Remembering Snowpocalypse -- 12/18-12/19, 2009

[Ian]

Jason's post on CWG made me figure I might as well copy him...

http://voices.washin..._of_snowpo.html

SLP

500mb

LWX SNOW MAP

RADAR

[marked8]

This is what I remember, trying to dig out so I could go to work the next morning. That was a fun 18.5 mile commute. Pics in Manassas, Va.

[aldie 22]

I just remember the excitement of tracking the event and getting really really nervous until the first flakes started flying. It was just an unreal time for us down here and to think....it was just the beginning. I remember so many nights last winter staying up until 2am or so for the euro then getting up early for work. I was exhausted all winter but loved every minute of it.

[H2O]

I remember watching those sick yellow bands set up and sit over my area for hours. Taking a Jebwalk with my kids while that was happening was an unbelievably special moment

[Avdave]

Going for a walk with a group of us in the neighborhood that night as the snow is ripping outside, drinking some brews as we walked around, it was a lot of fun.

Like Leesburg said, waiting for those first flakes were painful due to the previous track record down here.

So many pics to cherish from that storm

[MidlothianWX]

It was a great event for us down here as well. My final total was around 10.5" (unfortunately we changed over to heavy IP for quite a while during the early hours of the 19th).

And finally, one from my ski trip in the days following the storm.

[Ian]

I remember watching those sick yellow bands set up and sit over my area for hours. Taking a Jebwalk with my kids while that was happening was an unbelievably special moment

I remember talking to zwyts (Matt) during the early afternoon on the phone while I was out walking around. He had told me stories about the city in a big storm but this was really my first experience. I did get here right before the Feb 2006 storm but it happened at night, melted quick, and I had just arrived from New England so I barely paid attention to it. I just remember wandering local streets that are otherwise kind of mundane and being in awe of how much snow was on the ground here in the city and that everything basically came to a complete halt.

It was maybe a bit before this time

I tried to just take it all in as much as possible but I feel like I didn't have enough time. Who knew more was coming later..

[Ian]

MESOSCALE DISCUSSION 2258

NWS STORM PREDICTION CENTER NORMAN OK

0622 PM CST FRI DEC 18 2009

AREAS AFFECTED...PORTIONS OF THE CNTRL/SRN APPALACHIANS AND LOWER

MID-ATLANTIC

CONCERNING...HEAVY SNOW

VALID 190022Z - 190515Z

HEAVY SNOW WITH RATES OF 1 TO 2 IN/HR WILL GRADUALLY TRANSLATE

E/NEWD THROUGH 06Z...TOWARDS THE I-95 CORRIDOR FROM THE WASHINGTON

D.C. TO RICHMOND METRO AREAS. LOCALIZED CONVECTIVE BURSTS MAY YIELD

RATES UP TO 3 IN/HR. A NARROW TRANSITIONAL CORRIDOR OF SLEET TO

FREEZING RAIN MAY DEVELOP ACROSS PORTIONS OF THE PIEDMONT IN WRN NC

TO S-CNTRL VA.

AS OF 0015Z...A BROAD SWATH OF MODERATE TO HEAVY SNOW PERSISTED FROM

PORTIONS OF THE CNTRL/SRN APPALACHIANS INTO THE PIEDMONT OF WRN NC

AND CNTRL/SRN VA. MULTIPLE HOURS OF SNOWFALL RATES FROM 1 TO 2 IN/HR

HAVE BEEN REPORTED SINCE 21Z ACROSS FAR ERN TN/KY...WRN NC AND SWRN

VA. LATEST MODEL FORECASTS ARE CONSISTENT WITH WEAKENING THE LEAD

SHORT WAVE TROUGH...WHICH EXTENDED FROM ERN TN/KY SWD INTO GA PER

WATER VAPOR IMAGERY. NEVERTHELESS...UPSTREAM SHORT WAVE TROUGH OVER

THE MID-MS VALLEY AND ASSOCIATED MID-LEVEL JET ARE EXPECTED TO

AMPLIFY AS THEY EJECT EWD ACROSS THE TN VALLEY. THIS WILL MAINTAIN

GRADUAL DEEPENING OF SURFACE CYCLONE ALONG COASTAL SC THROUGH 06Z.

