Absolute Vorticity

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The forecast for today IMO has worked out very nicely! Windy as hell with most of the storms up to the north.

tron777 wrote: ↑Wed Apr 17, 2024 4:00 pm The forecast for today IMO has worked out very nicely! Windy as hell with most of the storms up to the north.

I agree Les and we had ton of wind energy so we sort of escape what could have been a rather busy day. Later Thursday will need to watch a complex that forms to the west. Should be an outbreak of severe weather but how strong will these storms be once they reach us. Will need to see if the models are ramping up the threat locally or lowering the threat. Either way more rain which is not a bad thing though my guess this will keep the rivers quite high for several more days.

tpweather wrote: ↑Wed Apr 17, 2024 4:05 pm

tron777 wrote: ↑Wed Apr 17, 2024 4:00 pm The forecast for today IMO has worked out very nicely! Windy as hell with most of the storms up to the north.

I agree Les and we had ton of wind energy so we sort of escape what could have been a rather busy day. Later Thursday will need to watch a complex that forms to the west. Should be an outbreak of severe weather but how strong will these storms be once they reach us. Will need to see if the models are ramping up the threat locally or lowering the threat. Either way more rain which is not a bad thing though my guess this will keep the rivers quite high for several more days.

Agreed Tim. Once we get past Friday, our next system to deal with looks to be around Tues or so of next week. We are typically active in the Spring and rivers / creeks are typically high as well. Nothing really out of the ordinary IMO rainfall and active pattern wise. The severe aspect has been above avg though depending on where you live in the region.

I agree Les and in a way lucky the snow melt was so light this season that the rivers are not quite as high compared to a year with lots of snow. Imo the severe is there on Thursday and with a nice sunny but warm day should bring up the instability. The timing will be key on how strong the storms are when they arrive

Just looking into the next couple of weeks and for the most part the country will be rather wet and overall slightly above normal in temps. Again love seeing the above normal rainfall in the spring and if you get it over a wider area that is even better. Will we hit a switch though sometime in June and become dry quickly. Have seen this happen before and sometimes the worse kind of short term droughts is when you have been wet and all of a sudden the faucet is turned off. We have plenty of time to see how the summer pans out but for the moment leading up to summer is looking nice for precip.

Warnings west of JP.

tpweather wrote: ↑Wed Apr 17, 2024 4:24 pm I agree Les and in a way lucky the snow melt was so light this season that the rivers are not quite as high compared to a year with lots of snow. Imo the severe is there on Thursday and with a nice sunny but warm day should bring up the instability. The timing will be key on how strong the storms are when they arrive

Timing bothers me for this one. For Cincinnati, I don't think we are fair game until the evening hours and by then the sun has set and instability is waning. If the timing were to speed up, then I would be more gung ho about it.

CVG reached 80 and both DAY / CMH 79 today.

I managed 80 today.

tron777 wrote: ↑Wed Apr 17, 2024 4:56 pm

tpweather wrote: ↑Wed Apr 17, 2024 4:24 pm I agree Les and in a way lucky the snow melt was so light this season that the rivers are not quite as high compared to a year with lots of snow. Imo the severe is there on Thursday and with a nice sunny but warm day should bring up the instability. The timing will be key on how strong the storms are when they arrive

Timing bothers me for this one. For Cincinnati, I don't think we are fair game until the evening hours and by then the sun has set and instability is waning. If the timing were to speed up, then I would be more gung ho about it.

Les I agree about the timing and though not the strongest system by any means but the low looks to be coming directly over us or close by and that is why I would put in the chance for a strong and maybe severe threat. What may happen though is we lose the instability and end up with a quick heavy rain event which can cause some local flooding because of how much we get in a few hours.

Good morning all! Some of the modeling is trying to bring in a nasty line of storms after midnight tonight. Strong to isolated severe storms as well as heavy rainfall would be possible. Until then, a warm and sunny day is on tap with much lighter winds thankfully. I still like the marginal risk from the SPC at this time, due to the timing of the front coming in overnight, but with a lot of wind energy maybe they can hold on to their intensity a bit longer. We will need to check some of the newer CAM's when they come out later today, esp 12 / 18Z runs.

The 6Z HRRR keeps the line more intact as it moves thru the Cincy area, weakening steadily once it gets past us. The 6Z NAM weakens the line much faster as it is entering our area. So that's the deal. How quickly does the line weaken in that 12-1am type window? Stay tuned...

SPC Meso Page this morning shows a 1004 MB low over NW Oklahoma that will be moving NE into the OV tonight. This will drag the boundary that is currently S of us, back N as a warm front. We will turn unstable this afternoon. However, the low / cold front is still well to the West and the best lift and forcing is also. Thus, I am not expecting anything to occur until around or shortly after midnight as the weakening low and surface cold front makes it s way into the region. We'll have to see what's left for shear and CAPE (if any) later this evening. Best chance is to our SW as those regions in the slight and enhanced risk areas, will have much better timing of the cold front during peak heating. I am not ruling out a severe storm for us, but I do feel they will be isolated in nature and the entire line will be weakening as it moves thru. As I said before, the question will be.... is how fast this process occurs.

The latest thinking from the boys matches up well with the thinking on AV.

