Western/Central Region Early December Arctic Outbreak

[Srain]

The guidance has converged on a significant Arctic Outbreak and a strong Winter Storm will drop SE from British Colombia into the Pacific NW, Northern/Central Rockies and the Northern/Central Plains lending to a multi day significant snow event  that will spread across the Western and Central Region during the first week of December. The 00Z ensembles and operational guidance suggest that as the week progresses, bitter cold Arctic air will settle across our Region and bring the potential of a multi day Winter Weather Outbreak that will extend very far S into the Southern Plains and possibly into Northern Mexico. By late in the upcoming week the trends suggest that freezing rain/sleet/snow will spread much further South into Texas, Oklahoma, Kansas, Missouri, Northern Louisiana an Arkansas. Temperature departures should range in the -20 to -30 F range with overnight lows approaching the -30 F range across the Northern/Central Rockies extending East into the Northern Plains. There are increasing odds that a widespread societal impact event could develop that will extend into the upcoming weekend very far S into Texas as several short waves drop S into the base of the trough and reinforce the very cold air and connect with a noisy sub tropical jet that may provide for freezing rain, sleet and snow as an over running pattern develops late Thursday into next Sunday.

[baroclinic_instability]

Blizzard in Nodak, ice storm across portions of the S. The setup us about as good as it gets with two energetic waves. The strong and shallow arctic front is not all that atypical, but the UA pattern is impressive. 

[baroclinic_instability]

Cold air originating from AK...this whole pattern has been one helluva impressive outflow gap wind pattern for us with high wind warnings for Valdez and Whittier...with a well entrenched 1040+ high over the Copper River Basin...and hurricane force gap winds across the coastal range. Thompson Pass earlier hit 84 MPH.

 

 

[prinsburg_wx]

URGENT - WINTER WEATHER MESSAGE

NATIONAL WEATHER SERVICE BISMARCK ND

809 AM CST SUN DEC 1 2013

...WINTER STORM WATCH FOR WEST AND CENTRAL NORTH DAKOTA MONDAY

NIGHT THROUGH WEDNESDAY AFTERNOON...

.LIGHT FREEZING RAIN WILL CREATE DANGEROUS TRAVEL CONDITIONS

ACROSS NORTHWEST NORTH DAKOTA THIS MORNING. CONDITIONS WILL

GRADUALLY IMPROVE AS AIR AND ROAD SURFACE TEMPERATURES WARM LATER

THIS MORNING.

STRONG LOW PRESSURE APPROACHING NORTH DAKOTA HAS THE POTENTIAL TO

CAUSE SIGNIFICANT IMPACTS MONDAY NIGHT THROUGH WEDNESDAY

AFTERNOON. UNCERTAINTY REMAINS WITH THE EXACT TRACK AND TIMING...

BUT THERE IS GROWING CONFIDENCE THAT MORE THAN 6 INCHES OF SNOW

AND WIDESPREAD BLOWING SNOW WILL OCCUR ACROSS MUCH OF WESTERN AND

CENTRAL NORTH DAKOTA.

DANGEROUSLY COLD ARCTIC AIR WILL MOVE INTO NORTH DAKOTA

WEDNESDAY...AND REMAIN OVER THE REGION THROUGH THE WEEKEND.

[Srain]

 

 

 

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
415 AM EST SUN DEC 01 2013

VALID 12Z SUN DEC 01 2013 - 12Z WED DEC 04 2013


DAYS 1 TO 3 ...

...PACIFIC NORTHWEST/NORTHERN TO CENTRAL ROCKIES/NORTHERN
PLAINS/UPPER MIDWEST...

HEAVY SNOWS ARE LIKELY ON DAY 1 FOR THE HIGHER ELEVATIONS OF THE
PACIFIC NORTHWEST/NORTHERN ROCKIES AS A 130-150 KT 300 MB JET
STREAMS ONSHORE INTO WA STATE FROM THE NORTHEAST PACIFIC
WITH THE JET DRIFTING SOUTH ACROSS WA/ID/WESTERN MT AND THEN INTO
NORTHWEST WY.

THE HEAVIEST SNOWS ON DAY 1...ARE EXPECTED TO FOCUS MAINLY ALONG
THE NORTHERN CASCADES
WHERE STRONG DIVERGENCE ALONG THE LEFT EXIT REGION OF THE JET
ALONG WITH OROGRAPHIC LIFT INTERACTS WITH A DEEP MOISTURE PLUME
CARRIED BY A LONG WESTERLY FETCH INTO THE REGION...TO ENHANCE THE
HEAVY SNOW THREAT OF 1-2 FEET ACROSS THE REGION.

