December 2014 Observations for the Pacific Northwest

[Gradient Keeper]

10:05 AM Analysis

12z NCEP/NWS Pacific Surface Analysis, 28 KM Water Vapor
The well advertised Kamchatka low is now undergoing explosive Cyclogenesis under a 180-200kt jet. It is located southwest of the Bering Sea. Forecast over next 24 hours to deepen near 957mb(maybe lower) over the south central Bering Sea. Water Vapor Imagery shows this will indeed be a monster.

 

 

[Gradient Keeper]

HR 96

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_5.png

[SilverFallsAndrew]

I really doubt anything colder than the GEM will verify. Would be awesome if we saw something close to that.

[Gradient Keeper]

Much stronger 1050mb ridge.... Southeast US ridge. Hmmm

[Gradient Keeper]

I really doubt anything colder than the GEM will verify. Would be awesome if we saw something close to that.

No kidding! That would rival some of our greatest cold waves with 850s -18c to -20c

[bainbridgekid]

Some interesting tidbits in the Seattle AFD this morning.

 

THE NAM12 AND ECMWF BOTH COOL THE AIR MASS SIGNIFICANTLY BEHIND THE
FRONT LATE TUESDAY NIGHT INTO WEDNESDAY MORNING AS PRECIPITATION
CONTINUES TO FALL BEHIND THE FRONT. SNOW LEVELS FALL TO AROUND 1800
FEET BY WEDNESDAY MORNING. THAT COMBINED WITH MODERATE PRECIPITATION
RATES APPEAR TO CAUSE THE HIGHER TERRAIN SOUTHEAST OF THE
SEATTLE-TACOMA-OLYMPIA METRO AREA...PLACES LIKE OUT TOWARD
ENUMCLAW...ORTING...AND YELM TO GET CLOSE TO THE SNOW LEVEL. AT THIS
TIME BOTH MESO MODELS AND THE ECMWF KEEP SNOW LEVELS JUST HIGH
ENOUGH TO LIMIT ANY ACCUMULATIONS THAT OCCUR TO THE CASCADE ZONES.
THIS WILL NEED TO BE MONITORED. BEHIND THAT FRONT...AN UPPER TROUGH
CROSSES THE AREA LATER CHRISTMAS EVEN AND GIVES SHOWERS IN NWLY FLOW
-ALONG WITH POSSIBLE CONVERGENCE ZONE ACTIVITY ON CHRISTMAS MORNING.
TEMPERATURES ARE MARGINAL...BUT THERE IS A CHANCE THAT SNOW LEVELS
IN HEAVIER SHOWERS AND CONVERGENCE ZONE ACTIVITY...IF IT
OCCURS...COULD RESULT IN SOME SURPRISE SNOWFLAKES FOR CHRISTMAS
MORNING IN PORTIONS OF THE EAST PUGET SOUND LOWLANDS AND AROUND THE
EVERETT AREA. THIS WILL NOT BE SOMETHING TO HOLD YOUR BREATH FOR
THOUGH. ALBRECHT

.LONG TERM...THE 12Z GFS BRINGS A WEAK SHORT WAVE TROUGH DOWN FROM
THE NORTHWEST CHRISTMAS NIGHT AND THIS IS FOLLOWED BY A STRONGER
SHORT WAVE TROUGH ON FRIDAY NIGHT. THE FIRST WILL ONLY BRING A
CHANCE OF LIGHT PRECIPITATION...BUT THE SECOND MAY GIVE THE
MOUNTAINS SOME MUCH NEEDED SNOWFALL. BEHIND FRIDAY NIGHTS
TROUGH...THE GFS BUILDS A RIDGE ALONG 140W THAT PROMISES COOL AND
DRY WEATHER FOR LATER IN THE WEEKEND THROUGH NEXT WEEK. THE
OPERATIONAL GFS APPEARS TO BRING COOL AIR IN QUICKLY FROM THE NORTH
WHILE THE PARALLEL RUN IS SLOWER AND STRONGER WITH A POTENTIAL
MODIFIED ARCTIC FRONT. THIS IS DUE TO MUCH STRONGER LOW DEVELOPMENT
NORTH OF HAWAII...A LESS PROGRESSIVE NORTHERN STREAM SHORT WAVE
COMING FROM THE WESTERN BERING SEA...AND BETTER RESOLVED TERRAIN
OVER SOUTH CENTRAL BRITISH COLUMBIA. WILL LIKELY NEED TO MAKE SOME
POP ADJUSTMENTS FOR THE THURSDAY NIGHT TO FRIDAY NIGHT PERIOD FOR
THE LEAD SHORT WAVE FEATURES...THEN DRY THINGS OUT FOR LATER IN THE
WEEKEND. THE CHALLENGE WILL BE TEMPERATURES. WILL NOT MAKE CHANGES
TO THE EXTENDED BEFORE LOOKING AT THE 12Z GEM AND ECMWF. ALBRECHT

[Gradient Keeper]

Some interesting tidbits in the Seattle AFD this morning.