STRONG LOW-LEVEL WAA...INFERRED BY LARGE VEERED HODOGRAPHS IN

REGIONAL VWP DATA...SHOULD CONTINUE AS 18Z NAM/21Z RUC FORECASTS

DEPICT INTENSE LOW/MID-LEVEL ISENTROPIC/FRONTOGENETICAL ASCENT

GRADUALLY PIVOTING EWD TO THE N/NW OF THE SURFACE LOW TRACK. THIS

WILL SUPPORT SNOWFALL RATES OF 1 TO 2 IN/HR PERSISTING...WHILE THE

STRENGTH OF THE WAA MAY RESULT IN A NARROW CORRIDOR OF SLEET TO

FREEZING RAIN ACROSS PORTIONS OF WRN NC INTO S-CNTRL VA.

..GRAMS.. 12/19/2009

...NOTICE...

SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A

SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR

TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC

FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...AKQ...LWX...RAH...RNK...PBZ...RLX...GSP...MRX...

JKL...

LAT...LON 38538173 38038263 37288338 36518351 36268282 36228199

35808150 35768061 35917987 36147945 36877738 37467624

38297615 39027688 39257777 39107915 38858058 38538173

MESOSCALE DISCUSSION 2259

NWS STORM PREDICTION CENTER NORMAN OK

1134 PM CST FRI DEC 18 2009

AREAS AFFECTED...PORTIONS OF THE CNTRL APPALACHIANS AND LOWER

MID-ATLANTIC

CONCERNING...HEAVY SNOW

VALID 190534Z - 191100Z

HEAVY SNOW WILL SLOWLY TRANSLATE E/NEWD FROM ERN KY/SRN WV/NRN AND

CNTRL VA INTO MD/DE AND SRN NJ/PA BY 12Z. SNOWFALL RATES OF 1 TO 2

IN/HR WILL REMAIN COMMON...WITH MOST PERSISTENT DURATION OF HEAVIER

RATES LIKELY LYING ALONG THE WV/VA BORDER EWD TO THE I-95 CORRIDOR

OF THE WASHINGTON D.C./BALTIMORE METRO AREAS.

AS OF 0530Z...RADAR/SURFACE OBSERVATIONS DEPICT A SWATH OF MODERATE

TO HEAVY SNOW FROM ERN KY EWD ACROSS THE CNTRL APPALACHIANS TO THE

I-95 CORRIDOR FROM DCA TO RIC. A MID-LEVEL DRY SLOT /EVIDENT IN

WATER VAPOR IMAGERY/ HAD EFFECTIVELY ENDED HEAVIER SNOW ACROSS WRN

NC AND FAR ERN TN/SWRN VA...MORE QUICKLY THAN INDICTED IN 00Z

NAM/HI-RES WRF-NMM/GFS FORECASTS. 03Z RUC GUIDANCE SUGGESTS THIS DRY

SLOT WILL OVERSPREAD MUCH OF CNTRL/SRN VA THROUGH 12Z...RESULTING IN

SIGNIFICANT DRYING OF THE DENDRITIC GROWTH LAYER. THUS...THE AXIS OF

HEAVIER SNOWFALL RATES MAY NOT LIE AS FAR SOUTH AS CONSENSUS OF

MODEL QPF/SREF SNOWFALL GUIDANCE WOULD INDICATE. EVEN SO...CONTINUED

GRADUAL DEEPENING OF A SURFACE CYCLONE TRACKING ALONG THE NC COAST

WILL MAINTAIN STRONG LOW/MID-TROPOSPHERIC ISENTROPIC AND

FRONTOGENETICAL ASCENT ACROSS THE LOWER MID-ATLANTIC REGION. THIS

WILL SUPPORT PERSISTENT 1 TO 2 IN/HR SNOWFALL RATES TO THE N OF THE

IMPINGING DRY SLOT.

..GRAMS.. 12/19/2009

...NOTICE...

SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A

SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR

TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC

FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...MRX...

JKL...

