Absolute Vorticity

The Happy Hour or 18Z GFS, brought that system back around Thursday. Still a swing and a miss for us locally but not suppressed along the Gulf Coast as earlier runs have shown. Lot of uncertainty honestly towards the end of next week. Solutions range from cold and dry to rain, a touch of sleet, and maybe first flakes.

Good Halloween morning to you all! As we have discussed... we will start November out on the cold side. We look to have below normal temps for the first 10 days of November the way it is looking right now. We'll start off in the 50s on Monday with a cold front coming thru Mon night into early Tues morning. I don't think we'll see much, if any precip as the front doesn't have a lot of moisture to work with for our local area. I suppose you could put in a shower or a flurry as a CYA kind of thing.

Highs will be in the 40s Tues thru perhaps Sat with lows primarily in the 30s. We do have some good frost threats and perhaps a light freeze coming as well. I don't see lows for CVG in the 20s yet due to possible cloudiness, but should a good radiational cooling situation set up later on in the week, it would then be possible. I foresee lows getting down into the 30 to 35 degree range. Rural locations and the colder valleys of course run the risk of perhaps seeing the 20s but I just don't see that for the Metro area at this time.

Still waiting to see how the Wed night thru Fri time period shapes up as we've discussed. Does this system amp up and does the upper low become more involved fast enough to give us some rain, sleet, and perhaps first flakes? Or does the process occur too late for us and it's a Mountain event for East KY, WVA, etc. That's pretty much the main weather challenge for us to solve.

The Euro continues to be the most robust with this system and the overnight run is no exception. The timing of all the players on the field is perfect. You can see rain and some snow for us as well thanks to the upper low tracking perfectly. If this were December, this would be a nice little snow storm for us.


The GFS keeps bouncing around between teasing us, esp KY and then taking it away. The overnight run indeed squashes everything again well to the south so no storm for anyone. The CMC shows the App. snow event with rain in the lower elevations. That's a swing and a miss to the SE for us so we are cold and dry. The UKMET has precip (rain due to time of day on Thurs, could end as flakes Thurs evening) for folks in our S and SE counties. The GEFS seems to support the OP GFS and the EPS looks to support the OP Euro. It'll be interesting to see if the GFS takes the Euro to school like last winter or does the Euro win one for a change. I am not forecasting dry weather or precip yet towards the end of the week. I am waiting it out to see what happens. I am confident with the temp forecast I have posted here, just not confident yet in the precip department.

I leave at 5am on Friday heading back to SC. Will be interesting to see if I see a little snow in the mountains. The pattern is shaping up well for my Hilton Head Golf Trip. Leaving on Nov 12th and returning on the 20th. That period looks milder and hopefully not much in the way of rainfall. Then I will head back to the local area on the 21st and hopefully that return is when we start seeing more winter weather popping up on the models for our area.

tpweather wrote: ↑Sun Oct 31, 2021 8:39 am I leave at 5am on Friday heading back to SC. Will be interesting to see if I see a little snow in the mountains. The pattern is shaping up well for my Hilton Head Golf Trip. Leaving on Nov 12th and returning on the 20th. That period looks milder and hopefully not much in the way of rainfall. Then I will head back to the local area on the 21st and hopefully that return is when we start seeing more winter weather popping up on the models for our area.

Good morning Tim! Let's hope that you'll bring us some good luck upon your return to the Tri-state! Hope you indeed see some nice weather on your golf trip too.

I found this interesting... Below are the updated model verification scores for the 500 MB pattern over the last 90 days. The image was last updated with the 0Z model runs back on 10/12. The operational GFS is the green line. The pink line was the old Euro before the upgrade took place. The blue line is the current operational Euro that we are currently using. Once you get past Day 5, the GFS comes in dead last with the old Euro second, and the newly upgraded Euro in first. So with that stated.... again... let's see who wins the model battle for the second half of next week. A swing and a miss from the GFS, which is what it is currently forecasting, or the more robust system that the Euro has bringing us rain and wintry mix chances in the Thurs - Sat time frame.

12Z GFS continues to squash the system towards the end of next week.

12Z CMC is a swing and a miss to the SE and the UKMET is going the squash route like the GFS. 12Z GEFS is also playing the squash game. So let's see if the Euro remains on its own island later with the more amp'ed up look or not.

12Z Euro has pretty much lost the storm now too.

tron777 wrote: ↑Sun Oct 31, 2021 2:25 pm 12Z Euro has pretty much lost the storm now too.

It is just a trick. It's halloween after all. It will be back tonight.

young pup wrote: ↑Sun Oct 31, 2021 4:57 pm

tron777 wrote: ↑Sun Oct 31, 2021 2:25 pm 12Z Euro has pretty much lost the storm now too.

It is just a trick. It's halloween after all. It will be back tonight.

LOL! It could easily come back over the next couple of days.

tron777 wrote: ↑Sun Oct 31, 2021 9:16 am I found this interesting... Below are the updated model verification scores for the 500 MB pattern over the last 90 days. The image was last updated with the 0Z model runs back on 10/12. The operational GFS is the green line. The pink line was the old Euro before the upgrade took place. The blue line is the current operational Euro that we are currently using. Once you get past Day 5, the GFS comes in dead last with the old Euro second, and the newly upgraded Euro in first. So with that stated.... again... let's see who wins the model battle for the second half of next week. A swing and a miss from the GFS, which is what it is currently forecasting, or the more robust system that the Euro has bringing us rain and wintry mix chances in the Thurs - Sat time frame.