BY DAY 2...MON...AS THE JET DRIFTS SOUTH ACROSS OR AND INTO
SOUTHERN ID AND WESTERN WY...THE WESTERLY STREAM OF MOISTURE AND
UPSLOPE FLOW ON TERRAIN FACING THE FLOW
PRODUCES A RISK FOR A FOOT OR SNOW IS INDICATED ALONG MUCH OF THE
OR CASCADES AND ALONG THE ROCKIES FROM NORTHERN ID/WESTERN MT INTO
NORTHWEST WY/NORTHERN UT WASATCH.

A SECOND AREA OF SNOW BREAKS OUT IN ADVANCE OF THE IN A REGION OF
LOW-MID LEVEL CONVERGENCE/UPPER DIVERGENCE NEAR THE 700 MB FRONT
ACROSS NORTHERN ND AND MN. SUBSTANTIAL TIMING DIFFERENCES DEVELOP
WITH THE GFS STILL ON THE FAST EDGE OF THE SUITE OF SOLUTIONS.

BY DAY 3...THE FLOW SPLITS WITH A PRIMARY NORTHERN CIRCULATION
REDEVELOPING WITH A TRAILING WAVY FRONT MOVING SOUTH ACROSS THE
GREAT BASIN AND CENTRAL ROCKIES.
THE TIMING AND INTENSITY DIFFERENCES CONTINUE ACROSS THE NORTHERN
PLAINS/UPPER MS VALLEY/UPPER GREAT LAKES.  THE ECMWF SPED UP ITS
FORWARD PROGRESSION OF THE 700 MB LOW ACROSS EASTERN MT AND ND TO
BE CLOSER TO THE UKMET AND CANADIAN GLOBAL TIMING...WITH THE
NAM/GFS AND THEIR RESPECTIVE GEFS/SREF MEANS STILL AHEAD OF THIS
CLUSTER.   STRONG CONVERGENCE NEAR THE 700 MB FRONT/CIRCULATION
DRIVES SNOW ACROSS CENTRAL UT TO NORTHERN CO...WITH THE 00Z ECMWF
DEVELOPING 130 KT JET MAXIMA AND ASSOCIATED DIVERGENCE MAXIMA OVER
THE UT WASATCH TO THE RANGES OF NORTHERN CO/ADJACENT SNOW RANGE OF
SOUTHEAST WY.  WITH THE FASTER TREND IN SINKING THE FRONT SOUTH
SHARED AMONG THE 00Z ECMWF/UKMET/CANADIAN...THESE SOLUTIONS WERE
GIVEN EQUAL WEIGHTING IN THE FORECAST. 
 

[OKpowdah]

The divergent wave activity vectors over the central Pacific are associated with wavebreaking. In this case there is cyclonic wave breaking over the central Pacific which is the beginning of the new wave train across North America and the pattern change this week.

 

[Mallow]

Not a great pattern for big snow in the big Pac NW cities, but there may be some snow showers when the cold air arrives. Looks to be quite chilly with a reinforcing shot from a secondary shortwave swinging southward. Euro is very cold for Portland/Seattle, GFS just chilly (keeps the coldest air bottled up east of the Cascades). NAM is frigid, but the NAM can almost always be discounted out there when it's unsupported by the global models.

 

Also of note that the Euro does send a small low through Oregon while the very cold longwave trough is still in place. At face value, that would give Portland a couple inches of snow. Of course, the GFS doesn't agree... there's lots of time for things to change around.

 

It will be interesting to see how the cold eventually breaks out there. As long as there's no big storm to move in, the low-level cold should stay trapped east of the Cascades. Usually when a storm does eventually move in, Portland (or at least the eastern suburbs) will start as snow or ice as the cold air is drawn through the Gorge.

[Chinook]

Interesting temp and wind profile under this 155 knot jet, in the Pacific Ocean, west of Vancouver Island

 

[1900hurricane]

Interesting temp and wind profile under this 155 knot jet, in the Pacific Ocean, west of Vancouver Island

 

Pac_ocean_RAP_255_2013120121_F00_49.5000N_132.0000W.png

That's right where that jet streak is crashing in.

 

[MCS_hunter]

GFS is projecting a foot of snow in northern MN.  Hopefully I see a couple of inches.  I'm so excited!

[OKpowdah]

Interesting temp and wind profile under this 155 knot jet, in the Pacific Ocean, west of Vancouver Island

 

Pac_ocean_RAP_255_2013120121_F00_49.5000N_132.0000W.png

 

Beautiful topopause fold!

