Absolute Vorticity

Bgoney wrote: ↑Fri Feb 10, 2023 8:28 am EPS/GEFS still in excellent agreement with the pattern Les described above at least to the 24th.

Hopefully we begin to see some changes after that. If the models do the ole delayed but not denied routine, then we're in trouble for additional wintry weather. But I am hoping that the weakening Nina and SSW along with the MJO being in a potentially more favorable phase will do the trick. We need the -EPO to be more poleward and less flat as it has been. The ridge continues to be a roll over ridge so the trough's can continue digging into the west as a result which of course pumps up the SE ridge here. That has been the pattern and it will continue to be the pattern over the next week plus. Trev will once again come out of his den next week for sure. Predicting him is easier then predicting the weather sometimes.

Easterlies forecast to lessen considerably near the dateline(west pac) and even a hint of westerlies taking the reigns In the coming days, which we have rarely seen in about 3 years . So this shows signs of the previous hostile conditions in the west pac more removed and now being more of an enabler for the MJO impulse to keep its eastward progression into the wintery phases going into March

Bgoney wrote: ↑Fri Feb 10, 2023 8:44 am Easterlies forecast to lessen considerably near the dateline(west pac) and even a hint of westerlies taking the reigns In the coming days, which we have rarely seen in about 3 years . So this shows signs of the previous hostile conditions in the west pac more removed and now being more of an enabler for the MJO impulse to keep its eastward progression into the wintery phases going into March



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Wonderful news!!! Maybe we can end this winter with a bang and go out on a high note! Definitely seeing more signs of the AO dropping in about a week or so from now. Some Ensemble members even have it going negative after Pres Day. NAO drops towards neutral but overall still positive. PNA is negative but if the -EPO can develop in the right location and have the right orientation as we've discussed then we can overcome the -PNA. Definitely seeing some more interesting times ahead. Just have to make it thru another week or two of false spring.

Currently for next week... SPC has the TN Valley and points south highlighted as the area to watch for severe wx on Wed and Thurs of next week. Rare to see them highlight anything at Day 6 and 7 but it's there atm. We need to keep an eye open ourselves for the track, strength, and timing of the cold front with this system. You know the old saying... during the winter time if you get thunder then a week or so later it snows.

12Z GFS definitely took a step towards the stronger Euro idea for next week. First system moves in Tues afternoon into Tues night with some showers. This isn't a huge deal. Wed is dry and a nice day in the 60s. The next low gets cranked up and tracks to our NW thru the Quad Cities area into Michigan and strengthening as it does so. Warm front comes thru Thurs morning with a round of rain. The wind cranks up after that once we get into the warm sector. On this run of the GFS, the timing of the cold front is ideal for strong to severe t-storms as it comes thru our area Thurs afternoon and evening. This is our next period to watch for active weather. Wind shear looks good. Moisture return is also good with dews progged to get into the upper 50s for Cincinnati. There is some weak SB CAPE as well around 200 J/kg. I am probably over analyzing this since it's not until Thurs of next week but as it stands right now, Trev will absolutely be coming out of his den for this system.

really warm and windy here today. actually not warm warm but sunny and 50 degrees. its really just a beautiful mid February day of you do not like cold and snow.

airwolf76 wrote: ↑Fri Feb 10, 2023 11:32 am really warm and windy here today. actually not warm warm but sunny and 50 degrees. its really just a beautiful mid February day of you do not like cold and snow.

We had winds yesterday in the 40-60 mph range in gusts along with record high temps! There were a couple of locations south of our area in Central KY that gusted over 70 mph! Could be doing a repeat next Thursday. Although this go around, it looks like a strong to severe t-storm threat to me instead of just non t-storm winds which is what occurred yesterday. At least it's not boring even though for us snow lovers we are currently not getting what we want. I still think we've got a shot later this month and into March. When people's minds are on spring, old man winter is going to have a trick or two up it's sleeve IMO before the season is over.

LOL! GFS is going bonkers with another deep, strong low and negatively titled trough a couple of days after Pres. Day! Sheesh! This month could be remembered for strong winds and big t-storms versus snow.

