vortex95

Look at the 500 cut-off on the 12z GFS. 509 dm "drilling for oil" "black hole sun" 75 mi SE of ACK. Ideally, and CoastalWx will "complain," you want the 500 low to come right over you for the best weenie comma head backlash, but "BEGGAAARRRRS can't be CHOOSAHS!"

So just logged in and check my emails for posts on this thread since 9pm last night. I had not check anything since the 18z runs ydy. 600 posts??? I knew immediately what had happened! The GFS..."WINNING!!!" and CoastalWx is dancin' in the streets!

More like "PHUN" and Games! We may be wtiness ECMWF bust history here! LOL.

Mark the day Feb 19, 2026. Watershed event, king EURO dethroned!

So what is going on here? The ECMWF AI has consistently been more impressive than its op run, esp. at 500 w/ the intensity of the 500 low cut-off when it moves off the E Coast. Now it is even more aggressive at 18z w/ an intense symmetric closed 500 low not far S of ACK at 96 hr, and a SNE crushing. So given the short history of AI versions vs. its own op, which one usually "wins?"

So I took a more detailed look at things. Several things are apparent: 1) This is a non-standard East Coast biggie set up at 500. Usually, it is already a pumped up ridge in the W, and troughing/confluence in the E, w/ *no* "predecessor" system like we get Fri, which is complex in itself b/c you have a moderately strong low pressure move to the Great Lakes, deeply occlude, shear out to the E, and then get a half-decent secondary low develop just SE of New England. Complexity #1 2) The NAMR pattern aloft is blocky. It is all southern stream jet w/ it over the central and southern CONUS. No polar jet at all. Along the border, flow is weak and a mess. You have two small 500 lows as "PLAY-UHS" here, one near DLH and another near YEG. Complexity #2 3) The differences from the GFS and the ECMWF lie mostly on how the YEG 500 low is handled, and to a lesser extent the DLH 500 low. The 18z GFS sheared out the YEG 500 low w/ a couple a discrete s/w trofs that fall into the mean trof position in the E, and the lead one dominates and cuts off quickly over the OH valley, and digs to ORF before lifting NE intact and intense as a cut-off 500 low. The 12z ECMWF, OTOH, bodily moves the YEG 500 low SE and it starts to cut off over the OH Valley. *However*, it appears the DLH 500 low sends a vort ESE as the low itself move N into Canada, *and* at the same time the trof/vort that is near SFO now, after coming out of the mean ridge position, re-amplifies and makes a new small cut-off low at 500 near DTW. So this results in a dumbbell effect of two 500 lows w/ an axis initially from BUF to AVL. And the result is an unphased mess at 500 as it all emerges off the Mid-Atlantic. This does not happen on the 18z GFS, The SFO trof/vort largely dampens out as it moves through the mean ridge position, does not do anything once in the DTW area, and thus is a non-factor, so no dumbbell effect and thus a much more coherent 500 cut-off low as it crosses the coast. Complexity #3 You can see all the above clearly by doing the 500 hgt/vort loops on Pivotal Wx for the 18z GFS and 12z ECMWF. So the large-scale synoptic pattern is good. What we are dealing w/ really is the smaller-scale here, namely the DLH and YEG small 500 lows, in-between the synoptic and mesoscale. Given the above, can we expect any model to handle such a complex pattern "better" here, even only less than 3 days before the event??? Very subtle differences as to what happens upstream in the next few days will be a *huge* IMHO as to what we eventually get on the East Coast! And I would argue no model is good enough to handle such smaller-scale details when slight differences can tip things either way.

More specifically, we want to (MUST) deliver big snows to Weymouth MA, as that is the center of the universe?!

"Trend is your friend?" LOL. You know the more I look back at those wx quips and anecdotes learned growing up, the more I tend to shun them. Mainly b/c "the details are EVERYTHING concerning sensible wx in an area or region!"

CoastalWx: ENJOY THE DIAMOND DUST AT 30,000 FEET!

Well, after such an epic period, it can *only* go down. Regression to the mean. So how is this an issue overall? You lived it, you loved it 1992-93 to 2015-16.

Going from 1981-2010 to 1991-2020 normals raised BOS avg snowfall 7" to 49". That's how lame the snowfall was in the 1980s and how great it was in the new 30-yr period. Such an avg snowfall increase is quite remarkable IMHO, esp. for a coastal location that battles "marine infections" often!

Staying power winters in SNE are much less common than winters w/ great snowstorms. But it's good you at least acknowledge this winter is good or decent. Now compare that to CoastalWx, who seems drowning in the cesspool no matter what happens!

Huh? You get two feet in a single storm and it is called a dream???? Negative Nancy.