Jan 17th-19th Rain/Snow/Mix/LES System

[Clinton]

What's your wind looking like? You could be pushing ice storm criteria.

We are suppose to have gust up to 35mph.  I expect an ice storm warning soon.

[bud2380]

DVN just issued Winter Storm Warnings for a large area including Iowa City and Cedar Rapids

[East Dubzz]

Here's the full 18z NAM:

 

[East Dubzz]

DVN just issued Winter Storm Warnings for a large area including Iowa City and Cedar Rapids

 

Now saying 3-6" for us instead of 2-4" as well.

[bud2380]

...WINTER STORM WARNING IN EFFECT FROM NOON FRIDAY TO 6 PM CST
SATURDAY...

* WHAT...Heavy mixed precipitation expected. Total snow
accumulations of 3 to 6 inches and ice accumulations of one
tenth to two tenths of an inch. Winds gusting as high as 45 mph
producing near whiteout conditions at times.

* WHERE...Portions of east central, northeast and southeast Iowa
and northwest Illinois.

* WHEN...From noon Friday to 6 PM CST Saturday.

[St Paul Storm]

As much spread the wealth as we’ve had it a LONG time.

[Cfweather]

DMX a bit concerned about power line issues with the wet snow and high wind plus any icing.

Where are you seeing that?  I don’t disagree it could be an issue.  I just don’t see where they called that out?

[Niko]

Dang, the 18Z NAM spits out almost 10" in mby.

[BrianJK]

For Northern IL folks, I don't see too much snow from this system and once the rain comes most that has fallen will be washed away. WAA most always is under modeled and the way this winter has gone I see it winning out again. I hope I'm wrong but I don't expect much.

Bingo!

[james1976]

Where are you seeing that? I don’t disagree it could be an issue. I just don’t see where they called that out?

Am becoming increasingly concerned with hazardous impact potential

for late Friday/early Saturday as potent cold air gradient +

strong winds punches southeastward across Iowa. The impacts could

be like that of a snow- squall warning... Temperatures may fall

around 20 degrees in less than 3 hours, accompanied by the

leading surge of 40 kt wind gusts. This may ultimately lead to

rapid freezing on surfaces... especially untreated surfaces... and

potentially very hazardous travel through Saturday morning. If

snow were to concurrently fall, this would reduce visibility on

top of the above impacts.

 

Also, wanted to increase mention of potential issues to power lines

and tree branches... If this were a "stand-alone" event with just

one-tenth of an inch, the concurrent strong winds would notably

amplify impacts. With snow ahead of this system, central to southern

Iowa may have higher-impact potential if the snow falls as more

wet/heavy snow.

 

Increasing confidence in high winds for Saturday. Cannot completely

rule out High Wind Warning criteria being neared across northern

Iowa. The strong northwesterly winds alone would create hazardous

travel conditions... but adding in the potential for icing/blowing

snow may amplify hazardous travel through Saturday afternoon and

evening. Will monitor this closely over the next few forecast

updates.

[Niko]

[bud2380]

3K NAM

 

[Stormgeek]

Models starting to back off on the weenie totals, finally. Looks like more spread the wealth though!

[Madtown]

3K NAM

 

Looks like the TWC map from yesterday! Still think anyone outside of msp area is gonna have a battle to get to 8" minus lake effect

[Stacsh]

I'm in a WWA for up to 8" lol.  Plus more LES on Sat and Sunday.  Good call GRR.....

[DSM WeatherNut]

Advisories and warnings posted now seem to mostly align with the NAM.

[james1976]

Finally a daytime event. That's awesome

[westMJim]

I'm in a WWA for up to 8" lol.  Plus more LES on Sat and Sunday.  Good call GRR.....

That don't surprise me at all after last weekends "Winter Storm Not!" 

[hlcater]

Gonna take the under on the NAMs

[East Dubzz]

Gonna take the under on the NAMs

Don't be a negative nelly. 

[hlcater]

Don't be a negative nelly.

 

6-8” tho? From this? Nahhhhh. I bet we see 4”, and I’ll consider myself lucky to see 5”. I think the band is too progressive to really cash in on what will likely be some intense (1”+/hr) rates in the WAA wing.

[East Dubzz]

6-8” tho? From this? Nahhhhh. I bet we see 4”, and I’ll consider myself lucky to see 5”. I think the band is too progressive to really cash in on what will likely be some intense (1”+/hr) rates in the WAA wing.

 

I was just kidding. I think we all know not to expect what the NAM is showing.

[jcwxguy]

20z rap lol

[FarmerRick]

[Cfweather]

Am becoming increasingly concerned with hazardous impact potential

for late Friday/early Saturday as potent cold air gradient +

strong winds punches southeastward across Iowa. The impacts could

be like that of a snow- squall warning... Temperatures may fall

around 20 degrees in less than 3 hours, accompanied by the

leading surge of 40 kt wind gusts. This may ultimately lead to

rapid freezing on surfaces... especially untreated surfaces... and

potentially very hazardous travel through Saturday morning. If

snow were to concurrently fall, this would reduce visibility on

top of the above impacts.

 

Also, wanted to increase mention of potential issues to power lines

and tree branches... If this were a "stand-alone" event with just

one-tenth of an inch, the concurrent strong winds would notably

amplify impacts. With snow ahead of this system, central to southern

Iowa may have higher-impact potential if the snow falls as more

wet/heavy snow.

