December 24-25 Snowstorm

[A-L-E-K]

i wasn't picking on you Pat....and you made a very good case and reason for what you believe. But that's my point, the mets from the MA are making equally good points for the low staying more south like previous gfs solutions. There is always going to be a backyard bias among mets, i don't care what anyone says. You see it all the time AFDs across the region. They always make the case why their region could/should get thumped.....but that's their job in a way, to watch out for the public in their 'neck of the woods'.

My comment about lobbying was tongue and cheek. It would be nice however to have a met from our backyard that also gave us meterologically-backed hope as well.

You must not read a lot of LOT AFDs. And FWIW i think the handful of mets we have in my local area do a pretty damn good job of not hyping events that need not be hyped.

We spoke on this in the weather and forecasting discussion forum a while back, but studies have shown satellite data has nearly closed the gap completely regarding data over the oceans. RAOBS still catch moisture that satellite feeds cant, but quite often they can catch the winds in the upper troposphere very well. GOES satellite derived winds are pretty darned good. West coast folks are a good example...they don't get to "wait" until a system has been observed by RAOB network for 2 successive launches. Just saying. Off hour runs have become very good because of this. Not saying having a system in the RAOB network isn't nice, but we can still forecast well before it is within the network.

http://www.emc.ncep....H500mb_day4.png

Very interesting, thanks.

[patrick7032]

We're talking about waiting until this wave hits the upper air network to make judgement calls, but it's doing just that over Alaska. The piece of jet energy that will become this storm is currently over the Bering Strait and Western Alaska, and surface observations from it should have been ingested in the 18Z runs. The 00Z runs should have upper air obs as well.

I never said to wait until the wave hits the upper network....and yes along the WEST COAST and ALASKA/PACIFIC regions you obviously have to go more on derived data....but in the Midwest we can wait on the energy to get into the network to supplement the model runs with actual obs. With regard to the jet energy the very lead edge is just now over the Cold Bay WSO and the core over St. Paul Island....with a ridge over interior Alaska....so again....WHAT I AM SAYING is that yes derived data is valuable and good....but not better than observed data (by more than one or two sites)....yes use the derived to forecast....you have to.

[patrick7032]

I never said they would. I just see that comment all the time as if we shouldn't even bother to forecast until something is within the RAOB network. Gets old, especially in this day and age when satellite data has become that good. I don't disagree though, RAOB data is nice to have, especially for short-term severe wx forecasting it helps a lot having that data. When it comes to upper tropospheric winds, etc., the satellites get us most of the information we need.

Why shouldn't forecast....you're TOTALLY missing the point....think less about proving a point and more about the content....and btw a few times doesn't signify all the time....what gets old is that.

[baroclinic_instability]

Why shouldn't forecast....you're TOTALLY missing the point....think less about proving a point and more about the content....and btw a few times doesn't signify all the time....what gets old is that.

Yeah I guess I am....since you mentioned you only bother with the global models once it has been observed for two cycles...

[patrick7032]

Why shouldn't forecast....you're TOTALLY missing the point....think less about proving a point and more about the content....and btw a few times doesn't signify all the time....what gets old is that.

Yes definitely forecast with derived data....the new satellites going into orbit and their new products are great....but do you know how many locations are used in derived soundings in the model initializations?

[Stevo6899]

I see some mets are saying a more northern track is possible (cincy or columbus) if things fall in place. I know it's early but I was just curious if it would transfer to a coastal with that track or would it move NE into new york giving the east coast and midatlantic rain?

[A-L-E-K]

Well since some of you seem to think that the raobs are not needed etc how about putting a call out now? We can come back and visit it after the storm?

Springfield, MO to Columbus, OH. 14-18" for Chicago.

[patrick7032]

Yeah I guess I am....since you mentioned you only bother with the global models once it has been observed for two cycles...

AGAIN.....swing and a miss....let me put what I am saying very S I M P L E L Y....I don't get "over-excited" about any one model....any one solution....until well sampled. That was the only point. I never said I don't bother with global models until in the network....whee did you get that from?

