Feb 24-25th Western Canada Winter Storm, Reality: Short Range Options

[bigmt]

This bears watching for interests on the west coast, don't wanna overstep my bounds with topic creation but I don't want to forget them either.

18z NAM @ hour 78:

 nam_namer_078_850_temp_mslp_precip.gif ( 60.46K ) Number of downloads: 0


18z GFS @ hour 75:

 gfs_namer_075_850_temp_mslp_precip.gif ( 60.53K ) Number of downloads: 0


24-hour snowfall @ hour 87:

 CAN_ASNOW24_sfc_087.gif ( 36.21K ) Number of downloads: 1


Images from the Euro, including snowfall maps which are updating from the 12z run finally in my next post.

This post has been edited by bigmt: Feb 23 2012, 11:11 AM

[hcr32]

Thanks bigmt!

[bigmt]

Snowfall maps from the 12z ECMWF.

Hour 72:

 eurosnow72.jpg ( 571.89K ) Number of downloads: 2


Hour 75:

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Hour 78:

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Hour 81:

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Hour 84:

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[bigmt]

HPC snow probability maps for day 3, 4+inches:

 day3_psnow_gt_04.gif ( 18.26K ) Number of downloads: 1


8+ inches:

 day3_psnow_gt_08.gif ( 16.5K ) Number of downloads: 1

[hcr32]

Wow, this is looking more and more like it could turn into something decent for here.

I will definitely keep you guys updated and if it does turn into a decent snowfall I'll get some pictures!

[bigmt]

00z NAM @ hour 69:

 nam_namer_069_850_temp_mslp_precip.gif ( 60.97K ) Number of downloads: 1


24-hour snowfall @ hour 78:

 USA_ASNOW24_sfc_078.gif ( 30.46K ) Number of downloads: 1

[bigmt]

HPC snow probability map, 4+ inches:

 day3_psnow_gt_04.gif ( 19.07K ) Number of downloads: 1


8+ inches:

 day3_psnow_gt_08.gif ( 16.91K ) Number of downloads: 1


HPC Winter Weather Discussion:

...PACIFIC NORTHWEST...
CONSENSUS APPROACH FOR FRIDAY AS DEEP AND INTENSE SURFACE WAVE
TRACKS EASTWARD INTO SOUTHERN BC AND THE PACIFIC NORTHWEST.
DEEP-LAYERED FRONTOGENESIS RESULTS FROM A BROAD LOW-LEVEL WARM
FRONT MIGRATING WEST TO EAST FROM THE CANADIAN BORDER INTO
PORTIONS OF SOUTHERN OREGON...ATOP A COLD AIRMASS IN PLACE
ALONG/EAST OF THE CASCADE SPINE. THE SYSTEM IS QUICKLY FOLLOWED BY
A RATHER DEEP AND UNSTABLE MARITIME AIRMASS AND PRONOUNCED COLD
FRONT THAT SURGES AS FAR SOUTH AS NORTHERN CALIFORNIA AND IS WELL
EAST OF THE 115W LONGITUDE BY SATURDAY MORNING. HIGHER SNOWFALL
AMOUNTS ARE PROGGED NEAREST THE PRIMARY SURFACE LOW MOVING THROUGH
PUGET SOUND AND OLYMPICS...WITH SNOW LEVELS PLUNGING TO NEAR SEA
LEVEL. ACROSS OREGON AND NORTHERN CALIFORNIA...ALONG THE LEADING
EDGE AND TAIL END OF THE FRONT RESPECTIVELY...SNOW LEVELS FALL TO
1000-1500FT MSL ALONG THE COASTAL RANGES AND VALLEY FLOORS INLAND.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.
VOJTESAK

[bigmt]

06z GFS @ hour 63:

 gfs_namer_063_850_temp_mslp_precip.gif ( 61.99K ) Number of downloads: 0


24-hour snowfall @ hour 69:

 USA_ASNOW24_sfc_069.gif ( 28.46K ) Number of downloads: 0


00z ECMWF @ hour 72:

 00zeuro850mbTSLPNA072.gif ( 76.41K ) Number of downloads: 0


Snowfall @ hour 63:

 eurosnow63.jpg ( 464.92K ) Number of downloads: 1


Hour 66:

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Hour 69:

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[bigmt]

12z GFS @ hour 60:

 gfs_namer_060_850_temp_mslp_precip.gif ( 60.84K ) Number of downloads: 0


24-hour snowfall @ hour 66:

 USA_ASNOW24_sfc_066.gif ( 28.35K ) Number of downloads: 1

[bigmt]

12z ECMWF @ hour 48:

 12zeuro850mbTSLPNA048.gif ( 75.84K ) Number of downloads: 1


Snowfall @ hour 48:

 eurosnow48.jpg ( 465.43K ) Number of downloads: 1


Hour 51:

 eurosnow51.jpg ( 463.96K ) Number of downloads: 1


Hour 54:

 eurosnow54.jpg ( 465.37K ) Number of downloads: 2


Hour 57:

 eurosnow57.jpg ( 467.63K ) Number of downloads: 1

[hcr32]

Thanks again for the updates bigmt!