 

Increasing confidence in high winds for Saturday. Cannot completely

rule out High Wind Warning criteria being neared across northern

Iowa. The strong northwesterly winds alone would create hazardous

travel conditions... but adding in the potential for icing/blowing

snow may amplify hazardous travel through Saturday afternoon and

evening. Will monitor this closely over the next few forecast

updates.

 

sorry-  I promise I’m not trying to be annoying!   So where is that from?  It’s not the AFD, which I usually read.  I’m just trying to figure this all out!

[East Dubzz]

 

Am becoming increasingly concerned with hazardous impact potential

for late Friday/early Saturday as potent cold air gradient +

strong winds punches southeastward across Iowa. The impacts could

be like that of a snow- squall warning... Temperatures may fall

around 20 degrees in less than 3 hours, accompanied by the

leading surge of 40 kt wind gusts. This may ultimately lead to

rapid freezing on surfaces... especially untreated surfaces... and

potentially very hazardous travel through Saturday morning. If

snow were to concurrently fall, this would reduce visibility on

top of the above impacts.

 

Also, wanted to increase mention of potential issues to power lines

and tree branches... If this were a "stand-alone" event with just

one-tenth of an inch, the concurrent strong winds would notably

amplify impacts. With snow ahead of this system, central to southern

Iowa may have higher-impact potential if the snow falls as more

wet/heavy snow.

 

Increasing confidence in high winds for Saturday. Cannot completely

rule out High Wind Warning criteria being neared across northern

Iowa. The strong northwesterly winds alone would create hazardous

travel conditions... but adding in the potential for icing/blowing

snow may amplify hazardous travel through Saturday afternoon and

evening. Will monitor this closely over the next few forecast

updates.

 

sorry-  I promise I’m not trying to be annoying!   So where is that from?  It’s not the AFD, which I usually read.  I’m just trying to figure this all out!

 

 

https://forecast.weather.gov/product.php?site=DMX&issuedby=DMX&product=AFD&format=CI&version=3&glossary=1

[dubuque473]

Winds up to 45mph...

[GDR]

20z rap lol

this will be up on Snowday in 10 minutes

[Cfweather]

https://forecast.weather.gov/product.php?site=DMX&issuedby=DMX&product=AFD&format=CI&version=3&glossary=1

 

thank you!  In my defense it’s not in the new one they issued this afternoon-  which is where I looked!  

I appreciate you linking that. 

[jcwxguy]

Oax

[Tony]

For Northern IL folks, I don't see too much snow from this system and once the rain comes most that has fallen will be washed away. WAA most always is under modeled and the way this winter has gone I see it winning out again. I hope I'm wrong but I don't expect much.

Looking at the latest models especially the RGEM I might have spoken too soon as they are getting colder/snowy but we still have 24hrs so not getting hopes up just yet. I hope I end up being wrong on my above post.

[bud2380]

GFS with almost 1" qpf for Iowa City, but only 4" of snow.  Yuck

 

 

[East Dubzz]

18z GFS freezing rain:

 

[Hawkeye]

The 18z HRRR surges mix way up into Minnesota.  Last storm, the HRRR was one of the farthest south with the snow/mix line.

 

I'm still going with 3-4 inches in Cedar Rapids.  I don't think it will snow long enough to get 6".

[East Dubzz]

The 18z HRRR surges mix way up into Minnesota.  Last storm, the HRRR was one of the farthest south with the snow/mix line.

 

I'm still going with 3-4 inches in Cedar Rapids.  I don't think it will snow long enough to get 6".

 

It's also the long-term HRRR. It may be true, but I don't really pay attention to that until it starts getting into the normal time frame. 

[jaster220]

Pssssst....you might wanna double check on that.

 

Nevermind amigo, just saw that your area is under WWA...WATTTT??? Makes no sense...very ironic tbh!!! Wow........GRR needs to rethink this.

 

It never does amigo, it never does. My head's worn raw from all the scratching over the yrs. That office is the "home of the 8-10" WWA". Might be another one freshly minted today  

[bud2380]

It's also the long-term HRRR. It may be true, but I don't really pay attention to that until it starts getting into the normal time frame. 

 

The HRRR performed terribly around these parts with the last storm (but most models did).  It consistently was showing 8" of snow and showing wave 2 moving in with solid snows on Saturday only for wave 2 to miss us entirely.  

[jcwxguy]

Oax afd

Based on the potential impacts of snow accumulation, light icing,

and eventually strong winds and flash freezing, opted to maintain a

Winter Weather Advisory across the forecast area through Saturday

morning. But we will be monitoring conditions closely to assess the

need for any potential upgrades.

[East Dubzz]

The HRRR performed terribly around these parts with the last storm (but most models did).  It consistently was showing 8" of snow and showing wave 2 moving in with solid snows on Saturday only for wave 2 to miss us entirely.  

 

Yeah, I mean if we're all being honest... there is no way to know which model will perform the best each storm. It seems like sometimes a model gets on a roll, but even this.. the next storm could be the only they totally mess up. 

[hlcater]

The 18z HRRR surges mix way up into Minnesota.  Last storm, the HRRR was one of the farthest south with the snow/mix line.

 

I'm still going with 3-4 inches in Cedar Rapids.  I don't think it will snow long enough to get 6".

 

Looks like it's mishandling things then. This is a skew T along the IA/MN border right when the HRRR progs mix. This skew-T would definitely be snow. However, I could still see freezing drizzle on backside if the upper levels dry out enough.