you out.   

A thank you to Tyler Mode (another regular) for the appropriate picture…a sunrise on the clouds this morning.  Clicking on the picture shows a much larger version.

Mark


Another SLOW Day

February 14, 2008

SnapshotAnother very slow day in the weather center.  But that’s good since we’re getting ready for our new 4pm newscast.
High pressure sitting pretty much directly over us at the surface.  Clearly the upper-level ridge is getting "dented" by systems passing by to the north, that’s where we are getting the clouds from.  Now the strongest system moves by to the north tomorrow afternoon and evening.  This brings rain as far south as Olympia, but not down to Portland.

The ridge rebuilds behind this system for offshore flow late Saturday through Monday.  Quite strong offshore flow in fact for Sunday.  We get solid sunshine and east wind on Sunday.  This time of the year we don’t get incredibly warm from an east wind…we still get some cool air through the Gorge which balances out the downslope warming.  So I figure 60 degrees in PDX-town with an 850mb temp around +10.  This same airmass 3 weeks from now could give us 72 degrees according to Mark’s Magic Chart.  I don’t have a chart for February because inversions still mess up the data a bit.

Cooler and wet westerly flow is definitely coming back by the middle of next week…Mark Nelsen


More Sunshine On the Way

February 12, 2008

SnapshotPretty slow weather again this evening.  A fast moving cold front passed through the metro area late this afternoon.  The change in the lowlands won’t be quite as dramatic as up in the mountains.  Timberline Lodge at 6,000′ was 39 degrees today.  Tomorrow it’ll be about 15 degrees colder.  Not a lot of snow though, just a few post-frontal showers this evening and tomorrow morning.

Then high pressure builds in over the Northwest at the surface through at least Sunday.  The best offshore flow and upper-level warming is Sunday and Monday, which should push our temps up to at least 60 degrees with full sunshine…maybe a bit warmer.  Either way the mild February is going to continue through Monday.  Long range models say the cooler and wetter pattern may be coming back next week.  That would fit the pattern we’ve seen so far this winter.  Stormy periods with only brief periods of ridging inbetween…Mark Nelsen


A “False” Spring

February 11, 2008

SnapshotI meant to put this graphic on the blog Friday, but I was negligent…apparently forgetting to even blog that day!  That hasn’t happened since last Fall.  Clearly the big slowdown in weather has taken it’s toll.
Wow, only 13 comments today as well…it’s like a midsummer day with no weather to talk about.  More likely we all found something else to do with the sunny weather Saturday, and today was nice for February as well.  I got my fruit trees all pruned and sprayed for the "spring", cut some trees down near my gate, and took a hike with the kids up the hill.  So "false" spring fever sure hit me hard.

The big story for the next 7 days is DRY AND MILD.  Models continue to show longwave ridging over the Northwest through at least the early part of the next week.  This weekend looks especially nice with very high 500mb. heights and a sharp ridge.  Some easterly wind at times bodes well for reducing low clouds and fog too.  We are just about past the season where we’ll get a prolonged period of cold easterly wind.   Too long days and increasing sun angle are beginning to "take their toll" as we go through mid-late February.  Very similar to mid-late August when we need a stronger east wind to get us up to 100 degrees.

I just checked reservoir levels and SNOTEL sites.  Plenty of storage room in reservoirs and no rain on the way, so no threat of flooding.  The low elevation snowpack is definitely melting now.  I see Saddle Mountain in the Coast Range has gone from 35" of snow water Friday down to 30" this evening…it’s as if 5"  of rain has fallen at that elevation.  A quick melt, but no rain to cause trouble on the Coastal Rivers…Mark Nelsen