Absolute Vorticity

CVG got to 18, DAY 13 and CMH 16 yesterday.

Currently 14 here in G'ville and look to top out at around 21 today.

The wind is picking up from the SW

cincy bud wrote: ↑Wed Jan 17, 2024 11:24 am The wind is picking up from the SW

Yep. It's all ahead of our next system that we are discussing in the storm thread.

Tim gets the full credit for this, but I am seeing more and more signals that we need to watch late Mon night into early Tues morning of next week for some snow / wintry mix going over to rain. Models can be too fast with scouring out the cold air and the ground and everything will still be very cold before we fully thaw out and warm up. Also, we will need to watch the sky cover and high temps on Monday too. After we get by Tues morning, we'll be plain old rain for the rest of the week and be plenty warm enough to avoid any problems in terms of slick conditions. It is the transition out of this cold pattern that we will need to watch.

Have exceeded today's high here in G'ville somewhat as currently its at 23.

25 at CVG but with a strong south wind, we won't drop off too much tonight. That and increasing clouds too will also help keep temps up from the frigid levels we have been seeing.

Man that wind was absolutely brutal today, coldest feeling day of the week for me

Both CVG / DAY reached 27 and CMH 24 today.

Currently 27 here in G'ville with a SW gust of 28 mph.

Pretty potent MJO pulse ongoing in the maritimes

Some MJO models get it into Phase 6 then it dies. Others Phase 7 then it dies. It is hard to trust the guidance since it's been so bad. I do think a lot of the model bias this winter has been to forecast the MJO as being weaker then it actually is. I would go with the idea that it keeps on moving at the present time. The above satellite pic kind of confirms my thinking. Also, per the Aussies... as of 1/16 the MJO was strongly in Phase 4 which also supports the above. It is stronger then what the models are showing in fact.

tron777 wrote: ↑Wed Jan 17, 2024 7:31 pm Some MJO models get it into Phase 6 then it dies. Others Phase 7 then it dies. It is hard to trust the guidance since it's been so bad. I do think a lot of the model bias this winter has been to forecast the MJO as being weaker then it actually is. I would go with the idea that it keeps on moving at the present time. The above satellite pic kind of confirms my thinking. Also, per the Aussies... as of 1/16 the MJO was strongly in Phase 4 which also supports the above. It is stronger then what the models are showing in fact.

Are 8, 1, and 2 still the cold phases for February?

snowbo wrote: ↑Wed Jan 17, 2024 7:53 pm

tron777 wrote: ↑Wed Jan 17, 2024 7:31 pm Some MJO models get it into Phase 6 then it dies. Others Phase 7 then it dies. It is hard to trust the guidance since it's been so bad. I do think a lot of the model bias this winter has been to forecast the MJO as being weaker then it actually is. I would go with the idea that it keeps on moving at the present time. The above satellite pic kind of confirms my thinking. Also, per the Aussies... as of 1/16 the MJO was strongly in Phase 4 which also supports the above. It is stronger then what the models are showing in fact.

Are 8, 1, and 2 still the cold phases for February?

Yep. They are typically cold phases in DJF.

We have 50s returning next week to go along with the rain. Not sure if we will hit 60 but if a low cuts far enough West of us, I wouldn't rule it out. So we were warm, then cold, now we're going back to warm. I expect we'll go back to cold late this month or early February time frame.

Great read from Dr. Butler about the PV


http://www.climate.gov/news-features/bl ... tex-acting

Bgoney wrote: ↑Thu Jan 18, 2024 7:52 am Great read from Dr. Butler about the PV


http://www.climate.gov/news-features/bl ... tex-acting

Hopefully this will be good news for February.

Currently 27 here in G'ville and progged for around 21 on Fri morning.

CVG got to 33, DAY 27 and CMH 29 today.

Shifting gears and looking at the Jan Thaw for next week, is there a cutoff low or stalled frontal boundary with shortwaves / lows riding along the boundary bringing in the multiple day rain event starting with some rain / frz rain at the onset Tues e.g. Currently it shows a chance of rainfall through at least Sun 1/28!

Sure would be nice to have some dry, exception being Mon, later in the week along with the mild up.

Oh well, will take the rain even though boring esp this time of year.

For the entire area....

...WIND CHILL ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO NOON EST SATURDAY...