[ArmyGreens]

You should be slightly careful here since you are talking about the difference between wish-casting (what goes on here on the weather forums 90% of the time) and forecasting done at offices. I can pretty much guarantee your NWS offices DO NOT hype up events. Bad idea, and it relates to public perception. Social sciences is big in the NWS these days.

I think you guys are missing what he is saying...he never said anything about hype. What he is saying(I have seen it many times) is that a majority of NWS offices will concentrate on a certain model(s) if it holds any legitimacy and poses a possible threat to the area. It is not a matter of hype for them but a way to make THEIR public aware of a weather threat to the area. The last big storm had offices from minnesota to kentucky explaining about impending hazards. Kinda hard to do if all were focused on the same model.

[Harry]

You should be slightly careful here since you are talking about the difference between wish-casting (what goes on here on the weather forums 90% of the time) and forecasting done at offices. I can pretty much guarantee your NWS offices DO NOT hype up events. Bad idea, and it relates to public perception. Social sciences is big in the NWS these days.

I don't think he was picking on their forecasting abilities but a number of them do have their own biases as MOST forecasters do. Anyone who denies it is lying. It does not have to be a cold and snow bias either. Right or wrong they exist. And while we are on this subject.. Frankly i am getting tired of seeing people getting jumped on when someone questions the models/NWS etc. It happens and a number of times it is justified. If someone in this field cant take some criticism then i suggest finding another career. Sorry but wx forecasting is not a exact science and so there will always be those who question others. Better believe when i see something questionable or whatever i am gonna say it. I know i sure as heck would wanna know about it if i put something out there that seems questionable to anyone.

[baroclinic_instability]

AGAIN.....swing and a miss....let me put what I am saying very S I M P L E L Y....I don't get "over-excited" about any one model....any one solution....until well sampled. That was the only point. I never said I don't bother with global models until in the network....whee did you get that from?

Calm down bud. If I misunderstood what you said regarding the 2 RAOB sampling, I apologize. For others who did not know how well satellite derived data has become, well they now at least have that information.

[Indystorm]

Well, as a member of the general public I would expect my pro mets to use derived data, RAOB, synoptic awareness, and a healthy dose of chaos and Heisenberg's uncertainty principle in making their forecasts. lol....good discussion here and on the main page in the model thread.

[Harry]

Springfield, MO to Columbus, OH. 14-18" for Chicago.

All heard it here first..

Wouldn't you **** if that is what happens?

Seriously all need to relax. sheesh..

[baroclinic_instability]

I don't think he was picking on their forecasting abilities but a number of them do have their own biases as MOST forecasters do. Anyone who denies it is lying. It does not have to be a cold and snow bias either. Right or wrong they exist. And while we are on this subject.. Frankly i am getting tired of seeing people getting jumped on when someone questions the models/NWS etc. It happens and a number of times it is justified. If someone in this field cant take some criticism then i suggest finding another career. Sorry but wx forecasting is not a exact science and so there will always be those who question others. Better believe when i see something questionable or whatever i am gonna say it. I know i sure as heck would wanna know about it if i put something out there that seems questionable to anyone.

No I wasn't at all. In fact I agree that as back-yard forecasters we most definitely will hope for the best and possibly hype certain events, but the NWS, if anything, has a tendency to play things down since busting high a lot is not a good thing.

But I agree, can't be sensitive to negative feedback in forecasting. It will happen to the best of us. I have busted so many times in my life; best you can do is just learn and move on.

[A-L-E-K]

All heard it here first..

Wouldn't you **** if that is what happens?

Seriously all need to relax. sheesh..

[A-L-E-K]

No I wasn't at all. In fact I agree that as back-yard forecasters we most definitely will hope for the best and possibly hype certain events, but the NWS, if anything, has a tendency to play things down since busting high a lot is not a good thing.

But I agree, can't be sensitive to negative feedback in forecasting. It will happen to the best of us. I have busted so many times in my life, just learn and move on.

LOT is a great example of this, almost to a fault, with a history of not pulling the trigger on WSW until places already have 6"+ on the ground.

[Indystorm]

Here's IWX's take on the Christmas storm with a snippet from their AFD...

