Winter 2018-19 Medium/Long Range Discussion

[ILwxchr]

Wouldn't be surprised to see a small window of freezing rain potential on Saturday morning. Models could be under-estimating snow depth and thus overdoing surface temps. Its something to keep an eye, probably won't know until it becomes a short term situation. One of friends at DVN was telling me he was concerned for icing locally in Eastern Iowa/Northwest IL, especially further northwest.

[cyclone77]

3 hours ago, Angrysummons said:

The UKMET just KO'd the GFS in terms of the storm/nonstorm(Ok ok, ECMWF wasn't keen on it) that won't happen. NCEP needs to turn up the processing power on the GFS or something because it has been the town drunk so far this cold season.

 

GFS and the FV3-GFS=

 

[Stebo]

DonS has some positive thoughts going forward for Chicago/Detroit

53 minutes ago, donsutherland1 said:

To date, Chicago has received 12.7" snow and Detroit has picked up 6.7".

At present, everything appears to be on track for a normal to snowier than normal winter. The odds probably lean toward the latter.

To examine where things stand and where they might wind up, I constructed a snowfall profile using the following criteria for total snowfall through November 30:

Chicago (12.7" so far): 4" or more
Cleveland (4.4" so far): 1" - 10"
Detroit (6.7" so far): 2" or more
Milwaukee (6.6" so far): 2" - 12"

The following years fit that criteria (for which a common record exists for the above cities):

1893, 1947, 1953, 1955, 1959, 1974, 1975, 1978, and 1980

Mean seasonal snowfall for Chicago and Detroit was as follows:

Chicago: 47.2" (standard deviation: 17.8")
Detroit: 44.2" (standard deviation: 10.7")

I also constructed a sum of the squares errors analysis. The 5 years with a sum of the squares error < 60" were:

1893, 1959, 1975, 1978, and 2015. 

Mean seasonal snowfall for Chicago and Detroit was as follows:

Chicago: 51.9" (standard deviation: 22.3")
Detroit: 44.0" (standard deviation: 8.7")

The majority of winters cited above did not feature an El Niño. Further, 2015-16 featured a super El Niño event.

Thus, at least at this point, my thinking is that the snowfall figures will likely exceed what is described above. Therefore, I continue to have confidence that my thinking for Chicago (45"-55") and Detroit (50"-60") remains reasonable.

 

[michsnowfreak]

11 hours ago, Stebo said:

DonS has some positive thoughts going forward for Chicago/Detroit

 

 Sounds good. DTX issued their Winter outlook finally. Pretty much call for December to be slightly warmer and slightly less snowy than normal and January and February to be slightly colder and slightly snowier the normal. A very broad brushed outlook not varying much from climo but the take away is what I have heard from several other sources- that December will be the weakest Winter month.

[Hoosier]

Could be something to watch around the 13th-15th?

[Stebo]

53 minutes ago, Hoosier said:

Could be something to watch around the 13th-15th?

Maybe another warm system, actually been watching that one for another severe potential as well.

[Malacka11]

The 13th-15th system looks interesting. Too bad it's still this far out

[Hoosier]

On 12/5/2018 at 10:43 AM, Malacka11 said:

The 13th-15th system looks interesting. Too bad it's still this far out

You couldn't draw up a much better Lake Michigan coastal flooding/erosion scenario than the 12z GFS.  Strong low meanders around southeast of the area.  Odds of both things happening (a low that deep and meandering around) aren't great, but otherwise, hopefully somebody can thread the needle.

[vpbob21]

4 hours ago, Hoosier said:

You couldn't draw up a much better Lake Michigan coastal flooding/erosion scenario than the 12z GFS.  Strong low meanders around southeast of the area.  Odds of both things happening (a low that deep and meandering around) aren't great, but otherwise, hopefully somebody can thread the needle.

And then the 12z Euro comes in and pretty much whiffs our subforum to the south.  Not sure where that came from.

[Hoosier]

10 minutes ago, vpbob21 said:

And then the 12z Euro comes in and pretty much whiffs our subforum to the south.  Not sure where that came from.

