1/28 - 1/29 Weekend Snowstorm - Plains/MW/GL

[bud2380]

Regional Canadian further south than the NAMs. 

[Clinton]

20 minutes ago, hawkstwelve said:

I'd take the consistency of the Euro over just about anything else. While it can still be subject to last minute shifts like every other model, when it's consistent like this it's not often that it's wrong, from my experience. 

The 00z 3km NAM is actually not too far off from the 18z Euro now. I wouldn't be surprised to see other 00z runs settle somewhere around there too.

The NAM showing the heaviest totals near your back yard and NW Iowa seems like a good bet to me.  And the NAM has been really good as of late.

[Grizzcoat]

00Z GFS--- 6" difference t between DSM and Lames--

[Grizzcoat]

CMC looks very similar to GFS-

[Grizzcoat]

ukie-

[Hawkeye]

3 minutes ago, Grizzcoat said:

ukie-

The UK has a 6-hour period where the snowfall doesn't show, which is why northeast Iowa is so dry.

[Hawkeye]

03z RAP... even farther north.  I have to think this may be too far north.  Heck, the GFS has several inches across the entire Chicago area while the RAP has zero.

[Grizzcoat]

6 minutes ago, Hawkeye said:

The UK has a 6-hour period where the snowfall doesn't show, which is why northeast Iowa is so dry.

I see that -- odd. add about .5 to 1.5" to those totals from C.IA on E if you use the 12Z

[hawkstwelve]

At this point I think 3-6 inches is a reasonable call for FSD, similar to the last storm.

Pair that with the inch or so we got tonight and it should put us over the 22.2 inch record (1929) needed in order to take the crown for January!

[hawkstwelve]

00z Euro with a slight shift north vs 18z with the first wave.

[hlcater]

Getting close on being time to punt for those south of 20. With the trends tonight its looking like this might be ANOTHER 1" snow.... yay.

[Hawkeye]

2 minutes ago, hlcater said:

Getting close on being time to punt for those south of 20. With the trends tonight its looking like this might be ANOTHER 1" snow.... yay.

Assuming we get a bit Friday and again Saturday, I may end up with six consecutive 0.5-1.3" snows.  Unfortunately, the fact is our snow climate sucks.  It's a nickel/dimer climate and it always will be.  Ten variables have to align perfectly just to get 6".

[hlcater]

2 minutes ago, Hawkeye said:

Assuming we get a bit Friday and again Saturday, I may end up with six consecutive 0.5-1.3" snows.  Unfortunately, the fact is our snow climate sucks.  It's a nickel/dimer climate and it always will be.  Ten variables have to align perfectly just to get 6".

I've got exactly 1 event down over 3" so far this year. Pathetic.

[Tom]

This is the type of system where we should really pay attn to the ensembles instead of each operational run.  There is stark consensus between the GEFS/GEPS...

0z GEPS...

 

 

0z GEFS...

 

0z GEPS...

[Tom]

0z GEFS...I'm also seeing more members suggesting another weaker wave on Mon that could add another 1-2" in spots...

 

[Tom]

0z EPS...hmm, surprised it trended north tonight...

 

 

[Tom]

06z GFS...

[Tom]

06z RDPS...I remember the Canadian model was one of the best to use tracking clipper systems during the '13-'14 season among others.  Some of the models are suggesting the lake get involved depending on the track of the wave, NE IL may score a few inches if things line up right.

[Tom]

LOT has some interesting wording suggesting convection within the meso bands that will develop...they are also suggesting snow ratios to be 12:-14:1...

There will be several sheared mid-level short-wave impulses
interacting with a quasi-stationary frontal boundary draped
across the area in a zone ranging between roughly I-80 on the
north end of model guidance and US-24 on the south end of model
guidance during the day on Saturday. The lower and mid-level wind
response to these disturbances acting upon a tight baroclinic
zone (thermal gradient) will help induce a frontogenetic
circulation and likely a narrow (~2-4 county wide) snow band
producing moderate to heavy snow. Finally, upper level jet
dynamics are also expected to aid in the large scale ascent.
A few additional pieces of the puzzle will be steep mid-level
lapse rates within and above the DGZ plus a plume of 150-200% of
normal PWATs to tap into. The reduced static stability and
potential for even some upright convection is a common trait of
mesoscale snow band events.

 

Izzi touches on bit on the lake enhancement scenario...

Finally, improving lake induced thermodynamics and convergence
should help at least loosely organized lake enhancement take shape
late Saturday night. Inversion heights are expected to be modest,
but good convergence and lake induced CAPE (100-300 J/kg) could
yield some additional minor accumulations near the lake in a zone
from the Chicago shore and points south and into parts of
northwest Indiana, depending on how quickly the convergence axis
shifts. The lake effect snow threat should wind down by mid day
Sunday. Temperatures will only recover to near/around 20 northwest
and mid-upper 20s elsewhere Sunday afternoon, with slowly
diminishing northerly winds keeping wind chills in the single
digits and teens.

 

[Tom]

06z GEFS...it's hard not to dismiss the consistency...

[Tom]

06z Euro...still north

[Clinton]

6 hours ago, hawkstwelve said:

00z Euro with a slight shift north vs 18z with the first wave.

Almost a perfect match with the map from the previous cycle I showed.  Congrats on what's about to be a record breaking January for you.  Now share some lol!

[westMJim]

1 hour ago, Tom said:

Izzi touches on bit on the lake enhancement scenario...