LAT...LON 39967520 39477481 38437555 37217752 37117889 37447996

37498123 37188246 37138329 37738322 38608156 39297967

39937836 40087619 39967520

MESOSCALE DISCUSSION 2260

NWS STORM PREDICTION CENTER NORMAN OK

0557 AM CST SAT DEC 19 2009

AREAS AFFECTED...ERN WV...NRN VA...MD...DE...SERN PA...NJ

CONCERNING...HEAVY SNOW

VALID 191157Z - 191800Z

BANDS OF HEAVY SNOW WITH RATES OF 1-2 IN/HR WILL PERSIST MAINLY FROM

ERN WV ACROSS NRN VA AND MD...DE...SERN PA AND SRN NJ. THE LONGEST

DURATION OF HEAVY SNOW RATES IS LIKELY TO BE OVER ERN WV...NRN

VA...AND MUCH OF MD.

A LARGE SHIELD OF SNOW CURRENTLY EXTENDS FROM NEAR THE UPPER LOW

CENTER OVER WV EWD N OF A DEEPENING SURFACE LOW. WARM ADVECTION

COUPLED WITH DEEP LAYER FRONTOGENESIS IS RESULTING IN PERSISTENT AND

MULTIPLE W-E BANDS OF HEAVY SNOW. DUE TO THE SLOW MOVEMENT OF THE

TROUGH...LONG DURATIONS OF HEAVY SNOW WILL OCCUR. THROUGH

18Z...EXPECT A SLIGHT PIVOT OF THE SNOW BANDS TO A WSW-ENE

ORIENTATION AS THE LOW LEVEL WINDS BACK A BIT. BROAD...PERSISTENT

FRONTOGENESIS SHOULD RESULT IN FURTHER CONSOLIDATION OF THE SNOW

BANDS OVER THE MCD AREA.

AS THE UPPER LOW PIVOTS EWD...COOLING ALOFT MAINLY ABOVE 650 MB WILL

RESULT IN A DEEPER DENDRITIC GROWTH LAYER YIELDING A MORE

TEMPERATURE PROFILE FOR PARTICULARLY HEAVY SNOW FROM 12-18Z ACROSS

ERN WV...NRN VA...AND CNTRL MD. SNOW RATES COULD INCREASE TO MORE

THAN 2 IN/HR AT TIMES.

..JEWELL.. 12/19/2009

...NOTICE...

SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A

SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR

TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC

FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...OKX...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX...

LAT...LON 37787819 37668022 38068133 39008107 39627971 40377822

40597660 40617420 39997393 38987476 38347589 37787819

MESOSCALE DISCUSSION 2261

NWS STORM PREDICTION CENTER NORMAN OK

1127 AM CST SAT DEC 19 2009

AREAS AFFECTED...VA...WV...MD...DE...NJ...PA...NY...CT

CONCERNING...BLIZZARD

VALID 191727Z - 192330Z

HEAVY SNOWFALL RATES OF 1-3 INCHES PER HOUR ARE LIKELY FROM THE D.C.

I-95 CORRIDOR NNEWD TOWARDS LONG ISLAND THIS AFTERNOON. WITHIN THIS

ZONE...BLIZZARD-LIKE CONDITIONS WILL LIKELY AFFECT PORTIONS OF THE

MEGALOPOLIS.

CENTER OF MAJOR EAST COAST CYCLONE/BOMB WILL MAKE GRADUAL NNEWD

PROGRESS FROM EAST OF VA CAPES TO SOUTHEAST OF CAPE MAY NJ THROUGH

EVENING WHILE UNDERGOING SUBSTANTIAL DEEPENING. STRONGEST

ASCENT...AND GREATEST HOURLY SNOWFALL RATES...WILL COINCIDE WITH

MOST INTENSE 850-700MB FRONTOGENESIS AND DEEPEST DENDRITE GROWTH

LAYER. LATEST NCEP-SREF GUIDANCE THROUGH 00Z SHOWS THESE DYNAMIC

AND THERMODYNAMIC FEATURES WILL TRANSITION ONLY SLOWLY NWD/NWWD

THROUGH LATE TODAY. BROAD AND QUASI-BANDED HEAVY SNOW FIELD SHOULD

GRADUALLY DECAY ON ITS SWRN FLANK...AND DEVELOP/INTENSIFY AND PIVOT

COUNTERCLOCKWISE FROM NRN MD/SERN PA TO SOUTH SHORE OF LONG ISLAND

THROUGH LATER THIS AFTERNOON.

