vortmax

OSUmet said it well on the LES thread...this is what I was asking about regarding dynamic cooling (isothermal snow w/lift). Seems it may happen here.

Lol, didn't realize I was in the wrong thread!

6z GFS definitely a tick east and gets it done for everyone west of SYR

That snow hole is right over my house if you look close.

The LP was more east.

18z NAM definitely east a bit.

Plenty of variation on the ensembles which shows how difficult this will be to resolve by the operational models. I think this will become a nowcasting event.

You have to admit this type of scenario isn't easily modeled.

The only good thing here is that the models seem to be having a hard time with the wave timing and strength. Could be some favorable surprises.

12z Euro was slightly weaker and slower, but a tad west from 00z. Hoping the trend is for a weaker wave as to not hold up the frontal passage.

What was the trend from 00z?

GFS is a little E, but not enough to make a difference. No synoptic for anyone. Any thoughts on dynamic cooling with a 990 LP close by?

Yes, you guys have insurance, we don't. NAM is way west -almost far enough to get DTW in the synoptic.

I'm talking about the low-end probability map. They have it at 0" for Roc because if this thing stays too far west, we won't get much of any synoptic snow. 12z NAM is still coming in even more west....stronger with the wave low by 2mb...bad look for all of WNY for synoptic. Now CLE is in play...unbelievable.

Unfortunately their low-end is 0" for most of us outside LE.

Yup, the GFS' position seems to be winning out here. Hoping the Euro follows suit with an eastward shift.

Out of it's good range still.

Yeah, a bit concerned this thing passes right over us, delaying the front and missing heavier synoptic to the west...we will see as I don't think the timing will be resolved with the globals. Will need the NAM & HRRR to sort it out once in range.

Wow, WSWs just came out for the LES...no mention of synoptic for anyone else....guess they are waiting?? URGENT - WINTER WEATHER MESSAGE National Weather Service Buffalo NY 218 PM EST Mon Dec 21 2020 NYZ006>008-220330- /O.NEW.KBUF.WS.A.0011.201225T0600Z-201226T1800Z/ Oswego-Jefferson-Lewis- Including the cities of Oswego, Watertown, and Lowville 218 PM EST Mon Dec 21 2020 ...WINTER STORM WATCH IN EFFECT FROM LATE THURSDAY NIGHT THROUGH SATURDAY AFTERNOON... * WHAT...Heavy lake effect snow possible. Total snow accumulations of more than 9 inches possible in the most persistent lake snows. * WHERE...The Eastern Lake Ontario Region. * WHEN...From late Thursday night through Saturday afternoon. * IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the morning or evening commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Narrow bands of heavy snow could impact portions of the region. Localized travel problems will be possible. && $$ URGENT - WINTER WEATHER MESSAGE National Weather Service Buffalo NY 218 PM EST Mon Dec 21 2020 NYZ010>012-019-020-085-220330- /O.NEW.KBUF.WS.A.0011.201225T0000Z-201226T1800Z/ Northern Erie-Genesee-Wyoming-Chautauqua-Cattaraugus- Southern Erie- Including the cities of Buffalo, Batavia, Warsaw, Jamestown, Olean, Orchard Park, and Springville 218 PM EST Mon Dec 21 2020 ...WINTER STORM WATCH IN EFFECT FROM THURSDAY EVENING THROUGH SATURDAY AFTERNOON... * WHAT...Heavy lake effect snow possible. Total snow accumulations of more than 9 inches possible in the most persistent lake snows. Winds could gust as high as 35 mph. * WHERE...Erie, Genesee, Wyoming, Chautauqua, and Cattaraugus counties. * WHEN...From Thursday evening through Saturday afternoon. * IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the morning or evening commute. PRECAUTIONARY/PREPAREDNESS ACTIONS... Narrow bands of heavy snow could impact portions of the region. Localized travel problems will be possible.

Yes! And this will be the pasty snow sticking to everything due to the flash freeze. Might look a bit like ice riming you see on mountains...

The Euro actually has a nice track, just a bit too west. Not sure why it doesn't produce a bit more.

From a purely Christmas standpoint...could be a really nice scene in the morning with the snow sticking to everything... Even a couple inches.

Thanks! Looks like the warm lakes really keep that cold air from advancing quickly. I'd imaging the temps 30ft off the deck are 2-4 degrees colder at the same time.

Was thinking the same, although that front was slower, more angled - we got a good 1" of rain before the passage. But, yes...this is a rare, but fun situation in the winter with lots of potential and wild transitions.

The sensible weather under that passage would be heavy rain...to heavy graupel...to heavy snow paste. Dave, what are the 2m temps doing during this time? Flash freeze? I remember one time where there was a strong cold frontal passage (anafrontal event) where heavy rain instantly turned to heavy snow. Was one of the coolest weather events I've witnessed.