Christmas Storm VI

[tnweathernut]

http://raleighwx.ame...com/models.html

Thanks, you are the man...............!

By the way, I am also from the TRI-cities of TN here and pulling for you guys south and east of me. Hope you guys get dumped on.

[eyewall]

Ukie appeared more west but weak to me. Anyone look at the Canadian?

[BIG FROSTY]

Got this on the 12z model thread don't know if it means anything ?

From BOX AFD:

"WE WANTED TO NOTE THAT WE HAVE RECEIVED MESSAGES FROM

HPC ABOUT INITIALIZATION PROBLEMS ON BOTH THE NAM AND GFS RUNS THIS

MORNING. "

[DaculaWeather]

From BMX 11:55 EST

FXUS64 KBMX 241655AFDBMX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE BIRMINGHAM AL

1055 AM CST FRI DEC 24 2010

.DISCUSSION...

MOSTLY CLEAR SKIES PREVAIL ACROSS CENTRAL ALABAMA THIS MORNING.

THIS WILL HELP TEMPERATURES WARM INTO THE 50S. NO SIGNIFICANT

CHANGES MADE TO TODAYS FORECAST. ENJOY THE SUNSHINE AND

RELATIVELY WARM TEMPERATURES TODAY AS THE WEATHER WILL GO DOWN

HILL AFTER MIDNIGHT. GOOD NEWS IS THAT NO WEATHER PROBLEMS

EXPECTED THIS EVENING AS THE PRECIPITATION WILL HOLD OFF UNTIL

AFTER MIDNIGHT. LATEST GFS MODEL RUN IS COMING IN WETTER AND

COLDER FOR SATURDAY...BUT THE SAVING GRACE MAY BE THE BOUNDARY

LAYER TEMPERATURES. MODEL SOUNDINGS INDICATE PROFILES NORTH OF

I-20 WILL BE COLD ENOUGH ALOFT FOR SNOW...BUT ABOVE FREEZING

TEMPERATURES IN THE LOWEST 1000-2000 FEET AGL SHOULD HELP MELT THE

SNOW BEFORE IT REACHES THE SURFACE. HOWEVER...SLIGHTLY COOLER LOW

LEVEL TEMPERATURES COULD CHANGE EVERYTHING.

STAY TUNED.

[BIG FROSTY]

Then this so maybe it want mess this run up !

MODEL DIAGNOSTIC DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

1016 AM EST FRI DEC 24 2010

VALID DEC 24/1200 UTC THRU DEC 28/0000 UTC

...SEE NOUS42 KWNO ADMNFD FOR THE STATUS OF THE UPPER AIR

INGEST...

12Z NAM EVALUATION

INITIALIZATION ERRORS DO NOT APPEAR TO SIGNIFICANTLY IMPACT ITS

SOLUTION.

[superjames1992]

Oh God, .5" of QPF here with awesome 850s making for awesome ratios, most likely on the 12z GFS. Raleigh gets like 10". Radar trends look nice. Try to temper my excitement!

Game back on!

Eastern SC and NC looked GOLDEN on this run, from what I could gather.

[eyewall]

PREFERENCE: EQUAL BLEND OF THE 06Z GFS/00Z ECMWF OR THE ENSEMBLE

MEANS

INITIALIZATION ERRORS IN NUMEROUS DIAGNOSTIC

QUANTITIES...INCLUDING HEIGHT/VORTICITY FIELDS/RH...ARE EVIDENT IN

BOTH THE 12Z NAM/GFS WITH SMALL BUT LIKELY SIGNIFICANT SHORTWAVE

TROUGHS OVER SOUTH DAKOTA/NEBRASKA ALONG WITH

SASKATCHEWAN/MANITOBA...WITH THESE AREAS ALSO NOT PARTICULARLY

RESOLVED OR PREDICTED WELL BY THE 00Z ECMWF. THUS...THE SPECIFIC

PREDICTIONS BY ALL DETERMINISTIC GUIDANCE ARE IN QUESTION...WITH

THE RECOMMENDATION TO FOLLOW CONTINUITY...WITH THE FINAL OUTCOME

MOST BELIEVED TO LIE BETWEEN THE 06Z GFS AND 00Z ECMWF...WITH ALL

ENSEMBLE GUIDANCE INCLUDING THE SREF MEAN/GEFS MEAN/ECMWF ENSEMBLE

MEAN ALSO CONSIDERED USEFUL TO ADDRESS THE CONTINUED UNCERTAINTY.

THIS APPROACH DISREGARDS THE SUBSTANTIALLY DEEPER AND WESTWARD

SHIFT OF THE 12Z GFS REGARDING THE POWERFUL LOW TRACKING UP THE

EASTERN SEABOARD...AND TO A LESSER EXTENT THE 12Z NAM WHICH LIES

NEAR THE FAST EDGE OF THE GUIDANCE WITH THE DEVELOPING LOW.

