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Season's First Potential Wintry Storm and Arctic Outbreak


Tom

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Euro is dry as a bone.  That seems odd.

 

 

For Iowa City

MON 18Z 10-NOV   6.2     5.1    1006      59      36    0.00     556     551    TUE 00Z 11-NOV   7.5     5.0    1002      74      49    0.00     555     554    TUE 06Z 11-NOV   3.8     3.1    1005      87      60    0.01     553     549    TUE 12Z 11-NOV   0.3    -5.6    1012      80      71    0.03     547     538    TUE 18Z 11-NOV                                          0.00                
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Nevermind, I found the snow.  It's in Wisconsin.  Below is LaCrosse

MON 12Z 10-NOV  -1.5    -7.6    1015      55      99    0.02     549     537    MON 18Z 10-NOV  -2.5    -5.7    1013      82      99    0.26     548     538    TUE 00Z 11-NOV  -1.6    -5.7    1011      89     100    0.35     547     538    TUE 06Z 11-NOV  -1.7    -6.5    1011      90      98    0.22     544     535    TUE 12Z 11-NOV  -3.1    -7.9    1014      87      97    0.10     540     529    TUE 18Z 11-NOV  -1.4    -9.4    1016      76      97    0.05     536     523    
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What should we digest from the 12z model runs today?  #1, looks like their is model agreement on developing a SLP in the Plains that heads into the Lakes and NOT a sheared system.  #2, track and strength still uncertain

 

 

The GFS doesnt try to phase the system until its way east which is the typical error of the model to skirt the energy out to fast to the east.

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Nevermind, I found the snow.  It's in Wisconsin.  Below is LaCrosse

MON 12Z 10-NOV  -1.5    -7.6    1015      55      99    0.02     549     537    MON 18Z 10-NOV  -2.5    -5.7    1013      82      99    0.26     548     538    TUE 00Z 11-NOV  -1.6    -5.7    1011      89     100    0.35     547     538    TUE 06Z 11-NOV  -1.7    -6.5    1011      90      98    0.22     544     535    TUE 12Z 11-NOV  -3.1    -7.9    1014      87      97    0.10     540     529    TUE 18Z 11-NOV  -1.4    -9.4    1016      76      97    0.05     536     523    

Looks like a juicy system for sure...over 1"qpf is well over 12" of snow....EURO/GGEM consistency

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The heavy snow will probably pass north of the Cedar Rapids to Chicago corridor, but I hope we can at least see something fall.

season snowfall: 34.8"

'22-23: 30.2"      '21-22: 27.1"      '20-21: 52.5"      '19-20: 36.2"      '18-19: 50.2"      '17-18: 39.5"

Average snowfall: ~30"

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It will be interesting to how far the cold air dome can press this system south. 

 

As far as ground temperatures. I've seen a foot of snow stick after a week of 50s and 60s in late November before! The cold air in place now will act to cool off the top layer of the soil.

Mercer Island, 350 ft

2021-2022: 11.6", 02/21

2020-2021: 15.6"

2019-2020: ~10"

2018-2019 winter snowfall total: 29.5"

2017-2018: 9.0", 2016-2017: 14.0"

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First post this young winter season-- so that is good being NOV 6th. Loved seeing the 12Z GFS run--)5"+ here in C.IA-- but I believe it's wrong. The Euro has been the most consistent and has superior physics to the GFS-- which is huge with what is transpiring around the globe (SOI index tanking etc-- PV about to get displaced and the adjustment of the seasonal jet(s).  Also--  I remind folks that 18Z and 06Z GFS/NAM DO NOT(at least last year they didn't)  ingest upper air parameters into the runs-- so take them with a grain of salt. I believe the Euro is locked in and do not see a shift of more then 50 miles N or S.

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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Impressive totals. Need to shave off 0.5-1.5" in parts of northern and central WI and a few inches in northern Lower MI from snow predicted this weekend.

 

 

Mercer Island, 350 ft

2021-2022: 11.6", 02/21

2020-2021: 15.6"

2019-2020: ~10"

2018-2019 winter snowfall total: 29.5"

2017-2018: 9.0", 2016-2017: 14.0"

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Been watching this storm with varying opinions.

 

On one hand, as has been mentioned, model guidance does hold a bias to be too slow with Arctic fronts. This could eventually favor another southward shift, though with consistency with snow up in Wisconsin, I wouldn't be surprised to see that end up verifying.

Additionally, my two cents on ground temperatures, they really can wreak havoc on snow accumulations. Depending on surface temps as far out as 14 days before the event, snow can either be very difficult to come by (i.e sunny and warm weather prior to a storm), or unexpectedly easy (i.e. frost/freezes on a nightly basis, generally cloudy during the day to suppress highs). Point is, ground temps, especially this early in the season, are quite a bit more variable than they may be made out.