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...

For tonight, a lead mid level s/wv will eject east from the
middle Mississippi Valley into the middle Ohio Valley.
Associated low pressure and a cold front to our west will move
east into the forecast area overnight. After analyzing various
CAMs, it appears that we will see the weakening north end of an
MCS complex. This weakening pcpn is expected to arrive into our
forecast area later in the evening and during the overnight
period when overall instability will be decreasing (falling
below moderate instability) Thus, it appears that the threat for
any strong or severe storm will be limited to mainly the
evening hours and across parts of our western CWFA. Isolated
strong or damaging wind gusts would be the main threat. Showers
and a few embedded thunderstorms will then continue overnight as
the system shifts farther into the CWFA. Lows will range from
the upper 40s northwest to the lower 60s southeast.

On Friday, the cold front will exit east out of the forecast
area by the afternoon hours. Pcpn will taper off and should then
end by the afternoon hours as well. Mostly cloudy skies will
gradually become partly cloudy in the afternoon. Under a
northwest flow, cooler temperatures are forecast. Highs will
range from the upper 50s northwest to near 70 southeast.

Good Morning Les as I believe we are on the same page. I had to put the threat of a strong or severe storm in the forecast because I believe the storms that do develop later today are going to be quite strong. How much they weaken before getting here locally is the big question and though I don't expect a big issue for us I still believe a storm or two could still be strong and maybe severe. Getting into the time of year that darkness is after 830pm so storms can remain strong longer into the evening and even around midnight. Could just be heavy rain with thunder and lightning and you see the localized flooding but one or two storms could be a tad stronger. See how the short term models seeing this pan out later today plus watch the buildup of storms to the west and see how strong they get.

Good morning Tim! I think we are on the same page also for this one. SPC will update their Day 1 outlook around 9am. Based on what I am seeing right now.... the wind shear looks good over MO but the instability is just S of the state where the boundary is. Once the low moves NE out of OK as the day goes on, I would expect storms to fire in MO and ILL this afternoon. Then, as we've said, we'll have to see how long they can maintain their intensity before they run out of fuel. The further west you are, the higher the chances, while the further east you go, the threat will be greatly reduced, if it all.

Just looking at some year to date stats and really rather simple we are about 10p/c above average in terms of temps and precip. So nothing out of the ordinary by any means and this should continue at least through the end of April

CVG managed to hit 80 yesterday and I expect the same for today. If so, then that would make for a 5th day in a row of 80 degree temps. Pretty remarkable for April IMO. Climate normals currently at CVG are 67 / 45.

tron777 wrote: ↑Thu Apr 18, 2024 8:11 am CVG managed to hit 80 yesterday and I expect the same for today. If so, then that would make for a 5th day in a row of 80 degree temps. Pretty remarkable for April IMO. Climate normals currently at CVG are 67 / 45.

No doubt some wild swings this April but really that is more the normal than we have seen in several years. Even with the possible 5 days in a row of 80 plus we are less than 10p/c above normal for temps. This tells me we had many days well below normal. Over the past several years we have been above normal but the main reason was overnight temps so having these days in the 80's is different than the last several years but more in line of what we would see back in the good old days.

I have noticed models are keeping rainfall totals light. I understand as the amount of time its actually raining will be short but I believe heavy so getting a quick 1/2 inch in an hour is very possible and in some areas that could be near an inch and why the localized flooding is possible for a few hours in a few spots. No way to predict exactly where this will happen until the storms get going and we see how strong they get and how fast they move through. Again not a big event for us and matter of fact very limited time we see storms. I still expect most folks in the 0.25-0.50 but I also expect some of the higher totals as well.

tpweather wrote: ↑Thu Apr 18, 2024 9:06 am I have noticed models are keeping rainfall totals light. I understand as the amount of time its actually raining will be short but I believe heavy so getting a quick 1/2 inch in an hour is very possible and in some areas that could be near an inch and why the localized flooding is possible for a few hours in a few spots. No way to predict exactly where this will happen until the storms get going and we see how strong they get and how fast they move through. Again not a big event for us and matter of fact very limited time we see storms. I still expect most folks in the 0.25-0.50 but I also expect some of the higher totals as well.

I agree Tim. Heaviest totals will be to the West, lighter totals to the East as the storms are weakening the further east that you go.

BG's video for today is currently in progress....

Watch the dewpoints too guys. We're in the 40s here while dews in the mid 60s are over Western KY. U60s to even low 70 dews in Western TN. Can we get into any of that juicer air or will our storms fall apart as a result of us NOT being in that juicier air? We shall have to wait and see!

Brief update from the boys:

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

Not too many changes to the previous forecast. Tweaked
temperatures and dew points slightly as it took us a bit longer
to warm, but otherwise, everything on track. Should get pretty
dry this afternoon and RHs south of I-70 fall into the low
30s/upper 20%s. However, not too concerned about any type of
fire weather, given recent rains and lack of wind today.

Dry air in the lower levels as you can see by their AFD has been my concern along with timing (instability will be weakening). No changes from me. We'll get wet overnight into tomorrow morning for sure, but the storms as they move in should be weakening. I'll keep a CYA low end severe risk in there just in case.