SnowGoose69

There's been a joke for a few years that the ICON is better at 120 or 144 than it is inside Day 4 and I've honestly felt thats overall true. I've seen many instances where a storm is inside that range and the Euro/GFS/UKIE/NAM all agree and the ICON is nowhere close yet 2 days before it had that idea the others all now agree on

I tend to ignore the ICON once inside 96. It actually seems to perform better on the end result often times beyond that, once inside it can do wild stuff. The NAM had a classic NAM run at 18Z for sure, not in a good way unless you're in a small niche of MD.

It sucks in -NAO/+PNA regimes...the one thing maybe going in its favor here is the Pac is still screaming so the S/W traverses the country insanely fast. The Euro has been owning the GFS for the last month or so on the grading numbers.

They would not get 6-10 in that scenario probably because the convection would rob moisture

I'd rather be in Philly or Richmond right now. DC you just know its moving one way or another given we are still 120 hours or more out.

With a strong -NAO not nearly as often. Some of the least track insanity inside 72-96 occurs in patterns like 09-10 or now when things are slowed down by the NAO. You won't often see massive changes.

There has been a wild snow drought in places like GSP/ATL. Those are not exactly snowy places but they also do not go 5 plus years without a 1-2 inch snow event that often, they both have gone I think 7-8 now

Always seems to me when models see raging confluence at D5-8 in a solid -NAO pattern they always overdo it and it inevitably ends up less suppressive as we get closer. The patterns where the blocking is not as raging and they pick it up late inside D5 its like a never ending congrats southern hemisphere as we get closer like March 2013

Funny thing is that would never happen. Having forecast for that area for years lows needs to usually be 1000mb or weaker or they'll track over cntrl or northern AL/GA. Its very rare you can get a low to deepen into the 990s and remain all snow in ATL, the track will usually end up over or near them

18Z GFS congrats Valdosta GA lol

the NavGEM is north of the GFS which is nice

The ATL measurable snow drought of nothing over 0.5 for 7 years should end next month.

Might be some showing that funky evolution where somehow the surface low sorta survives the meat grinder enough to exit into the Atlantic and then redevelop and throw moisture back. We've seen Op solutions with that the last 2 days.

It needs to be near BWI-RIC by 4 days out, its gonna be hard to get it back from anywhere south of RIC but I think if BWI is the bullseye at 96 unless this is the 1 in 10 case where confluence is not being overdone at Day 4 its coming north. I still don't know if it can come back enough those to save most of this subforum. Maybe NYC and SE parts of SNE

By 96 we probably want to see a consensus somewhere between the GFS/Euro. If it holds there through 96 if we go off historic tendencies it probably will gradually come north. I've not seen too many cases where confluence at this range is not overdone. Don't want to have to be bringing it back from Raleigh or Charleston though. Parts of SNE outside of the coast might be close to out of it though at this point.

Its crazy that today we've got convection in the area tonight. The OH Valley is getting a perfect track low and its not even snowing north of the low. If you were still living in the 1980s when models only went out 5 days you'd have no idea what was coming

The 18 upgrade was mostly focused on improving its accuracy over mainland Europe. It did take care of the progressive bias it was having in the US though inside of 72 after the 2014 upgrade. You could almost always shift every storm 50 miles north and it would work. It definitely caused a more amped Op bias though from 84-120.

for whatever reason the last 10 or so years it seems the Euro in winter does better in years where either its an El Nino or the PNA is + and the GFS does better in La Nina -PNA years.

the first storm to me the UKIE idea might be more accurate. I think the ridge out west is just way too far west that even with the -NAO the storm will cut

Somehow the NAO/AO both averaged negative that month, the first 10 days might have skewed it enough. That looks very Feb 2011 like from my memory. at least late month

I posted in the SNE thread how if you just took the a trained monkey could forecast this winter by saying where was the last cold neutral or very weak La Nina to follow a decent El Nino. That would be 80-81, 03-04 and 92-93 were warm neutral so you can basically throw them out. So far if you remove the Xmas 80 cold outbreak this winter and the next 2-3 weeks look a heck of alot like 80-81. It was pretty darn cold but could not snow at all. the pattern completely broke down after 2/10 and torched. It was not a Nina pattern though, it was just basically a raging zonal one

Strangely enough Feb 81 was mostly just zonal. The entire country likely torched based on the individual day height maps I see. It seems though that more often the last 25 years however that the February pattern in La Nina winters loves to revert back to whatever the December pattern was in the GOA/AK area. It would be strange if February reverted more to 12/8 onward with the sort of too far east and large displaced Aleutian low like a strong Nino. Prior to 99 or 00 many La Nina Februarys simple went classic Nina, 89 was an exception where the pattern sort of resembled December 88 but there was a SSW I believe which made Feb/Mar 89 as cold as they were over the Plains/Lakes and at times SNE down to MA

Right now this winter is attempting to follow 80-81 which was really the last case of a cold neutral winter following a decently strong Nino. It also peaked at Nina status very late, more in Jan than the usual Oct-Dec. The snow totals were awful though and 2/10 onward was a raging torch. December by modern day warming matched decently well too in many areas, the Xmas cold outbreak skewed 80 too.

Whether thats legit or not who knows. Might once again be the model trying to default to the ENSO state

I could definitely see if the MJO gets decent amplitude through 8-1-2 that any flip takes awhile to happen and its closer to 2/10 or 2/15 before things really change. I've never liked relying on late peaking Ninos or Ninas to be able to turn the background state as well as ones which are established by October or November.