For the snow maps, I'll go conservative purely because the liquid and snow parts of this storm are so close to each other, as usually happens in early-season storms (good example is that sharp cut-off in the GGEM snow map).

 

Edit to add the massive caveats in using 10:1 ratio snow maps. Ratios will likely end up lower than 10:1; it's only November, in addition to the aforementioned rain/snow mixing concerns.

 

Max totals of around 10-12" in central Wisconsin will be my going call for now.

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In regards to the ratios, it depends where you are imo. LSE has 850 MB temps on the EURO between -5 and -10 with 2M temps between -1 and -3. Closer towards the track of the low, I would agree with the lower ratios, but out towards LSE and that area on the EURO I can see 10-12:1 ratios. 

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Ground temps as of last evening from the DSM NWS office--

 

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
545 PM CST WED NOV 5 2014

...DAILY 4 INCH SOIL TEMPERATURES...

.BR DSM 1105 C DH1700/TSIRZZ
:
:ID LOCATION 4 INCH TEMP
:
CSAI4 : CASTANA : 47
DVNI4 : DAVENPORT : 51
DMXI4 : JOHNSTON : 44
DCRI4 : DECORAH : 42
ICYI4 : IOWA CITY : 44
KANI4 : KANAWHA : 46
3OI : LAMONI : M
NHUI4 : NASHUA : 46
OELI4 : OELWEIN : M
TLDI4 : TOLEDO : 42
.END

$

 

Those are 4" temps.. wont take much more cooling.

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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In regards to the ratios, it depends where you are imo. LSE has 850 MB temps on the EURO between -5 and -10 with 2M temps between -1 and -3. Closer towards the track of the low, I would agree with the lower ratios, but out towards LSE and that area on the EURO I can see 10-12:1 ratios.

 

Fair enough, let's dive deeper into the matter of location.

Using the ECMWF projected temperatures of a few degrees below freezing (minimum on the text chart posted above is -2.5, equivalent to ~27 degrees F). Noting that the going temperatures should range around -1.7 or so when the most precipitation falls, as that -2.5 value is a "blip" in the text, we can categorize the situation into a snow ratio table.

 

Using the NWS Snowfall/Meltwater table, using the left-most column for these surface temperatures, 1.00" of QPF on that text output would come out to 10.0" of snow. If you want to dig a bit deeper and favor the lower end of that temperature spectrum, maximum snowfall closer to 12" or 13" would probably be in the cards.

 

Snowfall table http://www.erh.noaa.gov/box/tables/snowfall-meltwater.html

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Been watching this storm with varying opinions.

 

On one hand, as has been mentioned, model guidance does hold a bias to be too slow with Arctic fronts. This could eventually favor another southward shift, though with consistency with snow up in Wisconsin, I wouldn't be surprised to see that end up verifying.

 

 

Yeah I've witnessed that point of yours before. Arctic air masses like to press southwards quicker and tighten up the baroclinic zone.

It will be interesting to see how cranked up the NAM can get with this system. I can only imagine it's going to put out some insane numbers.

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Mercer Island, 350 ft

2021-2022: 11.6", 02/21

2020-2021: 15.6"

2019-2020: ~10"

2018-2019 winter snowfall total: 29.5"

2017-2018: 9.0", 2016-2017: 14.0"

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Yeah, im not worried about snow not accumulating. I was just pointing out what our local met is saying. He is very conservative this far out. He does that with every system.

I am hoping for a southward shift with the Euro!

Snowman: Do you know if 18z and 6z runs have upper air parameters digested this season?

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Fair enough, let's dive deeper into the matter of location.

Using the ECMWF projected temperatures of a few degrees below freezing (minimum on the text chart posted above is -2.5, equivalent to ~27 degrees F). Noting that the going temperatures should range around -1.7 or so when the most precipitation falls, as that -2.5 value is a "blip" in the text, we can categorize the situation into a snow ratio table.

 

Using the NWS Snowfall/Meltwater table, using the left-most column for these surface temperatures, 1.00" of QPF on that text output would come out to 10.0" of snow. If you want to dig a bit deeper and favor the lower end of that temperature spectrum, maximum snowfall closer to 12" or 13" would probably be in the cards.

 

Snowfall table http://www.erh.noaa.gov/box/tables/snowfall-meltwater.html

 

Don't disagree with you, but in the bullseye on the euro it's showing 1.4-1.5 QPF. Using 8:1 ratios would give you 11-12 inches or so. If you use 10:1 it would be closer to 14-15.

 

We are talking about a system that is 96 hours out yet and probably going to change multiple times yet, so meh. I want to see consistency from the models in the 0z and 12z run tomorrow before getting excited. 

