The snow, sleet, and freezing rain oh my Dec 27-30 thread

[NC DataDude]

14 minutes ago, packbacker said:

Going to chase this to Goldsboro...

I'll wave as you pass me on 70.

Is there a time period where we lean on the short term models more so than the mid/long term? Also, I hear a lot of mention of scores. Do these scores only represent "winter" scenarios or are they year round scores totals?

[FLweather]

1 minute ago, mackerel_sky said:

Next , the rap will save us! 

Not even that.  On the second wave of LP. Retreating HP near Hudson Bay.  Lifting northward. LP and shortwave trough digging in from GL. Ridging along the apps.  Combined all together...  Waa appoarching caa retreating. All that ATM Nam showing for GA SC NC the 28th and 29th too much Waa in the lower levels to support CAD.  Maybe a slight cold pool where the precip at. But WAA from the GOM to NY in the lower levels.  No chance the second round either. 

[mackerel_sky]

9 minutes ago, WarmNose said:

If you believe these NAM 2m temperature profiles are correct at hr57 I feel sorry for your brain

Warmer temps are good. That means less confluence in the NE, and that lets it come back NW! It's a delicate balance!

[snowlover91]

For those wondering, here’s why the NAM came NW and qpf increased.

Here is the German model. Notice how far south the vort digs. 

 

Now notice the NAM is digging the vort in a similar fashion, not quite as much but close. 

[mackerel_sky]

NAM has dewpoints in the negative numbers down to CLT. So the temp profiles on the NAM were waaaay off! Hopefully wasn't a hiccup on precip ?

[Wow]

7 minutes ago, snowlover91 said:

For those wondering, here’s why the NAM came NW and qpf increased.

Here is the German model. Notice how far south the vort digs. 

 

Now notice the NAM is digging the vort in a similar fashion, not quite as much but close. 

 

Notice the mid level winds bending from the WSW to draw up moisture on the German model, no luck on any other model as the wave has been trending weaker over the last 24 hrs with the only moisture coming from the coastal that spins up late.

[mrdaddyman]

NW Trend?

[packbacker]

RGEM trying...

[tarheelwx]

In Situ CAD?  That’s some cold dry air. 

[snowlover91]

8 minutes ago, Wow said:

Notice the mid level winds bending from the WSW to draw up moisture on the German model, no luck on any other model as the wave has been trending weaker over the last 24 hrs with the only moisture coming from the coastal that spins up late.

NAM was pretty close this run and it took a big step towards it. That’s what we need to see from other models, wouldn’t take much. 

[burrel2]

7 minutes ago, FLweather said:

Maybe you should take you own advice

 

Can you explain to me how the NAM is showing southerly flow at the low levels from the Gulf to New York based off its modeled output? In fact, quite the opposite, it has northeasterly wedge flow making it all the way to the gulf of mexico.

[lilj4425]

14 minutes ago, burrel2 said:

Read more post less..... Nam has surface temps around 32 with single digit dew points in the upstate. If any precip makes it there it would drop surface temps in to the low 20's or colder.

Also, your bolded statement is just wrong... look at the wind profiles.

Yep. The evap cooling would take place due to extremely dry air. 

[Disco-lemonade]

nw trend

[DopplerWx]

pretty sig jump nw with precip at 30hrs from 06z gfs. may be a good run for e nc folks here for the weds night event

[Snow haven]

So looking like I may get some frozen precip here in Rockingham late tonight into tomorrow morning 

[WidreMann]

Dude, there's no low-level WAA. While the high is weakening slightly, it's still there and clearly ridging down east of the mountains. There's a ton of cold dry air in place and that won't be scoured by some piddly low pressure struggling over Michigan.

[Disco-lemonade]

not much but who knows, this is still developing 

[downeastnc]

1 minute ago, DopplerWx said:

pretty sig jump nw with precip at 30hrs from 06z gfs. may be a good run for e nc folks here for the weds night event

Temps are still meh though, and the GFS is the same as the NAM/Rgem in that regard.....still the GFS caved to the hi res models which have had the precip much more NW and expansive for several days....hopefully this works out with the Friday event too....

[DopplerWx]

gfs even more suppressed at 60, dry even for the sc lowcountry.

[mackerel_sky]

29th still severely squashed on GFS! NAM was not a trend setter, unfortunately 

[HKY_WX]

I guess we shouldn't be surprised to see some trends NW given this has happened about 10,000 other times. The only issues is the nature of this wave isn't impressive and is not going to dig enough for an impressive event. However, a light to perhaps moderate event is still possible in east/central NC/SC/E GA. I'm interested to see what happens w/ the NY'ers storm system, given the setup is more favorable for amplification.

[burrel2]

1 minute ago, mackerel_sky said:

29th still severely squashed on GFS! NAM was not a trend setter, unfortunately 

GFS did trend stronger with the vort, even though it didn't translate to the surface on this run.  If we can keep getting the vort to tick stronger and dig more, we would have a chance.  

Looks like the 12z CMC doesn't even have the vort though, so... I dunno.

[WidreMann]

The 500mb pattern looks a little better on the 12z vs the 00z, but it's too little too late in this run.

[Disco-lemonade]

Just now, DopplerWx said:

gfs even more suppressed at 60, dry even for the sc lowcountry.

if the short range models continue to stay juiced up I would expect the gfs to remain suppressed until at least tomorrow

[WidreMann]

1 minute ago, burrel2 said:

GFS did trend stronger with the vort, even though it didn't translate to the surface on this run.  If we can keep getting the vort to tick stronger and dig more, we would have a chance.  

Looks like the 12z CMC doesn't even have the vort though, so... I dunno.

The vort isn't coming onshore until tomorrow morning. So perhaps we'll get one of those rapid resurgences once the models sample it.

[CaryWx]

In the FWIW dept. RAL has taken out any possibilities after a slim one SE of the Triangle tomorrow. 

Looks cold and dry through the period.

...and they were fairly bullish up until yesterday.

[BullCityWx]

2 minutes ago, WidreMann said:

The vort isn't coming onshore until tomorrow morning. So perhaps we'll get one of those rapid resurgences once the models sample it.

Same thing happened with the Christmas storm in 2010. Not saying that’s applicable here but there’s precedent and not just with that storm.

[WidreMann]

Just now, Queencitywx said:

Same thing happened with the Christmas storm in 2010. Not saying that’s applicable here but there’s precedent and not just with that storm.

And January 2003 if I recall. In fact, I've seen plenty of storms come back from the dead. It's just really unlikely for all of these storms that the models have seen to disappear entirely. That's pretty rare. The question now is what configuration will they return in. We probably won't get the Thursday storm exactly as depicted, but it could well be a Wednesday or a Friday storm instead.

[frazdaddy]

1 minute ago, Queencitywx said:

Same thing happened with the Christmas storm in 2010. Not saying that’s applicable here but there’s precedent and not just with that storm.

Beat me to it. That storm completely vanished only to come back strong. I remember Fischell saying on air it wasn't going to happen.

[WarmNose]

GFS just looks late to the show. Has things firing up a good ways off the NC SC coast whereas the NAM gets the show started in South Georgia. One is wrong, obviously