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December 11-13th MW/GL Snowstorm


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N shift on GFS - with more coverage. Concern here is N shift holding and continuing N to even NW. I think the later. This system moved too much S from previous guidance 3-4 days ago. A shift N- to NW is expected. Twin Cities are not out.

The two loudest sounds known to man: a gun that goes bang when it is supposed to go click and a gun that goes click when it is supposed to go bang.

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Unfortunately we’ve had 3 fatalities in front of my house🤣🤣

Solid 1" here with a fairly heavy, wet snow falling at 30 degrees and enough of a north wind to blow it around a little.  Streets are awfully slick.  My grids say 1-3" today and 1" tonight with no WWA

Awesomeness!!!

Posted Images

DVN giving me hope for at least something..

 

Northern stream energy will be onshore Thursday night and its
strength and evolution with lead southern stream trof will help
determine how strong our Friday-Saturday system will be. Both the
00z NAM/00z ECMWF show a negative tilt wave developing which results
in a stronger and slower dynamic system and in contrast the 00z
GFS/GEM show more a neutral tilt to this incoming system, which
would be somewhat weaker and faster moving. Surface low track has
come into slightly better agreement with 00z runs and their
ensembles, with a consensus track from SGF at 00z Sat, to STL, to
northern IN by 18z Sat. This normally would favor the local area
receiving heavy snowfall. However, the complicating factor with
this system as mentioned in previous discussion is that we will
have no cold arctic air in place. We will have to depend on strong
dynamics and high snowfall rates to get snow to accumulate on
warm ground/pavement. This is still a possibility, but confidence
still remains low.

QPF/Snowfall...

Model PWs will be rising above 0.75" which is 2-3 standard
deviations from the climatological mean per NAEFS output. Strong
lift ahead of the wave will result in rainfall totals over a half
inch by Saturday, especially in our southeast half of CWA. Lighter
amounts are expected further north and west. NBM weather type progs
have been trending further south with the rain/snow line late Friday
night, with most areas north of a Fairfield to Quad Cities line
seeing a changeover to all snow early Saturday. Latest 00z NAM and
WPC internal snowfall guidance would suggest a def zone snowfall
region and potential accumulating snow to set up somewhere over
south central IA through the Cedar Rapids/Iowa City metro, to
Freeport,IL on Saturday, with little to no accumulating snow south
and east of this line. Any deviation or change in low track in later
forecasts will shift this snowfall area. Wide range of possible
snow totals still exist and will be further addressed in later
forecasts.

Dubuque 2007-2008 Winter


 


78.1"  Total snowfall


February Snowfall 32.5"


City salt usage  : 12,211 tons


Days of measurable snow  : 40

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30 minutes ago, dubuque473 said:

DVN giving me hope for at least something..

 


Northern stream energy will be onshore Thursday night and its
strength and evolution with lead southern stream trof will help
determine how strong our Friday-Saturday system will be. Both the
00z NAM/00z ECMWF show a negative tilt wave developing which results
in a stronger and slower dynamic system and in contrast the 00z
GFS/GEM show more a neutral tilt to this incoming system, which
would be somewhat weaker and faster moving. Surface low track has
come into slightly better agreement with 00z runs and their
ensembles, with a consensus track from SGF at 00z Sat, to STL, to
northern IN by 18z Sat. This normally would favor the local area
receiving heavy snowfall. However, the complicating factor with
this system as mentioned in previous discussion is that we will
have no cold arctic air in place. We will have to depend on strong
dynamics and high snowfall rates to get snow to accumulate on
warm ground/pavement. This is still a possibility, but confidence
still remains low.

QPF/Snowfall...

Model PWs will be rising above 0.75" which is 2-3 standard
deviations from the climatological mean per NAEFS output. Strong
lift ahead of the wave will result in rainfall totals over a half
inch by Saturday, especially in our southeast half of CWA. Lighter
amounts are expected further north and west. NBM weather type progs
have been trending further south with the rain/snow line late Friday
night, with most areas north of a Fairfield to Quad Cities line
seeing a changeover to all snow early Saturday. Latest 00z NAM and
WPC internal snowfall guidance would suggest a def zone snowfall
region and potential accumulating snow to set up somewhere over
south central IA through the Cedar Rapids/Iowa City metro, to
Freeport,IL on Saturday, with little to no accumulating snow south
and east of this line. Any deviation or change in low track in later
forecasts will shift this snowfall area. Wide range of possible
snow totals still exist and will be further addressed in later
forecasts.

