griteater

Yeah GFS run was similar...it was a little warmer in the E Piedmont Canadian was colder at the sfc with freezing rain down into SC

Both NWS offices have become more apt to be bullish in the extended range over the years. Not sure why that is, but in the old days, they were typically conservative until it got close in.

The Greenville NWS "changes everybody to rain" wording is a bunch of bunk IMO, especially for the hardcore CAD areas in the foothills. Yeah, Raleigh NWS is going with more of a Miller A with mostly snow where temps allow and Greenville NWS is going with the Miller A/B Hybrid, mixed bag scenario. I favor the mixed bag scenario, but not "changing to rain in all areas".

New Euro Weeklies

Yeah GFS bumped south this run - puts more folks in NC in play for wintry precip this run compared to last

Happy hour GFS coming in - 500mb suggests this isn't going to be as far north as last run

Looking at the Euro Ensemble Trends thru today's 12z run, the western U.S. ridging and the amplitude of our storm wave over the Mississippi Valley have increased (at least on its backside)...but the storm wave is trending more positive tilt - so the amplitude/tilt trade off is kind of a wash. If you increased the amplitude, but kept the wave more neutral tilt, you'd have a farther north/warmer solution (but you can see that the angle of the height lines thru North Carolina really hasn't changed). The cold air damming signal is increasing as well, as to be expected. It kind of looks like a central/northern mtns, foothills, NW Piedmont (and north) wintry event at the moment IMO, but plenty of time for it to change.

From NOAA's Weekly MJO Update

I always find the whole self-limiting thing kind of funny. Like you said, if it's 28 degrees with NE winds and lots of steady precip, the only thing limiting is going to be the extent of the power grid. If it's 32 degrees, well that's a whole different story.

GFS is just more wound up with the storm wave closing it off over Missouri, so that throws the parent low up into Tennessee. Euro and Icon are more broad with the trough, with more of a weak Miller A sliding low

For the GFS and Euro, this fits well with their common biases nowadays IMO. It was opposite in the old days

Euro coming in is more broad with the storm trough, similar to the UKMet. Fairly light with precip amounts. A light wintry event roughly NW of CLT to RDU

It's a little more suppressive at 500mb, but it's throwing a new, strong vort max / short wave down into the Great Lakes which is disrupting the cold inflow from the sfc high up north (more Ohio Valley low influence)

In the old days, the GFS suite would typically be on the suppressed side with storms in the medium range, and the Euro would be more likely to throw out some amped up model runs. In recent years, the 2 have flipped with the Euro tending to be more suppressed and the GFS throwing out some amped runs. Don't know what will happen here in the end, but I'm just saying that the GFS is more likely to throw out amped and north model runs in the medium range compared to the Euro nowadays.

The trough over SE Canada out ahead of the storm to trend stronger and farther south, with the associated damming sfc high building in behind that trough to extend more cold air to the south

Lots to sort out as usual, but this does look like a viable light to moderate wintry threat with damming high to the north and slider type southern low

12z Euro

12z Euro looks a lot like the ICON this run at 500mb with west coast ridge spike dropping the northern stream down into the southern plains and linking up with the southern wave. Not a heavy event, but temps look like what we've seen with many of our wintry storms of late....i.e. wintry along and northwest of GSP to CLT to RDU

The models are going about the winter threat in different ways. CMC and FV3 are dropping in the northern stream whereas the Euro and GFS keep the streams more separated...but each camp at the surface has the gulf to SE coast low. The surface high and damming setup is better with the Euro/GFS camp IMO as the northern stream interaction on the CMC/FV3 brings in more Great Lakes/Ohio Valley Low influence

During an El Nino, we would expect to see more periods than not of below normal convection over the Maritime Continent (phases 7-8-1-2) from fall thru winter, but since late Sept, we've seen a lot of cycling of the MJO/tropical forcing - the lower stratosphere -QBO / low solar combo that hailstorm mentioned and the weakened strat PV are likely contributing to the enhanced MJO cycling that we've seen.

Well the tropical convection over the Maritime Continent and the Western Pacific has calmed down over the past week. If we don't see colder conditions develop during the 2nd half of January, it may be time to just throw the hands up as the tropical forcing should be more favorable then. Februarys are almost always cool in the east during El Nino, but: 1) we haven't come close to locking in typical El Nino-like ocean-atmosphere coupling, and related, 2) the tropical forcing (MJO) may not be in the colder phases during that timeframe (7-8-1-2). On the image below, you can see the GFS FCST taking the VP portion of the MJO thru phases 7-8-1 during Jan 4-17 (the green line).

LOL, in this wretched pattern, the Euro is setting up for glory at the end of its run. Cold high out front, suppressive flow in the east, bowling ball wave moving into SCAL, with kicker wave behind it in the EPAC.

The EPS looks straight wretched in the mid & extended range with the Alaska/Gulf of Alaska/West Coast trough trifecta. That's about as bad as it gets out west. In contrast, the GEFS develops a nice pattern in its extended range. The GEPS is somewhere in between the 2, but closer to the GEFS The MJO on the RMM plots has made steady progress the last 2 days and has finally reached the beginning of phase 6. The dynamical model RMM plots bring the MJO into phase 7 in the next 5 days, then have varying long term MJO solutions. Given the current MJO amplitude, we should expect the MJO to continue on thru phases 6-7-8-1 over time, with the specifics around the timing to be determined. The filtered VP portion of the MJO shows that the enhanced convection associated with the MJO has moved from the Maritime Continent out into the western Pacific over the past week (blues and purple). Loop of those images shown here: http://www.atmos.albany.edu/student/ventrice/real_time/maps/mjo/global_analyses.html The week 2 GFS forecast of MJO filtered VP shows the suppressed convection moving east and centered over the Maritime Continent, with the enhanced convection extending from the central & eastern Pacific to Africa. That's where we want to be from a tropical forcing standpoint to begin to see improving western ridging / eastern troughing solutions in the models. The official SSWarming wind reversal is occurring today. The extent to which it propagates down into the troposphere to affect our weather remains to be seen. It this one does propagate downward, it looks like it's going to take some time - at least a few weeks. I think there is good reason to remain optimistic about wintry weather returning in the 2nd half of Jan into Feb, but until we see good ensemble runs showing consistently, it's all speculation. I did find it kind of funny that the very last image of yesterday's Euro Weeklies for Feb 9-14 was the best image of the run, as if the model is just wanting to tease us

Well the ensembles look kind of 'meh' right now. Nothing terrible, but nothing spectacular either

Here's the GEFS for days 10-15. It's out there in range, but it looks really good out west at the end with the strongest anomalies over the Northern Hemisphere contained in the Aleutian Low / W Canada & Alaska ridge couplet. The Aleutian Low anomaly is displaced to the south and would seed storm waves at a lower latitude (into California/Baja), and the W Canada / AK ridge would deliver January-level cold east of the Rockies.