Absolute Vorticity

Not really seeing anything interesting on the 12Z EPS either for snow lovers.

Someone has had a very good snowy winter stretch

Bgoney wrote: ↑Thu Feb 02, 2023 4:14 pm Someone has had a very good snowy winter stretch

I'm jealous! The Mountains of the West and the Northern Plains have done fantastic for sure this winter. Outside of those areas have been okay to horrible. What I think may happen for us is that spring tries to come in February but later this month or early March, winter will make a come back just to send Trev running back into his den once again.

Of course as I post the above, Larry Cosgrove had this to say on his Facebook page today:

After about a six day "grace period", the cold air and the storms are likely to return to much of the lower 48 states.
The long-lived winter weather event that has ensnared Texas and the Mid-South will be history by Friday afternoon, replaced by a gentler/warmer trend east of the Rocky Mountains. Now before you get your "winter cancel" memes out, take a long look at water vapor imagery off of the West Coast. You will see a full-latitude, neutral-tilt trough complex that has energy inputs from both the Madden-Julian Oscillation and the polar westerlies. This should tell you that a more active pattern will ensue after a period of "in between" ridging that allows for warmer values to overtake the middle and eastern chambers of the U.S.
The colder profiles should take over the western third of the continent by February 9. The trough in question will be progressive, pushed along by ridge development into Alaska. We may see another case of heavy rain and intense thunderstorms over the south central U.S. That forerunner disturbance should interact with a rebuilding Arctic motherlode over central Canada and Hudson Bay. And just as the cold air drains into the Great Plains and Mississippi Valley, the impulse now east of Japan should be nearing California. My suspicion is that this new storm will be forced to take a track into northern Mexico, then recurve along the western slopes of the Appalachian Mountains February 14-15.
So enjoy a nice warm-up before we head back into winter. That groundhog in Pennsylvania says that we have six more weeks of cold, snow and ice. So who am I to disagree?

There's a nod to that brief period I said to watch and I believe Tim is interested as well. Models show absolutely nothing to speak of right now for that period other then that fantasy 18Z GFS run from last evening which of course disappeared on the next run as expected.

Larry's due to get something in a long range forecast right maybe this is it

tron777 wrote: ↑Thu Feb 02, 2023 4:27 pm Of course as I post the above, Larry Cosgrove had this to say on his Facebook page today:

After about a six day "grace period", the cold air and the storms are likely to return to much of the lower 48 states.
The long-lived winter weather event that has ensnared Texas and the Mid-South will be history by Friday afternoon, replaced by a gentler/warmer trend east of the Rocky Mountains. Now before you get your "winter cancel" memes out, take a long look at water vapor imagery off of the West Coast. You will see a full-latitude, neutral-tilt trough complex that has energy inputs from both the Madden-Julian Oscillation and the polar westerlies. This should tell you that a more active pattern will ensue after a period of "in between" ridging that allows for warmer values to overtake the middle and eastern chambers of the U.S.
The colder profiles should take over the western third of the continent by February 9. The trough in question will be progressive, pushed along by ridge development into Alaska. We may see another case of heavy rain and intense thunderstorms over the south central U.S. That forerunner disturbance should interact with a rebuilding Arctic motherlode over central Canada and Hudson Bay. And just as the cold air drains into the Great Plains and Mississippi Valley, the impulse now east of Japan should be nearing California. My suspicion is that this new storm will be forced to take a track into northern Mexico, then recurve along the western slopes of the Appalachian Mountains February 14-15.
So enjoy a nice warm-up before we head back into winter. That groundhog in Pennsylvania says that we have six more weeks of cold, snow and ice. So who am I to disagree?

There's a nod to that brief period I said to watch and I believe Tim is interested as well. Models show absolutely nothing to speak of right now for that period other then that fantasy 18Z GFS run from last evening which of course disappeared on the next run as expected.