BUT BEFORE THE UPPER LEVEL RIDGE

BUILDS...A PACIFIC SHORTWAVE TROF WILL EJECT EAST FROM THE UPPER

LEVEL LOW AND PHASE WITH ENERGY COMING SOUTH IN THE NORTHERN STREAM.

THERE IS POTENTIAL FOR ACCUMULATING SNOW FRIDAY/FRIDAY NIGHT. FOR

THIS PACKAGE...PREFER THE 12Z ECMWF. THE ECMWF IS ABOUT 12 HOURS

SLOWER THAN THE GFS AND MAINTAINS MORE OF A CLOSED 700 MB

LOW...WHICH SEEMS REASONABLE GIVEN A DEVELOPING UPSTREAM RIDGE AND

THE PHASING OF ENERGY. THE GARCIA METHOD USING THE 295K SFC FOR THE

ECMWF YIELDS A POTENTIAL OF 6 INCHES OF SNOW FRIDAY OVER THE

SOUTHERN PORTION OF THE FCST AREA. HAVE UPDATED THE FCST/GRIDS IN

THIS REGARD. HAVE ADDED THE CHANCE FOR LAKE EFFECT SNOW SHOWERS

GIVEN A REASONABLY FAVORABLE FETCH AND DELTA T VALUES IN THE RANGE

OF 12 TO 16 USING A LAKE WATER TEMPS OF 4C.

[Thundersnow12]

LOT is a great example of this, almost to a fault, with a history of not pulling the trigger on WSW until places already have 6"+ on the ground.

12/26/09

[TheWeatherPimp]

LC"s take:

MEDIUM RANGE OUTLOOK (Four To Ten Days From Now) Storm, Snow Threat For The Eastern Seaboard On Christmas ECMWF NOAA/NCEP WEATHERAmerica Let me say first off that any time that someone predicts the potential for an important snow and/or ice event for the Christmas holiday, irritation ensues. On one hand you have the folks who insist, no matter what the evidence, that your track and weather scenario are dead wrong because their hometown does not get enough snowfall. On the other hand, almost surely a group of neigh-sayers will emerge proclaiming the disturbance to be either "wishcasting" or a "fantasy storm", as their favorite meteorologist or facsimile thereof said it would be fair and mild so "your outline cannot possibly be right"! Tossing aside those concerns, the fact is that there is a sizable (2 in 3 odds) risk of a large, if not intense, storm targeting much of the nation in the days about December 25. Yes, there are considerable difficulties since one major model shows only relatively weak development (the European equation). But weighted against all of the schemes, a potential scenario emerges which looks workable, and may make for either frustration or joy depending on your view of such things. In the case put forth by the ECMWF panels, suppression via force of cold, dry air and trough position prevent a long-lived snowfall risk to most living in the Midwest and Northeast (although middle Appalachia and perhaps Virginia could take home a prize). But the entire GFS model suite, in concert with the Canadian and European variant packages, strongly suggest a well-developed upper low which pulls in the surface low center and triggers sharp deepening against a very impressive baroclinic zone. The two dangers here are northwest revision of track (increasingly unlikely due to the still-extant -AO blocking ridge and vast cold air dome) or of course flattening and suppression, which would take far weaker impulse well out to sea with only lake-related orographic snows developing. The prediction that I post here deals with a path passing very near the classic "benchmark" for Nor'easters (40 N Latitude, 70 W Longitude) with intensification upon nearing the MA Islands on the morning of December 26. This thinking allows for a sizable ice and mix designation across parts of the Ohio Valley and the Virginias, while also leaving the door open for a heavy snowfall shield involving the Interstate 70 and 95 corridors (the latter above Fredericksburg VA). Besides, I think that "Ho, Ho, Ho" surely beats "Bah Humbug" any day....

[Sidewinder]

For our area south of Indy, this is the highest probs I've seen 5-6 days out.

Friday: A 50 percent chance of snow. Cloudy, with a high near 31.

[IWXwx]

Here's IWX's take on the Christmas storm with a snippet from their AFD...

BUT BEFORE THE UPPER LEVEL RIDGE

BUILDS...A PACIFIC SHORTWAVE TROF WILL EJECT EAST FROM THE UPPER

LEVEL LOW AND PHASE WITH ENERGY COMING SOUTH IN THE NORTHERN STREAM.