ModelSkillScores.jpeg

I never quite understand the verification scores and their are so many other ways to see which model performed better. Getting the 500mb pattern does not always mean the models get it correct on storms and even temps sometimes. Does look like the gfs will score with the system later this week though we still have a few days left and hey maybe the Euro had the correct 500 mb pattern but that does not help when you look at what exactly happened. Do I believe the Euro does better in the winter and yes but that gap has been much closer the last few years. There are certain patterns that fit each model and when that pattern is the main driving force then that model will do better of course.

tpweather wrote: ↑Sun Oct 31, 2021 8:21 pm

tron777 wrote: ↑Sun Oct 31, 2021 9:16 am I found this interesting... Below are the updated model verification scores for the 500 MB pattern over the last 90 days. The image was last updated with the 0Z model runs back on 10/12. The operational GFS is the green line. The pink line was the old Euro before the upgrade took place. The blue line is the current operational Euro that we are currently using. Once you get past Day 5, the GFS comes in dead last with the old Euro second, and the newly upgraded Euro in first. So with that stated.... again... let's see who wins the model battle for the second half of next week. A swing and a miss from the GFS, which is what it is currently forecasting, or the more robust system that the Euro has bringing us rain and wintry mix chances in the Thurs - Sat time frame.


ModelSkillScores.jpeg

I never quite understand the verification scores and their are so many other ways to see which model performed better. Getting the 500mb pattern does not always mean the models get it correct on storms and even temps sometimes. Does look like the gfs will score with the system later this week though we still have a few days left and hey maybe the Euro had the correct 500 mb pattern but that does not help when you look at what exactly happened. Do I believe the Euro does better in the winter and yes but that gap has been much closer the last few years. There are certain patterns that fit each model and when that pattern is the main driving force then that model will do better of course.

I think getting the 500 MB pattern correct in the medium to long range is key. Once you get inside 5 days, then you worry about the surface for sensible weather.

tron777 wrote: ↑Mon Nov 01, 2021 6:34 am

tpweather wrote: ↑Sun Oct 31, 2021 8:21 pm

tron777 wrote: ↑Sun Oct 31, 2021 9:16 am I found this interesting... Below are the updated model verification scores for the 500 MB pattern over the last 90 days. The image was last updated with the 0Z model runs back on 10/12. The operational GFS is the green line. The pink line was the old Euro before the upgrade took place. The blue line is the current operational Euro that we are currently using. Once you get past Day 5, the GFS comes in dead last with the old Euro second, and the newly upgraded Euro in first. So with that stated.... again... let's see who wins the model battle for the second half of next week. A swing and a miss from the GFS, which is what it is currently forecasting, or the more robust system that the Euro has bringing us rain and wintry mix chances in the Thurs - Sat time frame.


ModelSkillScores.jpeg

I never quite understand the verification scores and their are so many other ways to see which model performed better. Getting the 500mb pattern does not always mean the models get it correct on storms and even temps sometimes. Does look like the gfs will score with the system later this week though we still have a few days left and hey maybe the Euro had the correct 500 mb pattern but that does not help when you look at what exactly happened. Do I believe the Euro does better in the winter and yes but that gap has been much closer the last few years. There are certain patterns that fit each model and when that pattern is the main driving force then that model will do better of course.

I think getting the 500 MB pattern correct in the medium to long range is key. Once you get inside 5 days, then you worry about the surface for sensible weather.

Good Morning Les and was wondering for the end of the week which model had the 500 mb pattern correct.

tpweather wrote: ↑Mon Nov 01, 2021 6:51 am
Good Morning Les and was wondering for the end of the week which model had the 500 mb pattern correct.

Good morning Tim! Yesterday, we saw the Euro go the GFS's way with the stronger high to the north squashing everything. If that solution maintains over the next day or two then I'd absolutely say the GFS was correct with the 500 MB pattern at the Day 5 range for sure. The Euro isn't going to win every time and neither will the GFS of course. Right now for this next system, the GFS is the front runner. I have not looked at the overnight runs yet so this post is going off of yesterday.

Per the overnight runs, unless something changes, the GFS has won this model battle.

38 at CVG, 37 here. I would assume that there is some patchy frost in outlying areas.

37 is my low so far

Officially 37 at CVG also.

NAmerican snow cover as has been mentioned is off to a slow start as a whole. Awful in Canada. Siberia looks like its slightly below normal to me

Siberia is catching up and will continue to do so. It still looks slow on our side of the globe and may take until Thanksgiving before we get a nice build up. That's perfectly fine by me.

Well folks... for the first week of Nov, It looks to be mainly quiet weather wise with below avg temps thru the upcoming weekend. We should turn mild for Week 2 and the storminess will also pick up.

EDIT: Looks like your call is spot on at this time Tim.

55 at CVG today, 56 here. A front is moving in our direction. Radar shows some light rain but I think a lot of it will be virga esp north of the River and a small chance to see a touch of rain tonight south. LOU's forecast area IMO has the best chance at seeing measurable rain out of this front. The front will start our well below normal weather this week.

Bgoney wrote: ↑Mon Nov 01, 2021 9:33 am NAmerican snow cover as has been mentioned is off to a slow start as a whole. Awful in Canada. Siberia looks like its slightly below normal to me
siberi16.png

Les not only has the snow cover been awful in Canada but the temps well above normal. Siberia is getting really cold as it should and their are signs Canada will start to head towards normal for them but will be interesting if the snow cover remains below average for them.

Sunny day here, but it didn't help much with the coolness to the air. It was refreshing though.

Currently 43 here in Greenville and progged for around 33 Tues morning.