SREF PROBABILITY MATCHED-MEAN /PMM/ 3-HOUR SNOWFALL TOTALS WERE USED

TO ARRIVE AT THE 1-2 INCH AND 2 INCH PLUS PER HOUR RATES DEPICTED IN

THE MD GRAPHIC. FURTHERMORE...AS BOMBOGENESIS OCCURS OFFSHORE...THE

INCREASING PRESSURE GRADIENT WILL LEAD TO STRONG WINDS AOA 35 MPH

FROM DELMARVA NWD TOWARDS LONG ISLAND. THIS IS SUPPORTED BY THE 00Z

NSSL 4 KM WRF SHOWING MAX 1 HOURLY WINDS BETWEEN 30-40 KTS OVER THIS

CORRIDOR. THUS...CONSIDERABLE FALLING...BLOWING...AND DRIFTING SNOW

WILL RESULT IN BLIZZARD CONDITIONS WITH VISIBILITIES NEAR ZERO IN

THE HEAVIEST SNOW BURSTS.

..SMITH/CARBIN.. 12/19/2009

...NOTICE...

SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A

SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR

TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC

FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...OKX...PHI...BGM...AKQ...CTP...LWX...

LAT...LON 39127892 40467719 40917595 41227425 41117293 40697292

39697441 38617598 38537640 38207695 38337796 39127892

http://spc.noaa.gov/products/md/2009/md2262.html

http://spc.noaa.gov/products/md/2009/md2263.html

[usedtobe]

I remember posting about it and Jason quoting me on the Capital Weather Gang site and my neighbor telling me that he had seen me quoted. I think I said something like we hadn't seen a storm like this one before in dec for the dc area. Beyond that, I remember being excited that my part of Calvert county stayed all snow.

[Terpeast]

One of the greatest storms I've experienced, the other being the blizzard of 1996. I changed my flight plans in the last minute and made it just in time for the storm.

[aldie 22]

Never can I remember our area being in the good bullseye for all of those discussions. Simply amazing...I have a feeling someone will create a thread like this every year about the winter of 09-10

[aldie 22]

in the right thread this time

[PhineasC]

The amazing thing is that a little over a month later we started into an even more amazing stretch. Last winter is etched into my brain. I hardly remember tracking on the models because these all seemed to come easy. Even when the DEC 19 storm was south everyone simply knew it would come north.

[Kmlwx]

I have some good pics that I had posted over at Eastern before its demise. Will post here

[2010 extreme]

That storm was a nearly perfect miller a for ma, very similar to Feb 1983. The storm already had an eye and tons of moisture ahead of it before before it made land fall in western Florida! I was supposed to work from 10am to 6pm that day which was the time the worst would be. Im glad I called out even they were pressuring me to come in that morning because by the evening there was a solid 18-22 inch wall of snow between the main road and my street. Since I drive a corolla that would have been a disaster.

[MN Transplant]

Had waited since '04 for a true east coast snowstorm. It did not disappoint

Sure would be nice to have the obs threads from Eastern

[nieciez]

Early in the storm evening of the 18th:

9:00 a.m. on the 19th:

Later in the storm:

Son-in-law starts the dig out:

After this storm hubby decided to invest in a large gas snow blower which we had to order from Home Depot on-line.

[Casualbrain]

Cool roanoke snow photo by a local

We got 18.5 at my place.

[Ian]

[Ian]

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

439 PM EST FRI DEC 18 2009

VALID 00Z SAT DEC 19 2009 - 00Z TUE DEC 22 2009

DAY 1...

MID ATLANTIC STATES AND CENTRAL APPALACHIANS

AN AREA OF LOW PRESSURE OVER THE SOUTHEAST US WILL BE

INTENSIFYING/DEEPENING AS IT MOVES NORTHEAST TO JUST OFF THE OUTER

BANKS OF NORTH CAROLINA 12Z SAT AND ROUGHLY 150NM EAST OF THE

DELMARVA SAT EVENING. THE PRECIPITATION SHIELD HAS MOVED STEADILY

NORTH AND IS MOVING/EXPANDING NORTH A FEW HOURS FASTER THAN

FORECAST YESTERDAY AND ALSO BY TODAYS 12Z MODELS. THE MODELS ARE

SHOWING WELL DEFINED DIVERGENCE ASSOCIATED WITH THE ENTRANCE

REGION OF AN UPPER LEVEL JET AND COUPLED JET THAT LIFTS NORTH

ACROSS THE CENTRAL APPALACHIANS TO THE MID ATLANTIC REGION AND

TOWARDS SOUTHEAST NY SATURDAY EVENING.

