February 18-19th 2025 High Ratio Snow Event

[tron777]

The last couple of ICON runs have been coming more north and the 12Z run is coming in now and it is bumping back south again.

[tpweather]

You were correct Les about the RGEM and it stayed well south again.

[tpweather]

The last couple of ICON runs have been coming more north and the 12Z run is coming in now and it is bumping back south again.

A few things we are seeing is the placement of the low along the GOM and how strong is the upper system well north of there. My guess is the Nam believes the upper system to be rather strong and this not only brings up more moisture but also has the surface feature further north. Is that correct and at this point no way of knowing. Yes we want the surface feature to take its time in forming as this gives the upper system more time to stay stronger.

[tron777]

I'd like to get the GFS and Euro back on board.

[tpweather]

Watch that 50/50 low and this is important because it helps slow things down and you need a more southwest push to the trough coming into the central part of the USA. Some models like the ICON may not have this feature being a major part of their input and of course have no ideal but slow things down for a few days and this can be a nice storm. Speed things up and sure we can get a quick inch or so on the northern edge but nothing big in our local area.

[airwolf76]

as of now it looks like this storm is a miss to the south. at least for my area it went from 12-18 down to 1-3"

[tpweather]

Just to add a slower process gives the GOM more time to add more moisture to the system as well. So 6 hours can make a difference and with this storm my guess is yes

[tpweather]

GFS has the surface low about 50-75 miles further south on this run. Going to make a difference and will see how the euro is seeing today's data. Time to make the donuts or shovel the driveway though my wife is making a devils food cake with white icing so that makes me happy

[tron777]

12Z GFS gives CVG 0.23" of QPF. NAM / SREF combo is on an island of its own right now. I do think a high end advisory / low end warning event is most certainly still on the table, even if the shot at a big dog is low.

[tron777]

12Z Canadian is still suppressed with its solution.

Here's the 12Z GEFS ptype members. A lot more of them are north then not so the Ensemble does not agree with the weaker OP GFS solution at this time so that is good news.

GEFS.png

[BookNerdCarp]

Out of the loop this morning - when will we see the temperature drop? How drastic.

[tron777]

Out of the loop this morning - when will we see the temperature drop? How drastic.

Tonight. Lows 15 to 20 so get that junk removed from your driveway if you need to right now while you have the chance.

[tron777]

12Z UKIE is still south, just clips us with the snow shield.

EDIT: Then we get the upper low Wed night with more light snow. It's like the Canadian solution.

[airwolf76]

I guess for me anyways this is a saving grace that it will be going south of my area since I will not have my plow fixed till next Sunday

[tpweather]

Folks in southern half of Missouri have a forecast of 7-14 inches so nice to see and of course a cold weather alert just north of that area. Sounds like a 15-1 or higher with ratio's.

[tron777]

0.17" total QPF at CVG from the 12Z Euro as it also is now suppressing the first wave and we catch the upper low Wed night. If this continues on the guidance then we can trim off the 20th with the thread title.

[tpweather]

Euro just like most of the models a swing and miss for a bigger snow. Cold wins the battle and keeps us in the 1-3 inch range.

[tpweather]

0.17" total QPF at CVG from the 12Z Euro as it also is now suppressing the first wave and we catch the upper low Wed night. If this continues on the guidance then we can trim off the 20th with the thread title.

Les that is a 1-3 inch storm and very possible.

[tron777]

Here is the difference at 84 hours in the upper levels between the amp'ed NAM and the weaker Euro solutions. It is like night and day. Watch the PV lobe in Canada and well as where the shortwave comes in from the Pacific.

models-2025021612-f084.500hv.conus.gif.73a8e2c3e7c23f2193011057da121bda.gif

[tron777]

12Z EPS took a slight bump south.

[Pete1]

Let’s all get on the NAM train!!! Let’s go NAM… LETS GO NAME

Team NAM in full effect!!

[tron777]

The SREF is going up more lol 15Z mean is 5.6" for CVG and today's snow was not factored in. There is one weenie member as usual but most of the members are in the 2-9" range. Worst we do is 2". That's a nice run if you ask me. NAM should be good at 18Z one would think. Just wish the other guidance would latch on so we can run with this.

[tron777]

The outer edges of this storm are getting into hi res model land now. Watching the 18Z HRRR coming in now. It only goes out to 48 hours mind you, but so far the run is NAM like to me. S low is better, N high is weaker so things can amplify a bit. Less suppression. This is the look we want. Let's see what the HRRR does while we await to see the NAMing that will be coming up in the 3pm hour. Right?

[tron777]

IMO it is going to be important where this thing enters the CONUS, Wash State is SREF and NAM Oregon or N Cali is everyone else who is south of the these northern outliers. So the further north and stronger this wave comes into the US the better our chances are going to be. It is the angle of attack. We want the trough to go negative tilt for a whopper. That idea is decreasing but a good overrunning event can still occur with arctic air in place already if the wave has enough lift and can come far enough north to impact us. A more northern trajectory into the US would allow for better height rises in the east to slow things down enough for at least a partial phase of the upper energy. That is the difference guys between the NAM / SREF and everyone else.

[tron777]

That's a nice baroclincic zone on the 18Z HRRR. Monday afternoon -20s along the US / Canada border and 70s across portions of Eastern NM and West Texas. If we can get a strong enough wave, with that temp contrast precip will be able to blossom. We need a good wave to extract moisture from the Gulf. Let the upper level energy catch up and phase in.