March 23rd/24th snow - Working towards average by May!

[bud2380]

3k NAM vs. HRRR.  Big difference on that north edge in Iowa.  

 

 

http://maps3.pivotalweather.com/maps/models/nam4km/2018032318/039/snku_acc.us_mw.png

 

 

HRRR

 

http://maps2.pivotalweather.com/maps/models/hrrr/2018032319/018/snku_acc.us_mw.png

[Hawkeye]

If I lived anywhere in Dubuque county, I wouldn't know what the heck to expect from this.

[bud2380]

updated graphic from DVN

 

[bud2380]

my point forecast is up to 9" now as well.  

[Grizzcoat]

Likely wrong as most of the short range models are in their "longer range" -- but the latest RAP is trending interesting for C.IA.   Has 11" IMBY. NWS has 1"

 

[bud2380]

RGEM continues to be awesome.

 

http://maps3.pivotalweather.com/maps/models/rdps/2018032318/030/snku_acc.us_mw.png

[bud2380]

SREF plume viewer for Cedar Rapids has a 10" average with a high of 25".  

[bud2380]

Here's surprise, the HRRR with another crush job for Iowa City.  This thing has been incredibly consistent today.  It better be right!

 

 

http://maps2.pivotalweather.com/maps/models/hrrr/2018032320/018/snku_acc.us_mw.png

[bud2380]

Likely reason the GFS keeps underselling snow totals.  Shows dew points 5 degrees too warm at initialization.  Starts out at 25-26 instead of the 20-21 actual dew points.  

[bud2380]

And I guess, instead of saying it is underselling snow, i should probably just say it's probably taking too long to transition from rain to snow, because snow totals are still impressive.

 

 

http://maps1.pivotalweather.com/maps/models/gfs/2018032318/030/snku_acc.us_mw.png

[Grizzcoat]

Wouldn't be a snow event without a late disco from DMX. Just came out. .

[Iowawx]

IF I get 10 or more inches from this, that will be the first time since February 1, 2015 that I got 10+ inches of snow from a single storm system. Not to mention this is happening in spring. Now I’m just waiting to see how this all comes together.

[Tom]

TWC has CR right under the bullseye of 12-18”...let’s go!

[Money]

TWC has CR right under the bullseye of 12-18”...let’s go!

That seems optimistic

[bud2380]

HRRR finally shifting north and hitting Dubuque again. Still looks good down here though. Also we had a brief period of rain and sleet mix and it was 46 degrees out. Crazy

[bud2380]

Latest HRRR now showing a substantial amount of sleet on the southern edge. Really eating away at snow totals. Shows 14” for CR but only 7” for IC

[Hawkeye]

Latest HRRR now showing a substantial amount of sleet on the southern edge. Really eating away at snow totals. Shows 14” for CR but only 7” for IC

 

Ouch, no kidding!  The last several runs have really pushed the rain/snow line north quite a bit.  Even Cedar Rapids is in the mixing for most of the night.  I hope it's wrong.

[bud2380]

00z run seems to be showing more snow so far this run. Hopefully the 23z run was just a bad run.

[bud2380]

Nope. I was wrong. More sleet. Seems very odd that we would go from rain to snow then to sleet.

[bud2380]

Even with all that sleet mixing in HRRR still

Shows 14” here.

[bud2380]

2” qpf now on hrrr. Crazy

[Hawkeye]

Man, I only got a few hours of sleep last night, so I'm already a little tired.  I wanted to nap for a couple hours this evening, so I would be able to watch the snow tonight and not be dead Saturday, but I still haven't gotten around to it.  I'm sure I'll have to sleep at least a bit tonight even with the storm.

[Iowawx]

I’m just thinking of going to bed early and waking up early. Looks like snow is not going to really start around here until at least midnight anyway.

[bud2380]

Nam coming in way north again and more ice on the southern edge.

[bud2380]

Nam with a cool 2 feet for mason city. I’m also going to try to get a little sleep if I can. I want to watch basketball but I’m pretty tired

[hlcater]

What is the HRRR doing? It's tie-dye. Gonna make for a wonky snow map.

 

http://maps2.pivotalweather.com/maps/models/hrrr/2018032401/007/refcmp_ptype.us_mw.png

[hlcater]

^This is gonna be a really crummy run.

[Hawkeye]

What the heck, nam?!?  It's now doing what some of the GFS runs have been doing.... it has convection in central/western Iowa leading to the formation of a north-south surface trough that moves east across the state.  The south flow on the east side of the trough pushes the warm tongue way up into east-central IA, totally screwing CR/IC.  At least half of our snow this run has turned to sleet.  I'm beginning to worry.

[Hawkeye]

It appears the problem is at 700 mb.  The NAM has a stronger 700 mb low pushing eastward into central Iowa, pulling a big above-freezing wedge of air well north into the state.  If it's right, this thing will be a huge bust for us.

[Grizzcoat]

01Z HRRR has 13"  (Kuchera)for Northern Polk CTY. Not likely, but interesting/

[hlcater]

It appears the problem is at 700 mb.  The NAM has a stronger 700 mb low pushing eastward into central Iowa, pulling a big above-freezing wedge of air well north into the state.  If it's right, this thing will be a huge bust for us.

Nah, even the models that are teasing the warm nose still show CR proper getting at least 8". But I want this event to be memorable, so warm nose please stay away.

[Hawkeye]

DMX just upped Mason City to Waterloo corridor to 10-13" with isolated higher.

[hlcater]

Getting sleet. Temperature's tanking.

[bud2380]

Just look at the RGEM and blindly trust it.

[bud2380]

Thunder here

[hlcater]

CC is saying 1 of 2 things, I'm not really sure which. 1 being that the entire N portion of the band is sleet(or at least partially sleet), which I find hard to believe. Or 2(more likely) the DVN beam is just intercepting the freezing/mixing level. 

 

[hlcater]

Atmosphere's cooling fast. Sleet sig now much, much more pronounced. Should be snow in some spots within the hour.

 

[bud2380]

Gfs shows only about 2” by morning and then between 7-10am has 4-6” falling in 3 hours.

[Craig-OmahaWX]

Heavy rain here with some rumbles of thunder, all thats heading your way guys! Enjoy stressing out over this one! Ha! 

[Hawkeye]

Atmosphere's cooling fast. Sleet sig now much, much more pronounced. Should be snow in some spots within the hour.

 

The CC loop suggests the precip northeast of CR may have switched to snow in the last 20 minutes.  Another wave of sleet just pushed into the city.