[1900hurricane]

The fold is just as vivid in the actual 12Z sounding out of far NW Washington.

 

[Mallow]

Latest Euro is very interesting for Portland and Seattle. Keeps the cold coming down in shots, and the storm that brings the cold shot over the weekend brings several inches of snow to everyone west of the Cascades.

[Srain]

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
337 PM EST MON DEC 02 2013

VALID 00Z TUE DEC 03 2013 - 00Z FRI DEC 06 2013

DAYS 1 TO 3...

...WESTERN U.S...

A DEEP UPPER TROUGH WILL BE EVOLVING OVER THE WESTERN U.S. OVER
THE NEXT SEVERAL DAYS IN RESPONSE TO A STRONG MEAN LAYER RIDGE
DEVELOPING OFF THE WEST COAST OF NORTH AMERICA AND ESPECIALLY THE
GULF OF ALASKA. JET ENERGY AT 250 MB TO THE TUNE OF 130 TO 150 KTS
ALREADY ROUNDING THE BASE OF THE UPPER TROUGH OVER THE
INTERMOUNTAIN WEST AND CROSSING THE ROCKIES WILL BE REINFORCED
TUESDAY AND WEDNESDAY BY ADDITIONAL UPSTREAM ENERGY DIVING SOUTH
DOWN THE BRITISH COLUMBIA COAST...TO TO TUNE OF 110 TO 130 KTS.
THE RESULT WILL BE A STRONG LONGWAVE TROUGH BY THURSDAY OVER THE
WESTERN U.S....WITH AN INTRUSION OF ARCTIC AIR FROM WESTERN CANADA
THAT SHOULD PENETRATE SOUTH THROUGHOUT THE INTERMOUNTAIN WEST
WHILE ALSO SPILLING WELL EAST OF THE CONTINENTAL DIVIDE.

WIDESPREAD HEAVY SNOWFALL IS EXPECTED OVER PORTIONS OF THE GREAT
BASIN AND INTO THE CENTRAL AND NORTHERN ROCKIES WITH THE STRONG
HEIGHT FALLS AND INFLUX OF DEEP PACIFIC MOISTURE INITIALLY ALONG
THE MAIN FRONTAL BAND SETTLING SOUTH THROUGH THE WEST...BUT ALSO
IN A POST-FRONTAL FASHION WITH ADDITIONAL MOIST LOW TO MID LEVEL
UPSLOPE FLOW. CRASHING SNOW LEVELS ALONG AND BEHIND THE FRONTAL
BAND WILL FOSTER HEAVY SNOW SHOWERS FROM ESPECIALLY AREAS OF
EASTERN NV...INTO THE WASATCH OF UT AND EXTENDING FROM THE CO HIGH
COUNTRY WELL NORTH INTO THE TETONS AND BIG HORNS INCLUDING
ADJACENT VALLEY FLOORS. HOWEVER...A MORE ORGANIZED HEAVY SNOWFALL
THREAT SHOULD EVOLVE TUESDAY NIGHT THROUGH WEDNESDAY ESPECIALLY
FROM PORTIONS OF FAR EASTERN NV AND UT...EAST INTO MUCH OF CENTRAL
AND NORTHERN CO AND SOUTHERN WY...AS THE LARGER SCALE UPPER TROUGH
AMPLIFIES OVER THE REGION. MUCH OF THIS AREA IS PROGGED TO BE
UNDERNEATH FAVORABLE 250 MB RIGHT-ENTRANCE REGION JET DYNAMICS.
THIS COUPLED WITH A DEEPENING AND STRENGTHENING AXIS OF
FRONTOGENETICAL FORCING AND VERY MOIST UPSLOPE FLOW WILL FAVOR
ORGANIZED AND HEAVY SNOWFALL...WITH LOCALLY VERY INTENSE SNOWFALL
RATES FOR THE HIGHER RIDGE LINES AND ADJACENT PASSES. THE UPPER
TROUGH AXIS SHOULD TEND TO SHIFT EAST ON THURSDAY...BUT ADDITIONAL
ACCUMULATING SNOW WILL OCCUR WEDNESDAY NIGHT THROUGH THURSDAY FOR
THE UPSLOPE AREAS...WITH A FOCUS THIS PERIOD ON PARTS OF NORTHERN
AZ/EASTERN UT AND INTO MUCH OF CO. STORM TOTAL AMOUNTS ACROSS THE
HIGH COUNTRY WILL BE QUITE HIGH...WITH 1 FOOT AMOUNTS LIKELY FOR
THE TETONS/BIG HORNS...AND 1 TO 2 FEET IN THE WASATCH/UINTA RANGE.
HOWEVER...LOCALLY 2 TO 4 FEET OF SNOW IS EXPECTED SPECIFICALLY
ACROSS PORTIONS OF FAR SOUTHERN WY/NORTHWEST CO IMPACTING THE
SNOWY PEAK AND MEDICINE BOW RANGES AND ADJACENT SLOPES.