 

THE NAM12 AND ECMWF BOTH COOL THE AIR MASS SIGNIFICANTLY BEHIND THE

FRONT LATE TUESDAY NIGHT INTO WEDNESDAY MORNING AS PRECIPITATION

CONTINUES TO FALL BEHIND THE FRONT. SNOW LEVELS FALL TO AROUND 1800

FEET BY WEDNESDAY MORNING. THAT COMBINED WITH MODERATE PRECIPITATION

RATES APPEAR TO CAUSE THE HIGHER TERRAIN SOUTHEAST OF THE

SEATTLE-TACOMA-OLYMPIA METRO AREA...PLACES LIKE OUT TOWARD

ENUMCLAW...ORTING...AND YELM TO GET CLOSE TO THE SNOW LEVEL. AT THIS

TIME BOTH MESO MODELS AND THE ECMWF KEEP SNOW LEVELS JUST HIGH

ENOUGH TO LIMIT ANY ACCUMULATIONS THAT OCCUR TO THE CASCADE ZONES.

THIS WILL NEED TO BE MONITORED. BEHIND THAT FRONT...AN UPPER TROUGH

CROSSES THE AREA LATER CHRISTMAS EVEN AND GIVES SHOWERS IN NWLY FLOW

-ALONG WITH POSSIBLE CONVERGENCE ZONE ACTIVITY ON CHRISTMAS MORNING.

TEMPERATURES ARE MARGINAL...BUT THERE IS A CHANCE THAT SNOW LEVELS

IN HEAVIER SHOWERS AND CONVERGENCE ZONE ACTIVITY...IF IT

OCCURS...COULD RESULT IN SOME SURPRISE SNOWFLAKES FOR CHRISTMAS

MORNING IN PORTIONS OF THE EAST PUGET SOUND LOWLANDS AND AROUND THE

EVERETT AREA. THIS WILL NOT BE SOMETHING TO HOLD YOUR BREATH FOR

THOUGH. ALBRECHT

 

.LONG TERM...THE 12Z GFS BRINGS A WEAK SHORT WAVE TROUGH DOWN FROM

THE NORTHWEST CHRISTMAS NIGHT AND THIS IS FOLLOWED BY A STRONGER

SHORT WAVE TROUGH ON FRIDAY NIGHT. THE FIRST WILL ONLY BRING A

CHANCE OF LIGHT PRECIPITATION...BUT THE SECOND MAY GIVE THE

MOUNTAINS SOME MUCH NEEDED SNOWFALL. BEHIND FRIDAY NIGHTS

TROUGH...THE GFS BUILDS A RIDGE ALONG 140W THAT PROMISES COOL AND

DRY WEATHER FOR LATER IN THE WEEKEND THROUGH NEXT WEEK. THE

OPERATIONAL GFS APPEARS TO BRING COOL AIR IN QUICKLY FROM THE NORTH

WHILE THE PARALLEL RUN IS SLOWER AND STRONGER WITH A POTENTIAL

MODIFIED ARCTIC FRONT. THIS IS DUE TO MUCH STRONGER LOW DEVELOPMENT

NORTH OF HAWAII...A LESS PROGRESSIVE NORTHERN STREAM SHORT WAVE

COMING FROM THE WESTERN BERING SEA...AND BETTER RESOLVED TERRAIN

OVER SOUTH CENTRAL BRITISH COLUMBIA. WILL LIKELY NEED TO MAKE SOME

POP ADJUSTMENTS FOR THE THURSDAY NIGHT TO FRIDAY NIGHT PERIOD FOR

THE LEAD SHORT WAVE FEATURES...THEN DRY THINGS OUT FOR LATER IN THE

WEEKEND. THE CHALLENGE WILL BE TEMPERATURES. WILL NOT MAKE CHANGES

TO THE EXTENDED BEFORE LOOKING AT THE 12Z GEM AND ECMWF. ALBRECHT

Nice..... Fairbanks NWS also says they are going with the EC solution, but that is off 00z data.... no 12z data in there yet awaiting next discussion from Fairbanks, Anchorage, Juneau NWS

[Gradient Keeper]

HR 120

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_6.png

[Guest Winterdog]

12z GEM looks cold after HR 168 !

I'll take it even though it would be another backdoor event You Oregon people are the real winners.