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The end of the NAM run. Of course this will change many times!

 

 

Henry M. at Accuweather is siding with the snow area further south.

http://www.accuweather.com/en/weather-blogs/meteomadness/the-cold-is-coming-but-warmth-ahead-of-the-frontsee-video/36943053

Mercer Island, 350 ft

2021-2022: 11.6", 02/21

2020-2021: 15.6"

2019-2020: ~10"

2018-2019 winter snowfall total: 29.5"

2017-2018: 9.0", 2016-2017: 14.0"

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This is coming from the all too conservative Valley NWS...........

 

IN ADDITION...AND WHICH HAS BEEN THE CASE FOR A FEW RUNS
NOW...ECMWF GENERATED MUCH LESS QPF ACROSS THE FA THAN THE GFS AND
CANADIAN. IN FACT...THE GFS AND CMC WOULD SUGGEST THERE COULD BE
SOME SIGNIFICANT SNOW ACCUMULATIONS ACROSS NRN 1/2 OR SO OF THE FA
AS COLUMN COOLS AND A DECENT FRONTOGENETICAL PRECIP BAND SETS UP.
MODEL BLEND MAY STILL BE TOO LOW WITH POPS..BUT SINCE ECMWF
REMAINED MUCH DRIER...DID NOT ADJUST POP UPWARD JUST YET.

IF WETTER GFS/CMC WOULD VERIFY COULD SEE THE NEED FOR LOWERING
TEMPS A CATEGORY OR SO IN THE TUE-THU PERIOD ALTHOUGH EVEN ABSENT
POTENTIAL SNOW COVER

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How does this storm look for SEMI?! Im thinking by the projected track that my area gets a rain/snow mix and possibly changing to all snow with no accumulation or maybe little accumulation. I need this baby to go a little more south.

Snowfall for Winter 2023 -24 for Metro Detroit Area 

Oct 2023: 0.2" AN

Nov 2023: 2.2" AN

Dec 2023: 0.5" BN Insane!

Jan 2024: 17.0" AN

Feb 2024: 1.9"  BN

Mar 2024: 4.9" BN

April 2024:

Season So Far: 26.7"

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Yeah, im not worried about snow not accumulating. I was just pointing out what our local met is saying. He is very conservative this far out. He does that with every system.

I am hoping for a southward shift with the Euro!

Snowman: Do you know if 18z and 6z runs have upper air parameters digested this season?

Aside from the usual aircraft OBS & such, no 6z/18z soundings will be released this winter.

Relevant to the topic, however, is that after undergoing a study (can't recall who conducted it), the 6z and 18z runs were shown to maintain a relatively similar consistency/accuracy with the 0z/12z runs.

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Don't disagree with you, but in the bullseye on the euro it's showing 1.4-1.5 QPF. Using 8:1 ratios would give you 11-12 inches or so. If you use 10:1 it would be closer to 14-15.

 

We are talking about a system that is 96 hours out yet and probably going to change multiple times yet, so meh. I want to see consistency from the models in the 0z and 12z run tomorrow before getting excited.

 

I don't have access to the Euro maps as of now (though I'm tempted to get back in to WxBell); I had assumed the text output showed max QPF for the storm.

With 1.4" QPF projected, yeah, ~14" max accumulations would be expected, should the forecast verify as-is.

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http://www.tropicaltidbits.com/analysis/models/gfsp/2014110618/gfsp_mslp_pcpn_frzn_us_15.png

Check out the placement of the ULL in SE Canada above, then look at the 18z GFS....stark differences and this is why the map above has the storm cutting north earlier than the 18z GFS operational.  IMO, the placement of where this feature sets up will determine the storm track of this system.  This is why on the 18z GFS the track is farther south and ultimately doesnt cut up north.  Past experiences tell me this feature will want to push south and correct farther west (slightly) so maybe the GFS is hinting at that.

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Check out the placement of the ULL in SE Canada above, then look at the 18z GFS....stark differences and this is why the map above has the storm cutting north earlier than the 18z GFS operational.  IMO, the placement of where this feature sets up will determine the storm track of this system.  This is why on the 18z GFS the track is farther south and ultimately doesnt cut up north.  Past experiences tell me this feature will want to push south and correct farther west (slightly) so maybe the GFS is hinting at that.

 

Bastardi was getting at that in one of his discussions yesterday. The trough and ULL is placed too far east and will correct west. The low in Quebec or Ontario will acts to drag the cold air down in front of the Plains low. 

Mercer Island, 350 ft

2021-2022: 11.6", 02/21

2020-2021: 15.6"

2019-2020: ~10"

2018-2019 winter snowfall total: 29.5"

2017-2018: 9.0", 2016-2017: 14.0"

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