January 18th Event

[stormtracker]

1 hour ago, mappy said:

 

Lol, Ji is an idiot. 

[stormtracker]

36 minutes ago, WinterWxLuvr said:

Look at the modeled radar on the last GFS run at 18z Sat. Look at the precip shield at about 41 lat. Move that low to South Bend and you’re gonna move that precip shield. If we can get precip, I think we’ll stay cold enough for frozen if some sort.

Yeah. Too early to bail.  I admit it’s not looking good, but we’ve been comeback kids in less time before.  

[mappy]

I'm cool with anything wintry. It will be colder come the weekend, even if its mixed bag precip event. but def not worth jumping off the ledge over. 

[biodhokie]

22 minutes ago, mappy said:

I'm cool with anything wintry. It will be colder come the weekend, even if its mixed bag precip event. but def not worth jumping off the ledge over. 

Pretty much this. No matter what we get cold again. I'm tired of it feeling and smelling of spring, it's January and needs to be cold.

[Baltimorewx]

the 12z NAM clown map is hilarious in relation to what the actual model shows lol

[baltosquid]

13 minutes ago, Baltimorewx said:

the 12z NAM clown map is hilarious in relation to what the actual model shows lol

It’s more reasonable on the snow depth change map. About 1-3 inches. 10-1 has a lot of other freezing precipitation included so it looks nuts. Still an optimistic look, though.

[Scraff]

12K NAMing clown map. Lol. Everyone needs a digital snow fantasy, but hell I’ll hug it like there’s no tomorrow...
 

[ers-wxman1]

12z Icon has an impressive icing event. TT maps do not show sleet/freezing rain but 2m temp contours show it not getting above freezing until after 00z Sunday with decent QPF. Much of the area west of the fall line stays in the 20s into the afternoon. 

[yoda]

3 minutes ago, ers-wxman1 said:

12z Icon has an impressive icing event. TT maps do not show sleet/freezing rain but 2m temp contours show it not getting above freezing until after 00z Sunday with decent QPF. Much of the area west of the fall line stays in the 20s into the afternoon. 

Looks decent even into the i95 corridor tbh... not as bad as west of the BR... but 12z and 15z SAT temps at DCA are at 26 degrees

[yoda]

FWIW, seems like 12z GFS has a bit more of a south push than 06z... so maybe a bit better run for some of us in regards to frozen precip 

[Its a Breeze]

The 12Zs will save us from ourselves. 

No matter what happens on Saturday, it's a WIN for this winter so far. If we have to sacrifice and receive a few hours of slop for that coastal next weekend to be all snow, and a more favorable pattern (than what we've seen so far at least) for the foreseeable future then, I have spoken, sign me up, I'm all in, yes please....

[Ralph Wiggum]

Appears to be an isobaric camel dropping a deuce off the DelMarVa coast. Not sure what implications that would have if any.

[psuhoffman]

50 minutes ago, Baltimorewx said:

the 12z NAM clown map is hilarious in relation to what the actual model shows lol

the TT snowfall maps count "ice" as snow.  It's a known thing...so its kinda annoying when people post that map and say "haha look at how stupid this is showing 15" of snow when its going to be like 2".  The model is NOT showing that.  Those maps have a major  flaw.  That's why we call them "clown" maps.  

[Ji]

1 minute ago, psuhoffman said:

the TT snowfall maps count "ice" as snow.  It's a known thing...so its kinda annoying when people post that map and say "haha look at how stupid this is showing 15" of snow when its going to be like 2".  The model is NOT showing that.  Those maps have a major  flaw.  That's why we call them "clown" maps.  

yes but posting this on social media will get you alot of likes lol

 

[yoda]

Almost looks like we dryslot at 84 on 12z GFS lol

[Ji]

3 minutes ago, losetoa6 said:

Gfs showing a bit more expansive area of sleet and zrain this go round 

its amazing how the precip comes in at the exact time where snow isnt condusive anymore in the upper levels

[Weather Will]

NAM WB 12z Freezing Rain totals through the run.  Think we should now be worried about an ice storm.

[mappy]

3 minutes ago, Weather Will said:

NAM WB 12z Freezing Rain totals through the run.  Think we should now be worried about an ice storm.

i dont think anyone should be "worried" about anything. too many of you live and by die by the models. if a quarter inch of ice is still showing up on the models by friday, then people can be cautious. 

[WinterWxLuvr]

GFS said the hell with improvement, lol.

[mappy]

id be more worried about the dry air than any icing event. 

[Weather Will]

4 minutes ago, mappy said:

i dont think anyone should be "worried" about anything. too many of you live and by die by the models. if a quarter inch of ice is still showing up on the models by friday, then people can be cautious. 

Worried was the wrong word choice.  None of the models currently support a snow storm in our region.  They do support a potentially significant icing event.  12z GFS is similar to NAM.

[Kmlwx]

If the precip stays light - that *could* certainly lend some weight towards sig icing. Remember, with heavier rain it's tough to get icing due to the latent heat release. With a light (but perhaps semi steady) rain, fzra could more readily accumulate. 