My back porch reads 48 degrees today. Old man winter an Ma Nature need to get on the same page.

tron777 wrote: ↑Fri Feb 10, 2023 11:25 am 12Z GFS definitely took a step towards the stronger Euro idea for next week. First system moves in Tues afternoon into Tues night with some showers. This isn't a huge deal. Wed is dry and a nice day in the 60s. The next low gets cranked up and tracks to our NW thru the Quad Cities area into Michigan and strengthening as it does so. Warm front comes thru Thurs morning with a round of rain. The wind cranks up after that once we get into the warm sector. On this run of the GFS, the timing of the cold front is ideal for strong to severe t-storms as it comes thru our area Thurs afternoon and evening. This is our next period to watch for active weather. Wind shear looks good. Moisture return is also good with dews progged to get into the upper 50s for Cincinnati. There is some weak SB CAPE as well around 200 J/kg. I am probably over analyzing this since it's not until Thurs of next week but as it stands right now, Trev will absolutely be coming out of his den for this system.

Models under estimated yesterdays surge of warmth so with a stronger low I'm expecting temps to be higher than currently shown. I think its worth analyzing atp , it's the only game in town. And yes , a Trev sighting is very likely

12Z Euro isn't quite as strong with the system for Thurs but def still worth watching.

tron777 wrote: ↑Fri Feb 10, 2023 11:35 am

airwolf76 wrote: ↑Fri Feb 10, 2023 11:32 am really warm and windy here today. actually not warm warm but sunny and 50 degrees. its really just a beautiful mid February day of you do not like cold and snow.

We had winds yesterday in the 40-60 mph range in gusts along with record high temps! There were a couple of locations south of our area in Central KY that gusted over 70 mph! Could be doing a repeat next Thursday. Although this go around, it looks like a strong to severe t-storm threat to me instead of just non t-storm winds which is what occurred yesterday. At least it's not boring even though for us snow lovers we are currently not getting what we want. I still think we've got a shot later this month and into March. When people's minds are on spring, old man winter is going to have a trick or two up it's sleeve IMO before the season is over.

And like a lot of starts to MLB season could be an interesting Redlegs home opener vs the Pirates on March 30th wx wise.

18Z GFS looks pretty potent for Thurs of next week.

Latest ominous outlook from spc moving northward as expected





A potent mid-level shortwave trough is forecast to quickly move from the southern Great Plains northeastward into the Upper Midwest/Great Lakes and weaken on Tuesday into Tuesday night (day 4). Relatively limited moisture return is expected across the Arklatex into the lower MS Valley as the disturbance becomes increasingly displaced from the northwest Gulf Coast. Some risk for isolated severe thunderstorms may occur in the warm sector, but a 15% severe threat is not warranted at this time.

The focus for severe is overwhelmingly concentrated on Wednesday through Thursday across parts of the southern Great Plains eastward into the MS/OH/TN Valleys. Model guidance continues to show a very powerful upper-level system ejecting into the southern Great Plains on Tuesday from the Desert Southwest. Additional modification of the airmass across the northwest Gulf Coast will aid in severe-thunderstorm potential. Surface dewpoints will probably reach the lower-mid 60s in the Arklatex on Wednesday into Wednesday night. Model variability and greater confidence and a farther-west edge of low-level moisture/surface low placement in the southern Great Plains necessitated a shift of the severe probabilities west on Wednesday (day 5). Once model spread is reduced, a 30-percent severe area will likely be introduced. A continuation of thunderstorm activity will likely occur into Thursday as the warm sector potentially develops as far north as the OH Valley. Have expanded the severe risk as there is now greater confidence in the forecast surface-low track on Thursday being across parts of the Midwest. Model spread increases by late in the extended period before severe potential likely becomes very low next weekend.

Good morning everyone! 23 at CVG this morning with most folks dropping into the upper teens to the mid 20s across the OV. 21 IMBY. A nice heavy frost as well IMBY. I think we've had better and more frequent frost events then actual snowfall events this winter!

Anyway... Thursday continues to be the main weather story that we absolutely need to keep an eye on over the next week. We have that weak system to deal with first late Tues / Tues night which brings in the warmer and more moist air into the region. We have the wind picking up on Wednesday which will allows temps to skyrocket into the upper 60s if not 70 degrees! This type of warmth is concerning for this time of year. The warm front comes thru Thurs morning with a round of rain. How much instability can we get before the cold front blasts thru the area Thurs afternoon and evening. This is key to the severe threat. Dews should be nice in the upper 50s to lower 60s across the area esp from Cincy and points south. Wind shear will also be impressive. The temp drop behind the front is also very impressive going from the low to mid 60s on Thurs down into the upper 20s by Friday morning. Highs next Friday are only in the low to mid 30s! This is quite a drop of over 30 degrees so we have a classic clashing of the airmasses going on with this system. We will keep you all informed and this could become a thread worthy system in the coming days should the data continue to suggest it.

