Storm could mean 18 to 30 inches of snow in Cascad

Seattle Times:

Storm could mean 18 to 30 inches of snow in Cascades

Posted by Jack Broom

Skiers and folks returning Christmas trips across the Cascade passes could be in for a difficult go Saturday.

Between 18 and 30 inches of snow is forecast in a storm expected to hit Friday night and last through late Saturday night, according to a “winter storm watch” from the National Weather Service.

Meteorologist Chris Burke said the major mountain passes — Snoqualmie and Stevens — would likely be on the lower end of that range, “but still that’s a foot and a half of snow.”

Heavier snow is expected at Mount Baker and Mount Rainier.

Cascade foothill communities such as Marblemount, Darrington and Index are expected to get snow as the snow level drops to 2,500 to 3,000 feet.

The Seattle area also has a chance of snow Saturday night and Sunday, but the snow could be mixed with rain and little or no accumulation is expected.

Lighter mountain snowfall is in the forecast for Sunday. Stevens and Snoqualmie passes both have a 50 percent chance of snow showers on Sunday, with a sunny stretch beginning Monday.

Next week is expected to start cool and dry in the Puget Sound area, with low temperatures dipping into the 20s Monday night and Tuesday night. Normal temperatures for Seattle at this point in December would be a high of 45 and low of 36.

yup, need about ten of these events.

3 Feet of snow at Paradise tomorrow

3 Feet of snow at Paradise tomorrow

Guess the acid test for the new plow crew comes Sunday morning, eh?

3 Feet of snow at Paradise tomorrow

Andy, that NWS forecast is only for 12-20" of new snow ("TOTAL NEW SNOW ACCUMULATIONS 12 TO 20 INCHES"), not 10-16" + 12-20" != 22-36". Don't want anyone to be disappointed when 3 ft fail to appear at Paradise . . . but see the end of this post for a more optimistic forecast.

MOUNT RAINIER RECREATIONAL FORECAST
NATIONAL WEATHER SERVICE SEATTLE WA
420 AM PST FRI DEC 26 2014

SYNOPSIS...THE WEATHER WILL BE MOSTLY DRY THROUGH FRIDAY EXCEPT FOR ISOLATED SHOWERS IN THE MOUNTAINS. A STRONGER AND MORE ORGANIZED SYSTEM WILL MOVE THROUGH WESTERN WASHINGTON SATURDAY AND SATURDAY NIGHT GIVING SIGNIFICANT SNOW TO THE PARK. MODIFIED ARCTIC AIR WILL MOVE SOUTH ACROSS THE AREA SUNDAY NIGHT GIVING COLD AND DRY WEATHER TO THE AREA FOR THE FIRST HALF OF NEXT WEEK.

..WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM PST SUNDAY...

FRIDAY...MOSTLY CLOUDY. A CHANCE OF SNOW SHOWERS IN THE MORNING.
FRIDAY NIGHT...MOSTLY CLOUDY. A CHANCE OF RAIN AND SNOW SHOWERS. SNOW LEVEL NEAR 2500 FEET.
SATURDAY...WINDY. SNOW. SNOW ACCUMULATION OF 10 TO 16 INCHES. SNOW LEVEL NEAR 2500 FEET.
SATURDAY NIGHT...WINDY. SNOW SHOWERS. TOTAL NEW SNOW ACCUMULATIONS 12 TO 20 INCHES.
SUNDAY...CLOUDY WITH A CHANCE OF SNOW SHOWERS.

TEMPERATURE AND WIND FORECASTS FOR SELECTED LOCATIONS.

FRI FRI SAT SAT SUN
NIGHT NIGHT

SUMMIT (14411 FT) 5 7 -3 -11 -11
NW 50 NW 55 W 75 NW 55 NW 25

CAMP MUIR(10188 FT) 17 18 13 8 8
W 30 W 35 W 60 W 40 W 15

PARADISE (5420 FT) 25 23 28 20 25
W 5 W 5 SW 20 W 20 W 5

LONGMIRE (2700 FT) 35 28 32 27 31
CALM CALM SW 10 SW 10 CALM

++ TEMPERATURES AND WIND FOR THE SUMMIT AND CAMP MUIR ARE AVERAGE
CONDITIONS EXPECTED IN THE FREE AIR AT THOSE ELEVATIONS.
++ TEMPERATURES FOR PARADISE AND LONGMIRE ARE THE EXPECTED HIGHS AND
LOWS. WIND IS THE AVERAGE WIND EXPECTED DURING THAT PERIOD.

EXTENDED FORECAST...