Les, I keep looking at the animation over and over again on the past several runs of the GFS for that period and see that boundary setting up briefly to our SE during that period after that stronger cutter low later next week/weekend, It's been showing that off and on. Now, after looking at the 12z I've been looking at a wave moving up from the western GOM through the SE states and then out to sea but can a negative NAO be in place along with that positive PNA spike in the right place to bring up a western slope APP storm? I'm going to TRY to be positive on this one as there's nothing really else to look at currently. Lol

I see the pattern starting next week to look similar to January's. Vorts dropping down the center/west side of rockies and surface lows developing near the panhandles, then moving east/NE. We got lucky once in January, soooooo....

Good Evening and always interesting to see Larry's comments. Larry is like many met's and has good years and bad years. Larry all season was talking about the MJO and was completely different then what we saw from the Aussies. Tell you the truth his comments on where the MJO was more in line in terms of the weather we were getting. Does that mean his forecast were any better and the answer is no but I thought the MJO was more correct than models showed.

I do agree about the cold still in Canada and we know the northern plains still has plenty of snow on the ground and though they warm up some next week its nothing major at all. Looking that far out and seeing a system at least 10 days away is almost always hard to predict but I do understand where he is coming from.

I am leaving for SC next Thursday for about 10-14 days so my guess is we will get slammed lol.

Good evening folks...

Some nice discussion going on which is always great on our forum! I'm with Bgoney with regards that the overall pattern really hasn't changed. The cold shots we do see are going to continue to be transient (in and out) and any snow chances will be thread the needle situations. We did get lucky in January and we are going to need to get lucky again. I do think the period around mid month will be one of those chances to keep an eye on, otherwise, nothing really going on for snow lovers until then.

Warm weather lovers will be happy with the forecast for Sunday and most of next week. We have a weather system or two to track which will bring rain to the region after a quiet period that we are in right now. 18Z GFS this evening tries to cook up something for next weekend Feb 11th but the phasing between the two jet streams isn't quite correct for a decent event but it's close. GEFS also has a few members showing snow but not a lot so the signal isn't really strong at this point. But since nothing else is going on, I'll be keeping an eye on it just as I always do.

Great Post Les. I agree about the weekend of the 11th and its close to be a nice phase. So if we can get through the lovely milder spell next week hopefully a pattern that at least gives us a chance at some winter weather will come back around the 11th or so. There are signs but we have seen those before and they just don't pan out but since February seems to be the month for winter around here lets hope that is true once again.

tpweather wrote: ↑Thu Feb 02, 2023 7:22 pm Great Post Les. I agree about the weekend of the 11th and its close to be a nice phase. So if we can get through the lovely milder spell next week hopefully a pattern that at least gives us a chance at some winter weather will come back around the 11th or so. There are signs but we have seen those before and they just don't pan out but since February seems to be the month for winter around here lets hope that is true once again.

Thanks Tim! We certainly need more ensemble support before I'll bite. The signal is very weak but that's ok since we're talking the Day 9-10+ period. Once we get within 7 days you'd at least like to see a medium signal and then at Day 5 a strong signal. This is kind of a guideline that I personally like to use when you are looking at something from a distance like we are right now.

Good morning all! 19 this morning here and at CVG as of 7am, probably will drop to 18. Upper teens to the mid 20s ought to do it for highs today. There has been some LES over Warren, Clinton and Highland co's this morning. Lebanon looks to have picked up some light snow...paging Trev! Another night in the teens tonight then the warm up begins. Small rain chances Tues and Wed will lead to bigger rain chances by Thurs of next week. We should drop back into the 40s by next weekend. Models keep trying to show another cold shot of air but it has gotten pushed back by a few days as one more cutter comes thru then we get cold. Still watching the period around mid month but it is so far out there, there is no strong signal as I said last night for wintry weather.

PV update. For the first time all season , despite what the big boys have been saying, we finally have a legit chance at a SSWE. Eps/Gefs both showing a high number of wind reversals at 10hpa with another warming due in about 7-10 days. With the lingering effects of last week's warming, this next one , should it occur as modeled will have more bite to it and the best possibility to split the PV. Something to monitor over the coming days to see if this process is in motion as modeled





Eps

Thanks Bgoney... I'll believe it when I see it but if it occurs, we would see impacts by March so watch for a delayed spring IMO if this event occurs.

