griteater

Buyer beware of the Pivot precip type map on the Euro. The map says rain for Raleigh, but the sounding says snow (very, very shallow above freezing layer at the surface which is likely too warm)...and the sounding output at the bottom right says snow...granted, precip is light

3 days prior to go time, this is what storms that hit us look like. It's far from perfect, but we're in the game here.

The NAM looks really good here out west with the main northern stream wave dropping down thru the Great Basin-Utah-Colorado...Pacific shortwave that undercuts the western ridge tracks out ahead of the northern stream wave as it tracks from southern California into Kansas...energy/weak waviness in the subtropical jet moves from Baja to the ArkLaTex to the Carolinas. The suppressing feature is the shortwave that drops down thru the Great Lakes - so that's one to watch for the northern extent of precip.

The NAM really likes the idea of crashing temperatures in areas of steady precip

12km NAM Simulated Radar at hr84

Nice thing is that the precip on the northern part of the shield isn't meager

No, but it would be silly for most any of us to cancel/quit at this point anyway given the setup here

Ground temps guy has arrived...we are ready now for the storm!

The NAM goes ice cold here at 850mb across NE GA and northern SC as steady precip breaks out on Thursday, and the warm layer is very shallow near the surface. This is encouraging to see for those areas and north given, iMO, the NAMs likely better ability to resolve the arctic airmass. In terms of precip, it's going to be a long week me thinks. There are reasons on both sides as for whether the precip climbs north to where significant precip is realized. We need to see the shortwave interaction out west to work properly to get the needed return flow for moisture.

CMC dropped a significant wave from the northern stream down, tracking from the Great Lakes into E NC....an unlikely scenario, but who the heck knows

UKMet moved north, but it has been way suppressed. 00z run gets precip only as far north as Atlanta to Wilmington

Yeah, GFS was a scraper again. Meanwhile, the CMC has more of a traditional looking Miller A running from the NE Gulf to well off Hatteras...probably some significant snow totals over NE NC, but I don't have a map for it as of now

I'd say your eyes are trained. NAM looks good with precip. As precip surges into Arkansas, I'd say it probably begins to move more west to east from there based on the height pattern. Here's the sounding at Charlotte at hr84 on the NAM. Note the wet bulb (blue line in between the red and green lines) is below freezing except for a very shallow warm layer at the surface, and temp profiles are cooling thru the column as time goes on (dewpoint is dropping over time for example).

850mb zero degree line works south from Charlotte at 12z Thu to Columbia at 03z Fri as precip on the mean moves thru

Precip on the 18z EPS Mean bumped north. It seems to keep wobbling back and forth each run (north/south)

OK I failed on that one. Precip is light on the GFS - stayed more suppressed than I thought it would

Happy hour GFS looks like it’s setting up to be a good run with how it looks out west

...Developing positive tilt Western trof with winter precip in Southern High Plains Wed.. ---Prior Discussion--- Further west, as the tail end of the initial shortwave swings out of the Rockies into the Great Lakes on Tuesday; reinforcing shortwave energy over-tops the amplifying Pacific Ridge dropping into the developing larger scale trof over the West by Wed. This wave, in combination with emerging shortwave energy out of the east-central Pacific (under the Pacific ridge, as well as lingering frontal zone across TX into the Southern High Plains will set up the next system with the potential for wintry problems by late Wed into Thursday. Here, there is much more substantial spread, keying on the timing of the the central Pacific shortwave/moisture transport through the Desert Southwest into the area of concern. Here the ECMWF shows the greatest timing differences being quite slow with the wave, mainly as it lost some energy to the northern stream along the western side of the developing Pacific ridge, which delays the energy advancing as well as dropping the focus further south. So as the shortwave from the northern stream drops, it does not phase/amplify delaying its ejection into the Plains. The 12z GFS and 00z CMC are much faster with this shortwave capture and start to break out increased QPF across the southern High Plains/TX by 00z Thursday. Even though it is typical of the GFS to have a fast bias, the similarity in timing presented by the 00z CMC and UKMET suggest less or no influence of the ECMWF in a preferred blend at this time. While not favored due to typical deeper/over-amplified solution through the West; the 12z NAM is also faster like the GFS/CMC with this energy, providing some confidence, as a stronger more amplified system should be slower. Confidence in average in a 12z GFS and 00z CMC/UKMET blend for this feature. 19z update: The 12z UKMET is very strong rotating the Pacific shortwave under the northern stream positive tilt trof across the Southwest late Wed, this is likely too strong/too fast. The CMC remains on par with the prior run and the initial preference. The 12z ECMWF while still weak, shows better timing of the weaker wave through the Southwest. So will still favor the 12z GFS/CMC but will have some ECMWF inclusion in the preference.

Ha, WPC is mostly favoring a GFS/CMC blend at the moment

Pivotal has the Euro - https://www.pivotalweather.com/model.php?m=ecmwf_full&p=prateptype_cat_ecmwf&rh=2020021612&fh=loop&r=conus&dpdt=&mc=

With respect to precip, this one is tough to figure out. Some of the modeling is bumping north, which happens, say, 8 out of 10 times regardless of the specifics of the setup. Yet, the two models generally regarded as the best at 500mb (Euro and UKMet) want to dive the northern stream energy too far east preventing moisture from surging into the region

The joys of extrapolation ha. It looked great with the storm and slower to gather out west which is good like you mentioned...but it looked like the southward push of cold air was about maxed out based on the height pattern over the southeast

So much that it has a mid-atlantic hit look to it