Absolute Vorticity

Good morning all! Temps are down into the 30s now as we await the snow shower activity. The vort max is currently located up in Wisc producing snow showers there dropping SE. Winds are also very gusty already out of the west gusting to 32 mph as of 4am at CVG. We will see how steep the lapse rates get later on as well as if any instability can get involved for a more convective nature of the snow. If that can occur, this system will put down 1/2 to 1" amounts in a very short period of time and that will be the concern for road issues later this afternoon and evening as well as reduced visibilities making for difficult driving. In areas where the snow remains lighter, it won't be too bad. Not everyone will see the heavier snow bursts so a dusting to 2" is the forecast range which Trev has covered nicely already. We have to go with a range due to the banded nature of the snow shower / squalls. The action will wind down area wide late this evening and especially after midnight.

Cold tomorrow with lows in the teens and highs in the low to mid 30s. We then warm up with the 50s back by this weekend along with rain showers late Friday and also on Christmas Eve. A more significant system looks to occur around the 26-27th with rain perhaps ending as some snow on the backside. Depends on the track of course. This one could be a good one for Tim up in Wisc snow wise if all works out.

Good Morning and Les your forecast looks great. Around the world and what if any trends we are seeing this fall season leading into winter. Over the past month or so we have seen some nice winter weather which first poke its head in eastern Europe and then a brief period in western Europe. Eastern Canada has been really winter like for much of the fall and this is an area like the northeast USA that tends to get their worst weather deeper in the winter. Alaska for the most part has seen a normal winter and maybe a tad above normal temp wise and of course in southern Alaska some heavy snows. The current place to see winter like is in China and Beijing just got hit with very cold and snowy conditions.

So many folks in the lower latitudes have got in on some nice winter weather except much of the USA and south central Canada. Will the next outbreak be in the central USA and we will see but some the different models we look at does show more winter like conditions as we head closer to the new year.

With the different outbreaks in different parts of the world and what does this tell me. This tells me that the PV is not the strongest ever and very easy to move to lower latitudes. Sometimes a satellite can help but also there is more to just that and we need to look at conditions on earth itself. The Polar regions have been cold but nothing unusual and tell you the truth spikes of cold air within the PV are noticed but its not widespread and this tells me the PV is not that strong. Sometimes we use measures and those measures are nice to have but not always perfect in what is happening on the ground. Lowest temp this morning is -55 and sure that is cold but probably not to far away from normal in that part of the world. We are not seeing those -60 - -80 readings you sometimes see in the winter. I could go on and on about this but way to much info and fingers are starting to cramp by typing lol

Last night around 10:30 I saw snow squalls warnings up in Minnesota and Wisconsin. Should be interesting to see if any of us see those.

young pup wrote: ↑Mon Dec 18, 2023 8:51 am Last night around 10:30 I saw snow squalls warnings up in Minnesota and Wisconsin. Should be interesting to see if any of us see those.

One just issued north of Indy.

Edit: nvm that’s a special weather statement.

Scattered vigorous snow showers popping up

The energy is very impressive and it's dropping in now and getting ready to round the base of the trough here soon.

35 as of 10am at CVG. Latest AFD from the boys:

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Scattered light showers will continue through mid morning as
some weak mid level energy has overspread our area ahead of the
main trough. Any pcpn will remain mainly rain through about
daybreak when pcpn will begin to mix with/change to snow as
cooler air begins to move in from the northwest.

The strong mid and upper level short wave will then dive down
across our area later this morning and into this afternoon. This
will correspond with an impressive PV anomaly and strengthening
low level lapse rates/low level instability to allow for
widespread snow shower development. Winds will also increase
through late morning with gusts in the 30 to 40 mph range
possible through the afternoon. It looks like the strongest lift
and saturation into the DGZ should occur in about the 18-21Z
time frame, or early to mid afternoon. This will lead to
enhanced snow showers and potentially some snow squalls, with
bursts of heavy snow and rapidly reduced visibilities. The best
chance for this appears to be across northwest portions of our
area, where some enhancement from Lake Michigan will be
possible. In these areas, one to locally 2 inches of
accumulation will be possible. Elsewhere across
northern/eastern portions of our area, localized accumulations
should generally be less than an inch. Accumulations will become
more spotty toward southwest portions of our area, where
localized accumulations will be mainly a half inch or less.

Temperatures will be in the low to mid 30s through much of the
day and road temperatures will remain above freezing through
the daylight hours. Still though, some quick accumulations will
be possible on roadways in the heavier snow bursts, leading to
the potential for slick spots. Snow showers activity will begin
to taper off after sunset as we lose the diurnal enhancement.
However, air and road temperatures will then begin to fall
below freezing so there could be a few hour window late this
afternoon into early evening (during the evening commute) where
road conditions may become worse. Will therefore continue with
the Winter Weather Advisory as is.

Really starting to flare up over Indiana now.

Finally a snow shower mixed with a little ice as well

tron777 wrote: ↑Mon Dec 18, 2023 10:30 am The energy is very impressive and it's dropping in now and getting ready to round the base of the trough here soon.


500mb_sf.gif

Yep that is what is really getting things kicking now! Should be a fun afternoon.

Trevor wrote: ↑Mon Dec 18, 2023 10:34 am

tron777 wrote: ↑Mon Dec 18, 2023 10:30 am The energy is very impressive and it's dropping in now and getting ready to round the base of the trough here soon.


500mb_sf.gif

Yep that is what is really getting things kicking now! Should be a fun afternoon.

No doubt! The 12Z RGEM looks really good in that 1-3pm window.

Couple of nice snow showers in the metro area.

Snowing in Fairfield.

Snowing back home in Burlington per a text from the folks. Partly cloudy here in Mason attm.

30+ dbz in some of those cores so that’s going to look good for a short time.

Quick long range post - I will have more on it this evening, but the GEFS is starting to come around to the EPS's idea of a much better looking end of Dec into early Jan period. The MJO model forecasts are also improving. If correct... if... we may indeed be in for some fun and games in another 10-14 days. DT sure is honking about it (Not that it means much) but I do follow him for long range thoughts. Short to medium range not so much.

Trevor wrote: ↑Mon Dec 18, 2023 10:45 am 30+ dbz in some of those cores so that’s going to look good for a short time.

This is looking like a really nice flow off of Lake Michigan also which should assist in adding more moisture into the game. I think your forecast looks spot on buddy! Just sit back and watch the fun at this point lol

Dark clouds approaching the office building here in Mason so a snow shower should be starting up around here shortly. It'll give me something pretty to look at while I'm working since my lunch break is about up.

Lovely as a heavy snow shower with very strong winds and look like a snow tornado for a few minutes. Grass is covered but road and sidewalk just wet. Later this afternoon with these snow showers and I believe roads will also have some problems with these bursts

Wow, that snow shower was impressive, briefly covered the road and now the sun is out!

Also, the temp went from 34 to 28 in a matter of a few minutes!

An impressive squall is happening right now at lakota east high school!!

Just had a nice snow shower in Mason. Picked up a quick dusting.

In Fort Recovery in Mercer county. This snow squall means business. Brief white out conditions.