...HIGH PLAINS TO THE UPPER MIDWEST/UPPER GREAT LAKES...

A PORTION OF THE UPPER TROUGH CURRENTLY DIGGING ACROSS THE PACIFIC
NORTHWEST WILL EJECT EASTWARD ACROSS THE NORTHERN PLAINS AND THE
UPPER MIDWEST TUESDAY AND WEDNESDAY BEFORE THEN LIFTING NORTHEAST
INTO SOUTHERN ONTARIO ON THURSDAY. THERE HAVE BEEN SERIOUS MODEL
DISAGREEMENTS OVER THE LAST COUPLE OF DAYS WITH THE HANDLING OF
THIS ENERGY AS IT CROSSES THE REGION...WITH A SPLIT AMONG THE NCEP
AND NON-NCEP MODELS. THE NCEP MODELS AS PER THE NAM AND GFS INSIST
ON A FASTER AND MORE AMPLIFIED/AGGRESSIVE SOLUTION WITH THE
INITIAL HEIGHT FALLS AND ASSOCIATED DEVELOPING SURFACE LOW
PRESSURE. THE NON-NCEP MODELS AS PER THE UKMET/GEM GLOBAL AND
ECMWF HAVE BEEN CONSISTENT IN A WEAKER AND MORE SHEARED OUT SYSTEM
ACROSS THE REGION...AND WITH SLOWER DEVELOPMENT OF SURFACE LOW
PRESSURE. THIS IS DRIVING SIGNIFICANT WINTER WEATHER PARAMETER
DIFFERENCES WITH RESPECT TO SNOWFALL AMOUNTS AND TIMING...NOT TO
MENTION THE PROSPECTS OF A NARROW TRANSITION LINE OF SLEET AND
FREEZING RAIN. WPC WILL BE PREFERRING A NON-NCEP MODEL CONSENSUS
WEIGHTED TOWARD THE ECMWF...AND THUS PREFERRING THE DETAILS OF A
RELATIVELY MORE SHEARED/FLATTER WAVE IMPACTING THE CENTRAL AND
NORTHERN PLAINS OVER TO THE UPPER MIDWEST AND UPPER GREAT LAKES
REGION TUESDAY THROUGH THURSDAY.

NEVERTHELESS...A RATHER HIGH IMPACT WINTER STORM WILL AFFECT THE
REGION...WITH A SWATH OF HEAVY SNOWFALL EXPECTED TO BE IMPACTING
THE CENTRAL AND NORTHERN HIGH PLAINS/FRONT RANGE AND WITH TIME
ADVANCING INTO THE UPPER MIDWEST. A SIGNIFICANT SURGE OF ARCTIC
AIR DIVING SOUTH ACROSS THE HIGH PLAINS WILL FAVOR ENHANCED
UPSLOPE SNOWFALL ACROSS THE HIGH PLAINS AND FRONT RANGE...WHICH IS
EXPECTED TO BE AIDED BY THE STRONG HEIGHT FALLS/UPPER LEVEL JET
DYNAMICS AND MOIST MID LEVEL ALOFT AIR OVERRUNNING THE RELATIVELY
SHALLOW ARCTIC AIR. THIS ARCTIC AIR WILL SURGE ALL THE WAY DOWN
THROUGH THE SOUTHERN HIGH PLAINS BY WEDNESDAY AND SO THE THREAT
FOR UPSLOPE SNOWFALL WILL INCREASE IN POST-FRONTAL FASHION BEFORE
EVENTUALLY DRY AIR ARRIVES AND TAPERS THE SNOW OFF. LOCALIZED
SNOWFALL AMOUNTS OF 6 TO 12 INCHES CAN BE EXPECTED...AT LEAST
LOCALLY.

