December 2017 Observations and Discussions

[Tom]

My ideas of a large storm system coming out of the SW Jan 7th-9th has characteristics of a bowling ball CO Low as well as a cutter.  Based on the EAR, 12z GEFS showing a High over Low pattern near Japan indicative of a classic CO Low system.  Today's 12z GEFS provide some clues as we look down the road.

 

 

[Tom]

Tom, can you see the future? You just mentioned this earlier in the morning and bingo. Do you pick the lottery numbers or point spreads?

Haha!  Somewhat...if you look in the right places my friend!

[bud2380]

Euro finally showing a larger scale system from the SW in the day 8-10 time period.  At least the models are active.  Not that its amounted to much of anything.  

[Minny_Weather]

With the brutal cold air and more coming, at least we have snow on the ground. There's nothing worse than last December where we had brutal cold with nothing but brown grass to look at.

[westMJim]

Todays high so far at GRR is 11° this makes today one of the coldest maximum temperatures for a December 26^th at Grand Rapids. The record is 10° in 1993 and the same 11° in 1990. Right now it is 10° with light snow falling.

[Craig-OmahaWX]

EURO came south a tad for the weekend system but not budging much. Thinking any day now somethings got to give. GFS has been scary consistent.

[Tom]

Big differences at 500mb across NW NAMER and the NE PAC Day 10-15 between the GEFS/EPS.

 

12z GEFS...

 

 

vs EPS

 

By Day 13 the difference grow even farther...the lack of any ridging in the NE PAC on the EPS is a known bias.  I think the GEFS have the right idea.  We'll see who wins this battle.

 

 

vs EPS...I think the model is having problems in the NE PAC.

 

http://wx.graphics/models/ecmwf/2017122612/noram/eps_z500a_noram_300.png

 

 

Day 15...

 

 

vs EPS...

 

http://wx.graphics/models/ecmwf/2017122612/noram/eps_z500a_noram_360.png

[hlcater]

Big differences at 500mb across NW NAMER and the NE PAC Day 10-15 between the GEFS/EPS.

 

12z GEFS...

 

 

 

vs EPS

 

By Day 13 the difference grow even farther...the lack of any ridging in the NE PAC on the EPS is a known bias.  I think the GEFS have the right idea.  We'll see who wins this battle.

 

 

 

vs EPS...I think the model is having problems in the NE PAC.

 

 

 

 

Day 15...

 

 

 

vs EPS...

 

 

For our sake I hope the GEFS is right, it has a better look for our area.

[Tom]

Here is a good test-case to see if the GEFS strat forecasts will prove again, or not, if they indeed are a good tool for long range forecasting.  Check out the hint of an upper level ridge at 10mb in the NE PAC.  Also, the vectors spinning around the PV seed cold air into N.A.

[Craig-OmahaWX]

18z GFS continues the same song and dance for two snow systems to move through Nebraska late this week into the weekend! 

[Tom]

For our sake I hope the GEFS is right, it has a better look for our area.

TBH, the GEFS have been very good at predicting Week 1-2 10mb strat forecasts.  I've shown on here how good they can be.  EPS may not have the right idea here.

 

18z GFS continues the same song and dance for two snow systems to move through Nebraska late this week into the weekend! 

Inside 4-5 days and there is a wild difference between the GFS/EURO.  Great test-case battle shaping up.

[CentralNebWeather]

GFS with brutally cold temps after this storm departs on December 31st. Wow. Would be something to experience if it verifies.

[Craig-OmahaWX]

No comment needed.

 

http://maps1.pivotalweather.com/maps/models/gfs/2017122618/120/snku_acc.us_c.png

[Tom]

Last night, the forecasted high temp for today at ORD was 10F, this morning the local news corrected to 8F...ended up with a balmy 4F high for the day. #Coldwon #Chiberia

 

Edit: +5F was the official high

[Craig-OmahaWX]

Last night, the forecasted high temp for today at ORD was 10F, this morning the local news corrected to 8F...ended up with a balmy 4F high for the day.  #Coldwon  #Chiberia

Yeah near 9 was forecasted here and it only got up to 5.

[CentralNebWeather]

Brrrrrrrr.....

[jcwxguy]

I hope not. I work outside everyday

[Jaycee]

I hope not. I work outside everyday

 

 

You know something is coming when an OG like jcwxguy pops in. Happy to have your input on stuff again my dude!

 

18z GFS really hammers Omaha, and heck, I'd take half of what they get on that run like it's showing. Maybe it'll go further south with the temps being so cold? Idk, doubt it. I just hope the EURO is wrong, I can't believe the difference amongst them rn.

[CentralNebWeather]

NWS Hastings Nebraska afternoon forecast discussion for this weekend. Very interesting

 

 

On Saturday, the GFS brings another, potentially more

significant, band of snow through the area on the leading edge of

another strong surface high...presumably with some strong

frontogenetic forcing. The Canadian and Euro are having absolutely

nothing to do with this, though. As such, we have broad snow

chances through this period, but uncertainty remains relatively

high.

 

Regardless of the precipitation on Saturday, it appears that we

will have another blast of cold air. Of course, some fresh snow

cover would make for even colder temperatures, but even the -5 to

-10 degree range Sunday and Monday mornings. The GFS is even

colder...especially on Monday morning (new year's day) when it has

widespread temperatures around -25 degrees! The gefs and Euro

ensembles remain equally split, with a 10 to 15 degree difference

between the means. For now, we have highs in the 5 to 15 degree

range and lows in the -5 to -10 degree range. These forecast

temperatures have been trending downward, and I wouldn't be

surprised to see this trend continue.

