December 2014 Observations for the Pacific Northwest

[SilverFallsAndrew]

Chilly....

 

http://mag.ncep.noaa.gov/data/nam/12/nam_namer_054_1000_500_thick.gif

[SilverFallsAndrew]

Nam gets -12c 850s to sea and near pdx.

[Gradient Keeper]

12z NAM

 

http://mag.ncep.noaa.gov/data/nam/12/nam_namer_054_500_vort_ht.gif

Nice tilt to block..... So both 6z Op/Parallel didn't deliver after day 7, but did anyone notice how long the Parallel keeps cold air into the Columbia Basin with relatively low heights. If that panned out PDX-Gorge would be cold for over a week even without a reload.

[SilverFallsAndrew]

Their could be a nice valley inversion fest too.

[SilverFallsAndrew]

Everybody waking up right now, getting primed for those 12z runs!

[SilverFallsAndrew]

Remember, without a catalyst to scour out the cold air, it's going to hang around. I'd imagine the inversion would be very deep as well.

[Gradient Keeper]

6z GFS Ensembles HR 192 - 216 shows many cold members.

For PDX 850mb did improve showing a cluster now of -5 to -10c January 4th - 6th with the mean around -4c. This hints at a possible reload. Nice improvements.

[Gradient Keeper]

Remember, without a catalyst to scour out the cold air, it's going to hang around. I'd imagine the inversion would be very deep as well.

I agree and suspect for my area a prolonged, cold east wind.... and one of those situations where as we get into it we(or models) realize this is going to last longer than previously thought.

[Gradient Keeper]

Here we go.....

[Prairiedog]

NWS forecast:  Portland

http://forecast.weather.gov/product.php?site=PQR&issuedby=PQR&product=AFD&format=CI&version=1&glossary=1

[MR.SNOWMIZER]

Heading over pass. Should be fun

[SilverFallsAndrew]

Heading over pass. Should be fun

Going to republic?

[MR.SNOWMIZER]

Going to republic?

Yep just me and my son. Trying to get the cabin done.

[Gradient Keeper]

This is interesting possibly....

 

HR 144 Op reload approaching southern BC already

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_z500_vort_namer_25.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_25.png

[Gradient Keeper]

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_z500a_namer_25.png

[Gradient Keeper]

HR 156 If 500mb pattern shapes up with a digging trough out of BC. LOOK OUT

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_z500_vort_namer_27.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_27.png

[TT-SEA]

Once again the WRF shuts off all precip up here as soon as it actually gets cold enough to snow.   

 

Going to suck missing snow with this first event.

[Gradient Keeper]

Holy CRAP

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T2m_nwus_29.png

[Gradient Keeper]

Cold air may stall just north of Olympia

[jaya]

Don't get excited or depressed. After a quick look at the 12z and last night's solutions...the operational GFS and last nights Canadian seem to be meshing various low pressure systems into one north of Hawaii, the GFS Parallel does not (likely more realistic).  The bad thing is that these small features in the middle of no where will be very difficult for any solution to pick up on, then handle properly. Details on exactly how strong and where the low(s) set up and move will be critical to downstream ridge placement and amplification.  I'd just say that there is massive POTENTIAL after hr 144 - but nothing is set one way or another. In the shorter term, snow for the Puget Sound area looks most likely to be light, but even SMALL differences in the amount of development we get off Vancouver Island and western WA (this is dependent on how much and how fast cold air spills offshore) can mean the difference between a flurry before things get dry and a few inches (possibly local) with an arctic boundary that looks like a convergence zone. 

[catnip]

HR 156 If 500mb pattern shapes up with a digging trough out of BC. LOOK OUT

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_z500_vort_namer_27.png

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_27.png

 

That low just sits out there and dumps moisture overtop the cold air!

[Gradient Keeper]

Parallel on the other hand is garbage through HR 174

[jaya]

Once again the WRF shuts off all precip up here as soon as it actually gets cold enough to snow.   

 

Going to suck missing snow with this first event.

I have found the WRF to underperform when flow is onshore (arctic boundaries and CZs) and to over perform in overrunning events (S Interior and Shelton area).  I no longer give a great deal of thought to this model when we are moving into a cold event.  It is pretty good (though overdone) with heavy rainfall events.

[jaya]

Holy CRAP

 

Look at the baroclinicity around Seattle.  If this were to happen - Seattle watch out.  But, we'll see.