...HIGH AMPLITUDE SHORTWAVE TROUGH ENTERING THE WEST SATURDAY

NIGHT/SUNDAY...

PREFERENCE: NAM OR 00Z ECMWF ACROSS CALIFORNIA AND THE SOUTHWEST

THE GFS HAS TRENDED SLOWER WITH SOUTHERN PORTIONS OF THE TROUGH

ENTERING CALIFORNIA AND THE SOUTHWEST SATURDAY NIGHT AND

SUNDAY...BUT IS STILL FASTER THAN THE AGREEING NAM/00Z

ECMWF...WHILE THE GFS IS ONLY SLIGHTLY FASTER WITH NORTHERN

PORTIONS OF THE TROUGH. GIVEN GFS TRENDS AND SUPPORT FROM THE 00Z

UKMET/CANADIAN...THE PREFERENCE ACROSS THE SOUTHWEST IS FOR THE

NAM OR 00Z ECMWF.

...LOW PRESSURE NEARING THE PACIFIC NORTHWEST COAST LATE MONDAY...

PREFERENCE: 2/3 NAM OR 00Z ECMWF TO 1/3 GFS

THE NAM/00Z ECMWF ARE IN RELATIVELY GOOD AGREEMENT WITH A SURFACE

LOW AND ACCOMPANYING LEADING EDGE OF ITS FRONTAL SYSTEM

APPROACHING THE COAST JUST WEST OF PORTLAND BY 00Z TUE...WHILE THE

12Z GFS IS ABOUT 200 NM FARTHER SOUTH AT THE SAME TIME. WHILE

SOLUTION SPREAD IS QUITE LARGE AT THIS TIME FRAME...

RECOMMEND LEANING TOWARD THE MORE NORTHERN SOLUTION OF THE NAM/00Z

ECMWF.

...MODEL TREND GRAPHICS AT

WWW.HPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML...

...500MB FORECASTS AT WWW.HPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML...

JAMES

[tgarren]

this has been the most insane storm to track that i can ever remember. only other time i recall things changing so much was during a storm during the EasternWx days when HKY_Wx preached about the CAD being underdone and it held and brought us several inches before the ice. even if it doesn't pan out this has been one of the best rides as far as tracking goes.

[Rankin5150]

Oh my!!! I am not a pro, but I am dangerous enough o look at radar trends. Look down in Texas....NEUTRAL TILT??? It's SO ON folks! I have not read through the other posts, as I am on my iPhone, so If this has already been published or reported on, then feel free to delete Mods. I am sure Foothills or Allan can elaborate? Thanks!

[Cheeznado]

Wow I get up and looks what happens. I should give up on more storms......Still a close one here though. Remember this could change again either way.

[eyewall]

so these errors mean our great gfs run was false?

Not entirely but HPC's opinion is basically not to buy into it too much.

[Carvers Gap]

INITIALIZATION ERRORS IN NUMEROUS DIAGNOSTIC

QUANTITIES...INCLUDING HEIGHT/VORTICITY FIELDS/RH...ARE EVIDENT IN

BOTH THE 12Z NAM/GFS WITH SMALL BUT LIKELY SIGNIFICANT SHORTWAVE

TROUGHS OVER SOUTH DAKOTA/NEBRASKA ALONG WITH

SASKATCHEWAN/MANITOBA...WITH THESE AREAS ALSO NOT PARTICULARLY

RESOLVED OR PREDICTED WELL BY THE 00Z ECMWF. THUS...THE SPECIFIC

PREDICTIONS BY ALL DETERMINISTIC GUIDANCE ARE IN QUESTION...WITH

THE RECOMMENDATION TO FOLLOW CONTINUITY...WITH THE FINAL OUTCOME

MOST BELIEVED TO LIE BETWEEN THE 06Z GFS AND 00Z ECMWF...WITH ALL

ENSEMBLE GUIDANCE INCLUDING THE SREF MEAN/GEFS MEAN/ECMWF ENSEMBLE

MEAN ALSO CONSIDERED USEFUL TO ADDRESS THE CONTINUED UNCERTAINTY.

THIS APPROACH DISREGARDS THE SUBSTANTIALLY DEEPER AND WESTWARD

SHIFT OF THE 12Z GFS REGARDING THE POWERFUL LOW TRACKING UP THE

EASTERN SEABOARD...AND TO A LESSER EXTENT THE 12Z NAM WHICH LIES

NEAR THE FAST EDGE OF THE GUIDANCE WITH THE DEVELOPING LOW.