[SilverFallsAndrew]

No kidding! That would rival some of our greatest cold waves with 850s -18c to -20c

 

I'd be happy with -10C lol

[HighlandExperience]

I'll take it even though it would be another backdoor event You Oregon people are the real winners.

 

There is decent potential with this for Puget Sound area snow as well. 

 

I am happy to see the mountains getting a decent amount of snow this week leading into Christmas, and New Year Holiday.

[luvssnow_spokane]

I'll take it even though it would be another backdoor event You Oregon people are the real winners.

Personally I want snow! The meager half inch in November is purely insulting.

[Guest Winterdog]

There is decent potential with this for Puget Sound area snow as well. 

 

I am happy to see the mountains getting a decent amount of snow this week leading into Christmas, and New Year Holiday.

I'm not complaining at all. The GEM solution would be great but the real cold air moves into eastern Oregon rather than from a direct northerly shot that I would prefer.

[Gradient Keeper]

HR 144

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_7.png

[Gradient Keeper]

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500a_namer_7.png

[Bryant]

Personally I want snow! The meager half inch in November is purely insulting.

 

I saw some flakes falling in November... that was it. Nothing actually stuck. Ready for redemption!

[Gradient Keeper]

HR 168 ... crap! ridge slides inland

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_8.png

[SilverFallsAndrew]

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500a_namer_7.png

Not to bad. Bulk of the coldest air just east.

[SilverFallsAndrew]

HR 168 ... crap! ridge slides inland

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_8.png

 

Looks like the GFS

[Gradient Keeper]

Yep, progessive just like the GFS.... brief cold shot....

[MossMan]

Some interesting tidbits in the Seattle AFD this morning.

 

THE NAM12 AND ECMWF BOTH COOL THE AIR MASS SIGNIFICANTLY BEHIND THE

FRONT LATE TUESDAY NIGHT INTO WEDNESDAY MORNING AS PRECIPITATION

CONTINUES TO FALL BEHIND THE FRONT. SNOW LEVELS FALL TO AROUND 1800

FEET BY WEDNESDAY MORNING. THAT COMBINED WITH MODERATE PRECIPITATION

RATES APPEAR TO CAUSE THE HIGHER TERRAIN SOUTHEAST OF THE

SEATTLE-TACOMA-OLYMPIA METRO AREA...PLACES LIKE OUT TOWARD

ENUMCLAW...ORTING...AND YELM TO GET CLOSE TO THE SNOW LEVEL. AT THIS

TIME BOTH MESO MODELS AND THE ECMWF KEEP SNOW LEVELS JUST HIGH

ENOUGH TO LIMIT ANY ACCUMULATIONS THAT OCCUR TO THE CASCADE ZONES.

THIS WILL NEED TO BE MONITORED. BEHIND THAT FRONT...AN UPPER TROUGH

CROSSES THE AREA LATER CHRISTMAS EVEN AND GIVES SHOWERS IN NWLY FLOW

-ALONG WITH POSSIBLE CONVERGENCE ZONE ACTIVITY ON CHRISTMAS MORNING.

TEMPERATURES ARE MARGINAL...BUT THERE IS A CHANCE THAT SNOW LEVELS

IN HEAVIER SHOWERS AND CONVERGENCE ZONE ACTIVITY...IF IT

OCCURS...COULD RESULT IN SOME SURPRISE SNOWFLAKES FOR CHRISTMAS

MORNING IN PORTIONS OF THE EAST PUGET SOUND LOWLANDS AND AROUND THE

EVERETT AREA. THIS WILL NOT BE SOMETHING TO HOLD YOUR BREATH FOR

THOUGH. ALBRECHT

 