ON THE SYNOPTIC SCALE FARTHER EAST...A STRIPE OF LIGHT TO MODERATE
SNOW SHOULD STREAK NORTHEAST OUT ACROSS THE CENTRAL AND NORTHERN
PLAINS AND THEN BECOME MORE CONCENTRATED AND FOCUSED OVER THE
UPPER MIDWEST TUESDAY AND WEDNESDAY. INCREASING ISENTROPIC LIFT
AND DEEPER LAYER FRONTOGENESIS AIDED BY THE DEVELOPMENT OF A WEAK
JET COUPLET BY TUESDAY NIGHT SHOULD FOSTER MULTIPLE BANDS OF
LOCALLY HEAVY SNOW FOR PARTS OF CENTRAL AND NORTHERN MN/NORTHWEST
WI AND THE U.P. OF MI. BY WEDNESDAY...LOW PRESSURE THOUGH WILL BE
DEVELOPING OVER THE MIDWEST...AND THIS SAME CORRIDOR SHOULD SEE AN
AXIS OF MORE PERSISTENT HEAVY SNOWFALL AS AIDED STRONGLY BY
ENHANCING 250 MB LEFT-EXIT REGION JET DYNAMICS...AND STRONG DEEP
LAYER FRONTOGENESIS WITHIN A DEVELOPING COMMA-HEAD. THIS WILL
CONTINUE THROUGH WEDNESDAY NIGHT. LOW PRESSURE WILL EXIT THE
REGION ON THURSDAY...BUT ADDITIONAL DEFORMATION ZONE/WRAP-AROUND
MOISTURE/FORCING WILL PROMOTE ADDITIONAL LIGHT ACCUMULATIONS.
STORM TOTAL SNOWFALL AMOUNTS OF 1 TO 2 FEET ARE EXPECTED FOR
PORTIONS OF THE UPPER MIDWEST.


...SOUTHERN PLAINS INTO THE LOWER/MIDDLE MISSISSIPPI VALLEY AND
LOWER OHIO VALLEY...

AN ARCTIC COLD FRONT WILL BE CROSSING THE REGION LATE WEDNESDAY
NIGHT AND THURSDAY IN THE WAKE OF DEPARTING LOW PRESSURE OVER THE
GREAT LAKES REGION...AND WITH SIGNIFICANT ARCTIC HIGH PRESSURE
DIVING SOUTHEAST ACROSS THE PLAINS AND MIDWEST. THE MODELS
INDICATE THE AXIS OF A DEEP LONGWAVE TROUGH STILL FOCUSED UPSTREAM
OVER THE CENTRAL AND SOUTHERN ROCKIES IN THE MEANTIME...WITH
EMBEDDED SHORTWAVE ENERGY EJECTING OUT OF THE BASE OF THE TROUGH
WITHIN STRONG MID/UPPER LEVEL SOUTHWESTERLY FLOW. THIS FLOW SHOULD
OVERRUN THE SHALLOW ARCTIC AIRMASS...AND WITH THE APPROACH OF THE
LONGWAVE TROUGH AXIS AND STRONGER FORCING ALOFT...MOISTURE AND
DEEPER LAYER ASCENT WILL FOCUS ALONG AND BEHIND THE ARCTIC
BOUNDARY. THIS IS A RATHER CLASSIC SET-UP FOR A SIGNIFICANT ICE
STORM. THE FOCUS RIGHT NOW APPEARS TO BE ALONG AN AXIS FROM NEAR
THE RED RIVER VALLEY NORTHEAST UP ACROSS EASTERN OK...THE
NORTHWEST THIRD OF AR...AND INTO SOUTHEAST MO AND SOUTHERN IL.
THERMAL PROFILES SUPPORT A VERY SHALLOW SUB-FREEZING AIRMASS AND A
GREAT SET-UP UP FOR SIGNIFICANT FREEZING RAIN... ESPECIALLY OVER
NORTHWEST AR. A LITTLE FARTHER NORTH...ESPECIALLY ACROSS NORTHEAST
OK INTO SOUTHERN MO...THE COLD AIR WILL BE DEEPER AND THERE WILL
BE A THREAT FOR MUCH MORE SLEET AND ALSO ACCUMULATING SNOWFALL.
THE BEST POTENTIAL FOR HEAVY SNOWFALL SHOULD BE ACROSS
SOUTH-CENTRAL AREAS OF MO WHERE AT LEAST SEVERAL INCHES WILL BE
POSSIBLE.

ORRISON
 

[1900hurricane]

A few of the recent model runs are beginning to get pretty aggressive with icing again. Could be a high-impact event coming up, but I'm hesitant to jump aboard just yet considering what happened two weeks ago.

[DFWWeather]

Much of Texas to take a direct discharge of Arctic air Monday. Full blown McFarland signature to 500mb pattern. Perhaps the coldest air in nearly 20 years at DFW. Lows next Wednesday morning could be in the single digits. Both ECWMF and GFS are showing just that. GFS had 15 below zero in parts of central Oklahoma.

