Winter 2017-18 Medium/Long Range Disco

[snowlover2]

ILN mentioning the GFS/GGEM scenario being possible for not having high confidence in it yet.

 

Quote

Area Forecast Discussion
National Weather Service Wilmington OH
247 PM EST Thu Nov 30 2017



.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
A beautiful fall weekend, will be followed by stormy weather and a
major pattern shift.

Surface high pressure over the region on Saturday will
weakened from the north as a H5 s/w swings across the northern
Great Lakes. The region will remain dry, with some high cloudiness.
Highs on Saturday, will range from around 50 to 55 degrees. As
the shortwave works off quickly to the east, the sfc high will re-
establish itself for Sunday. Highs will be in the 50s.

For the new work week, models are showing different timing with a
system that will affect the region. In general, the models have
trended slower for Monday, with only the ECMWF bringing in some
pcpn Monday afternoon to the west. The GFS and Canadian
hemispheric leave the region dry. Will bring 20 PoPs into the
west Monday afternoon. Temperatures will warm into the upper 50s to
lower 60s.

The ECMWF is the quickest with the band of rain, pushing it
through Monday night into Tuesday. THe GFS and Canadian are
slower, waiting until Tuesday to bring the majority of the pcpn
through. Trended towards the majority forecast for pcpn timing.

Cold air will begin to work in behind the front. With the majority
forecast lingering pcpn longer Wednesday, added a gradual change of
pcpn from rain through a mix to all snow. Confidence in this
scenario is not high in this solution at this time, as the models
flip back and forth with the speed of the frontal timing.
 

 

[RCNYILWX]

After positive trends yesterday in the position of the ridge and trough axes, can't say I was a fan of the EPS today, which has the ridge axis inland of the West coast in the medium range. With that being said, the brief relaxation it shows roughly 12/10-12/11 could be favored time for a stronger clipper. This would be possible as the baroclinic zone/thermal gradient tightens across the western sub with positive height and 850 anomalies encroaching into western IA. The reload at the end of the EPS run is quite impressive.

Sent from my SM-G935V using Tapatalk

[michsnowfreak]

Looking like this will be the 2nd straight year we have a nice wintery December which adds to the Christmas mood Let's just hope that unlike last year it stays that way after new years.

[josh_4184]

Checking out the AFD's this morning and NWS Buffalo had an excellent right up for the upcoming well advertised pattern change. Not my office area obviously but very well done and definitely gets me even more pumped up for the next couple weeks for snow leading into X-Mas week.

 

Quote

.LONG TERM /MONDAY THROUGH THURSDAY/...
On Monday surface high pressure will drift to the New England coast.
Associated subsidence and dry air will keep enough influence across
our region to keep any rain with the next system at bay until at
least Monday evening. Expect increasing clouds from west to east,
with increasing southerly flow bringing temperatures notably above
average. Expect highs in the lower 50s on the lake plains of Western
NY, with mid to upper 40s elsewhere.

Monday night and Tuesday a sharp mid level trough will dig into the
Upper Midwest, forcing a deepening surface low to track across Lake
Superior to James Bay. A cold front surging east ahead of the low
will cross our region Tuesday. Increasing large scale ascent and
moisture transport ahead of the trough will bring increasing chances
of rain from west to east Monday night, with rain coverage likely
peaking late Monday night and Tuesday. The surface low is stronger
in the 00Z GFS and ECMWF than in past runs. This will produce a
decent wind field across the area as well, but the low is likely too
far away from our region to produce a wind event.

Model guidance diverges Tuesday night. The past few runs of the GFS
develop a baroclinic wave along the front, forcing it to become
anabatic in nature with a stripe of synoptic snow developing across
our region. The ECMWF on the other hand develops this wave later and
much farther east along the east coast, with the precip ending prior
to the arrival of the cold air. The ECMWF solution of a clean cold
frontal passage is preferred and more likely, but the trends in the
GFS will need to be watched in the coming days.

Behind the cold front the GFS and ECMWF become better aligned again
as cold air steadily filters into the Great Lakes. Temperatures are
only marginally cold on Wednesday for a lake response, with rain and
wet snow showers east of the lakes. The cold air deepens Wednesday
night and Thursday, which may set the stage for a more robust lake
response. Model guidance has shown variability with wind direction,
shear, and synoptic scale moisture for this period, which is
expected at this time range. It will be several more days before
more details are known on more precise timing, intensity, and
placement for lake effect snow potential Wednesday night and
Thursday.

