February 5th-6th Midwest Snow Storm

[hlcater]

the 3km NAM upped totals significantly. It is also slightly further north than the rest of guidance.

 

http://maps3.pivotalweather.com/maps/models/nam4km/2018020500/030/snku_acc.us_mw.png

[GDR]

Nam loves the north trend

[hlcater]

Nam loves the north trend

but it's been trending south???

[GDR]

Icon hits Dsm northwest hard

[Hawkeye]

Icon hits Dsm northwest hard

 

The ICON and RGEM are holding steady with central to southeast Iowa, vs the NAM's nw to ec.

[Hawkeye]

Whoa, the 00z GFS went even farther south, is now the driest run for CR of any model in the last three days, with only 0.2".

 

The ICON, RGEM, and GFS are trying to dive the heavy snow southeast instead of east/ese.

[Madtown]

added to the wwa 2-4". Shocked wasn't expecting anything outta this one

[Hawkeye]

Uh oh, the 00z GFS went even farther south, is now the driest run for CR of any model in the last two days, with only 0.2".

 

The ICON, RGEM, and GFS are trying to dive the heavy snow southeast instead of east/ese.  I hope the NAM and Euro are seeing something the others are missing.

[hlcater]

Uh oh, the 00z GFS went even farther south, is now the driest run for CR of any model in the last two days, with only 0.2".

 

The ICON, RGEM, and GFS are trying to dive the heavy snow southeast instead of east/ese.  I hope the NAM and Euro are seeing something the others are missing.

Looks like we have the HRRR/RAP and the WRFs(from what I can tell, no precip amounts whatsoever, which makes things complicated) on our side though, whatever that combo of CAMs is worth.

[james1976]

GFS op run looked like 18z to me....however i have not seen snowfall maps.

[james1976]

is the 3k nam any good within 24 hours?

[bud2380]

Canadian has the heaviest snow in central and south central Iowa.  looks like about 1/4" qpf for most of eastern Iowa. 

[jaster220]

GRR AFD headline

 

 

.UPDATE...

Issued at 1032 PM EST Sun Feb 4 2018

 

I have issued a winter weather advisory for Monday evening into

the mid morning hours of Tuesday for most of the counties between

the Lake Michigan shore and US-131. It appears there will be one

of those southwest flow enhanced snowfall events Monday evening.

As the shortwave approaches southwest Michigan we get southwest

winds ahead of the surface trough. That creates the classic

enhanced southwest to northeast snow bands from southwestern Van

Buren County into southern Kent County. The max lift is in the DGZ

and the DGZ is unusably deep, from 2000 ft agl to 15,000 ft on

the latest NAMNEST. Most of the heaviest snowfall will be Monday

night prior to midnight. The Hi Res WRF NMM, WRF- ARW, WRF- ARW2,

and NAM 3km are all showing a band of 3 to 6 (locally 8`) in that

band. It would seem lingering snow showers will continue most of

the day on Tuesday as there is lift in the DGZ, it is more than

cold enough and winds are northwest. The limiting factor for snow

during the day Tuesday is the shallow inversion heights, near

5000 ft agl.

[Minny_Weather]

The "North" in "North American Mesoscale" has a double meaning tonight.

[Tabitha]

It is not a hobby anyone can quit...giving up smoking would be 100 times easier.

 

NNM (or is NMM?...always get that confused) and the 18z ICON only hope here for tonight.

 

What looked like a non-event 12 hours ago suddenly has some additional support from 0z HRDPS & 0z NAM...with close to 1/4 inch LE...with temps in the teens; it could be a nice little snowfall after 1 AM MDT Monday morning.

[Tabitha]

The "North" in "North American Model" has a double meaning tonight.

 

The NAM is the North American Mesoscale; actually.

[Tabitha]

is the 3k nam any good within 24 hours?

 

Yes it is.  It has had a good handle on the pattern (at least here) for the last three months.  Very good in fact; inside 24.

 

For example; yesterday all the models had snow continuing after 5 PM all through the night.  The NAM shut things off after 0z (which is 5 PM MDT).  Practically nothing but light flurries & snow showers fell after dark here yesterday.

[Hawkeye]

00z UK is holding serve, if not a hair north.

[Minny_Weather]

The NAM is the North American Mesoscale; actually.

Excuse me, I'm running off not sleeping for 24 hours.

[Tabitha]

Excuse me, I'm running off not sleeping for 24 hours.

 

Then you should take a nap so you can enjoy the snow; if it does come your way.

[Tabitha]

The NAM is most known for very sharp QPF cutoffs; and a general rule of thumb is that if the EC and the NAM agree; the outcome is more or less written in stone; no matter what any dissenting models might say.

[Minny_Weather]

Then you should take a nap so you can enjoy the snow; if it does come your way.

I should be out of class by the time it starts tomorrow. I'll probably have to enjoy it from downtown Lincoln instead of on my couch with a fire going like usual.

[Tabitha]

I should be out of class by the time it starts tomorrow. I'll probably have to enjoy it from downtown Lincoln instead of on my couch with a fire going like usual.

 

Gee; you must be one of those "Rich Kids"; the son of a Texas oil baron; perhaps?

[Hawkeye]

00z UK precip.... loses a bit of its punch as it reaches eastern Iowa.

 

[Minny_Weather]

Gee; you must be one of those "Rich Kids"; the son of a Texas oil baron; perhaps?

Well I did come here from Texas, but sadly my dad is a consultant who currently works in Detroit.

[Hawkeye]

The HRRR is now in nearly full range, so here is its initial qpf forecast for Iowa... much more like the NAM/Euro, showing squat for southern Iowa where the GFS/GDPS/ICON are painting heavy precip.

 

[james1976]

Love where I'm at with this one!

[Craig-OmahaWX]

Yeah won't get anything from the HRRR lol. GFS / RGEM / CMC both gives us 2 inches. I would take that in a heartbeat.

[james1976]

Looks like an IA special......just 'where' in IA? lol

[Tabitha]

What looked like a non-event 12 hours ago suddenly has some additional support from 0z HRDPS & 0z NAM...with close to 1/4 inch LE...with temps in the teens; it could be a nice little snowfall after 1 AM MDT Monday morning.

 

The ARW 2 hits this are very hard with some intense snow starting...well; in less than an hour...with 0.3 LE +

 

We'll see.

[james1976]

The ARW 2 hits this are very hard with some intense snow starting...well; in less than an hour...with 0.3 LE +

 

We'll see.

Did it initiate well?

[Hawkeye]

00z Euro.... holding serve, a bit drier here... just under 0.30".

 

Models, in general, are showing the qpf peaking out in central Iowa.

 

[Tabitha]

Did it initiate well?

 

I didn't take the time to look...if it didn't; I rather not know.

 

Sometimes ignorance is bliss.

[james1976]

I didn't take the time to look...if it didn't; I rather not know.

 

Sometimes ignorance is bliss.

No doubt about that

[james1976]

​Time to lock in to radar and short term model trends. Should be wide spread advisory snows at least.

[Tabitha]

The ARW 2 hits this are very hard with some intense snow starting...well; in less than an hour...with 0.3 LE +

 

We'll see.

 

Few flurries at 12:23 AM MDT.

[Grizzcoat]

Potential pound town MBY???  Literally 10 miles N of me.

[dubuque473]

Looks great

[bud2380]

The rap and hrrr have consistently been targeting highway 30 in Iowa with some very heavy snow

[bud2380]

The cutoff on the HRRR is very sharp between CR and Iowa City. Iowa City keeps showing up on the southern edge of the heaviest band. Cedar Rapids looks to be in a great spot. I’m right in between.