Dmx talking several inches C and S IA. ( Potentially) 

Thursday.

.LONG TERM.../Friday through Tuesday/
Issued at 410 AM CST Wed Dec 9 2020

Attention then shifts to the evolution of the weekend system as
it opens and lifts northeast into the Midwest. 00z deterministic
model output has shifted the storm track slightly to the NW
compared to runs 24 hours ago now putting the best band of snow
across generally the southern half of IA. Additionally, less
variability was noted amongst model solutions which has added to
confidence in the Friday-Friday night period. Open-wave reaches
the central plains around midday Friday, with initial moisture
surge arriving into southern IA at around the same time. Have
continued following the NBM trend boosting precipitation chances
into likely category across the south. Precip type on Friday will
be tricky and depend on the amount of cold air in place along w/
wet-bulbing if rates are sufficient. For now, have kept the
hedged forecast on Friday, maintaining -SN OR -RA. Cold air will
certainly be sufficient for snow accumulations mainly for Friday
night and Saturday morning, before the system departs Saturday
afternoon. Too early to get detailed on amounts, but some areas
across central and southern IA have the potential for several
inches of snow from this system. Storm track and amounts will
continue to be refined over the next few days, so those w/ travel
interests late Friday into Saturday morning will certainly want to
monitor future forecast updates.

The two loudest sounds known to man: a gun that goes bang when it is supposed to go click and a gun that goes click when it is supposed to go bang.

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06z Euro...nail biter around these parts...5-10 miles is going to make a big difference I think...sorta reminds me of the Nov '15 snowstorm that rocked the NW burbs while the city got zilch...

1.png

 

2.png

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Come to think of it, this storm is actually trending towards more of a "share the wealth" TX Panhandle cutter....we usually don't see much snow up into NE/ from these type of storms so consider this a win if it does happen.

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The majority of the snow in Iowa from I80 on north comes Friday night.  There are two waves with this.  The first wave comes through Friday with rain changing to snow and then looks pretty heavy at times, then a bit of a lull before the 2nd wave comes in Saturday morning.  That one hits southern Iowa harder and then into Illinois, which is why you are seeing the heavy totals in Northern Illinois and Southern WI.  

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Season Snowfall: 39.5"

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It's looking ok for Iowa, but models generally show the best moisture/dynamics/cold air coming together a bit farther east.

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season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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1 minute ago, bud2380 said:

The majority of the snow in Iowa from I80 on north comes Friday night.  There are two waves with this.  The first wave comes through Friday with rain changing to snow and then looks pretty heavy at times, then a bit of a lull before the 2nd wave comes in Saturday morning.  That one hits southern Iowa harder and then into Illinois, which is why you are seeing the heavy totals in Northern Illinois and Southern WI.  

This could be a trend towards a more robust second wave which was one of the features in the LRC pattern.

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I meant to reference, that is what the 6z Euro showed.  For my backyard it could come down to how quickly the rain transitions to snow and then how long does it take to accumulate.  It will require some heavy rates early on to get the accumulation going. 

Season Snowfall: 39.5"

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I have to think the NAM is too amped.  It cuts the surface low almost due north at the end, which seems unlikely.

season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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12z RGEM

snku_acc.us_mw.png

  • Snow 1

season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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49 minutes ago, Madtown said:

Maybe a bit too north, but I gotta believe the lack of cold air, the lack of snow cover and still somewhat early in winter makes this thing end up farther north than what everything was showing yesterday. Who knows.

It may come down to how much cold, dry air tries pushing in from the NW. Models the last few days had really been hitting the dry air hard, thus forcing the storm south. Now they seem to be backing off. While I don't think it's coming all the way back up this way, it's safe to assume there are more changes coming. 