[beavis1729]

Incredible cold in WY tonight.  Cheyenne may hit -20 with wind chills to -40, and Laramie hay hit -30.  

 

Earlier today, Laramie had Heavy Snow with a temp of -5 and NW winds at 18 mph.

[ice1972]

Latest Euro is very interesting for Portland and Seattle. Keeps the cold coming down in shots, and the storm that brings the cold shot over the weekend brings several inches of snow to everyone west of the Cascades.

 

Is this the same system showing up on the NAM and GFS with snow to the valley floor in Sacramento and the hills of the Bay Area?  Cold out there this early December.....

[Mallow]

Is this the same system showing up on the NAM and GFS with snow to the valley floor in Sacramento and the hills of the Bay Area?  Cold out there this early December.....

 

Yes. Sliding in further south now so Portland and Seattle stay dry.

[tacoman25]

Hit -13 earlier this evening at DEN. That's the coldest it's ever gotten before Dec 5. Previous record was -8.

[Srain]

STORM SUMMARY NUMBER 03 FOR SOUTHERN PLAINS TO OHIO VALLEY WINTER
STORM
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
900 AM CST FRI DEC 06 2013

...MAJOR ICE STORM ALONG WITH SLEET AND SNOW IS UNFOLDING OVER A
WIDE AREA FROM THE SOUTHERN PLAINS TO THE OHIO VALLEY... 

ICE STORM WARNINGS AND FREEZING RAIN ADVISORIES ARE IN EFFECT FROM
EXTREME EASTERN OKLAHOMA TO WEST TENNESSEE.

WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES ARE IN EFFECT
FOR A LARGE AREA FROM WEST AND CENTRAL TEXAS NORTHEASTWARD TO
SOUTHWESTERN NEW YORK STATE.

FOR A DETAILED GRAPHICAL DEPICTION OF THE LATEST WATCHES...
WARNINGS AND ADVISORIES... PLEASE SEE WWW.WEATHER.GOV

AT 800 AM CST... AN ARCTIC COLD FRONT EXTENDED FROM JUST OFF THE
NEW ENGLAND COAST SOUTHWESTWARD TO THE LOUISIANA GULF COAST AND
WAS MOVING SLOWLY EASTWARD. AHEAD OF THE FRONT... A WARM AND MOIST
AIR MASS WAS IN PLACE WITH SPRING-LIKE TEMPERATURES ACROSS THE
SOUTHEAST AND EASTERN MID-ATLANTIC REGIONS. BEHIND THE FRONT... A
FRIGID ARCTIC AIR MASS WAS MOVING IN WITH TEMPERATURES QUICKLY
DROPPING BELOW FREEZING IN MANY AREAS. WARM MOIST AIR FROM THE
GULF OF MEXICO OVERRUNNING THE COLD FRONT WAS RESULTING IN THE
DEVELOPMENT OF WIDESPREAD PRECIPITATION GENERALLY WEST OF THE
FRONTAL BOUNDARY. NATIONAL WEATHER SERVICE RADARS AND SURFACE
OBSERVATIONS INDICATED LIGHT TO MODERATE SNOW FALLING IN A BAND
FROM EASTERN OKLAHOMA TO CENTRAL OHIO. SOUTHEAST OF THE SNOW... A
MIXTURE OF SLEET AND FREEZING RAIN WAS OCCURRING FROM CENTRAL
TEXAS NORTHEASTWARD TO SOUTHERN INDIANA. SOUTHEAST OF THIS AREA...
AN AREA OF LIGHT TO MODERATE RAIN... WAS FALLING FROM EAST TEXAS
TO THE CENTRAL APPALACHIANS.

...SELECTED STORM TOTAL SNOWFALL IN INCHES FROM 500 AM CST THU DEC
05 THROUGH 800 AM CST FRI DEC 06...

