DECEMBER 2023 Observations and Discussion

[Stacsh]

5 hours ago, Madtown said:

I dunno. All I see on all three major models is warm air all the way up into Saskatchewan and Manitoba through the 15th and beyond. Upper 40's to near 50 in a ton of places. No real storms outside of a narrow band of snow here or there. What was a its gonna cool down early maybe mid December hopefully will happen by Jan maybe. Out around town today and everyone is starting to get a little worries on if winter ($$$) will show. Here's hoping, I just don't see it atm.

This was never going to be the winter  for sustained cold.   Up and down all year.   

[Clinton]

I started a thread for the upcoming storm/storms.

[Grizzcoat]

DR Judah Cohen thoughts on the AO /  PVA as we get into Dec.  (-- Cliff Notes  -thinks possible Arctic outbreak - magnitude unknown- for Lower 48 starting mid DEC).

https://www.aer.com/science-research/climate-weather/arctic-oscillation/

[MIKEKC]

Local forecasters here in KC on KSHB did a winter special last night (Lezak's old station he worked for) and they went warmer and well below average on snow for KC this winter. They thought it would be a wetter winter, however.

 

I think wetter is a good bet, can we time out the cold or will we have a bunch of what is about to happen tonight in KC, 34 degrees and raining. 

[Tom]

It is JMA Thursday, not a good MJO run as it inclines we still rotate through the warmer phases thru the opening 10 days, but as we head past the 10th, it'll be a "step down" towards Real Winter.  I have no doubts that by the 15th of the month, many are going to be tracking real winter storms not these "border line" systems we are tracking right now.  

 

I'm going to jump ahead and show the Week 3-4 outlooks...about as good as it gets for a 500mb map 

 

Temps/Precip...Classic amped up STJ...I'm getting pretty darn stoked that AZ will be hammered by real winter storms by mid month and through the Christmas holidays....

 

 

 

The CFSv2 weeklies are showing the same signal....

[Iceresistance]

Look at this GEFS!
 

[bud2380]

Potent clipper showing up on the GFS for early next week.

 

[bud2380]

Canadian also has the clipper, just weaker.

 

[hawkstwelve]

It's a ways out there but the GFS is seeing a system around the 10th. 12z run dumps hefty snow from Iowa into Michigan.

[bud2380]

And the predicted (by several on here) cold blast to follow.  Long ways out, could still change, but like the trends this morning.

 

[Minny_Weather]

3 hours ago, Tom said:

It is JMA Thursday, not a good MJO run as it inclines we still rotate through the warmer phases thru the opening 10 days, but as we head past the 10th, it'll be a "step down" towards Real Winter.  I have no doubts that by the 15th of the month, many are going to be tracking real winter storms not these "border line" systems we are tracking right now.  

 

I'm going to jump ahead and show the Week 3-4 outlooks...about as good as it gets for a 500mb map 

 

Temps/Precip...Classic amped up STJ...I'm getting pretty darn stoked that AZ will be hammered by real winter storms by mid month and through the Christmas holidays....

 

 

 

The CFSv2 weeklies are showing the same signal....

This is gonna be such a lame winter for me lol

[hawkstwelve]

Snow chances definitely seem to pick up post December 10th or so. 

Given Sioux Falls inability to get any meaningful precip so far this season, I'm not holding my breath. I keep watching various deterministic runs waiting for them to show something, anything remotely fun for this area and nothing ever happens. But at least there should be more chances after the upcoming warmup for the first week of December.

[Hoosier]

Interessting that the CFS has been running so dry for a large part of the country for December, although the last run did back off a bit on the magnitude of the dryness.

We'll be coming out of the gate with a pretty moist system for some areas of the Midwest, so unless the pattern gets really dry for the remainder of the month, it may be difficult to end up drier than average in places like MO to IN.

 

[Grizzcoat]

2 hours ago, bud2380 said:

And the predicted (by several on here) cold blast to follow.  Long ways out, could still change, but like the trends this morning.

 

It's just one run- but coupled with the Euro at HR 240 - this makes sense with how fast the MJO is moving out of the warm phases into colder phases for our region.  I like what I'am seeing from the 12Z suite of longer range guidance. Not sure if correct- and only one suite of guidance showing this- but it's better then it was 12-24 hours ago when it looked (may still be) a torch until DEC 17th or so. Expect more back and forth - but I do expect a colder solution (with a storm that "snaps" the pattern) about Mid Dec. just my .02

[Hoosier]

Quite the closed/cutoff low in the southwest at the end of the 12z Euro.