[Gradient Keeper]

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_mslp_wind_nwus_31.png

[Timmy]

https://mobile.twitter.com/fox12weather/status/548851442132336641/photo/1

[Gradient Keeper]

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_31.png

[Gradient Keeper]

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_z500_mslp_namer_31.png

[antipex]

Looks like there's at least potential for some backdoor action in this one!

 

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_31.png

[Gradient Keeper]

Cold air is hanging up where I thought, Olympia north.. maybe next frame only need a small push... but you see it's flooding into Columbia Basin with strong E wind transporting it through Gorge into PDX

[jaya]

Toggle between the GFS and the parallel GFS at this time frame http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=namer&pkg=z500_mslp&runtime=2014122712&fh=120&xpos=0&ypos=0. Notice the handling in the western Gulf of Alaska. Where is the deep low that you see on the parallel on the operational?  Huge implications and that is where the big ensemble spread is originating (actually further south early on).  Initialization from satellite can only do so much (it has gotten impressive but isn't everything). 

 

I have found that model performance can be better in the 7-10 day period than the day 5 period (then increases again in the short term).  Could this be due to the void/quality of the initialization in the central Pacific in these situations?  Seems to be. But there are so many unknowns.  Maybe NOAA will fly some recon flights between Hawaii and Alaska (though I haven't seen anything on this during the current year). 

[Gradient Keeper]

MAJOR backdoor blast HR 192 .... Day 8... PDX would be frozen big time

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T850_nwus_33.png

[TT-SEA]

I have found the WRF to underperform when flow is onshore (arctic boundaries and CZs) and to over perform in overrunning events (S Interior and Shelton area).  I no longer give a great deal of thought to this model when we are moving into a cold event.  It is pretty good (though overdone) with heavy rainfall events.

 

 

Yeah... it does not seem to match up to the GFS operational run for Sunday night.

 

http://mag.ncep.noaa.gov/data/gfs/12/gfs_namer_048_precip_p12.gif

 

http://www.atmos.washington.edu/mm5rt/data/current_gfs/images_d3/ww_pcp1.45.0000.gif

[Gradient Keeper]

Oh yeah

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_mslp_wind_nwus_33.png

[jaya]

I see a lot of posts that seem to be over analyzing (or weather porn watching) the models and getting depressed or excited from run to run.  The big problems occur early on in the model run.  For myself, I'll be watching satellite over the central Pacific to see what the structure is of the low north of Hawaii...that is the player.  There are other problems further NW.  Unfortunately, at home I don't have as many resources available to me.

[Gradient Keeper]

Wow! As I thought huge blast through Gorge

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T2m_nwus_33.png

[Gradient Keeper]

I see a lot of posts that seem to be over analyzing (or weather porn watching) the models and getting depressed or excited from run to run.  The big problems occur early on in the model run.  For myself, I'll be watching satellite over the central Pacific to see what the structure is of the low north of Hawaii...that is the player.  There are other problems further NW.  Unfortunately, at home I don't have as many resources available to me.

Yeah the cut-off low north of Hawaii is huge we need it west of 155 W.

[Gradient Keeper]

..... Nothing to see here. Save this image even if it doesn't happen

 

http://www.tropicaltidbits.com/analysis/models/gfs/2014122712/gfs_T2m_nwus_35.png

[jaya]

Yeah... it does not seem to match up to the GFS operational run for Sunday night.

 

 

I really like Cliff Mass and the work he and his students/coworkers have done with mesoscale modeling here in the northwest. But the WRF has issues that have not and seemingly cannot be resolved yet.  First, it mixes too much energy downward. That is why we won't see good northerly winds in this situation in the Puget Sound. Second, it seems to produce too much downslope warming even in somewhat stable situations.  Then, there is the issue of using the operational GFS as a lateral boundary (this model really misses things on occasion over the all important central and northwest Pacific in these situations).  Winds don't look strong enough in the Fraser outflow area (it can get this right on occasion - but not always). Winds with the initial surge are typically too easterly (over mixing of geostrophic flow downward?)  I remember some situations (I get the dates mixed up now as I age) where the NAM - despite its poor initialization using an early data cutoff - beats the WRF with wind directions, mixing, and convergence boundaries including the strength of the arctic front.  I am thinking Nov 2009 or 2010 (can't remember). I look at it, think about it, then look at lots of other things giving the WRF a bit of weight but not all in like some others.

[luvssnow_spokane]

Not sure if the Candian geese are sensing something but they have been flying over our house from north to south in huge flocks this morning: there have been six different flocks of them over the last hour and a half. Just thought it was interesting and unusual for this late in the season as this usually happens in October and early November. For some reason they are high tailing it out of the area now.