Pretty big shift.  I wouldn't take that seriously at this point, and the EPS doesn't really agree.

[zinski1990]

wouldn't surprise me

[chuckster2012]

GFS now says rain for everyone...

[RCNYILWX]

I'm mildly interested in Wednesday's clipper/hybrid. Pretty stout little wave with it, along with steep mid-level lapse rates. Quickly cooling 850s shown on the models are indicative of the rapid height falls and evaporative cooling given very dry low and mid levels ahead of system.

 

Someone could get a surprise slushy inch or two or three *if* the wave ends up as strong as shown on recent Euro/GFS/NAM op runs. It's somewhat reminiscent to me of the fast moving burst of heavy snow this past Feb 17th. We had a very marginal air mass ahead of it but the steep lapse rates & evaporative cooling more than made up for it.

 

After the possible Wednesday system, late week closed low is a crap shoot and not worth trying to figure specifics yet, also any snow accums will be very thread the needle with it. Thereafter, our mild +EPO pattern should continue until about the 20th or so. At that point, ensembles are indicating the GOAK vortex retrograding to the Aleutians for classic weak Nino position allowing -EPO to build and cold to return. There's also a decent chance of -AO returning with SPV displacement/split possibly further aided by a SSW.

 

There could be a window for some winter fun somewhere in the sub in the runup to Christmas, with the -EPO induced downstream trough possibly dumping cold air mass into the west/Plains and sub forum and then spreading east. Euro ensemble runs have been pretty consistent with this idea toward the end of the runs the past few days and 06z GEFS also hinting at that. Way out there, but worth watching for if we can get a stronger west/southwest system before trough axis maybe shifts farther east after Christmas. The pattern will almost certainly continue to suck in general between now and about the 20th, but I'm cautiously optimistic for the last 10-11 days of the month.

 

 

 

 

 

 

[Frog Town]

1 hour ago, RCNYILWX said:

I'm mildly interested in Wednesday's clipper/hybrid. Pretty stout little wave with it, along with steep mid-level lapse rates. Quickly cooling 850s shown on the models are indicative of the rapid height falls and evaporative cooling given very dry low and mid levels ahead of system.

 

Someone could get a surprise slushy inch or two or three *if* the wave ends up as strong as shown on recent Euro/GFS/NAM op runs. It's somewhat reminiscent to me of the fast moving burst of heavy snow this past Feb 17th. We had a very marginal air mass ahead of it but the steep lapse rates & evaporative cooling more than made up for it.

 

After the possible Wednesday system, late week closed low is a crap shoot and not worth trying to figure specifics yet, also any snow accums will be very thread the needle with it. Thereafter, our mild +EPO pattern should continue until about the 20th or so. At that point, ensembles are indicating the GOAK vortex retrograding to the Aleutians for classic weak Nino position allowing -EPO to build and cold to return. There's also a decent chance of -AO returning with SPV displacement/split possibly further aided by a SSW.

 

There could be a window for some winter fun somewhere in the sub in the runup to Christmas, with the -EPO induced downstream trough possibly dumping cold air mass into the west/Plains and sub forum and then spreading east. Euro ensemble runs have been pretty consistent with this idea toward the end of the runs the past few days and 06z GEFS also hinting at that. Way out there, but worth watching for if we can get a stronger west/southwest system before trough axis maybe shifts farther east after Christmas. The pattern will almost certainly continue to suck in general between now and about the 20th, but I'm cautiously optimistic for the last 10-11 days of the month.

 

 

 

 

 

 

sweet write up, RCNYILWX.  

[Hoosier]

2 hours ago, Frog Town said:

sweet write up, RCNYILWX.  

Agree.  Looks like about a 5 day window for most areas to try to pull off a white Christmas.  

[Hoosier]

00z Canadian tries to get a little interesting with the late week system.

[chuckster2012]

41 minutes ago, Hoosier said:

00z Canadian tries to get a little interesting with the late week system.

What's it showing? GFS has rain for almost everyone..

[Hoosier]

4 minutes ago, chuckster2012 said:

What's it showing? GFS has rain for almost everyone..