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GFS going more amped.

gfs_mslp_pcpn_frzn_ncus_14.png

season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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I would like to see the storm amp up earlier so Iowa can get into the heavier snow.  Models are split on this.  The GFS doesn't really get going until farther east.

season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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Canadian a little warmer this run with wave 1 and brings a lot of rain to CR and IC.  Then the secondary wave is further north than the GFS and brings some decent snows to eastern Iowa.  Further north fairs better since they stay snow the whole event.

 

gem_asnow_ncus_14.png

Season Snowfall: 39.5"

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12z Canadian is stronger, but marginal temps keep it all rain in se WI.

season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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Canadian snow map is very different than the GFS.  The two are only off by 12+ inches over southeast WI.

 

snku_acc.us_mw.png

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season snowfall: 52.5"

 

'19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"      '16-17: 17.9"      '15-16: 20.0"      '14-15: 30.4"      '13-14: 48.3"      '12-13: 34.1"

 

Average snowfall: ~30"

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Looks like KC will see some rain(not much) and maybe a few wet snowflakes Saturday.(We really need moisture(moderate drought here) The data never shows us getting below 33-34 degrees while the precipitation is here. Even in the snow areas, temps look just cold enough. Likely a really wet snow for the ones that get it. 

For the ones that get the snow, enjoy it, as the GFS goes back to a flame thrower across the country in the mid range. No deep cold anywhere to be found. Hopefully that changes soon. 

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7 hours ago, Tom said:

00z EPS and Control...

1.png

 

 

 

3.png

 

2.png

Crazy to see the Euro Op run so far removed from it's own Ensemble Mean. The Ens map seems in line with other models leaving the Op on it's own island. I see 6z finally fell in line with others but wow it was way off for several runs with the S track tease.

Winter 2020-21 Snow Total = 35.1"  Largest Storm: 10.2" (2/15-16)        Oct: 0.0 Nov: 1.5 Dec: 3.6 Jan: 10.0 Feb: 20.0 Mar: 0.0 Apr: 0.0

 

Annual avg for mby = 49.7"  Avg for last 10 seasons = 58.4" (118% of normal)

2019-20 = 48.0"  2018-19 = 56.1"  2017-18 = 68.3"   2016-17 = 52"   2015-16 = 57.4"   2014-15 = 55.3"   2013-14 = 100.6" (coldest & snowiest in the modern record!)  2012-13 = 47.2"   2011-12 = 43.7"

 

Legit Blizzards (high winds and dbl digit snows): Feb 2011, Dec 2009, Jan 2005, Dec 2000, Jan 1999, Mar 1998, Nov 1989, Jan 1982, Jan 1978, Jan 1977, Apr 1975, Mar 1973, Jan 1967, Feb 1965, Jan 1918

 

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3 hours ago, Stacsh said:

Another cold December rain for SMI.  This is getting old.  

Don't forget the part where we wait another 50 days for our next chance hoping it's actually cold enough then. We aren't getting a "winter" this year. Maybe a random storm in April when we don't want one, but not a winter. If it does get cold, track will prolly move over to the EC or such.

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Winter 2020-21 Snow Total = 35.1"  Largest Storm: 10.2" (2/15-16)        Oct: 0.0 Nov: 1.5 Dec: 3.6 Jan: 10.0 Feb: 20.0 Mar: 0.0 Apr: 0.0

 

Annual avg for mby = 49.7"  Avg for last 10 seasons = 58.4" (118% of normal)

2019-20 = 48.0"  2018-19 = 56.1"  2017-18 = 68.3"   2016-17 = 52"   2015-16 = 57.4"   2014-15 = 55.3"   2013-14 = 100.6" (coldest & snowiest in the modern record!)  2012-13 = 47.2"   2011-12 = 43.7"

 

Legit Blizzards (high winds and dbl digit snows): Feb 2011, Dec 2009, Jan 2005, Dec 2000, Jan 1999, Mar 1998, Nov 1989, Jan 1982, Jan 1978, Jan 1977, Apr 1975, Mar 1973, Jan 1967, Feb 1965, Jan 1918

 

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Loving the UKIE.  Man that would be about as good as I can hope for with this storm.  I'm guessing the NWS will wait until at least tomorrow morning to post any headlines.  Even though model consensus is tightening there is enough variance yet to be cautious. 

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Season Snowfall: 39.5"

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