Well, that stinks - just no other good way to say it. Hopefully, the Euro will come in west. That said, I think many of the mets on this board have had great discussions on what sensible weather would look like. (I have no idea why this was taken from the board...I don't post much banter.) Anyway, good luck to all of you. Hope you get a ton of snow!

[DopplerWx]

Wow. So the gfs run may have not initialized correctly.

[RaleighWx]

PREFERENCE: EQUAL BLEND OF THE 06Z GFS/00Z ECMWF OR THE ENSEMBLE

MEANS

INITIALIZATION ERRORS IN NUMEROUS DIAGNOSTIC

QUANTITIES...INCLUDING HEIGHT/VORTICITY FIELDS/RH...ARE EVIDENT IN

BOTH THE 12Z NAM/GFS WITH SMALL BUT LIKELY SIGNIFICANT SHORTWAVE

TROUGHS OVER SOUTH DAKOTA/NEBRASKA ALONG WITH

SASKATCHEWAN/MANITOBA...WITH THESE AREAS ALSO NOT PARTICULARLY

RESOLVED OR PREDICTED WELL BY THE 00Z ECMWF. THUS...THE SPECIFIC

PREDICTIONS BY ALL DETERMINISTIC GUIDANCE ARE IN QUESTION...WITH

THE RECOMMENDATION TO FOLLOW CONTINUITY...WITH THE FINAL OUTCOME

MOST BELIEVED TO LIE BETWEEN THE 06Z GFS AND 00Z ECMWF...WITH ALL

ENSEMBLE GUIDANCE INCLUDING THE SREF MEAN/GEFS MEAN/ECMWF ENSEMBLE

MEAN ALSO CONSIDERED USEFUL TO ADDRESS THE CONTINUED UNCERTAINTY.

THIS APPROACH DISREGARDS THE SUBSTANTIALLY DEEPER AND WESTWARD

SHIFT OF THE 12Z GFS REGARDING THE POWERFUL LOW TRACKING UP THE

EASTERN SEABOARD...AND TO A LESSER EXTENT THE 12Z NAM WHICH LIES

NEAR THE FAST EDGE OF THE GUIDANCE WITH THE DEVELOPING LOW.

...HIGH AMPLITUDE SHORTWAVE TROUGH ENTERING THE WEST SATURDAY

NIGHT/SUNDAY...

PREFERENCE: NAM OR 00Z ECMWF ACROSS CALIFORNIA AND THE SOUTHWEST

THE GFS HAS TRENDED SLOWER WITH SOUTHERN PORTIONS OF THE TROUGH

ENTERING CALIFORNIA AND THE SOUTHWEST SATURDAY NIGHT AND

SUNDAY...BUT IS STILL FASTER THAN THE AGREEING NAM/00Z

ECMWF...WHILE THE GFS IS ONLY SLIGHTLY FASTER WITH NORTHERN

PORTIONS OF THE TROUGH. GIVEN GFS TRENDS AND SUPPORT FROM THE 00Z

UKMET/CANADIAN...THE PREFERENCE ACROSS THE SOUTHWEST IS FOR THE

NAM OR 00Z ECMWF.

...LOW PRESSURE NEARING THE PACIFIC NORTHWEST COAST LATE MONDAY...

PREFERENCE: 2/3 NAM OR 00Z ECMWF TO 1/3 GFS

THE NAM/00Z ECMWF ARE IN RELATIVELY GOOD AGREEMENT WITH A SURFACE

LOW AND ACCOMPANYING LEADING EDGE OF ITS FRONTAL SYSTEM

APPROACHING THE COAST JUST WEST OF PORTLAND BY 00Z TUE...WHILE THE

12Z GFS IS ABOUT 200 NM FARTHER SOUTH AT THE SAME TIME. WHILE

SOLUTION SPREAD IS QUITE LARGE AT THIS TIME FRAME...

RECOMMEND LEANING TOWARD THE MORE NORTHERN SOLUTION OF THE NAM/00Z

ECMWF.

...MODEL TREND GRAPHICS AT

WWW.HPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML...

...500MB FORECASTS AT WWW.HPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML...

JAMES

The things to take away from this is that the ECMWF and likely all detrerministic models are not initializing features correctly and thus the spread in solutions. Also the comment about the GEFS ensemble membres was in reference to the 00z and 6z GFS ENS members, the 12z ENS is actually even more bullish than the op GFS.

With that said the GGEM and UKMET did shift west, but not far enough west for anything to significant from the Triangle west or really east for that matter.

I will be interested to see what the ECMWF shows. If it is still east, then we have to keep the GFS in mind and be ready to pull the trigger if it holds and the 00z guidance shifts west too, but you cant go lock stock and barrel with it if the other models are not showing it.

[Marion_NC_WX]

Can somebody tell me how reliable the numerical output is from the IPS MeteoStar?