[Tom]

6 minutes ago, Hoosier said:

Quite the closed/cutoff low in the southwest at the end of the 12z Euro.

That the storm I’ve been waiting for to kick start winter and reshuffle the pattern.

[Tony]

This could be the makings of something big, but it is 10 days out.

[Hoosier]

New CPC for December...

 

 

 

Here's the one from 2 weeks ago for comparison...

 

[Hoosier]

Based on seasonal and long range models and the general expected timing of things, I'd go with something like a +2 departure for ORD for December.  Most of the departures in the early days of the month will be due to mild nighttime lows and not so much the highs, but eventually the highs should end up significantly above average too.  I'm on board with some of you for a change to a more wintry regime around mid-month and especially beyond.  I don't think it will be enough to overcome the warm departures earlier in the month, but I'll say this... if December does manage to be closer to average, then it would greatly increase the chances of DJF ending up colder than average for Chicago as I am expecting Jan/Feb to be colder than Dec, relative to average.

[gimmesnow]

They are calling for 50s next weekend. If I didn't have my jet ski in storage I'd totally throw on my diving suit and finally achieve merging of snowboard and jet ski season. At least it's going to be dry if it's going to be that warm.

[Iceresistance]

Hmmmm, watch the core of the cold in Siberia towards the end of the run

[jaster220]

Same 12z Euro puts together a pretty intense little storm for NY and N New England/Maine late weekend into Monday. Winter isn't totally "gone" from the CONUS.

[jaster220]

Would be nice to view the NL's

[westMJim]

Welcome to December and the start of meteorological winter. The November mean at Grand Rapids was 39.7 that is a departure of -0.3 the high for the month was 66 on the 16^th and the low was 18 on the 25^th and 28^th there was 1.67” of total precipitation 3.10 is average. There was 1.8” of snowfall 7.1” is average. At Lansing the mean was 39.1 for a departure of -04. There was 2.04” of precipitation 2.46 is average there. The official snowfall is not complete yet there.

The official H/L at Grand Rapids yesterday was 51/26 there was no precipitation the sun was out 78% of the time. The highest wind gust was 32MPH out of the SW. For today the average H/L is 41/28 the record high of 65  was set in 1970 the record low of 6 was set in 1976. The wettest December 1^st was in 2006 when 0.86” fell as 2.4” of snow fall. The most snowfall of 5” was in 2010 the most snow on the ground is 10” in 1940. Last year the H/L was 36/26 and there was a trace of snow fall.

 

[westMJim]

Some climate information for parts of SW Michigan.  The current 30 year mean temperature at Grand Rapids for December is 30.4.  The warmest day in December is 69 and that was on December 5, 2001 The coldest low in December is -18 and that was on December 5, 1983. The warmest mean temperature for any December is 39.1° in 2015 the coldest mean for any December is 17.1 in 1989. The average December snow fall at Grand Rapids is 20.8” the most snow to fall in any December is 59.2” in 2000 the least snow fall is 1” that fell in 2014 Last year 39.0”” of snow fell in December.  At Lansing the 30 year average temperature is 29.5 and the average snow fall amount is 11.3. The warmest mean was 39.0 in 2015 and the coldest was 13.9 in 1876. The most snow fall was in 2000 with 33.5” and the least snowfall was in 1889 when no snow fall was reported. The record high of 70 was set on December 31 1875 that was in the middle of a 4 day “heat wave” that saw highs of 60,70,65 and 62. The record low for December at Lansing is -25 on December 18, 1884.

Weather history for December 1st in SW lower Michigan. 2006: A snow and ice storm strikes southwest Lower Michigan. From 6 to 12 inches of snow falls from Muskegon to Ludington, while an ice storm causes power outages and treacherous travel conditions from Kalamazoo to Lansing.

For SE lower Michigan 1974, 19.3 inches of snow fell in Detroit. This was the second-highest snowfall ever recorded in the city.

