Potential Winterstorm 1/30-2/1

[Niko]

Per NOAA:

Quote: Northern Pacific wave to arrive onshore over California on Friday
and will aid in orographic cyclogenesis where low pressure
strengthens over the Texas panhandle and arrives over the Ohio
Valley in the Sun 12Z - Mon 00Z timeframe.

 

Such a classic look to this.......

[Hawkeye]

18z NAM is south.  We have to be careful, though, as it feels like sometimes the 18z and 06z go one way and the 00z/12z go back the other way.

[Hawkeye]

HRRR is just getting into range.

[bud2380]

DVN came out with a graphic with % chance > 2" and 4" and it looks like they basically just took the GFS and weighted it at about 90% and 10% from other models.  

[bud2380]

NWS blend, which looks almost nothing like any model other than the GFS.  So clearly this is heavily weighted towards it. 

 

 

[Hawkeye]

2 minutes ago, bud2380 said:

DVN came out with a graphic with % chance > 2" and 4" and it looks like they basically just took the GFS and weighted it at about 90% and 10% from other models.  

They are probably using a blend of models, of which the GFS is one.  The Euro ensemble has about a 55% chance of 6" in Cedar Rapids.

[bud2380]

Here's the graphic.

 

[Hawkeye]

18z 3k NAM is farther north

[edhalen]

15 minutes ago, bud2380 said:

NWS blend, which looks almost nothing like any model other than the GFS.  So clearly this is heavily weighted towards it. 

 

 

NWS - the GFS huggers!!!!

[Kristie]

I am having trouble finding forums to discuss the potential storm for toledo ohio. Can anyone give me the possibility and snow amounts for my area?

[bud2380]

Point forecast is 2-4" is all.  Looks like DVN is riding the model blend.  

[Hawkeye]

DMX is going with a middle road between the GFS and Euro.  DVN says 4-6" in their nw Iowa counties, but much heavier in Illinois.  Basically, both offices are being conservative.

[bud2380]

RDPS is further south with the snow.  It's really a matter of how far north does the  850 line get?

 

[dubuque473]

DVN has me at 3-7" now...

[Tony]

18z runs seem to be running a little south 

[bud2380]

18z GFS still way north with the warm air.

 

[bud2380]

GFS just still not cold enough for as much snow.

 

[bud2380]

It's also much further south with the higher QPF amounts than the Euro.

 

 

 

[bud2380]

GFS v16 has a big difference between Kuchera and 10:1.  Ratios would be more like 8:1 or so.

 

 

[bud2380]

Here was the 12z GDPS since it never updated on Pivotal or TT.

 

http://img.meteocentre.com/models/gemglb_amer_12/accum/SN_000-120_0000.gif

[East Dubzz]

57 minutes ago, dubuque473 said:

DVN has me at 3-7" now...

Seems to make sense to me for the time being. 

The question is.. what curveball will be thrown our way between now and when the storm starts?

There’s always a curveball...

[BMT]

3 minutes ago, East Dubzz said:

Seems to make sense to me for the time being. 

The question is.. what curveball will be thrown our way between now and when the storm starts?

There’s always a curveball...

Correct

[jaster220]

4 hours ago, Stacsh said:

ever so slightly inching north into SMI.  

Need a bit more at game time

[Cfweather]

Local Mets have Waterloo at 4-7”

[brianc400]

1 hour ago, East Dubzz said:

Seems to make sense to me for the time being. 

The question is.. what curveball will be thrown our way between now and when the storm starts?

There’s always a curveball...

The GFS will actually prove correct this time. 

[james1976]

Yup local met with 4-7 " for much of E IA. Said it should be all snow for the most part.

[bud2380]

The 21z RAP came in snowy

[Niko]

GFS

 

[bud2380]

Hilarious troll job by the NAM with a finger of rain right over my county while it snows on every direction around me. 

[bud2380]

3K NAM way north. Glad it’s the NAMs. 

[Hawkeye]

I sure hope the NAMs are just a hair too warm.  What both of them are doing is keeping the initial precip surge rain/mix farther north, but then quickly turning it to snow from west to east.  That's why there is a finger up through Iowa City that remains rain and is the last to change over.

The HRRR is much more favorable for CR/IC.  Compare the 3k NAM and 00z HRRR at 22z Saturday.  The HRRR changes to snow across the area more quickly.

[Sciascia]

[Hawkeye]

00z HRRR.... has 1.5"/hr for the first couple hours in CR/IC.

[whatitdo]

 

1 minute ago, Sciascia said:

that gradient in south michigan is cruel. 5 inch difference down a row of counties. bump up north please

[snowstorm83]

0.75" of rain here on the HRRR. I know there's this drought thing going on but no thanks lol. 

[hlcater]

WRF suite is warm and has rain to CR/IC to start. 

Gonna place my initial call for IC at a conservative 3" to account for the possibility that the initial band is rain for us.

[Hawkeye]

I think it was the HRRR that nailed the colder thermals during the late December storm.  Hopefully, it's right again.  Of course, I'm a bit concerned.  I'll be biting my nails Saturday afternoon, praying for the surging precip to start changing to mix as far south as possible and then snow as it nears Iowa City.

I just remembered that, for the late December storm, when the colder HRRR was right, it was the NAM that was dead wrong about a blob of sleet surging northeast through east-central Iowa.  The precip stayed snow down to Iowa City.

[hlcater]

The WRFs appear to be faster, which in this scenario, makes all the difference. A slower system likely means more snow for Iowa 

[Hawkeye]

The RDPS is plenty cold, but it veers the heavy precip east of Iowa.  We never get into the heavier snow.  The RDPS's qpf for Cedar Rapids is half of what the Euro is predicting.

[Grizzcoat]

The difference between GFS and 3km NAM through HR 60 is truly remarkable. Not saying either is correct but, Holy Smokes.