THERE IS POTENTIAL FOR ACCUMULATING SNOW FRIDAY/FRIDAY NIGHT. FOR

THIS PACKAGE...PREFER THE 12Z ECMWF. THE ECMWF IS ABOUT 12 HOURS

SLOWER THAN THE GFS AND MAINTAINS MORE OF A CLOSED 700 MB

LOW...WHICH SEEMS REASONABLE GIVEN A DEVELOPING UPSTREAM RIDGE AND

THE PHASING OF ENERGY. THE GARCIA METHOD USING THE 295K SFC FOR THE

ECMWF YIELDS A POTENTIAL OF 6 INCHES OF SNOW FRIDAY OVER THE

SOUTHERN PORTION OF THE FCST AREA. HAVE UPDATED THE FCST/GRIDS IN

THIS REGARD. HAVE ADDED THE CHANCE FOR LAKE EFFECT SNOW SHOWERS

GIVEN A REASONABLY FAVORABLE FETCH AND DELTA T VALUES IN THE RANGE

OF 12 TO 16 USING A LAKE WATER TEMPS OF 4C.

Yes, I like it when local mets start talking sexy about a storm that is still 5 days out. I read the above, then read this from IND:

AS MENTIONED SATURDAY...IT REMAINS

TOO EARLY TO INTRODUCE POTENTIAL SNOWFALL ACCUMULATIONS FROM THIS

SYSTEM ON CHRISTMAS EVE. WITH THAT BEING SAID...DOES APPEAR THAT A

SIGNIFICANT SNOWFALL WILL BE POSSIBLE NORTH OF THE OHIO RIVER ON

FRIDAY. HAVE BUMPED TO 50 POPS LATE THURSDAY AND FRIDAY...AND WILL

CONTINUE TO MONITOR VERY CLOSELY OVER THE NEXT FEW DAYS AS MORE

DETAIL CAN BE EMPLOYED.

I'm all 'd up now for a possible significant snow on Christmas eve. It would nicely make up for the several near misses this area has experienced so far this winter.

[patrick7032]

Calm down bud. If I misunderstood what you said regarding the 2 RAOB sampling, I apologize. For others who did not know how well satellite derived data has become, well they now at least have that information.

Oh is no problem bud....Here is a summation of sorts from what I was thinking from a portion of the AFD. Figured I might as well check the AFD's....usually I go right to the data.

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI

351 PM EST SUN DEC 19 2010

.LONG TERM... MONDAY THROUGH NEXT SUNDAY

ANOTHER CYCLE OF MODEL RUNS HAS NOT DONE MUCH TO RESOLVE THE

TIMING, TRACK, AND STRENGTH UNCERTAINTY ASSOCIATED WITH THE NEXT

SYSTEM TO AFFECT THE GREAT LAKES. THE BULK OF THE UPPER JET ENERGY

ASSOCIATED WITH THIS SYSTEM WILL MOVE IN FROM THE WEST COAST

TONIGHT WITH THE UPPER AIR NETWORK THEN EXPECTED TO HELP NARROW

THINGS DOWN. THIS REMAINS AN IMPORTANT POINT IN THE FORECAST DUE

TO THE SMALL SCALE NATURE OF THE SYSTEM.

[Indystorm]

Do hope we here in the Heartland get our Christmas snow even if it does make a mess of travel plans for some...including me.

[patrick7032]

For the Ohio folks you may like part of the DTX discussion.

ANOTHER STRONGER SYSTEM IS THEN SHOWN TO MOVE ONSHORE FROM THE

PACIFIC BUT CUTTING UNDER THE LONG WAVE RIDGE. THIS DOES FAVOR A

FARTHER SOUTH TRACK THROUGH THE TENNESSEE VALLEY BUT WITH A CHANCE

THAT THE NORTHERN FRINGES OF THE MOISTURE PATTERN WILL BRUSH SE

MICHIGAN DURING CHRISTMAS EVE AND CHRISTMAS DAY. THIS SYSTEM WILL

HELP REAMPLIFY THE LONG WAVE PATTERN OVER NORTH AMERICA THROUGH

CHRISTMAS WEEKEND. GLOBAL MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON

THE LARGE SCALE PATTERN EVOLVING INTO AN OMEGA BLOCK THAT SETS UP

ANOTHER ROUND OF DEEP NORTHERLY FLOW ALOFT OVER THE GREAT LAKES. DUE

TO THE HIGH PREDICTABILITY OF SUCH A LARGE SCALE PATTERN, THERE IS

HIGH CONFIDENCE IN THE CORRESPONDING BELOW NORMAL TEMPERATURES

EXPECTED FOR SE MICHIGAN. THERE IS ALSO A GOOD SHOT AT A PERIOD OF

ACTIVE LAKE EFFECT SNOW SHOWERS BEFORE A WESTERLY COMPONENT DEVELOPS

IN THE LOW LEVEL FLOW BY LATE SUNDAY.

[Indystorm]

Yes, Patrick, I frequently read met Gil Sebenste from NIU Weather in Dekalb making references to the need for things to get fully sampled to narrow down the forecast. I see this as a both/and rather than either/or situation with respect to techniques for gathering data.

[patrick7032]

Do hope we here in the Heartland get our Christmas snow even if it does make a mess of travel plans for some...including me.

I hope you do too as for STL through Ohio....The kids would love to go sledding in those areas....hopefully DTX is correct on the track for you....I still like my track though....and what csnavy said about the energy in Canada is definitely a key....will be a fun few days to watch this in the model data.

[patrick7032]

Then how do you explain the Euro being farther south than the GFS?

Looking back at the data it actually has trended north over the past few runs. I just now started reading the AFD's but GRR stated the same.

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE GRAND RAPIDS MI

315 PM EST SUN DEC 19 2010

THE NAM CONTINUES TO BE THE SLOWEST MOVING A LOW ACROSS THE CWA

TUESDAY. THE GFS/ENSEMBLES/ECMWF/GEM ARE QUICKER AND MOVE THE SYSTEM

OUT BY WEDNESDAY. FOR NOW WE/RE LEANING TOWARD THE QUICKER

SOLUTIONS. AS SUCH WILL HAVE GENERALLY DRY GRIDS WEDNESDAY AND

THURSDAY. A STORM MOVING THROUGH THE OHIO/TN VALLEYS FRIDAY-SATURDAY

HAS THE POTENTIAL TO DUMP A SWATH OF SNOW SOUTH OF THE CWA BEFORE

HITTING NEW ENGLAND OVER THE WEEKEND. THE TRACK OF THE LOW IS A BIT

FARTHER NORTH THAN YESTERDAY. THUS WE INCREASED POPS A BIT ON

THURSDAY NIGHT AND FRIDAY. THAT SAID THE ENSEMBLE SPREAD IS

TIGHTENING AROUND A LOW TRACK THROUGH KENTUCKY WHICH WOULD MEAN THE

BULK OF THE PCPN WOULD STAY SOUTH OF THE CWA. THE FIM AND ECMWF BOTH

JUST CLIP THE SW CWA FRIDAY AFTERNOON/NIGHT AND HAVE THE HEAVIEST

SNOW SOUTH OF THE CWA.

[patrick7032]

For the Ohio Folks this would be good.

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE WILMINGTON OH

511 PM EST SUN DEC 19 2010

NUMERICAL MODELS DEVELOP A SFC WAVE

OVER THE SRN PLAINS THURSDAY NIGHT AND THEN TRACK IT THRU THE TN

VALLEY ON FRIDAY. THIS STORM HAS THE POTENTIAL TO PRODUCE

SIGNIFICANT ACCUMULATING SNOW. 12Z GFS SOLN IS A LTL QUICKER AND

KEEPS THE PRECIPITATION ALL SNOW. 00Z ECMWF WAS A LTL SLOWER...