WIND SPEEDS IN THE JET CORE ACCELERATE FROM AROUND 120 KTS EARLY

ON INTO THE 150-170 KT IN THE 15Z SREF MEAN.

THIS LEADS TO A COMBINATION OF LARGE LOW TO MID LEVEL MOISTURE

FLUXES AND CONVERGENCE LEADING TO WIDESPREAD MODERATE TO HEAVY

SNOW. UPSLOPE FLOW WILL ENHANCE SNOW AMOUNTS IN THE EAST SIDE OF

THE APPALACHIANS FROM VIRGINIA NORTHWARD.

THE MODELS STILL HAVE SIGNIFICANT SPREAD ALTHOUGH ALL OF THE

NAM/ECMWF/SREF MEAN/GEFS MEAN/GFS/CANADIAN GLOBAL/UKMET SOLUTIONS

ALL SHOW HEAVY SNOW WITH POTENTIAL UP TO TWO FEET IN THE CONSENSUS

OF THESE SOLUTIONS IN PORTIONS OF CENTRAL VA...WHICH WOULD BE

RECORD SNOW FOR MANY AREAS. HEAVY SNOW EXTENDS ACROSS THE

BALTIMORE AND WASHINGTON AREAS UP TO SOUTHERN NJ SAT.

MANUAL PROGS USED A BLEND OF THE 12Z NAM/12Z GFS/12Z UKMET/09Z-15Z

SREF MEAN/12Z GEFS MEAN/00Z ECMWF TO MITIGATE DIFFERENCES AMONG

SOLUTIONS. CONFIDENCE IS LOW IN THE 12Z ECMWF TREND TO LOWER

AMOUNTS GIVEN ITS FAVORABLE COUPLED 300 MB JET WITH SUSTAINED

DIVERGENCE IN THE CORRIDOR FROM WV ACROSS VA/MD.

FREEZING RAIN AND/OR ICE PELLETS ARE EXPECTED ACROSS CENTRAL NC

SINCE FORECAST SOUNDINGS NOW SHOW A DEFINED INVERSION ALOFT

BETWEEN 800-700 MB ABV FREEZING WHICH SHOULD MELT FALLING SNOW FOR

A PERIOD OF SEVERAL HOURS TONIGHT BEFORE THE LOW PASSES AND THE

INVERSION ERODES AND PRECIP TAPERS OFF.

DAY 2...

NJ/NY/SRN NEW ENGLAND...

THE LOW TO MID LEVEL CYCLONE SHOULD BE TRACKING NORTHEAST ON DAY

TWO...WITH ASCENT ACROSS

LONG ISLAND/SOUTHERN NEW ENGLAND AS THE BROAD LEFT EXIT REGION

PROVIDES A BROAD AREA OF UPPER DIVERGENCE AND SUPPORTS LOW LEVEL

MOISTURE ASCENDING INTO THE LOW LEVEL COLD AIR.

WITH THE MODELS STARTING TO CONVERGE ON SOLUTIONS..AS THE FARTHER

WEST 12Z NAM TRENDED EAST AND THE FARTHER EAST 00Z GFS TRENDED

WEST ON THE 12Z RUN WITH ITS LOW POSITIONS AND TRACK. THE SPREAD

HAS NARROWED TO A NORMAL RANGE OF TIMING/AMPLITUDE DIFFERENCES.

THE 12Z-18Z NAM IS ON THE SLOW SIDE OF THE MODEL/ENSEMBLE

SOLUTIONS. PRECIPITATION GRADIENTS ARE SHARP...SO THE FULL RANGE

OF PROBABILITIES ARE USED AS THE 12Z GEFS MEAN/ 09-15Z SREF

MEAN/18Z NAM SUPPORT POTENTIAL FOR A FOOT OF SNOW OVER LONG ISLAND

AND SOUTHEAST NEW ENGLAND. THE 12Z ECMWF HAS NUDGED ITS QPF

HIGHER THAN THE 00Z RUN DUE A SUSTAINED UPPER LEVEL DIVERGENCE

MAXIMA DOWNSTREAM FROM THE 300 MB CIRCULATION CENTER. MANUAL

PROGS BLENDED THE 12Z NAM/12Z GFS/09Z-15Z SREFMEAN/12Z GEFS

MEAN/12Z ECMWF.

