fountainguy97

Hrrr is not a fan of eastern areas. Hopefully we see it trend wetter this afternoon.

Honestly. I think the B word could be thrown around. Atleast brief Blizzard conditions. Hrrr has an absolutely ripping frontal passage across the whole state. It won't be much snow but it will be some of the most severe winter conditions most places have seen in a long time.

Unfortunately ugly trends today for most. This arctic air mass sucks the life out of our moisture way too fast. It's a curse in disguise really. 

Parent low too far north so we can't tap into any extra NW flow energy.
 

Not a non-event by any means! But this will be a pretty brief 1-2hr changeover to snow before the moisture dries up. 
 

fun fact: this will be by far the slowest start to winter in the short 4 years I've been here. (I know we have been spoiled the last few decembers. Still makes me sad lol)

Models really drying this front up as it makes its way across. EURO may end up correct after all haha

The hrrr is simply jaw dropping. Most places lose 20-30 degrees in a single hour.

Hrrr pumping out good totals. NWS across the state are going to be forced to acknowledge these meso-models soon. 

Looks like models mostly held serve at 0z. Atleast GFS has some NAM support at 6z.  
 

06z gfs holds serve. Ticking north a touch a 500mb but nothing major. It and NAM are lock step. Euro still north.

1 minute ago, John1122 said:

I'm not sure why the NAM loses the dynamics of the storm as soon as it hits the western Plateau. It looks healthy as all get out then just dies out. 

I think the nam has issues long range with de-amping storms. It used to be the opposite but they gutted it and seems it's now too far the other way. It usually doesn't "catch-up" precip wise until inside 60 hrs. 

28 minutes ago, tnweathernut said:

Isn’t the precip shown for the 6 hours before (i e. not a snapshot representation  of that specific time).  Maybe the temperature map IS at that exact hour?  Just guessing here……..

You are right! These maps are very misunderstood and they always make storms look way better Than reality.  The precip map is a 3 hr averaged precip map. That's why it's so large of a precip shield when in reality it'll be abt a third that size.

the way I understand the Ptype is that it's an average. So if the bulk of it is rain it'll show as rain. 2hrs rain and 1 hr snow gives you a rain result.   Gfs maps are even worse because they are 6 hr averaged. Yuck.

gfs 6 hr averaged

gfs radar at that exact time.

Deep dive into the model differences.

There are a couple slight differences between gfs and euro. The most prominent is that the 500mb vort is further south and in a better alignment to funnel cold our way on the gfs.  (The gfs just has a better cold push) We need to see this heavy negative tilt persistent on the GFS. I believe that orientation is a large reason that our cold push is ahead of the moisture vs behind. The gfs has a scooping trajectory that really helps accelerate our cold into the region. The EURO is more of a Linear trajectory not to mention much further north.. This goes for all levels as well.

the NAM is leaning toward the GFS on the trajectory at 500mb but not fully there.  We want to see the gfs hold it's southern most vort trajectory and even tick further south. It is our main driver for moisture.

The GFS is also just straight up more energetic with our moisture. Possibly due to our Vmax convo from above.  But it's 925-700mb moisture is a tap straight from the Great Lakes with the Gulf side aiding transport on the front line. The EURO has a much more anemic transport across all areas.

00z we want to see the GFS vort trajectory stay or even tick south. They are prone to ticking one way or the other up until go time.  I'm probably not understanding the root cause but rather just seeing the surface levels but that's just what my untrained eye sees right now.

20 minutes ago, John1122 said:

We are still maybe 24 hours from the NAMRGEM wheelhouse on these type of events. I expect the GFS to either throw in the flag or get others onboard in 36 hours or so.

On a positive note it is very encouraging to see the NAM favor the GFS with most of the precip behind the cold front. NAM has a long range dry bias. So maybe it'll beef up in time.

Gfs is certainly some eye candy. 
 

legit death band with temps plummeting. Places are getting smoked with 6" in 3hrs or less.

Can't get behind the GFS. 3KM NAM paints a .5-1" swatch across the state.  I think it's a novelty event.

There is very little NW flow of any kind associated with this event. It's nearly all frontal. And even that is in question.  Should be a very very minor snow event looking at things this afternoon. Gfs is in need of an emergency shutdown and repair. Maybe this will age poorly lol

12z  euro and GFS still have the same qpf. One is frozen one is not.
 

Main show is the sheer amount of cold we will have Friday. 

There is really no major difference in qpf between euro and GFS. The GFS has the bulk of precip falling behind the 32 line will EURO has it in front. 
 

for now the RGEM/NAM seem to favor the gfs although I'm skeptical of meso models until inside 48hrs.

06z gfs is actually a nice hit for many. It has MUCH more of the front as snow than euro and crew.  I remain extremely skeptical after the GFS performance with this one. I've never had fun with "cold chasing moisture" setups.  Although this is on an extreme level.

Ratios will be extreme. So even .2 more qpf can stack on 4+ inches.

Oh she cutting hard this run. What a storm this is going to be this week.

I'll be interested to see how long my inch of snow lasts with this airmass lol. 
 

Very impressive cold shot for sure.

3 minutes ago, Carvers Gap said:

Yeah, it's complicated for sure.  In my years of tracking weather the engine/caboose setup is probably the most difficult for modeling to handle.  A few days ago, modeling was trying to pop a Miller A.  Then modeling began to emphasize the western cutter.  We are right about where modeling rediscovers storms.  I think the cutter is most likely, but I am not convinced there aren't some surprises embedded.

I feel like this is one of those storms that has 1000 scenarios that mostly don't work for us and only 1 that does.  Even if we get more focus on the miller A low it doesn't really matter unless it's the primary. No way we get back to that. 
 

In fact, a coastal transfer could end up dryslotting ETN more. This is all or nothing I believe.

06z gfs undid all the positive trends and is now the least snowy it's been lol.  Towel has been thrown for me. Let's kick the can another 10 days down the road like we have done since thanksgiving 

6 minutes ago, John1122 said:

Looks completely saturated all the way to the surface at 141 for instance. The DGZ is at the surface as noted. When that happens you'll see little ice crystals floating down even if the sky is blue. 

Yeah don't think the DGZ level means a whole lot really but still crazy to be on the surface in our area.

With the DGZ literally on the ground I will be extremely curious to see how Meso Models handle the NW aspect of this event. In uncharted territory as far as my NW experience here. Could be single digits and NW flow.

The only negative is it's relatively short lived.

5 minutes ago, Bigbald said:

GfS is a western jog as expected.  Given the fact we have 5 days left about the only place I'd be feeling good about is western Illinois/mizzou.  

Gfs has been ticking east since 12z.

it may not be 2feet across the entire state but this isn't over. We have a LONG time before it's completely set.

I mean the 18z gfs is still a substantial hit. Maybe we can see euro trend toward a snowier solution. 
 

I'll admit the gfs scenario does seem a bit odd. Possible. But not sure I've seen anything quite like it before.