The biggest challenges for next week are going to be any mixing or frz rain concerns for Tues morning before changing over to rain. I will be taking a closer look at this over the weekend. The other concern is for mod to hvy rainfall falling over the cold, frozen ground which will run off into creeks and streams. Models are showing 1-2" of rain if not more coming next week. ATTM, periods of rain can be expected Tues thru the following weekend as multiple lows bring moisture up from the SW and Gulf of Mexico. Flooding is absolutely going to be a concern for some folks.

tron777 wrote: ↑Fri Jan 19, 2024 6:59 am The biggest challenges for next week are going to be any mixing or frz rain concerns for Tues morning before changing over to rain. I will be taking a closer look at this over the weekend. The other concern is for mod to hvy rainfall falling over the cold, frozen ground which will run off into creeks and streams. Models are showing 1-2" of rain if not more coming next week. ATTM, periods of rain can be expected Tues thru the following weekend as multiple lows bring moisture up from the SW and Gulf of Mexico. Flooding is absolutely going to be a concern for some folks.

Great Post Les and I agree about the chance for some frz/rain early in the week. Again it takes a little while to get surface temps above the 32 degree mark so even if you have rain falling at 36 degrees some ice can form especially in places that see very little sun plus sidewalks always tricky. Once we get that out of the way then how much rain do we get and no doubt like you mentioned Les some flooding is possible.

tpweather wrote: ↑Fri Jan 19, 2024 7:41 am

tron777 wrote: ↑Fri Jan 19, 2024 6:59 am The biggest challenges for next week are going to be any mixing or frz rain concerns for Tues morning before changing over to rain. I will be taking a closer look at this over the weekend. The other concern is for mod to hvy rainfall falling over the cold, frozen ground which will run off into creeks and streams. Models are showing 1-2" of rain if not more coming next week. ATTM, periods of rain can be expected Tues thru the following weekend as multiple lows bring moisture up from the SW and Gulf of Mexico. Flooding is absolutely going to be a concern for some folks.

Great Post Les and I agree about the chance for some frz/rain early in the week. Again it takes a little while to get surface temps above the 32 degree mark so even if you have rain falling at 36 degrees some ice can form especially in places that see very little sun plus sidewalks always tricky. Once we get that out of the way then how much rain do we get and no doubt like you mentioned Les some flooding is possible.

Yes Sir... we are on the same page for sure next week. We have multiple lows coming up from the SW in the STJ. Depending on how each one tracks will determine how much rain we receive but the flooding potential is going to be high IMO for folks in low lying areas and near creeks, streams, and the OH river itself.

tron777 wrote: ↑Thu Jan 18, 2024 8:04 am

Bgoney wrote: ↑Thu Jan 18, 2024 7:52 am Great read from Dr. Butler about the PV


http://www.climate.gov/news-features/bl ... tex-acting

Hopefully this will be good news for February.

Hopefully, what we saw in the last half of December with the signals coming for a cold active STJ for the first half of January, we'll start seeing those signals again at the last half of January for a return to the Arctic and active STJ for the first half of February? Looks like the mostly mild to some cold shots with rainy periods that we saw in the last half of December is coming back for a couple weeks or so with that same weather pattern we saw in December. In short, I believe we should see a repeat performance and back to the Arctic cold and that active STJ.

winterstormjoe wrote: ↑Fri Jan 19, 2024 9:18 am

tron777 wrote: ↑Thu Jan 18, 2024 8:04 am

Bgoney wrote: ↑Thu Jan 18, 2024 7:52 am Great read from Dr. Butler about the PV


http://www.climate.gov/news-features/bl ... tex-acting

Hopefully this will be good news for February.

Hopefully, what we saw in the last half of December with the signals coming for a cold active STJ for the first half of January, we'll start seeing those signals again at the last half of January for a return to the Arctic and active STJ for the first half of February? Looks like the mostly mild to some cold shots with rainy periods that we saw in the last half of December is coming back for a couple weeks or so with that same weather pattern we saw in December. In short, I believe we should see a repeat performance and back to the Arctic cold and that active STJ.

I agree Joe. As long as the MJO doesn't screw us over, my thought process has been for it to continue thru the warmer phases 4, 5, and 6 at this time which is why the cold pattern is going to be breaking down and the warmer pattern coming starting next week. Per the Aussies, as of 1/17 the MJO was getting ready to cross into Phase 5 so by now we can go ahead and say it is in Phase 5 lol Models continue to underdo the amplitude of the MJO impulse and I suspect that will be the case again. The guidance dies the wave off too quickly by getting it into the COD down the road, which I also think is incorrect. So as long as my MJO thoughts pan out, combine that with the weakened PV and actual SSW event that is now ongoing... at some point in Feb, we should get another cold and stormy spell as you said. My original thought was that we'd flip back to cold late this month and into the first week of Feb, but I could be rushing that a bit. I'll have more time to look at the longer term ensemble guidance probably over the weekend to comment more on that.