It only prints out .05 QPF (IMBY) for this newest run...

[BullCityWx]

Euro should be rolling in 15 minutes...big winner on the GFS according to bufkit is RWI with 10.6".

[strongwxnc]

current 500 mb Look

GOES

http://www.ssd.noaa.gov/goes/east/eaus/flash-wv.html

[NCSNOW]

Thanks Allan. Hopefully Euro can give some clues in 30 minutes.

Correct me if Im wrong, But we need the spin in central Texas to reach the GOM and be in front of the little spin up in SW Minnesota. If so then it can drop down in behind our southern stream Low and initiate the phase. Or is their another piece of energy up in the dakotas not depicted on radar?

[BullCityWx]

It should be noted too that along I-95 from KRWI to KFLO, Bufkit gives almost everyone at least half a foot of snow.

[Jason Campbell]

It should be noted too that along I-95 from KRWI to KFLO, Bufkit gives almost everyone at least half a foot of snow.

Where are those locations?

[eyewall]

It should be noted too that along I-95 from KRWI to KFLO, Bufkit gives almost everyone at least half a foot of snow.

Taking the GFS verbatim it would give me around 4 to 5 inches.

[snowlover91]

Thanks Allan. Hopefully Euro can give some clues in 30 minutes.

Correct me if Im wrong, But we need the spin in central Texas to reach the GOM and be in front of the little spin up in SW Minnesota. If so then it can drop down in behind our southern stream Low and initiate the phase. Or is their another piece of energy up in the dakotas not depicted on radar?

Here is our piece of energy that we are waiting for.

[strongwxnc]

Here ya go

Where are those locations?

[Cheeznado]

Still not convinced the TX short wave will be a significant player, but so far on the sat loops no sign of the dive SE forecast on all the models, The northern stream is still the area to watch closely. No reason to believe the GFS, but no reason to disbelieve it either. Stay tuned.

[strongwxnc]

Before the euro rolls. Here is Andy Wood's updated thoughts. Again this would be the WNC, Upstate SC and NEGA locations.

**Updated for post 12z model run analysis**

0z Euro and 0z GFS last night both trended wetter/more precip. over our area, yet NAM stays fairly dry… also the 12z GFS just trended showing more moisture as well... (good sign if you want at least a little bit of snow). But, we also have to take into account the drier NAM of 0.05″ to 0.1″ it spits out.

Importantly…. because I have seen it many times before: With a track like this along the coast, this is the stage of the game when forecast model projections usually play catch-up and start “upping the ante” a bit on moisture arrival at the time when the storm begins to strengthen.

We are closing in on 2 days of the event and we are 80% sure we have nailed down the track, but the strength of the storm is still very much in question due to the timing of the double-barreled jet stream interaction. Again, the storm is most likely going to be somewhat weak and intensify too late for significant accumulations. But, there is some wiggle room with the strength and it could be under-estimated if the northern jet doesn’t outrun the southern and tucks in behind the southern stream piece of energy… also if the southern branch is more closed and stronger it could mean a big difference with the moisture. The reason I point this out is there is still slim potential for a MAJOR BUST AND HIGH ACCUMULATIONS OF SNOW.

Still, I think our moisture limit or ceiling might be around 0.2- 0.4″ (water equivalent to 2-4″ & maybe 5" of snow) but we’ll see…. it all depends on when that storm system strengthens… if it strengthens sooner and the southern stream jet gets out ahead of the northern stream then we would see more moisture and could expect more snow…. if it shows up weaker as most projections stand now…. there will be some snow in the grass and no big deal on the roads.

___________________________________

**Finally, it will be very important for us to watch radar today and tonight and see if there are any surprises or if models are handling precipitation correctly. My guess is they won’t handle it correctly at all.

[FoothillsNC]

Euro out to 12. Not sure if the model will matter at this point so much for the details, but its got a still closed low at 12 in central Tex. Lot of qpf in Texas around the low. Nice amplification the western Central Canada. at 18 the low is coming off Houston. That doesn't look right. Already it went that far in 6 hours??

[burgertime]

@12 the Euro looks pretty damn similar to the GFS.

[burgertime]

Euro out to 12. Not sure if the model will matter at this point so much for the details, but its got a still closed low at 12 in central Tex. Lot of qpf in Texas around the low. Nice amplification the western Central Canada. at 18 the low is coming off Houston. That doesn't look right. Already it went that far in 6 hours??

Hey Robert @24 it's taking the same track as the 12z GFS they practically look like twins right now.

[Marion_NC_WX]

Why does Andy Wood say we are closing in on 2 days of the event ? Isn't the event a day away ?

Andy is probably counting today as Day 1, Day 2 would be tomorrow.

[burgertime]

Euro @24 is a little colder with more moisture into WNC.