Natester

Just now, hawkeye_wx said:

The HRRR is ramping the snowfall back up for east-central Iowa.  The 18z is the best run since yesterday.

As does the 18z RAP.

18z HRRR Kuchera snow map ending at 11 am Sunday.  Disregard the lake enhancement part since it'll likely not verify.

18z RAP showing over 7 inches of cement for NE Illinois and almost 6 inches here.

Just now, cyclone77 said:

Ha well we ain't no stranger to a string of 60s in Feb and that would nuke it all to hell, but it would have the capability to hold on longer than a "normal" 10" snowpack lol.

Ah yes, you're referring to Feb 2017, right?  That was a recordbreaking stretch of warm weather with extremely rare 70s in CR.

Just now, cyclone77 said:

If mixing issues end up being an issue and we only get a few inches of snow it's only going to make the snowpack in place that much more formidable.  Would prefer an all-snow 6+ incher but there is an upside to the mixing scenario at least lol.  Would have loved to get in on that 2"/hr scenario the models were putting out in previous cycles.  It's still possible but looking less likely for these parts.

Let me guess, that glacier won't melt until late April? 

Both the NAMs have the changeover to snow 2 hours later.  Cuts the totals even more.

0z HRRR says areas south of I-80 in NE Illinois gets 9-10 inches of cement based off of the kuchera ratio, whereas areas north of I-80 have a slightly drier snow.  That's going to cause some damage.  At least for here the 0z HRRR shows just under 4 inches of cement via kuchera ratio.  I'd gladly take 4 inches of extremely wet snow over 10 inches of extremely wet snow because I like having the power on.

Just now, Chicago Storm said:

have you checked on the CRAS?

What's CRAS?  Never heard of CRAS.

Well the good news for here is that when the freezing rain starts, it'll already be 31F, thus limiting accretion.  21z RAP has CR going above freezing at 4 PM before switching to cement snow at 7 PM.

Just now, hawkeye_wx said:

Yep.  I'm not expecting more than a few inches of slop.  Bummer.

At least temps will be very marginal (lower 30s) so that we won't get any notable ice accretion.

From DVN:

GIVEN THE ABOVE SCENARIO THERE IS A SIGNIFICANT CONCERN. THE  
925-850 MB WINDS ARE AVERAGING 30-40 KTS WHICH IS BRINGING A  
FREIGHT TRAIN OF MOISTURE INTO THE AREA. THE CONCERN IS THAT THE  
WARM LAYER ALOFT WILL BE PUSHED FURTHER NORTH THAN WHAT THE   
MODELS ARE INDICATING. IF THIS OCCURS THEN ICE AMOUNTS WOULD BE   
HIGHER AND SNOW AMOUNTS LOWER. THIS SITUATION WILL NEED TO BE   
WATCHED CAREFULLY WITH BOTH MODEL AND REAL DATA OVER THE NEXT   
12-18 HOURS.  

DMX thinks that parts of central Iowa could get up to two tenths of a inch of ice accretion.  That combined with the winds could cause power problems.

According to the NWS forecast, CR only forecast to get 2-4 inches of snow on top of a tenth of an inch of ice.

Just now, SchaumburgStormer said:

The NAM twins smoking NE IL

Not as quite as a paste job as in Iowa since temps hold 3-4 degrees below freezing for NE Illinois.

Yikes!  NAM 3k doesn't even give CR 2.5 inches.  The NAM 12k is a bit better but just below 4 inches.  I hope the HRRR verifies unless the 0z run shows CR in cold rain for a few hours.  Going to lower my call by an half an inch to 5.5 inches if the HRRR is to be believed.

1 minute ago, SchaumburgStormer said:

NAM giving IA a bit more rain. 

I saw.  Both the NAM 12k and NAM 3k puts CR above 32F changing the ZR to plain rain before changing to snow at 6-7 PM.  Likely going to be a 6:1 ratio snow.

8 minutes ago, hawkeye_wx said:

The HRRR has a 7:1 ratio over here.  That'll be fun to clean.

At least we aren't getting a foot of 7:1 ratio snow.  That much wet snow is enough to collapse flat roofs and cause major tree and power line damage.

HRRR 18z Kuchera ratio gives CR 5.4 inches.  Still has changeover from sleet to snow at 6 pm Saturday.

Just a FWIW, HREF FRAM 24 totals have widespread .10 ice accretion in Iowa and Illinois.

Just now, McHenrySnow said:

That's 10-1. Kuchera gives you 5". 

Yeah, you're possibly right since this is a wet sticky snow.

15z RAP gives CR 7.2 inches of cement on Saturday evening.  Also winds are somewhat weaker as shown on the NAM 3k.  

Still sticking to my call of 6 inches although it might need to be lowered by an inch if the models keep cutting forecast totals.  However, if CR does indeed get 6 or more inches of snow with this very wet consistency, it's going to be detrimental to the trees, especially with the wind gusts.  HRRR and NAM have temps flirting at freezing during the bulk of the snow.

15 minutes ago, hawkeye_wx said:

Keep in mind this should be pretty wet stuff with a lousy ratio.

Off topic, but are you going to update your signature to account for the snow from this past Monday? 

Just now, hawkeye_wx said:

Keep in mind this should be pretty wet stuff with a lousy ratio.

Yeah, not good for the heart and back.  Also not good for the damaged trees especially with the wind gusts.

27 minutes ago, hawkeye_wx said:

Those of us in Iowa are wondering what happened to our big snow event that appeared as locked in as any storm could be a few days out.  Nearly all models are either cutting the precip down, warming us up, or both.  Even the HRRR, which nailed the colder, snowier late December storm, has now warmed us up and drops at least a few hours of mix crap here.  The 6-9" snow event has been cut in half.

12z HRRR still shows CR getting nearly 8 inches although that will possibly change in the 18z run.  Let's see what the 15z RAP says.  The good news is that with temps at 30-31F, there won't be any notable ice accretion during the 2-3 hour period of ZR before changing to sleet.