Been noticing a trend overnight and today with the front for Thurs not passing until the late evening hours, if not midnight. We'll have to continue to monitor the timing of the cold front since that will make a big difference as to how much fuel these storms will have to work with.

The MJO is on the move and moving pretty quickly at that. Phase 4 almost to Phase 5 as of 2/9 on the Aussie site so it is probably in Phase 5 as we speak. Models continue to show it racing thru the warmer phases and getting into Phase 8 by next weekend then slowing down and stalling or going into the neutral circle. I'm wondering with the weakening PV how long it will take the AO to drop as well as the NAO per favorable MJO phases. I would suspect that sometime in the 20-25th period we should see a better pattern and more colder air getting involved with passing storm systems. What is concerning for snow lovers is the -PNA. Models continue to show a -PNA developing underneath the -EPO block. That can work should the EPO ridging be more poleward and not a roll over ridge or an Aleutian Ridge which is what we have been seeing allowing the SE ridge to flex. If we can see slight improvements in the Pacific pattern, then I think that the SE ridge should be flattened just enough for us to score or nearby anyway. Definitely still interested in the last week of the month and as we head into March as well. Still watching the PV and SSW which models continue to show getting beat to death. It's impacts we won't know until early to mid March due to the typical atmospheric lag. Long term indications are for an El Nino type look thanks in part to the decaying La Nina and everything else we have been discussing on here. This would mean a delayed spring so enjoy the warmth we have had this winter *Trev AHEM* because us snow lovers may get our revenge at some point. I am still optimistic to be quite honest.

12z GEFs in line with 0z EPS low track for Thursday taking it into Northern Indiana

Bgoney wrote: ↑Sat Feb 11, 2023 1:21 pm 12z GEFs in line with 0z EPS low track for Thursday taking it into Northern Indiana

12Z Euro agrees and I like the timing better too for the frontal passage as it has sped back up a tad. Late afternoon / early evening.

tron777 wrote: ↑Sat Feb 11, 2023 8:03 pm

Can you translate this for us novices?

Closet Meteorologist wrote: ↑Sat Feb 11, 2023 8:11 pm

tron777 wrote: ↑Sat Feb 11, 2023 8:03 pm

Can you translate this for us novices?

The tweet is talking about the Stratospheric Warming Event (SSW) event we've been discussing on here for the last few weeks. The Polar Vortex (PV) is weakening due to warming in the stratosphere in the Arctic region. If the winds reverse direction then the PV could split. There are different layers in the atmosphere if you remember that from high school earth science class. We need that warming to work down from the stratosphere into the troposphere for us to see impacts where we live at the surface. We won't know until early or mid March most likely if it has the desired effects for snow lovers. Blocking returns in March and a delayed spring would be likely. There are no guarantees of course. These SSW events don't always go our way so at this point, we are in watch and wait mode. I will say this... if the MJO also gets into the colder phases, which it is forecast to do after Pres. Day then we may have something to work with late in the winter season.

possible record warm temps coming next week. my thought process remains the same though for the end of the month though. which may set up a March to remember perhaps

Good morning all and Happy Super Bowl Sunday! A gorgeous day to fire up the grill or have a party for the big game this evening! Go Eagles! (For obvious reasons)

So anyway, the forecast going forward is pretty straight forward. A weak system Tues night then all eyes are on Thursday. The SPC has expanded the severe threat area for Day 5 as you can see below.


The timing of the cold front will be critical to see how much heating we can get as well as CAPE. In the colder months you don't need as much CAPE as you would during the spring and especially the summer months. The dynamics are most certainly going to be there with some guidance showing 75 knot wind shear 200-300 J/kg of CAPE and decent 0-3KM helicity values of 400!

tron777 wrote: ↑Sun Feb 12, 2023 9:05 am Good morning all and Happy Super Bowl Sunday! A gorgeous day to fire up the grill or have a party for the big game this evening! Go Eagles! (For obvious reasons)

So anyway, the forecast going forward is pretty straight forward. A weak system Tues night then all eyes are on Thursday. The SPC has expanded the severe threat area for Day 5 as you can see below.


day5prob.gif


The timing of the cold front will be critical to see how much heating we can get as well as CAPE. In the colder months you don't need as much CAPE as you would during the spring and especially the summer months. The dynamics are most certainly going to be there with some guidance showing 75 knot wind shear 200-300 J/kg of CAPE and decent 0-3KM helicity values of 400!

Going to be interesting to see what the NAM puts out once in range