ALLOWING FOR A LTL MORE WARM AIR TO WORK INTO THE SYSTEM FRIDAY

NIGHT. THIS WUD SUGGEST A PD OF A WINTRY MIX OVER THE EXTREME

SE...BEFORE CHANGING BACK TO ALL SNOW BY SAT MORNING. ALTHOUGH

LATEST 12Z ECMWF...CONTINUES TO BE A LTL SLOWER...THE THERMAL FIELDS

ARE COLDER. GFS ENSEMBLE MEAN IS A LTL FURTHER N THAN THE

OPERATIONAL GFS ALSO POINTING TOWARD THE POSSIBILITY OF A MIX

OVER THE SE.

[ArmyGreens]

For the Ohio folks you may like part of the DTX discussion.

ANOTHER STRONGER SYSTEM IS THEN SHOWN TO MOVE ONSHORE FROM THE

PACIFIC BUT CUTTING UNDER THE LONG WAVE RIDGE. THIS DOES FAVOR A

FARTHER SOUTH TRACK THROUGH THE TENNESSEE VALLEY BUT WITH A CHANCE

THAT THE NORTHERN FRINGES OF THE MOISTURE PATTERN WILL BRUSH SE

MICHIGAN DURING CHRISTMAS EVE AND CHRISTMAS DAY. THIS SYSTEM WILL

HELP REAMPLIFY THE LONG WAVE PATTERN OVER NORTH AMERICA THROUGH

CHRISTMAS WEEKEND. GLOBAL MODEL SOLUTIONS ARE IN GOOD AGREEMENT ON

THE LARGE SCALE PATTERN EVOLVING INTO AN OMEGA BLOCK THAT SETS UP

ANOTHER ROUND OF DEEP NORTHERLY FLOW ALOFT OVER THE GREAT LAKES. DUE

TO THE HIGH PREDICTABILITY OF SUCH A LARGE SCALE PATTERN, THERE IS

HIGH CONFIDENCE IN THE CORRESPONDING BELOW NORMAL TEMPERATURES

EXPECTED FOR SE MICHIGAN. THERE IS ALSO A GOOD SHOT AT A PERIOD OF

ACTIVE LAKE EFFECT SNOW SHOWERS BEFORE A WESTERLY COMPONENT DEVELOPS

IN THE LOW LEVEL FLOW BY LATE SUNDAY.

Am I a liitle excited? Sure. Did getting burned multiple times make me hesitant on jumping on the "Snow is falling!" bandwagon? Yes! LOL. What sucks is I, like others have posted, will be wasting a lot of time following models this week based on "possibilities" with the chance of having another miss. Like I said before, if I can end up with at least 3 inches from this i would be more than satisfied!

[JoMo]

Looking back at the data it actually has trended north over the past few runs. I just now started reading the AFD's but GRR stated the same.

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE GRAND RAPIDS MI

315 PM EST SUN DEC 19 2010

THE NAM CONTINUES TO BE THE SLOWEST MOVING A LOW ACROSS THE CWA

TUESDAY. THE GFS/ENSEMBLES/ECMWF/GEM ARE QUICKER AND MOVE THE SYSTEM

OUT BY WEDNESDAY. FOR NOW WE/RE LEANING TOWARD THE QUICKER

SOLUTIONS. AS SUCH WILL HAVE GENERALLY DRY GRIDS WEDNESDAY AND

THURSDAY. A STORM MOVING THROUGH THE OHIO/TN VALLEYS FRIDAY-SATURDAY

HAS THE POTENTIAL TO DUMP A SWATH OF SNOW SOUTH OF THE CWA BEFORE

HITTING NEW ENGLAND OVER THE WEEKEND. THE TRACK OF THE LOW IS A BIT

FARTHER NORTH THAN YESTERDAY. THUS WE INCREASED POPS A BIT ON

THURSDAY NIGHT AND FRIDAY. THAT SAID THE ENSEMBLE SPREAD IS

TIGHTENING AROUND A LOW TRACK THROUGH KENTUCKY WHICH WOULD MEAN THE

BULK OF THE PCPN WOULD STAY SOUTH OF THE CWA. THE FIM AND ECMWF BOTH

JUST CLIP THE SW CWA FRIDAY AFTERNOON/NIGHT AND HAVE THE HEAVIEST

SNOW SOUTH OF THE CWA.

For that area, yes.

For this area, it has been South and stronger.

Read Goodland, KS, Dodge City, KS, Wichita, KS and St. Louis, MO.