...ARKANSAS...
BENTONVILLE                           7.0                   
BEAVER                                6.5                   
CENTERTON                             6.5                   
BELLA VISTA                           6.0                   
PEA RIDGE 1 W                         6.0                   
GAMALIEL 2.2 SSW                      5.5                   
FAYETTEVILLE                          5.0                   
CALICO ROCK 6.1 WNW                   4.0                   
MOUNTAIN HOME 5.8 NE                  4.0                   
SILOAM SPRINGS                        4.0                   

...ILLINOIS...
MOUNT VERNON                         10.0                   
SUNFIELD                             10.0                   
CHESTER 2 SSE                         9.5                   
OLNEY                                 9.0                   
CLAY CITY                             7.5                   
FAIRFIELD                             7.5                   
MARISSA                               7.5                   
CHESTER                               7.0                   
DU QUOIN                              7.0                   
FLORA                                 7.0                   
RUMA                                  6.2                   
ALBION                                6.0                   

...INDIANA...
SPENCER 7.0 S                         6.2                   
GREENCASTLE 3.6 ESE                   5.5                   
BROOKLYN 0.5 ENE                      5.0                   
GOSPORT 4.0 WSW                       5.0                   
JASONVILLE 4.0 ENE                    4.8                   
INDIANAPOLIS 8.7 S                    4.3                   
MOORESVILLE 6.1 SSE                   4.2                   
BROWNSBURG 4.6 S                      4.0                   
INDIANAPOLIS INTL ARPT                3.5                   
LAWRENCE                              3.1                   

...MISSOURI...
FREDERICKTOWN                         9.0                   
CASSVILLE 4.8 SSE                     8.3                   
PERRYVILLE                            8.3                   
FARMINGTON                            8.0                   
LEADWOOD                              8.0                   
ROUND SPRING 2 NW                     8.0                   
SUMMERSVILLE 3 S                      8.0                   
LESTERVILLE                           7.5                   
AVA                                   7.0                   
VAN BUREN                             6.7                   
CENTERVILLE                           6.0                   
CLEVER 4.0 ENE                        6.0                   

...OHIO...
CONNEAUT I-90                         3.0                   

...OKLAHOMA...
BETHANY 0.7 SSW                       5.0                   
FORT COBB 0.4 NNW                     5.0                   
JAY 3.3 NNE                           5.0                   
OKEMAH                                5.0                   
OKMULGEE                              5.0                   
BRISTOW                               4.0                   
CHECOTAH                              4.0                   
KEEFETON                              4.0                   
MIDWEST CITY 1.6 NNW                  4.0                   
JENKS 4.5 ENE                         3.8                   
TULSA                                 3.7                   

...SELECTED STORM TOTAL SLEET IN INCHES FROM 500 AM CST THU DEC 05
THROUGH 800 AM CST FRI DEC 06...

...ARKANSAS...
JOHNSON 3 SW                          3.00                   
HARRISON                              2.00                   
HUNTSVILLE 4 S                        0.75                   
SAINT PAUL                            0.75                   
BENTONVILLE 1 SSW                     0.50                   
FORT SMITH                            0.50                   
POCAHONTAS                            0.33                   
LESLIE 11 SW                          0.30                   

...ILLINOIS...
COBDEN                                1.50                   
CARBONDALE                            0.75                   
MOUNT VERNON                          0.75                   
CLAY CITY 4 SE                        0.40                   

...INDIANA...
MORRISTOWN                            2.00                   
EVANSVILLE                            0.20                   

...KENTUCKY...
HENDERSON                             0.70                   

...MISSOURI...
WHITE CHURCH                          1.50                   
POPLAR BLUFF                          1.00                   
TECUMSEH                              1.00                   
MARBLE HILL                           0.50                   

...OHIO...
EATON 3 E                             1.00                   

...OKLAHOMA...
MUSKOGEE                              3.00                   
POTEAU                                2.00                   
WILBURTON                             2.00                   
CHECOTAH                              1.25                   
EUFAULA                               1.00                   

...TENNESSEE...
UNION CITY                            0.13                   

...TEXAS...
LITTLE ELM                            3.50                   
HURST                                 2.50                   
LINDSAY                               2.50                   
DECATUR 3 SSW                         2.25                   
DENISON                               2.00                   
EDEN                                  2.00                   
KELLER 2 E                            2.00                   
BLUFF DALE                            1.75                   
FORT WORTH                            1.50                   
GAINESVILLE                           1.50                   
OAK TRAIL SHORES                      1.50                   
DALLAS 5 E                            1.00                   

...SELECTED STORM TOTAL FREEZING RAIN ICE AMOUNTS IN INCHES FROM
500 AM CST THU DEC 05 THROUGH 800 AM CST FRI DEC 06...

