Absolute Vorticity

Good morning Tim, Bgoney, all...

GFS and Euro both give me 5". Channel 12 gives me 4". I think up to 1/4" of ice for my hood and a few inches of concrete sleet, followed by 2" of snow is my own personal forecast for my hood. I would be tickled to death to see 4" of snow. I think I-70 Crew has a shot at 6" if things break right. Probably more like 3-4" of snow. Then Eric hood, is still my 10" to perhaps a foot if things break right. 8-12" zone for sure up there. NW Ohio S Mich and N Indy is my 10-15" zone. Some models have 20" in Central ILL into Indy so we'll see. St. Louis will get hammered as well.

For those that didn't see it last night...

Here's what I'm rolling with for Cincinnati:

-Periods of heavy rainfall today-tonight
-Rain will transition to a period of freezing rain late tonight through tomorrow morning with up to 0.20" accretion, mainly on elevated surfaces.
-Freezing rain will then transition to several hours of heavy sleet.
-Sleet changes to snow tomorrow evening -- don't sleep on the back-end snows -- it'll likely be heavy for a time and stack up a quick 2-4" on top of the icy mess...more if the changeover is sooner.

Subject to change, but that's what I'm going to roll with for now.

Hey Les and I can see the higher totals of snow as well especially since at the heart of the storm we may have that period of heavier snow late afternoon or early evening. I can see where we get less as well if the warmer layer sticks around an extra hour or two.

Trevor wrote: ↑Wed Feb 02, 2022 6:58 am Here's what I'm rolling with for Cincinnati:

-Periods of heavy rainfall today-tonight
-Rain will transition to a period of freezing rain late tonight through tomorrow morning with up to 0.20" accretion, mainly on elevated surfaces.
-Freezing rain will then transition to several hours of heavy sleet.
-Sleet changes to snow tomorrow evening -- don't sleep on the back-end snows -- it'll likely be heavy for a time and stack up a quick 2-4" on top of the icy mess...more if the changeover is sooner.

Subject to change, but that's what I'm going to roll with for now.

Hey Trev, great forecast and funny how almost everyone is coming into decent agreement on here though the storm itself is really not that easy in regards to precip types. Once the second wave comes in you will get that 4-6 hour period where if its sleeting at your house it may be that way for awhile before the upstairs cools down. The accretion is always a tough call and a somewhat easier call when before hand its been cold and dry but because we had a nice little warm up before and the ground will be wet the accretion part can be tricky but I would tend to go on the lower side here locally but probably southeast of Louisville may be a key area for accretion and that could be more towards the 0.40 or even 0.50 which is a problem for sure.

tpweather wrote: ↑Wed Feb 02, 2022 7:06 am

Trevor wrote: ↑Wed Feb 02, 2022 6:58 am Here's what I'm rolling with for Cincinnati:

-Periods of heavy rainfall today-tonight
-Rain will transition to a period of freezing rain late tonight through tomorrow morning with up to 0.20" accretion, mainly on elevated surfaces.
-Freezing rain will then transition to several hours of heavy sleet.
-Sleet changes to snow tomorrow evening -- don't sleep on the back-end snows -- it'll likely be heavy for a time and stack up a quick 2-4" on top of the icy mess...more if the changeover is sooner.

Subject to change, but that's what I'm going to roll with for now.

Hey Trev, great forecast and funny how almost everyone is coming into decent agreement on here though the storm itself is really not that easy in regards to precip types. Once the second wave comes in you will get that 4-6 hour period where if its sleeting at your house it may be that way for awhile before the upstairs cools down. The accretion is always a tough call and a somewhat easier call when before hand its been cold and dry but because we had a nice little warm up before and the ground will be wet the accretion part can be tricky but I would tend to go on the lower side here locally but probably southeast of Louisville may be a key area for accretion and that could be more towards the 0.40 or even 0.50 which is a problem for sure.

The warmth ahead of this storm is definitely a positive re: ice accretion. It'll buy us a little time (along with the heavy rates). Having said that, travel is going to be nightmareish by late tomorrow for sure.

We're now in the HRRR's range. 06z run keeps the predominant precip type tomorrow being freezing rain with temps in the lower to middle 20s.

Trevor wrote: ↑Wed Feb 02, 2022 7:14 am We're now in the HRRR's range. 06z run keeps the predominant precip type tomorrow being freezing rain with temps in the lower to middle 20s.