12Z GFS brings in showers late Tues into Wed. Then the main system comes thru on Thurs. The GFS is much further south with this front then the Euro or CMC (0Z runs, have not seen 12Z yet from these two). So then the follow up wave next weekend has a shot to create some snowfall. Yes on this run of the GFS it's a miss for us but this far out not concerned about that. We are just discussing the actual set up here. If the foreign models continue to keep Thursday's system more north then the weekend deal won't be snow, probably rain maybe ending as some flakes or something. So for snow lovers, you need to see the Thurs front stall out south of us to have a chance at the next weekend wave. SE Ridge you would think, should keep the front more north on Thurs per the overnight foreign models. We shall see! TONS of time to watch this particular set up.

You can see the issue on the 12Z Canadian. SE ridge won't be denied so the system is more north and thus, rain ending as some snow showers.

Les we have plenty of time and the GFS is probably showing the colder and further south system as the NAO seems to want to go negative for a few days. The Euro of course is much milder and the CMC somewhere in between. I will be in SC and even the gfs wants to bring a touch of snow there.

Temp at 26 so running a few degrees higher than models showed. My guess 27 or 28 should be the high today. Sunshine makes it seem nicer though. Love to get some rain to clean up the streets somewhat before I wash the car.

tpweather wrote: ↑Fri Feb 03, 2023 11:59 am Les we have plenty of time and the GFS is probably showing the colder and further south system as the NAO seems to want to go negative for a few days. The Euro of course is much milder and the CMC somewhere in between. I will be in SC and even the gfs wants to bring a touch of snow there.

12Z Euro is running now so we'll see what it shows today. The 12Z GEFS members are all over the place, so they are no help at this time.

12Z Euro keeps us dry on Tues with a wash out of a Wednesday. The model has over an inch of rain falling at CVG so that would be a good road rinser. You can also see the next wave (the one in question) digging down into the TX Panhandle by next Thursday morning while our Wed rain maker low continues to occlude over ILL with the upper low rolling into Southern IN. Could see a few showers Thurs mainly north of the river due to the upper low moving thru. Meanwhile, our big rain maker is now over New England and the East Coast bringing those folks rain while the follow up wave continues to dig further south into Texas, Remember, there is no arctic air behind this system whatsoever. By Thurs night into next Friday, the wave in Texas appears to be more of a closed low, like a bowling ball type of system instead of an open wave like previous runs. This is a step in the GFS's direction to be honest. CMC is more of an open wave which we don't want. We do want a closed low type of solution for snow lovers. In time, this system moves towards the bootheel of MO region by Friday evening. We are starting to see some colder air getting wrapped into the circulation as well. Rain arrives by next Sat morning. The problem is two fold. One, the track is a bit too far north. The main problem is strength. This is not a strong system with the surface low only at 1015 MB. You won't get significant dynamic cooling needed for a good thumping of wet snow. Remember, there is no arctic air involved for this system to work with. You need a stronger low for better dynamic cooling and that is the main issue I am seeing on this run of the Euro. I am probably overanalyzing a Day 8 threat but it's what I do! So there you go. We need a storm evolution like the Euro shows but a bit further south track and a much, much stronger upper low and bingo!

Great Post Les and you covered it perfectly. At least we are not waiting 2 weeks for some kind of action to follow besides rain

tpweather wrote: ↑Fri Feb 03, 2023 2:10 pm Great Post Les and you covered it perfectly. At least we are not waiting 2 weeks for some kind of action to follow besides rain

Thanks Tim! This is true. Hopefully in a few more days we'll get some ensemble support. 12Z EPS is much further south but no cold air to work with and the system is again way to weak. Track wise a blend of the OP Euro and EPS would be great but we've got to have a stronger system for sure or it'll be rain no matter what the track.

Les the CMC on this run is looking like the normal gfs and speeding it right along. The Euro and GFS are really closer to each than normal this far away.

tpweather wrote: ↑Fri Feb 03, 2023 2:35 pm Les the CMC on this run is looking like the normal gfs and speeding it right along. The Euro and GFS are really closer to each than normal this far away.

Exactly Tim. An open wave / progressive system isn't going to work. We have to have the closed low solution and a stronger low to boot or it also won't work. When you have no arctic air to work with, it is tough to get snow, but this is one way to do it.