A Slow Weather Night

August 28, 2008

Junk So why not look at the latest NHC forecast for Gustav.  Exciting times ahead in the Gulf of Mexico apparently.  (11:10pm update:  00z HWRF intensifies the storm to 200 mph in the Gulf and makes a direct hit on New Orleans!  Link is here)That plus Russia saying they may cut off oil this weekend could make the energy situation even MORE interesting, but that's well beyond the scope of my little weather blog.

A surge of moisture into our airmass this evening…dewpoints have pushed up to around or just above 60 degrees.  Looks like a slight push up the Columbia River did it.  This goes really well with MOS data that showed high dewpoints (for us) tomorrow, then sudden drying with dewpoints into the 40s tomorrow night and Saturday behind a mainly dry cold front.

Quite a sharp trough dropping in Saturday and Sunday.  I like the look…if it was January.  A strong wave rotates south into the Pacific Northwest around a cold polar vortex over western/central Canada.  This could probably bring a nice show of low elevation snow (or at least in the hills) and then cold/dry air from the north.

Not much else to say tonight and I'm running a bit behind.  Mark Nelsen

 


Time For Debate!

August 26, 2008

Seaice_2008 I figure the weather is REALLY slow lately, so let's spice up the discussion with some data.

You may remember that the least amount of Arctic Sea Ice Cover was recorded last September.  Of course thats the least since satellite measurements began around 30 years ago…keep that in mind.

Of course each winter a large area refreezes and then melts in the spring/summer.  So obviously you can ONLY compare the maximum in any winter and/or the minimum at the end of each summer.  I remember some posters last winter mentioning that the sea ice had "recovered".  It does that every year.  But how low is the minimum each September or how high is the maximum in March?  Well, take a look at the chart.  As of today, 2008 has the 2nd lowest sea ice cover on record.  Notice the line is dropping quickly and probably will for another week to 3 weeks.  This year MAY end up with the smallest ice cover on record!  Here's the press release from the National Snow/Ice Data Center.

So what does that have to do with our weather?  Not much, at least in the short term, but it's like screaming tornado in a theater full of weather nuts.  Just something fun for this cool Tuesday evening.

The arctic climate is clearly warming, that's no surprise, but will it continue?  Sunspots anyone?  IPCC?  Mothership behind the moon?  Smoking Man?  Cylons? Go ahead and discuss, just don't get up in each other's "grills" and make me have to ban anyone.

My thoughts on global warming are here.  Feel free to put yours in the comments below.

Mark Nelsen 


A Wet August?

August 22, 2008

Snapshot I just noticed this evening that we're within .09" of our average August rainfall.  That shouldn't be too hard to get Sunday evening or early Monday morning.  The approaching cold front sure won't be a soaker, especially compared to the last one earlier this week.  But maybe .20" is a likely number for PDX.  Otherwise nice sunshine again for tomorrow and briefly again Sunday morning.  A bit more easterly flow than expected this morning.  I see Corbett gusted over 30 mph.  I stopped by and fixed the minor networking issue out there yesterday.  Got to have that thing working for the approaching east wind season!  I see the easterly gradient has not returned this evening, so we'll only have a light easterly drift early tomorrow before onshore flow returns late in the day.  But with a warmer airmass, I still expect 5-7 degrees warming.  We hit 81 today, so that should get us in the 86-89 degree range tomorrow.

Not a whole lot to talk about this evening otherwise…I'll be working all next week, so more blogging then.  Enjoy the warm weekend!  Mark Nelsen


A Wet August?

August 22, 2008

Snapshot I just noticed this evening that we're within .09" of our average August rainfall.  That shouldn't be too hard to get Sunday evening or early Monday morning.  The approaching cold front sure won't be a soaker, especially compared to the last one earlier this week.  But maybe .20" is a likely number for PDX.  Otherwise nice sunshine again for tomorrow and briefly again Sunday morning.  A bit more easterly flow than expected this morning.  I see Corbett gusted over 30 mph.  I stopped by and fixed the minor networking issue out there yesterday.  Got to have that thing working for the approaching east wind season!  I see the easterly gradient has not returned this evening, so we'll only have a light easterly drift early tomorrow before onshore flow returns late in the day.  But with a warmer airmass, I still expect 5-7 degrees warming.  We hit 81 today, so that should get us in the 86-89 degree range tomorrow.

Not a whole lot to talk about this evening otherwise…I'll be working all next week, so more blogging then.  Enjoy the warm weekend!  Mark Nelsen


Warmer Weather Ahead

August 21, 2008

Snapshot Apparently I chose the wettest, coolest, most useless days to take off in the month of August.  I was off Monday-Wednesday, although Saturday and Sunday were neat with the thunderstorms and nice warm nights (Luckily, I have a heat pump that keeps the house cool during the day).

I took my usual between-show ride this evening.  It's obvious that I can only do that for a few more weeks…that sun angle is getting pretty low by 7:30 pm.  And in two weeks I'll won't be able to even start until 6:30pm.  Well, I'll be back at it in March.