PACIFIC NORTHWEST/NORTHERN ROCKIES...

MOIST ONSHORE FLOW AHEAD OF AN AREA OF LOW PRESSURE OVER THE ERN

NOPAC SHOULD

COMBINE WITH UPPER DIVERGENCE IN THE RIGHT ENTRANCE REGION OF A

JET STREAK CROSSING THE US CANADIAN BORDER TO PRODUCE ASCENT IN

THE RANGES OF WA INTO THE NORTHERN ROCKIES.

LOW TO MID LEVEL WARM ADVECTION AIDS ASCENT BUT ALSO COMPLICATES

THE FORECAST DUE TO RISING SNOW LEVELS WITH TIME. A RISK OF 4 TO

8 INCHES OF SNOW IS EXPECTED MAINLY IN THE HIGHER ELEVATIONS OF

THE CASCADES TONIGHT...AND THEN INTO THE NORTHERN ROCKIES

AFTERWARD. PARTS OF THE WA CASCADES HAVE A THREAT OF A PERIOD OF

FREEZING RAIN AS THE WARM ADVECTION MAY PRODUCE WARMING ABV

FREEZING ALOFT FIRST BEFORE SCOURING OUT THE SFC SUB FREEZING AIR

WHERE COLD AIR PERSISTS.

DAY 3...

PACIFIC NORTHWEST/NORTHERN ROCKIES...

THE MODELS ARE IN AGREEMENT IN AMPLIFYING THE MID-UPPER LEVEL

TROUGH AS IT MOVES SLOWLY FROM THE EASTERN PACIFIC TOWARDS THE

PACIFIC NORTHWEST. THE DOWNSTREAM UPPER LEVEL JET MOVES ONSHORE

ACROSS OREGON INTO ID AND THEN MT. DIVERGENCE IN THE DIFLUENT

FLOW FURTHER NORTH SUPPORTS ASCENT COMING ACROSS THE WA CASCADES

INTO THE NORTHERN ROCKIES.

SUSTAINED DEEP LAYER SOUTHWEST FLOW FAVORS HEAVIER SNOW AT HIGHER

LEVELS OF THE WA CASCADES. THE SOUTHWEST FLOW THEN PROGRESSES

INLAND INTO THE RANGES OF ID AND WESTERN MT/NORTHWEST MY. TIMING

DIFFERENCES AMONG THE MODELS GROW...AND EVENT THE EVOLUTION OF THE

MID-UPPER LEVEL SHORTWAVES VARIES AMONG MODEL SOLUTIONS. A

GROWING SPREAD OF FORECAST QPF RESULTS WITH THE 12Z ECMWF ON THE

LIGHT END OF THE SPECTRUM AND 09-15Z SREF MEAN ON THE HEAVIER END.

MANUAL PROGS BLENDED SOLUTIONS TO FIND A CONSENSUS...AND LEFT

OPEN AREAS OF MOSTLY LOW-MDT SNOW PROBABILITIES...WITH HIGH 4 INCH

PROBABILITIES OVER THE CASCADES WITH THE MOST AGREED UPON HIGHER

QPF AND FAVORABLE DEEP LAYER MOISTURE PROFILES.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

PETERSEN

[Ian]

12z GFS Ensemble mean 12/18/09

[Scarlet Pimpernel]

Ahhh, good memories of that, as I dig up my photos! I remember leaving work early Friday, getting the last minute shopping done (only chance I had to do it) with checkout lines backed up down the aisles. Seeing the first of the snow begin around 9:30PM. 9" on the ground by mid-morning on the 19th, total of 20". Here's some pictures:

Pretty much looked like this for much of the day on Dec. 19.

Icicles the following day after the storm.

[Ian]

it's coming!

[aldie 22]

it's coming!

Look at that backedge by Atlanta...it's a miracle it ever snowed here

[bubba hotep]

Duke St just a couple of miles N of Old Town - Never thought I would see it 100% void of vehicles!

The courtyard down the street from our house

[Ian]

Look at that backedge by Atlanta...it's a miracle it ever snowed here

look west!

[aldie 22]

time to shovel

[Ian]

[aldie 22]

I see what Ian is doing...nice with the time

[Ian]

I see what Ian is doing...nice with the time

too bad i wont be here all night.

wtf happened?

oh wait.