Not putting much stock in it given the model inconsistency/disagreement.  Just pointing it out.  Still not a great outcome but better than all rain.

 

[Stebo]

34 minutes ago, chuckster2012 said:

What's it showing? GFS has rain for almost everyone..

The GFS nearly pitches a shut out here all the way to Christmas. That would be something.

[RCNYILWX]

Impressive flip from ++EPO to -EPO on 06z GEFS next week through Christmas. The good news is the ensembles continue to be consistent with this pattern flip. The bad news is the pattern will be brutal for most for winter interests until then. When the flip occurs, and from reading other long range gurus, have no reason right now to doubt that it will, the hope is that the look shown on the ensembles will equate to chances for some events instead of a big cutter followed by cold and dry.

 

 

 

 

[OHweather]

If the PNA is initially neutral or negative (as the EPS in particular shows) when the EPO drops, have to think that may favor a window for possible wintry weather in the Midwest before it gets too suppressive.  I suspect the East Coast might have to impatiently wait through the week of Christmas for better snow chances along I-95, though I still think we’re recovering from the mid November coastal/fiasco anyways. 

[hlcater]

Yea that advertised pattern change can’t come soon enough. Out here in IA, I can’t remember the last time the first half of December was any good. Seem to always find our way into a bad pattern.

[Jonger]

8 minutes ago, hlcater said:

Yea that advertised pattern change can’t come soon enough. Out here in IA, I can’t remember the last time the first half of December was any good. Seem to always find our way into a bad pattern.

Lately the 20th to the 27th has sucked. 

[slow poke]

3 hours ago, Jonger said:

Lately the 20th to the 27th has sucked. 

Last year the weather during Christmas week was awesome in my location. Plowed fresh snow all morning after opening gifts then lake effect kicked in and we got another 4" on top of the 6"+ we already had on the ground. Not sure I can remember a more beautiful Christmas morning weather wise then last year. I'm kinda thinking we've had more white Christmases then not the past 5 years or so at least at my location. I'm kinda thinking we're due for a brown/wet not so pretty one.

[Frog Town]

Lock it in.  It's the 18Z 380hrs out.  It's as good as gold......

[hlcater]

One thing consistent on the deterministic GFS and the GEFS is that big dump of cold air as a result of the -EPO around Christmas.

[josh_4184]

18z GFS at least showed some life after 240 hours which is pretty useless but its "something", previous runs were showing zilch for pretty much everyone. Hopefully its a trend in the right direction and would coincide with the much talked about cooling trend for end of the month. 

[Malacka11]

40 minutes ago, Frog Town said:

Lock it in.  It's the 18Z 380hrs out.  It's as good as gold......

Especially since we celebrate Christmas on the 24th... I'd pay money for this to happen. 

[cyclone77]

GEM with a nice little thread the needle event later this week.  It's highly unlikely, but sort of shows how close this system is to being something halfway decent for a limited area.  

[RogueWaves]

2 hours ago, slow poke said:

Last year the weather during Christmas week was awesome in my location. Plowed fresh snow all morning after opening gifts then lake effect kicked in and we got another 4" on top of the 6"+ we already had on the ground. Not sure I can remember a more beautiful Christmas morning weather wise then last year. I'm kinda thinking we've had more white Christmases then not the past 5 years or so at least at my location. I'm kinda thinking we're due for a brown/wet not so pretty one.

Always tough to know if you're talking about home in SEMI, or your place in the Northland? Just looked at the last five Dec 20-27th's here in Marshall. He's correct in saying the vast majority have sucked. Last year started with 4 warm days and bare ground by the 23rd, but another brown Christmas was avoided by the system snow that began on the 24th and peaked on Christmas Day. I measured snow all four days 24-27th and actually for an 11 day stretch every day featured at least some snow to measure. One of the better stretches of last season. Ofc, 2016 we started that period with a nice snow cover but were above freezing every day leading up to the torch-off on the 26th. '14 & '15 were dumpster fire bad. Even 2013 lost traction during that period. Some light snows kept Christmas from being totally brown, but we were down to piles again until the New Years storm.