SUNDAY NIGHT...MOSTLY CLOUDY WITH A CHANCE OF SNOW SHOWERS.
MONDAY...MOSTLY SUNNY. FREEZING LEVEL NEAR THE SURFACE.
MONDAY NIGHT...MOSTLY CLEAR. FREEZING LEVEL NEAR THE SURFACE.
TUESDAY...SUNNY. FREEZING LEVEL NEAR THE SURFACE.
TUESDAY NIGHT...MOSTLY CLEAR. FREEZING LEVEL NEAR THE SURFACE.
WEDNESDAY...MOSTLY SUNNY. FREEZING LEVEL NEAR 1000 FEET.
WEDNESDAY NIGHT...PARTLY CLOUDY. FREEZING LEVEL NEAR 1500 FEET.
NEW YEARS DAY...MOSTLY SUNNY. FREEZING LEVEL NEAR 7000 FEET.

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The NWS has also downgraded snowfall amounts for the WA Cascades from yesterday afternoon's Winter Storm Watch (18-30") to this morning's Winter Storm Warning (12-20"), as latest model solutions show the heaviest snowfall a bit farther south than previous solutions, with the greatest snowfall totals in the northern and central Oregon Cascades. Yesterday afternoon:

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA

CASCADES OF WHATCOM AND SKAGIT COUNTIES-
CASCADES OF SNOHOMISH AND KING COUNTIES-
CASCADES OF PIERCE AND LEWIS COUNTIES-
INCLUDING THE CITIES OF...MARBLEMOUNT...CONCRETE...SNOQUALMIE PASS...DARRINGTON...INDEX...RANDLE...PACKWOOD...ASHFORD...MORTON
329 PM PST THU DEC 25 2014

...WINTER STORM WATCH IN EFFECT FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT...

THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A WINTER STORM WATCH...WHICH IS IN EFFECT FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT.

* SOME AFFECTED LOCATIONS...MOUNT BAKER...STEVENS PASS...SNOQUALMIE PASS...WHITE PASS...AND MOUNT RAINIER NATIONAL PARK.

* TIMING...SNOW WILL DEVELOP FRIDAY NIGHT AND BECOME HEAVY AT TIMES SATURDAY THROUGH SATURDAY EVENING.

* SNOW ACCUMULATIONS...18 TO 30 INCHES.

* MAIN IMPACT...THERE IS A POTENTIAL FOR SIGNIFICANT SNOW ACCUMULATIONS ON SATURDAY THAT MAY IMPACT TRAVEL THROUGH THE PASSES. CONTINUE TO MONITOR THE LATEST FORECASTS.

* SNOW LEVEL...2500 TO 3000 FEET.


This morning:

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE SEATTLE WA

CASCADES OF WHATCOM AND SKAGIT COUNTIES-
CASCADES OF SNOHOMISH AND KING COUNTIES-
CASCADES OF PIERCE AND LEWIS COUNTIES-
INCLUDING THE CITIES OF...MARBLEMOUNT...CONCRETE...SNOQUALMIE PASS...DARRINGTON...INDEX...RANDLE...PACKWOOD...ASHFORD...MORTON
412 AM PST FRI DEC 26 2014

...WINTER STORM WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM PST SUNDAY...

THE NATIONAL WEATHER SERVICE IN SEATTLE HAS ISSUED A WINTER STORM WARNING FOR HEAVY SNOW...WHICH IS IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM PST SUNDAY. THE WINTER STORM WATCH IS NO LONGER IN EFFECT.

* SOME AFFECTED LOCATIONS...MOUNT BAKER...STEVENS PASS...SNOQUALMIE PASS...WHITE PASS...AND MOUNT RAINIER NATIONAL PARK.

* TIMING...SNOW WILL DEVELOP FRIDAY NIGHT AND BECOME HEAVY AT TIMES SATURDAY INTO SATURDAY NIGHT. THE SNOW WILL TAPER OFF LATE SATURDAY NIGHT.

* SNOW ACCUMULATIONS...12 TO 20 INCHES OF NEW SNOW BY LATE SATURDAY NIGHT.

* MAIN IMPACT...SIGNIFICANT SNOW ACCUMULATIONS ON SATURDAY INTO SATURDAY NIGHT WILL IMPACT TRAVEL THROUGH THE PASSES. CONTINUE TO MONITOR THE LATEST FORECASTS.

* SNOW LEVEL...2000 IN THE NORTH TO 3000 FEET SOUTH OF MOUNT RAINIER.

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This morning's run of the high-resolution UW WRF-GFS model predicts snowfall amounts of 1-3 ft over the Washington Cascades and 1-4 ft over the Oregon Cascades during the 72-hour period from Friday evening through Monday evening:





The maximum amounts of up to 4 ft (marked by white inside yellow) are shown at higher elevations on Mounts Hood and Jefferson:



The zoomed Western Washington graphic does still show amounts of 2-3 ft on Rainier all the way down to Paradise (located where the dark navy blue Pierce-Lewis county line intersects the brown 1600 meter contour line), so there is a good chance that snowfall there will exceed the current NWS forecast of 12-20":