Big Snow Threat Disco Jan2/3

[WeatherX]

Did you draw that? In a simple way, low placement is from PVA and WAA which 300-200mb jet streaks augment. I looked at detailed 300mb and 200mb and I can't make a glaring argument for the GFS being wrong knowing that other physics go into low pressure placement. Sure maybe it's a bit too far east perhaps, but it isn't a huge issue being 4-5 days out.

Looking at these maps gives some comfort and illustrates my point. This is all based on the GFS forecast which is always suspect.

 

[Ginx snewx]

FWIW, it was too far East but like Scooter said, 4-5 days out. I would say NJ to Maine moderate 6-10

[CoastalWx]

Using 850-500 RH is real voodoo to argue low placement.

 

If you did draw that, then my apologies because I thought it was a met who did.  Like I said...I don't have an issue with arguing too far east...may times it is...but to argue the center is that far SW isn't correct IMO. Notice that the low has an appendage WSW and this is due to the forcing you describe as well as the PVA from the incoming s/w.  Many times an amplifying jet forms from diabatic heating or the latent heat release from precip generation. So you get a feedback process where as the jet amplifies..the jet streak back builds or sort of remains stationary. This is partly the reason why as lows develop..they sometimes slow down or pull more NW before heading NE.

[Bostonseminole]

either way good discussion guys.

[jamesnichols1989]

Honestly I would argue that the GFS is possible as a solution regardless of its eastward bias.  Plus with a block developing somewhat for this timeframe, I would argue even more that the GFS could be sensing the block and force the storm ENE instead of NNE into the Gulf of Maine.

[HoarfrostHubb]

Lol. My Wunderground app has -17F for my low on Friday

[SnowMan]

Wow mine is only -8

[Typhoon Tip]

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1049 AM EST SUN DEC 29 2013

VALID 12Z WED JAN 01 2014 - 12Z SUN JAN 05 2014


...SNOW AND BITTER COLD TO GRIP MUCH OF THE NORTHEAST LATE IN THE WEEK...

RELIED ON THE 12Z/28 EUROPEAN CENTRE ENSEMBLE MEAN AS A SYNOPTIC GUIDE THIS FORECAST. THAT PARTICULAR MEAN AFFORDS A SMOOTHER
TRANSITION FROM YESTERDAY'S MANUAL PROGS THAN THE 00Z/29 VERSIONS--ECENS, GEFS, CMCE. WHILE ALL OF THE GLOBAL NUMERICAL
MODELS AGREE ON A SHARP ARCTIC OUTBREAK FROM THE UPPER MIDWEST TO THE INTERIOR NORTHEAST AFTER THE TURN OF THE YEAR, THE SOLUTION
SPREAD WITH REGARD TO THE SHORTWAVE INTERPLAY OVER THE EASTERN STATES IS STILL LARGE--DISCONCERTINGLY SO GIVEN THE WINTER WEATHER
IMPACT THIS EVENT IS CAPABLE OF DELIVERING. IF THERE IS A TREND TO BE GLEANED FROM THE LAST 24 HOURS OF GUIDANCE, IT WOULD BE THE
TIPPING OF THE SCALES TOWARD MILLER-B-TYPE CYCLOGENESIS--E.G., MULTIPLE LOW PRESSURE CENTERS DIVIDED BY THE APPALACHIAN MOUNTAIN
CHAIN. THE DENOTED COMPLEXITY OF MILLER-B-TYPE SYSTEMS MAKES FORECASTING THE ATTENDANT HAZARDS FAR DICIER THAN MILLER-A-TYPES--ONE LOW TRACKING FROM THE GULF OF MEXICO UP THE ATLANTIC COAST. IN GENERAL, THE CLIMATOLOGY OF MILLER-B-TYPES REVEALS INCREASING INCIDENCE OF HEAVY SNOWFALL NORTHWARD AND EASTWARD ALONG THE ATLANTIC COAST--UNDER THE COMMA HEAD TRACK OF THE COMPOSITE CYCLONE. THE SHORTWAVE ENERGY LIKELY TO COMPRISE THE UPCOMING SYSTEM HAILS FROM BOTH SIDES OF THE SPLIT FLOW OVER ALASKA AND THE YUKON. THE DATA DEARTH OVER THE NORTH PACIFIC AND ARCTIC OCEANS IS MOST PROBABLY THE BIG MUDDLING FACTOR. THINGS SHOULD COME INTO BETTER FOCUS ONCE THE ENERGY OF ORIGIN IS BETTER READ.