As for weather?  It's a bit slow this evening.  Clouds gradually clearing out behind all the muck of the last few days.  Plenty of clearing and wet ground should lead to some fog or low clouds later tonight.  Weak or slightly offshore flow tomorrow and Saturday plus 850mb temps peaking out around +16 should give us highs in the mid-80s Saturday.  Earlier I had a 90, but that was based on the "east wind" part of my chart.  As I mentioned, 00z models have very weak or light east flow on Saturday, so I dumped that 90 degree idea as fast as Northwest weather geeks run from high pressure and inversions in the winter.

Models seem to be slightly faster with the next trough/cold front for late Sunday.  Looks like the Coast may be wet the 2nd half of the day, with rain into the interior by sunset.

Some sort of ridging and warmer temps comes back in the middle of the week.  Mark Nelsen


Warmer Weather Ahead

August 21, 2008

Snapshot Apparently I chose the wettest, coolest, most useless days to take off in the month of August.  I was off Monday-Wednesday, although Saturday and Sunday were neat with the thunderstorms and nice warm nights (Luckily, I have a heat pump that keeps the house cool during the day).

I took my usual between-show ride this evening.  It's obvious that I can only do that for a few more weeks…that sun angle is getting pretty low by 7:30 pm.  And in two weeks I'll won't be able to even start until 6:30pm.  Well, I'll be back at it in March.

As for weather?  It's a bit slow this evening.  Clouds gradually clearing out behind all the muck of the last few days.  Plenty of clearing and wet ground should lead to some fog or low clouds later tonight.  Weak or slightly offshore flow tomorrow and Saturday plus 850mb temps peaking out around +16 should give us highs in the mid-80s Saturday.  Earlier I had a 90, but that was based on the "east wind" part of my chart.  As I mentioned, 00z models have very weak or light east flow on Saturday, so I dumped that 90 degree idea as fast as Northwest weather geeks run from high pressure and inversions in the winter.

Models seem to be slightly faster with the next trough/cold front for late Sunday.  Looks like the Coast may be wet the 2nd half of the day, with rain into the interior by sunset.

Some sort of ridging and warmer temps comes back in the middle of the week.  Mark Nelsen


Stormy Night For Some of Us

August 17, 2008

Lightning1 As always you can click on the image for a closer view, but my main reason for posting on a day off is to save the lightning image from last nights storm for posterity…or at least for the blog.  It's quite possible that you slept through the action (as I did) if you live in the middle of the city or eastside of town.  Lots of strikes from I-5 westward and down into Marion County east of I-5 too.  A heck of a warm night.  IF we don't get a massive marine push before midnight tonight, we'll probably break our all-time August low temperature record (the warm one) of 68 degrees.  We tied it yesterday.

I'm up so early because I was woken up by a strong northwest wind around 6:10am.  That early of a wake up call makes me tired, but I can catch up when it's clouds, cool, and drizzly sometime in the next 3 days.  There must have been some leftover outflow from a thunderstorm, but 22 mph seemed REAL windy with every single house/door on my house open.  I slept through the action overnight, except that first cell that formed around midnight in Clackamas county.  I saw plenty of lightning from that, but then fell asleep. 

Not wanting to get anyone too excited, but I see SPC has us (or at least the Cascades) in the SLIGHT chance for severe weather this afternoon/evening.  Here is their morning discussion:

…THERE IS A SLGT RISK OF SVR TSTMS LATER THIS AFTERNOON INTO
   TONIGHT FOR THE ORE CASCADES AREA…
  
   …WA/ORE CASCADES AREA THIS AFTERNOON INTO TONIGHT…
   A PLUME OF LOW-MID LEVEL MOISTURE HAS SPREAD NWD OVER ORE/WA…NEAR
   AND IMMEDIATELY W OF THE CASCADES…AND THIS MOISTURE HAS SUPPORTED
   A FEW THUNDERSTORMS OVERNIGHT FROM NW ORE INTO WRN WA.  THIS INITIAL
   CONVECTION WILL LIKELY WEAKEN LATER THIS MORNING…WITH ADDITIONAL
   THUNDERSTORM DEVELOPMENT EXPECTED OVER THE ORE CASCADES LATER THIS
   AFTERNOON/EVENING IN CONJUNCTION WITH DAYTIME HEATING AND THE
   APPROACH OF EMBEDDED WEAK SPEED MAXIMA IN ADVANCE OF AN ERN PAC MID
   LEVEL TROUGH.  OBSERVATIONS OF STEEP MID LEVEL LAPSE RATES ATOP
   BOUNDARY LAYER DEWPOINTS RANGING FROM THE MID 50S TO LOCALLY LOWER
   60S WILL CONTRIBUTE TO MLCAPE VALUES OF 1000-1500 J/KG BY LATER THIS
   AFTERNOON/EVENING.  THE COMBINATION OF MODERATE INSTABILITY AND
   GRADUALLY INCREASING VERTICAL SHEAR THIS AFTERNOON INTO TONIGHT
   APPEARS SUFFICIENT FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL
   AND DAMAGING WINDS. 


Okay, let's hope for some more this afternoon or evening!  Mark Nelsen


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