Wintry 1/20 - 1/23 Winter Storm

[Oconeexman]

I think, just as important as what yall are saying, maybe more? If we don't get the front down far enough on the initial wave and push down the high and into CAD, then forget snow (outside of mtns) and get ready for rain or ice.

Totally agree with ya Chris. I'm not sure which system to root for here. One bombogenisis like euro or 2 waves like gfs. Higher potential with one system but that brings in more warm air. The upstate was lucky with the last one and fought it off but too many times that doesn't happen. You'd have to think by tomorrow the gfs or gefs would agree with euro/eps unless the gfs is about to bring up its awful 4/5 day score.

 

[Myfrotho704_]

Lol end of the SREFs are already lighting up

 

[GaWx]

Would someone please post the individual member wintry precip (not just snow) maps of the 12Z GEFS for wave #2, specifically? That would be mainly covered by hours 126-150 (24 hours ending at 150). I have not seen that posted as I saw only maps only near hour 108 (first wave) from the 12Z GEFS. The 2nd wave on the 12Z GEFS has a bunch of well offshore surface low tracks:

 

[Myfrotho704_]

This CAD/spillover of shallow artic air will probably overperform, as we saw last year, SHALLOW artic air from strong sfc high pressure over performs quite a bit vs modeling

 

[accu35]

Nam getting there?

 

[CaryWx]

Looks like it's showing the front pass there

 

[Chazwin]

View attachment 107390
Nam getting there?

Geez that’s 1046 high over the Northern Plains!!! I don’t remember the last time we actually had a high that strong moving in with a storm threat, and this only hour 69 this isn’t fantasy land stuff

 

[$alt]

View attachment 107390
Nam getting there?

Pay attention to what's happening out in Texas. The 500mb heights are invaluable versus the surface map.

 

[brendan123]

Overrunning starting at the end of the NAM

 

[Myfrotho704_]

Overrunning already beginning on the end of the nam

 

[Shaggy]

Morehead city AFD



A p-type forecasting nightmare scenario may be taking shape, as
the sfc front hangs up just off the coast, oriented WSW to ENE,
while significant CAD develops, esp interior, and has the
earmarks of icing or sleet. As this system is still several days
away, will only mention RA/SN in the forecast at this time, but
some areas could see significant icing, as is advertised by
latest CMC/ECM solns. Along the immediate coast (Crystal Coast
through the OBX), sided with climo and kept p-type rain, but
even here a threat for wintry weather may come into play. Temps
will be below climo with hts/thicknesses quite low.

 

[accu35]

Ice could be an issue with this look. It’s the LR Nam tho.

 

[Myfrotho704_]

Lol talk about a shallow cold airmass

 

[$alt]

View attachment 107395
Ice could be an issue with this look. It’s the LR Nam tho.

You are waiting for heights to crash; that 540 thickness line is sometimes a good judgement for a column that's cold enough for snow/some sleet... but that's not all you need.

 

[Cary_Snow95]

NAM is very different from the euro. Much less stream interaction

 

[BullCityWx]

Overrunning already beginning on the end of the nam View attachment 107394

Up here, we’d back slide from RN to ZR to IP to SN which is highly unusual.

 

[Myfrotho704_]

That wave in the PNW is a issue on the NAM

 

[brendan123]

Last run of the RGEM (12Z) looked similar to the NAM, we'll see soon if it keeps this look at 18Z

 

[$alt]

NAM is very different from the euro. Much less stream interaction

Looks to me there will be Wintry weather of sorts, but nothing amped up like the Euro.. Might would look a little GFS like if it went further... but 84 hour NAM... pointless really.

 

[brendan123]

That wave in the PNW is a issue on the NAM

How would it affect the system on Friday/Saturday?