.LONG TERM...THE 12Z GFS BRINGS A WEAK SHORT WAVE TROUGH DOWN FROM

THE NORTHWEST CHRISTMAS NIGHT AND THIS IS FOLLOWED BY A STRONGER

SHORT WAVE TROUGH ON FRIDAY NIGHT. THE FIRST WILL ONLY BRING A

CHANCE OF LIGHT PRECIPITATION...BUT THE SECOND MAY GIVE THE

MOUNTAINS SOME MUCH NEEDED SNOWFALL. BEHIND FRIDAY NIGHTS

TROUGH...THE GFS BUILDS A RIDGE ALONG 140W THAT PROMISES COOL AND

DRY WEATHER FOR LATER IN THE WEEKEND THROUGH NEXT WEEK. THE

OPERATIONAL GFS APPEARS TO BRING COOL AIR IN QUICKLY FROM THE NORTH

WHILE THE PARALLEL RUN IS SLOWER AND STRONGER WITH A POTENTIAL

MODIFIED ARCTIC FRONT. THIS IS DUE TO MUCH STRONGER LOW DEVELOPMENT

NORTH OF HAWAII...A LESS PROGRESSIVE NORTHERN STREAM SHORT WAVE

COMING FROM THE WESTERN BERING SEA...AND BETTER RESOLVED TERRAIN

OVER SOUTH CENTRAL BRITISH COLUMBIA. WILL LIKELY NEED TO MAKE SOME

POP ADJUSTMENTS FOR THE THURSDAY NIGHT TO FRIDAY NIGHT PERIOD FOR

THE LEAD SHORT WAVE FEATURES...THEN DRY THINGS OUT FOR LATER IN THE

WEEKEND. THE CHALLENGE WILL BE TEMPERATURES. WILL NOT MAKE CHANGES

TO THE EXTENDED BEFORE LOOKING AT THE 12Z GEM AND ECMWF. ALBRECHT

 

I love Jay's AFD, always quite in-depth! It is also great when he contributes to the forum!

[Gradient Keeper]

12z JMA also exactly the same as GFS/ECMWF>.. for what its worth

[MossMan]

Looks like the GFS

I have a gut feeling things will trend better for us over the coming days. Usually a theme when we get cold.

[Snow]

[Snow]

I have a gut feeling things will trend better for us over the coming days. Usually a theme when we get cold.

Yeah I'm feeling the same way.

[Gradient Keeper]

I wonder how 12z GFS/GEM/ECMWF Ensembles will fare.....

[Gradient Keeper]

HR 240 Pattern reset?

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_11.png

 

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500a_namer_11.png

[Gradient Keeper]

....El Niño Watch....
Update prepared by:
Climate Prediction Center / NCEP
December 22 2014

ENSO - neutral conditions continue.*
Positive equatorial sea surface temperature (SST) anomalies continue across the Pacific Ocean. There is an approximately 65% chance of El Niño during the Northern Hemisphere winter, which is favored to last into the Northern Hemisphere spring 2015.*

Last weeks SST Departures:
Niño 4: 0.9ºC
Niño 3.4: 0.8ºC
Niño 3: 0.7ºC
Niño 1+2: 0.0ºC

The new latest weekly SST Departures:
Niño 4: 1.0ºC
Niño 3.4: 0.8ºC
Niño 3: 0.8ºC
Niño 1+2: 0.1ºC

Full technical and detailed information can be found here:
http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

 

[Snow]

HR 168 ... crap! ridge slides inland

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_z500_mslp_namer_8.png

Yeah, practically the entire Western US is cold except for us people west of the Cascades.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2014122212/ecmwf_T850_wus_9.png

[MossMan]

Uh....

 

Uh....

?

 

And not a bad morning, 35 for a low with some ice on the windshield!

[Guest Winterdog]

?

 

And not a bad morning, 35 for a low with some ice on the windshield!

Gotta love that ice! Sometimes I am so thrilled with it I don't even scrape it off, I just roll down my window and drive with my head out the side.

[HighlandExperience]

Yeah, practically the entire Western US is cold except for us people west of the Cascades.

 

 

Fake cold is boring.

[Tyler Mode]

HAHA

 

Down here in the banana belt, the low was only 44, which, sadly, is the average high. 

 

No below average high temps since December 5th.

 

Only 3 below average low temps for the entire month.

Gotta love that ice! Sometimes I am so thrilled with it I don't even scrape it off, I just roll down my window and drive with my head out the side.

[Front Ranger]

The latest trend in the models in the mid range is to still tank the EPO, but not the AO. And going back and forth on the PNA (the 0z runs really wanted to tank it, Euro/GEM especially, today not quite as much).

[Front Ranger]

12z GEM ensemble mean is much closer to the GFS/Euro solution...so close, but the ridge is just a little too far east and progressive. Still time for this to improve as we get closer, of course.

 

You don't get a -EPO signal much stronger than this.

 

 

 

 

[MR.SNOWMIZER]

Going to be close to great. No doubt.

[MikeInEverett]

How are snow chances looking for the Seahawks game and the #1 seed on Sunday?

[Gradient Keeper]

12:41 PM IR Loop
http://www.atmos.washington.edu/~ovens/wxloop.cgi?ir_common+12
Believe it or not we can now actually monitor the pattern change now in real-time. Yep. The soon to be massive Kamchatka low is churning away with ridging out ahead of it. I always like it when we can watch things unfold before our eyes on IR/WV Loop and not have to always rely solely on model data for information and initialization. This gives us a pretty decent idea what to look for, how strong the ridge is building/amplifying, and how soon it may be doing so.

 

 

 

[GHweatherChris]

How are snow chances looking for the Seahawks game and the #1 seed on Sunday?

Snow chance=2%

#1 Seed chance=99%

[Parksvillewx]

Todays update.

 

Things look shifted west a bit. Compared to yesterday