...ARKANSAS...
GREENWOOD                             1.25                   
OZARK                                 1.00                   
FORT SMITH                            0.25                   
JETHRO                                0.25                   

...ILLINOIS...
VALIER                                0.50                   
SUMNER                                0.30                   
CAIRO                                 0.20                   
LAWRENCEVILLE                         0.10                   

...INDIANA...
CHARLESTOWN                           0.10                   
LEAVENWORTH                           0.10                   
MILAN                                 0.10                   

...KENTUCKY...
CALVERT CITY 2 S                      0.10                   
PROSPECT                              0.10                   
ROCHESTER                             0.10                   

...MISSOURI...
ELLSINORE                             0.25                   
LANTON 1 N                            0.25                   
DONIPHAN                              0.20                   
JACKSON                               0.20                   

...OHIO...
XENIA 3 SE                            0.16                   

...OKLAHOMA...
POTEAU                                1.00                   
VALLIANT                              0.25                   
CHECOTAH                              0.10                   

...TEXAS...
FORT WORTH 2 S                        0.40                   
DALLAS 5 NE                           0.30                   
MESQUITE                              0.30                   
RICHARDSON                            0.30                   
MENARD                                0.25                   
BRADY                                 0.20                   
DECATUR 3 SSW                         0.20                   
ROUND ROCK                            0.10                   


THIS SIGNIFICANT WINTER WEATHER EVENT IS EXPECTED TO CONTINUE
TODAY AS BITTERLY COLD ARCTIC AIR CONTINUES TO SPREAD AND FILL IN
BEHIND THE COLD FRONT. SNOW... SLEET... AND FREEZING RAIN WILL
CONTINUE THROUGHOUT THE DAY ACROSS MUCH OF THE SOUTHERN PLAINS AND
LOWER MISSISSIPPI RIVER VALLEY BEFORE TAPERING OFF BY LATER THIS
AFTERNOON. FROM THE OHIO RIVER VALLEY INTO THE NORTHEAST... THE
WINTRY PRECIPITATION WILL CONTINUE THROUGH THE EVENING HOURS
TONIGHT. ADDITIONAL ICE ACCUMULATIONS OF GREATER THAN A QUARTER OF
AN INCH ARE EXPECTED FROM PARTS OF ARKANSAS NORTHEASTWARD TO
KENTUCKY. BEHIND THE FREEZING RAIN AND FARTHER NORTHEAST INTO THE
OHIO VALLEY AND NORTHEAST... SNOW AND SLEET IS EXPECTED WITH
AMOUNTS OF 4 TO 8 INCHES POSSIBLE FROM NORTHERN ARKANSAS
NORTHEASTWARD TO SOUTHERN NEW YORK STATE.

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE WEATHER PREDICTION
CENTER AT 300 PM CST. PLEASE REFER TO YOUR LOCAL NATIONAL WEATHER
SERVICE OFFICE FOR ADDITIONAL INFORMATION ON THIS EVENT.

MONARSKI
 

[famartin]

Finally got below zero at my house this morning... hoping for 3-6" of fluffy snow tonight.

[Chinook]

The RAP is significantly colder for the northern Plains tonight, vs the NAM or GFS. This would be blisteringly cold at -30 to -35F for NE Montana. The NWS has -32F in the point-and-click forecast for NE Montana, agreeing with the RAP

 

 

 

 

 

 

 

[Chinook]

Montana got to -39

 

 

 

[famartin]

It looked nice... for a little while... this morning.  Only got 1.6" of snow so far though... well below expectations.  Heaviest snow seems to have missed us to our north.

[Srain]

A few images from Meteorologist Jeff L (Harris County Flood Control District) from the Dallas/Ft Worth area and US 75 in Grayson County.

"Major Ice storm continues over N TX for the second day in a row. While precipitation has ended, the impacts of .25-.60 of an inch of ice and 1-2 inches of sleet continue to be felt. Temperatures have yet to reach freezing and roadways remain ice covered and extremely hazardous. Some travelers have been trapped on US 75 north of Dallas to OK for the past 18-24 hours in Grayson County due to near impossible driving conditions. Power outages continue across the entire area, but progress is being made to restore power. Oncor (power) currently has 3700 linemen (1200 from outside the state) deployed to bring power back online…there was very significant damage to the above ground system in the counties that line the Red River. 270,000 customers lost power midday Friday and that number is down to 130,000 currently. Should begin to see some minor melting Sunday afternoon, but not a real increase to above freezing until likely Monday afternoon. So far 2700 flights have been cancelled since Thursday out of DFW stranding almost 4000 passengers in the airport."

[beavis1729]

Montana got to -39

 

 

 

Jordan, MT hit -42 yesterday morning, and only warmed up to -14 during the day.

[Chinook]

The polar vortex is a diamond type shape of negative anomalies. At this point, the cross-polar flow has been evident on the 500mb charts for a few days. (but it wasn't evident at the beginning, last week)

 

 

[Chinook]

20 deg F below normal for 9 days