Looking farther ahead, the major pattern change ushered in by the
early-to-midweek system will mature by the end of next week, and
then last at least into mid December, and possibly beyond. Long
range ensemble and deterministic guidance remains in excellent
agreement on this pattern change, and has only grown stronger with
forecast blocking over the past few days. The anomalously strong and
eastward extending East Asian Jet is in the process of weakening,
and this will allow for a strong amplification of the Pacific wave
train. This will force the downstream pattern across North America
to strongly amplify, with a strengthening ridge along the west coast
forcing the downstream development of a deep longwave trough over
central and eastern North America. At the same time, blocking over
Greenland will strengthen.

The increasing high latitude blocking will project on an
increasingly strong negative AO (Arctic Oscillation), with the
Greenland Block also strengthening with time. Meanwhile, the western
ridge/eastern trough and amplification farther west in the Pacific
will force an increasingly positive PNA (Pacific North American)
pattern.

The coupling of a negative NAO and positive PNA pattern will result
in an extended period of below normal temperatures and active winter
weather for the Great Lakes starting late next week, and lasting for
an extended period of time. The first few days of the pattern change
late next week will be routine cold, but after about December 10th-
12th there are increasing signals in long range ensemble guidance
that several blasts of true arctic air may be in play for the Great
Lakes and Northeast. Obviously details are impossible to predict at
this time range, but the large scale pattern suggests the
possibility of numerous high impact lake effect snow events during
the 8-14 day period taking us into mid December. Stay tuned.

 

[michsnowfreak]

Winter is roaring in no doubt. Should be snow and cold for everyone and a lot of fun in the belts.

[BuffaloWeather]

1 hour ago, josh_4184 said:

Checking out the AFD's this morning and NWS Buffalo had an excellent right up for the upcoming well advertised pattern change. Not my office area obviously but very well done and definitely gets me even more pumped up for the next couple weeks for snow leading into X-Mas week.

 

 

I literally posted those same thoughts in upstate section few days ago. I learn so much from this forum and am finally getting to the point that I can predict patterns, snowfall, and temp. I have so much to learn on the severe side of things though. This sub forum has some of the best for learning that. Long range looks great, the operational euro had some pacific issues with a zonal flow but wasn’t backed by the ensembles.

[Hoosier]

Manitoba Mauler late next week?

[hlcater]

Euro isn't as on board with the cold. At day 10, the Euro(and the EPS) have the ridge placed over British Columbia and the NW, while the GFS(and the GEFS) generally keep the ridge offshore in the Gulf of Alaska. This allows warmer air to push back in to the western portions of the sub by FH240, while the GFS has all of us firmly entrenched in the cold for the entire run.

 

Euro:

 

GFS

[Jonger]

The operational Euro stinks in my opinion. It always leans warm in the long range and plays catchup.

[Hoosier]

11 minutes ago, Jonger said:

The operational Euro stinks in my opinion. It always leans warm in the long range and plays catchup.

The verification scores don't stink, at least within about 5 days.  That being said, we are talking about something well past 5 days when the skill drops off dramatically for all models. 

[snowlover2]

4 hours ago, Hoosier said:

Manitoba Mauler late next week?

18z GFS is pretty jacked with this. Showed a nice defo band with the heavier totals in IN then sits over Detroit and has lake enhancement where the heaviest totals show up in NE IN/sw MI. Everything from E IA and eastward is from this clipper.

[Jonger]

18 minutes ago, Hoosier said:

The verification scores don't stink, at least within about 5 days.  That being said, we are talking about something well past 5 days when the skill drops off dramatically for all models. 

I guess we will see. It seems every year the GFS shows cold, the Euro plays catchup.

[cmillzz]

5 minutes ago, snowlover2 said:

18z GFS is pretty jacked with this. Showed a nice defo band with the heavier totals in IN then sits over Detroit and has lake enhancement where the heaviest totals show up in NE IN/sw MI. Everything from E IA and eastward is from this clipper.

Lol @ the giant screw hole over N IL and WI. They really do have some of the worst climo in the country.

[cmillzz]

10 minutes ago, Jonger said:

I guess we will see. It seems every year the GFS shows cold, the Euro plays catchup.

It does seem like the EURO is slightly more reliable than the GFS, at least in recent years. It’s the GEM/CMC that is absolutely horrendous and a model that should definitely be avoided. 

[Jonger]

5 minutes ago, cmillzz said:

It does seem like the EURO is slightly more reliable than the GFS, at least in recent years. It’s the GEM/CMC that is absolutely horrendous and a model that should definitely be avoided. 