[bigmt]

Thanks again for the updates bigmt!

I wouldn't forget about you guys out there

Brett has something too in his blog.

http://www.accuweather.com/en/weather-blog...-the-west/61917

Western Cold

Two to three day shot of very cold air coming into western Canada starting this weekend then a brief recovery before a longer duration period of cold weather sets up across Alaska and a large part of western Canada through the first 10 days of March.

In addition to the cold, a storm will spread anywhere from 5-15 cm of snow from southern/central Alberta to southern Saskatchewan Saturday and Saturday evening.

By the time it gets cold enough for snow in Vancouver, BC Saturday night and Sunday the bulk of the moisture will have already shifted to the south and east, but during this period there will likely be some snow showers.

[hcr32]

So Im guessing Brett thinks it'll be mostly a rain event here..

[bigmt]

So Im guessing Brett thinks it'll be mostly a rain event here..

You'll have to let us know what happens, along with the other posters from the area.

There's a big question mark about whether this is the beginning of a longer-term cold pattern for the west or if it's temporary as was the cold spell in January, since this will have broad implications if the east coast is going to be warm. Many of the analog years we've looked at in the spring thread are weighted towards a cooler spring for the west and this could be a preview of that setup perhaps, although this is anything but certain.

I'll be continuing to look at possibilities in the spring thread.

[hcr32]

Snow Probability Maps:

4"+


8"+


And just for fun, 12"+

[bigmt]

00z NAM @ hour 48:

 nam_namer_048_850_temp_mslp_precip.gif ( 59.27K ) Number of downloads: 0


24-hour snowfall @ hour 51:

 USA_ASNOW24_sfc_051.gif ( 30.14K ) Number of downloads: 4

[bigmt]

06z NAM @ hour 39:

 nam_namer_039_850_temp_mslp_precip.gif ( 59.1K ) Number of downloads: 0


Precip type:

 USA_PTYPE_sfc_039.gif ( 17.7K ) Number of downloads: 1


24-hour snowfall @ hour 48:

 USA_ASNOW24_sfc_048.gif ( 30.43K ) Number of downloads: 0


HPC snow probability maps, day 2 4+ inches:

 day2_psnow_gt_04.gif ( 19.06K ) Number of downloads: 1


Day 2, 8+ inches:

 day2_psnow_gt_08.gif ( 17.13K ) Number of downloads: 1

[bigmt]

SWS from EC.

http://www.weatheroffice.gc.ca/warnings/SW..._e.html?prov=bc

WOCN11 CWVR 231247
Special weather statement
Issued by Environment Canada
At 4:47 AM PST Thursday 23 February 2012.
---------------------------------------------------------------------
Special weather statement for:
=new= Metro Vancouver
=new= Fraser Valley
=new= Sunshine Coast
=new= East Vancouver Island
=new= Inland Vancouver Island.

Highly variable snowfall accumulations across the south coast
Thursday night and Friday...

---------------------------------------------------------------------
==discussion==
A Pacific low pressure system will approach the BC coast Thursday
evening. Moisture from the low mixed with cold air over the south
coast will produce a mixture of snow and rain across the region.

Precipitation is expected to begin over Vancouver Island and the
Sunshine Coast late Thursday evening then spread to Metro Vancouver
before Friday morning. In this weather pattern with temperatures near
or just above freezing, variability in snowfall accumulations due to
local effects is to be expected.

The freezing level is forecast to remain at or below 400 metres
through Friday morning. Snowfall accumulations will be somewhat
elevation dependent but snow is also possible at sea level. Also, at
higher elevations local snowfall accumulations in the range of 5
centimetres are possible. There is enough moisture with this low to
produce locally higher accumulations perhaps as high as 10
centimetres.

At present snowfall warnings have not been issued. However, slight
increases in expected accumulations may prompt snowfall warnings for
some regions. The precipitation may change to rain before Friday
afternoon as slightly warmer air moves in from the coast.


The public is advised to monitor future forecasts and warnings as
warnings may be required or extended.

Please monitor the latest forecasts and warnings from Environment
Canada at www.weatheroffice.gc.ca


End

[bigmt]

12z ECMWF @ hour 24:

 12zeuro850mbTSLPNA024.gif ( 76.37K ) Number of downloads: 0


Snowfall @ hour 27:

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Hour 30:

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Hour 33:

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[bigmt]

15z HRRR precip type @ hour 11:

 ptyp_t1sfc_f11.png ( 79K ) Number of downloads: 1