...


CISCO 

[jamesnichols1989]

I love CISCO's discussions, so informative.

[Boston-winter08]

00z NAM verbatim looks like it would be crap for SNE

[weathafella]

00z NAM verbatim looks like it would be crap for SNE

No it doesn't. It is similar to other guidance, Initial burst is more north. Look on the coast SE.

[SnowGoose69]

00z NAM verbatim looks like it would be crap for SNE

 

NAM is perfectly where you want it, it tends to be insanely NW and amped at 84 hours...if you displace its primary low further south where it will ultimately verify much better chance for big time phasing early.  The fact this run of the NAM is less NW than the 12Z Op Euro was with the primary pretty much tells you that run was out to lunch with the primary into BGM.

[jamesnichols1989]

NAM is perfectly where you want it, it tends to be insanely NW and amped at 84 hours...if you displace its primary low further south where it will ultimately verify much better chance for big time phasing early.  The fact this run of the NAM is less NW than the 12Z Op Euro was with the primary pretty much tells you that run was out to lunch with the primary into BGM.

I thought the NAM was more so the Northwestern outlier so far, it appeared to be further north with the precip.  Maybe I was reading it wrong since I have the PSU ewall maps.

[Boston-winter08]

No it doesn't. It is similar to other guidance, Initial burst is more north. Look on the coast SE.

 

Doesn't it look like warming/dryslotting would be an issue at some point? (probably looking to far into this anyway given it's the nam at 84hr)... I def see that area to the SE, but verbatim that looks to probably shoot too far SE, while the primary slugs NNE (take the 12z EURO solution and amplify it further)

 

NAM is perfectly where you want it, it tends to be insanely NW and amped at 84 hours...if you displace its primary low further south where it will ultimately verify much better chance for big time phasing early.  The fact this run of the NAM is less NW than the 12Z Op Euro was with the primary pretty much tells you that run was out to lunch with the primary into BGM.

Agreed

[weathafella]

Doesn't it look like warming/dryslotting would be an issue at some point? (probably looking to far into this anyway given it's the nam at 84hr)... I def see that area to the SE, but verbatim that looks to probably shoot too far SE, while the primary slugs NNE (take the 12z EURO solution and amplify it further)

 

I think the nam is following other guidance wi it's typical whacky 84 hour iteration.

[78Blizzard]

Primary seems much weaker at 78 hr than 18Z at 84hr, while development off SE coast is stronger and further north.

[Typhoon Tip]

NAM is perfectly where you want it, it tends to be insanely NW and amped at 84 hours...if you displace its primary low further south where it will ultimately verify much better chance for big time phasing early.  The fact this run of the NAM is less NW than the 12Z Op Euro was with the primary pretty much tells you that run was out to lunch with the primary into BGM.

 

It's overall not likely to be correct, but as is... that's a prelude to a bomb.  It's about to contact arctic air with a lower SE Gulf baroclinic wave, just as an intense jet max is about to ride overhead, if extrapolating.  

 

BOOM

[HoarfrostHubb]

Mike Wankum (TV met) putting GFS and Euro snowfall maps out.

[SnowGoose69]

The RGEM is similar down in the Gulf at 48 hours but its about 5 states more progressive with the northern energy than the NAM

[dryslot]

NAM is right where we want it right now

[jamesnichols1989]

GFS is about to reach the critical time as the energy comes onshore in Canada at 24 hours.

[dendrite]

NAM >24hr = WGAF

[78Blizzard]

NAM >24hr = WGAF

Agreed, but it is useful in checking the trends from run to run.

[weathafella]

Gfs continues the trend towards a bit more trof depth.

[weathafella]

Another big snow run.

[weathafella]

Dumper!

[Bostonseminole]

Another big snow run.

 

yeap, stronger again it seems.. from a 1010 @87 low to 999 @ 93

[weathafella]

Runs the impulse right I've the bm and out ENE.

[RUNNAWAYICEBERG]

another fun work day, getting to and from.....CT traffic commence!

[weathafella]

Plenty of lift with decent snow rates continuing all night Thursday night. Verbatim this is a lot of snow.