The euro and GFS are nearly on par. The euro leans warm long range. The GFS has locked onto this solution for days.

[Stebo]

A bit of a bomb late in the GFS run, I am betting it will be breezy in New England

[Jonger]

Actually, the 220 to 240 point of the Euro and GFS is similar... The GFS reloads just after that point and obviously the Euro ends at 240 hours. So, it's different, but not that different.

[Jonger]

31 minutes ago, Angrysummons said:

you mean like after Thanksgiving.............it just wasn't the ECMWF. The GGEM bolted and the UKMET never has looked like the GFS in the long long range(if you get the 168-240 extension. The -aam plunge wears off by the 10th. There will be some leftover ridging lasting a few days longer, but I don't know why you want a GFS solution to verify. That kills snow.

I'm all about LES....  I need NW flow.

I don't enjoy the stress of trying to snag SW ejecting systems and the chance of them wiping out snowpack.

[Stebo]

Just now, Jonger said:

I'm all about LES....  I need NW flow.

Which is clouding your judgement because you are outright believing a statistically worse model because it shows what you like. That is the point people are making here.

[Jonger]

2 minutes ago, Stebo said:

Which is clouding your judgement because you are outright believing a statistically worse model because it shows what you like. That is the point people are making here.

Read post #80. The GFS has had this pattern for days.

[Stebo]

Just now, Jonger said:

Read post #80. The GFS has had this pattern for days.

Yes but the end of the pattern has been all over the place, which is what we are discussing. We aren't discussing if it will become cold but whether for how long it will stay that way. The assumption that this pattern is going to be locked in from here on out is incorrect.

[Jonger]

8 minutes ago, Stebo said:

Yes but the end of the pattern has been all over the place, which is what we are discussing. We aren't discussing if it will become cold but whether for how long it will stay that way. The assumption that this pattern is going to be locked in from here on out is incorrect.

You're not going 15 days without the trough relaxing, but the GFS has shown the current pattern and now the reload after the relaxation on day 9 though 11.

[weatherbo]

I remember a lot of Madison Jackpots

[IWXwx]

2 minutes ago, weatherbo said:

I remember a lot of Madison Jackpots

Nothing wrong with their climo. Yeah, back a few years ago Madison was hawt

[bdgwx]

18Z GEFS mean has that low along the US/CA border at hour 156. The 18Z GFS is in Missouri. That's a huge difference.

[OHweather]

FWIW, the Euro ensembles never really relax the cold pattern and have had a big re-load by December 13-14 after a "relaxation" in which temperatures stay below normal across the entire region.  I suppose a brief milder day could sneak in there and probably does on a few ensemble members, but I wouldn't be that concerned about the day 10 op Euro.  If anything maybe a brief relaxation/reload opens the door for a better synoptic snow threat than what we're looking at with the first cold shot late next week (I don't buy the GFS super-amped clipper yet). 

[UMB WX]

On 11/30/2017 at 2:04 PM, cmillzz said:

LES gets tiring after a while. I want to see some legit synoptic snow for a change, and some true blizzard conditions. Seems like the last good one was GHD in 2011. 

 

Did you receive a lot of snow in GHD 2011.

[UMB WX]

3 hours ago, cmillzz said:

Lol @ the giant screw hole over N IL and WI. They really do have some of the worst climo in the country.

When did you move?

[IWXwx]

31 minutes ago, OHweather said:

FWIW, the Euro ensembles never really relax the cold pattern and have had a big re-load by December 13-14 after a "relaxation" in which temperatures stay below normal across the entire region.  I suppose a brief milder day could sneak in there and probably does on a few ensemble members, but I wouldn't be that concerned about the day 10 op Euro.  If anything maybe a brief relaxation/reload opens the door for a better synoptic snow threat than what we're looking at with the first cold shot late next week (I don't buy the GFS super-amped clipper yet). 

It's been showing it for several runs now, and has been fairly consistent with the track. The past couple of runs have shown it being pretty strong. We'll have to watch trends I suppose.

[OHweather]

15 minutes ago, IWXwx said:

It's been showing it for several runs now, and has been fairly consistent with the track. The past couple of runs have shown it being pretty strong. We'll have to watch trends I suppose.

That's true, and though the op isn't at all enthused the EPS mean suggests the trough could take on a negative tilt over the Ohio Valley, so I'm not completely dismissing it. But would like to start seeing more of the Euro and its ensemble members showing a similar solution to really buy in and get excited.  Eventually it will snow with this cold pattern and next weekend appears to be the first chance, I'm just not yet at the point of enthusiasm for it.