 

&&

[Minny_Weather]

Fobert from OAX said GFS is bullish but otherwise kicked temperature forecasting under the rug for the next shift. I should get a job there if that's all you have to do!

[Niko]

Clear and frigid. Heading down to -6F tanite. Brrrr.

[NEJeremy]

18z GFS continues the same song and dance for two snow systems to move through Nebraska late this week into the weekend!

It did an absolutely crappy job with Wednesday night and Thursday’s system

[WBadgersW]

Meanwhile in PA...

[Niko]

Currently @ 5F w clear skies.

[jaster220]

@Jaster

 

What was your low temp this morning? Did ya go subzero?

Negative on the negative, lol

 

Around 7 am when it normally bottoms out, I was still getting Hvy snow with a temp of 5 deg's

 

Uber cold doesn't thrill me tbh, but to the extent it helps get the ground solidly frozen I'm fine with it.

[Niko]

 

Duluth, MN this morning @ -21F and a WCF of -44F.

[Niko]

Negative on the negative, lol

 

Around 7 am when it normally bottoms out, I was still getting Hvy snow with a temp of 5 deg's

 

Uber cold doesn't thrill me tbh, but to the extent it helps get the ground solidly frozen I'm fine with it.

It even gets colder next week.

[Minny_Weather]

NWS Hastings Nebraska afternoon forecast discussion for this weekend. Very interesting

 

 

On Saturday, the GFS brings another, potentially more

significant, band of snow through the area on the leading edge of

another strong surface high...presumably with some strong

frontogenetic forcing. The Canadian and Euro are having absolutely

nothing to do with this, though. As such, we have broad snow

chances through this period, but uncertainty remains relatively

high.

 

Regardless of the precipitation on Saturday, it appears that we

will have another blast of cold air. Of course, some fresh snow

cover would make for even colder temperatures, but even the -5 to

-10 degree range Sunday and Monday mornings. The GFS is even

colder...especially on Monday morning (new year's day) when it has

widespread temperatures around -25 degrees! The gefs and Euro

ensembles remain equally split, with a 10 to 15 degree difference

between the means. For now, we have highs in the 5 to 15 degree

range and lows in the -5 to -10 degree range. These forecast

temperatures have been trending downward, and I wouldn't be

surprised to see this trend continue.

 

&&

Yeah I saw that too. I'm not sure if I like how much they're buying into the GFS. Yes it's run-to-run consistent, but that's about the only thing it has going for it right now. When compared with other models, it's in a different universe.

[jaster220]

My ideas of a large storm system coming out of the SW Jan 7th-9th has characteristics of a bowling ball CO Low as well as a cutter.  Based on the EAR, 12z GEFS showing a High over Low pattern near Japan indicative of a classic CO Low system.  Today's 12z GEFS provide some clues as we look down the road.

 

 

Comes outta Japan almost due east while strengthening. Ooohhh yeah baby!

[jaster220]

Calm winter evening under a fresh blanket of snow..

 

[Niko]

My temps are dropping like a rock. Currently @ 4F. I can easily see some records being broken tanite.

[Tabitha]

Its already -5 F @ 5 PM MST at the Rapid City Airport; but it won't get as cold as last night as a weak warm front will move through the area before midnight.

 

-1 F at my house.

[Niko]

The weekend storm might be a little too far south for folks north of i-80. Still, some changes likely until that time. I am thinking strong Arctic HPA might suppress this.

[gosaints]

The weekend storm might be a little too far south for folks north of i-80. Still, some changes likely until that time. I am thinking strong Arctic HPA might suppress this.

I am thinking it's a bit a of a turdcicle anyhow.

[westMJim]

It is now +3° with light snow falling. Had to go to my son's house on the other side of town. One thing with lake effect snow as long as the lake is open it can not get too cold to snow and with it this cold salt does not work so all of the roads are snow covered even the expressways.

[Tabitha]

-5 F here and -14 F down at the Rapid City Airport...pretty common for such a discrepancy; as cold air is heavier & shallower & denser and tends to sink; thus it tends to pool in valleys; while it will always be warmer on clear, anticyclonic mornings as one moves up a hill; the so-called "inversion" effect.

 

Edit:  Down to -7 F here and down to -16 F at the airport just before the sun comes up.

 

The Rapid City Airport had a high of 0 F after a morning low of -19 F; a Departure from Normal for the day of -33...which is pretty extreme...I don't think I saw any model bring the temperature at the airport that low.

 

The state low was -31 F at Aberdeen.

[Minny_Weather]

As ridiculous as GFS looks (We won't have a high on New Year's in the teens below zero), it is fitting to point out the Euro's major warm bias. As realistic as it looks, I'd have to say it's bullish with how warm it is advertising. For example, it is showing a low of 3 in Lincoln tonight when it is already down to -1 there ATM. I think we'll be seeing both models trend towards each other soon.

[james1976]

As ridiculous as GFS looks (We won't have a high on New Year's in the teens below zero), it is fitting to point out the Euro's major warm bias. As realistic as it looks, I'd have to say it's bullish with how warm it is advertising. For example, it is showing a low of 3 in Lincoln tonight when it is already down to -1 there ATM. I think we'll be seeing both models trend towards each other soon.

I think the colder solution is the way to go in this pattern. Maybe not as bullish as the GFS but i think that model has the right idea.

[Snowlover76]

OAX is so bad

[gabel23]

It’s already down to -11 in ord and -14 in broken bow. Hastings had them only getting to -9 and -11!