Mentioned earlier that ILN probably goes with ice storm warning for the southern and eastern most counties in their FA

tron777 wrote: ↑Wed Feb 02, 2022 6:26 am Good morning all! I have looked at the text data from the 6Z NAM, GFS and 0Z Euro models. I have no changes either. The post I made last night for timing and Bgoney's map are still perfectly valid. I'd start watching short term guidance and meso scale guidance today along with SPC mesopage. The global models and hi-res guidance are pretty much lock and step. GFS and Euro maybe give you a little more snow on the backside versus the NAM and RGEM where its more sleet and ice related. It's going to be a mess anyway you slice it by tonight for I-70 and NW counties and tomorrow for the rest of us. Friday area wide too as the light snow lingers and things begin to wind down. No one gets above freezing until Sunday afternoon once we get below later tonight.

The only difference between the global models and the meso scale models is that the southern extent of the 3-8 inch accumulations are further south on the global models. Otherwise we do have good agreement. I will have to side with the meso scale models in that the warm air aloft will prevent the global models from being right about the southern extent of the snow.

Temperatures at 12pm and 6pm on Thursday is tricky and can make a huge difference not only with precip types but how road surfaces react. Yes we had this nice little warm up but it has been short-lived and it was cold before so the warm up helped somewhat but maybe not that much. Later today as the first wave passes I will be watching temps to the west to see if models are doing a good job. I am still in the camp that a longer period between waves can make a difference in how colder air works in here. Sure we can have drizzle the whole time because the atmosphere is filled with moisture but I am talking about the period between heavier rains and then whatever falls on Thursday. A longer period between the waves imo would allow colder air to sink a little further south and east. Will that break be 3 hours or 6 hours can no doubt change the outcome of the forecast in terms of precip types. Models no doubt help with this kind of storm but nothing beats old time looking out the window and trying to gauge the changes in your own neighborhood.

Bgoney wrote: ↑Wed Feb 02, 2022 7:16 am

Trevor wrote: ↑Wed Feb 02, 2022 7:14 am We're now in the HRRR's range. 06z run keeps the predominant precip type tomorrow being freezing rain with temps in the lower to middle 20s.

Mentioned earlier that ILN probably goes with ice storm warning for the southern and eastern most counties in their FA

I can see that being needed.

I agree with you all on the ice storm warnings. LOU has 'em out for their CWA.

Light rain here and at CVG. 46 degrees. We should drop into the low 40s and settle in there for the remainder of the day.

Bring it on. Going to hide in the woodpile now.

Woolyworm wrote: ↑Wed Feb 02, 2022 7:25 am Bring it on. Going to hide in the woodpile now.caterpillar.gif

Love it! Hope you all enjoy the storm!

Well Trev... hope our PTSD of pingers can handle another one.

tron777 wrote: ↑Wed Feb 02, 2022 7:30 am

Woolyworm wrote: ↑Wed Feb 02, 2022 7:25 am Bring it on. Going to hide in the woodpile now.caterpillar.gif

Love it! Hope you all enjoy the storm!

Grandma Wooly and me ol' Grandpa got the tarp on the woodpile and hunkering down and in after a trip to exercise at PF.

tron777 wrote: ↑Wed Feb 02, 2022 7:30 am Well Trev... hope our PTSD of pingers can handle another one.

09z RAP (extended range run) snowfall.

Don't know if it's going to make a difference in the end, but St. Louis changed over to snow a couple hours earlier hen guidance. STL dropped to 25 degrees.

Trevor wrote: ↑Wed Feb 02, 2022 7:38 am 09z RAP (extended range run) snowfall.

Love this map as my back yard gets 8 inches and my front yard gets 1inch

I don't know how much to trust Kuchera in this sleet/FRZ set-up . Contamination is rampant

Bgoney wrote: ↑Wed Feb 02, 2022 7:45 am I don't know how much to trust Kuchera in this sleet/FRZ set-up . Contamination is rampant

I agree and even in all snow situations the Kuchera seems always to be to high in terms of snow totals.

Trevor wrote: ↑Wed Feb 02, 2022 7:38 am 09z RAP (extended range run) snowfall.

Damn and that is not tainted by sleet coming from Dupage. I don't know... not going to get sucked into that right now lol

tron777 wrote: ↑Wed Feb 02, 2022 7:42 am Don't know if it's going to make a difference in the end, but St. Louis changed over to snow a couple hours earlier hen guidance. STL dropped to 25 degrees.

Les the forecast has them dropping to 21 by 4pm. That number is one that I will watch plus further south and east to see how temps are doing as the front progresses.