[psuhoffman]

2 hours ago, WinterWxLuvr said:

Look at the modeled radar on the last GFS run at 18z Sat. Look at the precip shield at about 41 lat. Move that low to South Bend and you’re gonna move that precip shield. If we can get precip, I think we’ll stay cold enough for frozen if some sort.

That precip you are looking at isn't the main result of the primary low back in Wisconsin though.  It's the result of the WAA , which is primarily driven by the low and mid level winds ahead of the trough into the cold air.   

This was the last really good run of the GFS from 6z yesterday and look at where the mid level winds were directed....

now look at the primary low location

Now look at last nights crap awful run....the primary low is much further southeast...but it doesn't matter

Because look where the mid level winds that will be the main culprit for any WAA precip have shifted

The flow that was directed right into us on the guidance that showed a healthy WAA thump of snow is now directed well to our northwest and that is because of the increase in the ridging and sharper trough alignment not the primary low.  

The precip from the primary low is irrelevant to us, by the time that gets here we will have lost the mid levels and likely the surface.  Whatever snow we get will be from WAA out ahead of the primary system.  But the winds that would cause that are being directed away from us by the ridge/trough alignment.  

We would need a radical shift in the primary low track for that to due us any good...yea if it did track through central Indiana into northern Ohio that would likely redirect those winds towards us as it would indicate a radical shift south of all the features, including the mid level wind flow.  But it would be the shift if that wind flow not the primary that would help.  And that is a HUGE shift...were talking like 150-200 miles in only 3-4 days.  Not sure how likely that is.  Seeing the mid level winds shift back to a more favorable configuration is more likely...but only slightly.  

So a shift south of the primary if it is associated with a weaker ridge and flatter solution would be good...but a shift in the mslp absent the improvements we need at the mid levels ahead of the system would do us no good really unless its a 250 mile shift in track.  

 

 

[WinterWxLuvr]

3 minutes ago, psuhoffman said:

That precip you are looking at isn't the main result of the primary low back in Wisconsin though.  It's the result of the WAA , which is primarily driven by the low and mid level winds ahead of the trough into the cold air.   

This was the last really good run of the GFS from 6z yesterday and look at where the mid level winds were directed....

now look at the primary low location

Now look at last nights crap awful run....the primary low is much further southeast...but it doesn't matter

Because look where the mid level winds that will be the main culprit for any WAA precip have shifted

The flow that was directed right into us on the guidance that showed a healthy WAA thump of snow is now directed well to our northwest and that is because of the increase in the ridging and sharper trough alignment not the primary low.  

The precip from the primary low is irrelevant to us, by the time that gets here we will have lost the mid levels and likely the surface.  Whatever snow we get will be from WAA out ahead of the primary system.  But the winds that would cause that are being directed away from us by the ridge/trough alignment.  

We would need a radical shift in the primary low track for that to due us any good...yea if it did track through central Indiana into northern Ohio that would likely redirect those winds towards us as it would indicate a radical shift south of all the features, including the mid level wind flow.  But it would be the shift if that wind flow not the primary that would help.  And that is a HUGE shift...were talking like 150-200 miles in only 3-4 days.  Not sure how likely that is.  Seeing the mid level winds shift back to a more favorable configuration is more likely...but only slightly.  

So a shift south of the primary if it is associated with a weaker ridge and flatter solution would be good...but a shift in the mslp absent the improvements we need at the mid levels ahead of the system would do us no good really unless its a 250 mile shift in track.  

 

 

Great post. Thanks

[mappy]

great writeup @psuhoffman

[psuhoffman]

4 minutes ago, WinterWxLuvr said:

Great post. Thanks

 

4 minutes ago, mappy said:

great writeup @psuhoffman

Thank you!  I just wish I spent more time explaining why it was going to snow instead of why it wasn't...

[SnowGolfBro]

7 minutes ago, psuhoffman said:

 

Thank you!  I just wish I spent more time explaining why it was going to snow instead of why it wasn't...

Do better. Make it snow! Just kidding.  The write up was excellent as always.  Thank you for all of the time and effort you put into your analysis.  I always look forward to reading your posts.  Hopefully in the next couple weeks the we can get some write ups about why we all need to stock up on milk and toilet paper lol!

[mappy]

13 minutes ago, psuhoffman said:

 

Thank you!  I just wish I spent more time explaining why it was going to snow instead of why it wasn't...

nah, its good. lets everyone know what the main parts of the system are and what we really need for a snowier outcome. thanks again. 

[WinterWxLuvr]

Now we just need to get the models to shift those 700 mb winds back toward us. I’m assuming a weaker less wound up low would do that. Regardless, perhaps the euro starts the trend back at least a little in our direction.

[CAPE]

11 minutes ago, WinterWxLuvr said:

Now we just need to get the models to shift those 700 mb winds back toward us. I’m assuming a weaker less wound up low would do that. Regardless, perhaps the euro starts the trend back at least a little in our direction.

Would take some serious deamplification to get the mid level flow back where we need it. No signs that is happening at this point, but I am sure it isn't a meteorological impossibility!