For the USA 1970: Four tornadoes impacted east-central Wisconsin during the morning hours. The strongest tornado, an F3, formed at 10:15 AM near Medina in Outagamie County.  The twister moved northeast at 50 mph and destroyed twenty barns and five houses

 

[Stacsh]

Happy “winter”…

[Tom]

Happy Friday!  I can't believe it is already DEC as the Holidays are in full swing.  It is looking and feeling like winter here across the valley and up in the mountains.  Last night, I had my first Thunderstorm as a loud bolt of lightning struck with rolling thunder not far from my place just past 9:00pm.  Sunrise Ski Resort opens today in the White Mtn's and Mother Nature is laying down some timely snowfall today.

https://www.sunrise.ski/winter/snow-report/

 

 

[chescowxman]

Large range of temps this morning across the county with lower spots down into the mid-20's while the ridge locations stayed above freezing. Today should be close to normal high temps for the first day of December before a milder than normal weekend followed by a return to below normal temps next week. It looks like rain will overspread the area from SW to NE over the 3pm hour today and be over by 1am Saturday morning. More showers by Sunday AM but we should see a drier PM before more showers at night.

Records for today: High 70.9 (2006) / Low 7 (1967) / Rain 1.80" (1996) / Snow 0.5" (1907)

[Iceresistance]

MJO expected to be in Phases 7-8-1 by Mid to Late December

Then you have this in Mid-December, impressive signal from the GEFS.

[hawkstwelve]

Euro starting to pick up on the system around the 10th. Looking messy.

[Iceresistance]

CMC now has the Monster Trough the Euro had the other day

[tStacsh]

See ya'll in January.  Maybe Xmas time!   

[Black Hole]

For the most part models have been in good agreement on a deep trough over the west trying to move this way and a subtropical intrusion of moisture...but its been out of phase. Today, a few of the models bring them in at the same time giving the potential for a snow or ice storm near Dec 12th (+/- a few days)

Here is the CMC for the 10th with a sig snow storm and some ice over NM/NW TX. Lots of rain for the rest of OK (or ice if there is more low level cold air).

As the upper level low closes off and moves east it spins up a good surface low. The run doesn't go far enough to see the final result but this would be a snow or ice event for much of OK and the surrounding areas.

Now look at the ECMWF control for this period. This is probably a lot of snow in western OK and southern KS and ice for NE OK.

Now as the low tracks east it looks like a lot of snow for OK/KS/MO. 

Given that we are relying in the forecast of an ejecting closed low phasing with adequate moisture as well as the right timing of the cold air from the north its bound to change a bunch but at least we have something to watch now. 

 

 

 

[mlgamer]

A gentle light snow has been falling at times this afternoon, but our 7" storm has melted away so the ground is bare again.

I'm still seeing a 51-52 day LRC but what do I know...lol. Recent Decembers have been pretty snowless here for the most part so hopefully this one is more exciting.

[westMJim]

1 hour ago, tStacsh said:

See ya'll in January. 

Maybe not this winter. Of if so March/Arpil

[Iceresistance]

@hawkstwelve GFS now wants snow close to you by December 10th

[Clinton]

1 hour ago, mlgamer said:

A gentle light snow has been falling at times this afternoon, but our 7" storm has melted away so the ground is bare again.

I'm still seeing a 51-52 day LRC but what do I know...lol. Recent Decembers have been pretty snowless here for the most part so hopefully this one is more exciting.

You are correct on the 51 to 52 day Cycle per Lezak. That would make the storm talked about above the hurricane Norma part of the pattern.

[westMJim]

The official H/L at Grand Rapids yesterday was 40/33. That 40 was recorded at 2:30AM during the day there was a cold rain mixed with snow with 0.46” of rain and a official trace of snowfall. The average H/L for today is 40/28 the record high of 67 was set in 1982 and the record low of -11 was set in 1976 the wettest day was 1.48” that was in 1982 so that was a warm and wet day in 1982. The most snowfall of 4.8” fell in 1985 the most snow on the ground was 12” in 1940. Last year the H/L was 51/32 and there was 0.03” of rain.

[Tom]

This is one storm that we will be tracking over the next 7+ days...

0z Euro...

 

 

One thing that is almost certain as all the models are pretty much in agreement, is that the #STJ will be firing up next weekend into the middle part of DEC.

 

Out here in the SW, I can see the beautiful orange tint in the sky to my east as the first glimmers of daylight begin to emerge.  Sunrise is at 7:15am out here and Sunset is at 5:20pm.  The days are getting quite short out here and nights quite cool...nothing compared to your experiences out east.  

[hawkstwelve]

Iowa folks get buried again on the 06z GFS.