With a NE wind your area has a good chance of lake enhancement 

[westMJim]

The temperatures have fallen here in the last hour and looking out the window the wind has also picked up as well. At this time there is a little bit of red/pink to the sky looking to the west. That is a little odd as the sky to the east is clear but there are clouds to the west and they (the clouds) are red. 

[Up_north_MI]

3 minutes ago, westMJim said:

The temperatures have fallen here in the last hour and looking out the window the wind has also picked up as well. At this time there is a little bit of red/pink to the sky looking to the west. That is a little odd as the sky to the east is clear but there are clouds to the west and they (the clouds) are red. 

I always like your detailed updates. Our son goes to Grand Valley University and it’s nice knowing what kind of weather he’s dealing with over there.

[hawkstwelve]

NWS FSD is not buying the northern solutions. They mentioned dry air below 700mb on the northern side of the band that they expect to cut totals more than models are showing. Winter weather headlines extend right to the county across the street to the south but not to Minnehaha for Sioux Falls. 

This all feels very familiar to the last storm system we had where they had no advisory for us until the last minute. We ended up with 4.5 inches here. Slightly different scenario but expecting the same possible outcome.

[Hawkeye]

12z HRRR... 

[hawkstwelve]

8 minutes ago, Hawkeye said:

12z HRRR... 

What the heck... HRRRRRRR is starting Friday off with a shot of whiskey apparently. Almost doubled FSD total from 06z run. No way we end up with close to a foot. It's off it's rocker.

[Stacsh]

Models have consistently showed my area with 6+ between the next two storms.  This set up could certainly over-perform as well.  

[bud2380]

Well models keep trending further and further north. Even the further south FV3 just barely keeps Cedar Rapids in the heavier bands now. Highway 20 in Iowa is where you want to be. 

[Tom]

Either the NAM and CAM's score a massive win..or...the GEFS/GEPS/UKIE fail bigly inside 48 hours...

[james1976]

Had an overnight refresher up here in MN. Eyeballing at least an inch....maybe 2? Down in IA my place is in a WWA tomorrow for 3-5"

[bud2380]

18 minutes ago, james1976 said:

Had an overnight refresher up here in MN. Eyeballing at least an inch....maybe 2? Down in IA my place is in a WWA tomorrow for 3-5"

Yeah I drove right through all that last night on my way up to Menahga MN. It really came down for a while. Roads were nearly 100% snow covered. Couldn’t even see the lines at times. Made for an interesting drive. Looks like they got about 1.5” here in Menahga. 

[hawkstwelve]

WWA issued for Minnehaha just a bit ago, calling for 2-5 inches. RGEM went from 4.1" on the 06z to 6.5" on the 12z. The more northern NAM made a slight shift south, moving from 9.2" to 8.0" on the 12z. FV3 went from 2.1" on the 00z to 5.7" on the 12z. WRF ARW went from 3.2" to 7.8" and the WRF-NSSL went from 7.6" to 10.3".

All to say that so far 12z runs appear to be increasing totals for FSD. I wouldn't be surprised if they upgrade the WWA to a WSW with this afternoon's forecast package if the remaining 12z suite comes in following the same trend. Unless they are putting a lot of weight on dry air screwing up totals.

[hawkstwelve]

 

[hlcater]

All the NAM derivatives are crazy north. Just don’t think this pans out well here but we’ll see I guess

[tStacsh]

Models are all over the place still.  So I'm going with the globals at this point.  Euro and GFS are very similar.   Canadian is south.  Nam is way too far north.  

[CentralNebWeather]

I think the Canadian will be pretty close to what pans out in my area.  It has stayed very steady with these amounts.  Still believe in the Arctic air that a band or two could set up and drop higher amounts of snow over a small area, but those are nowcast and radar.

[bud2380]

Pray for the Canadian. 

[Bellona]

The NAM has me concerned but otherwise I feel pretty good for 4-6 around Waterloo and along Highway 20. 

[westMJim]

No snow falling here, in fact there is some filtered sunshine at this time. There is also some wind. The temperature is 27. As for the snow today and tomorrow? Well we shall see. For today I do not expect much and for tomorrow? As I said we shall see.  

[hawkstwelve]

15z RAP with a shift to the south vs 09z.

[jaster220]

CAM's slow to pick-up on the density of incoming cold (yeah, actual real-deal winter cold temps-go figure)??

[jaster220]

Congrats @Tom (and other ORD Peeps ofc) for reeling this one in:

 

[hawkstwelve]

NWS FSD updated zone forecast showing total accumulations of 4-6 inches for Minnehaha, up from 1-5" earlier this morning. Pretty close now to what I've been expecting out of this one.

[hawkstwelve]

12z Euro shifts slightly back to the south vs 06z.

[Hawkeye]

Man, there's still a wide range of solutions from the models today.  Most likely, the far north (HRRR) and far south (GDPS) are wrong and it will end up in the middle.

[CentralNebWeather]

Have made it up to 37 so far.  Some melting going on, but the glacier is still intact with the massive piles and drifts looking good. Hoping for an 1-2" over the next few days, but most forecasts are very pessimistic on accumulations in our area.  

[bud2380]

Euro up to 4.7” for CR. Not bad. It’s riding a fine line though. But if it can shift 10-15 miles south even total would jump even more. 

[Hawkeye]

18z HRRR south a bit, still well north of the globals.