Absolute Vorticity

Thoughts on the Kettering/Dayton area for this storm? And timing? Thanks!

wrmwxfreak wrote: ↑Wed Jan 17, 2024 1:26 pm Thoughts on the Kettering/Dayton area for this storm? And timing? Thanks!

2-3 inches by most models on today's runs. 1-3 is a safe forecast.

With regards to CB's snow map, I guess with a range of 1-4" it is tough to be wrong.

dce wrote: ↑Wed Jan 17, 2024 1:29 pm

wrmwxfreak wrote: ↑Wed Jan 17, 2024 1:26 pm Thoughts on the Kettering/Dayton area for this storm? And timing? Thanks!

2-3 inches by most models on today's runs. 1-3 is a safe forecast.

I'm on the 1-3" train for our I-70 Crew. Could see a bit of light snow tomorrow Casie but the bulk of the event will be Thurs night and esp Fri morning.

Trevor wrote: ↑Wed Jan 17, 2024 1:25 pmCB's first call...

Looks like wishcasting to me…

SPC Meso Page this afternoon is showing a 1030 MB arctic high to our south which has provided the dry weather and some sunshine today. High clouds are already coming in from the West ahead of this system and will continue to do so. Meanwhile, the first piece of energy is a weak 1006 MB low dropping down thru the CO front range while the main low for the Thurs night into Fri snow is a 996 MB low near Seattle, Washington. The first low will attempt to bring in some Gulf moisture but most of it will be to our south. The stronger low in Seattle is the main show and it will provide the frontogenic WAA snows to our north tonight into tomorrow (maybe a bit of that for I-70 folks). The main snow chance for the vast majority of us is on the backside of the stronger low as it takes on a bit of a negative tilt. When this occurs will determine the track and the dreaded dry slot which is a concern for those of us in the Cincy Metro and S of the river.

I maintain my call of 4-6"+ for S Mich, N IN, and N OH. 1-3" for our I-70 Posters in Dayton and Columbus. I think folks like Dave in Minster and Eric in Greenville could rack up 2-4". For the rest of us in the Cincy Metro and folks S and SE of Cincinnati, the dry slot may ruin our fun and I am going with an inch or less as a result of that. This is how I see things playing out based on meso analysis and model data from today. As a side note, there will be heavy lake effect snows in the favored snow belts throughout a good chunk of Saturday. Not that LES impacts AV Land too much though.

Debbie Downer

I don’t have any changes from this morning’s forecast. A dusting to 2” for counties bordering the river and 1-3” range north of that zone to I70 . A NAM /EU combo since they’ve been the most consistent with lighter qpf totals throughout.

Winter Weather Advisory has been issued from the Louisville NWS Office for their IN counties and Northern half of KY counties that they service. This does include Louisville and Lexington Metros.


...WINTER WEATHER ADVISORY IN EFFECT FROM NOON EST /11 AM CST/
THURSDAY TO 7 PM EST /6 PM CST/ FRIDAY...

* WHAT...An initial wintry mix of snow and some freezing rain is
expected Thursday afternoon with a short period of freezing
drizzle Thursday evening. Widespread light to moderate snow is
expected late Thursday night and through the day on Friday.
Total snowfall accumulations of 1 to 3 inches with a small glaze
of icing will be possible across southern Indiana and northern
portions of Kentucky.

* WHERE...Southern Indiana and the northern half of Kentucky.

* WHEN...From noon EST /11 AM CST/ Thursday to 7 PM EST /6 PM
CST/ Friday.

tron777 wrote: ↑Wed Jan 17, 2024 1:47 pm SPC Meso Page this afternoon is showing a 1030 MB arctic high to our south which has provided the dry weather and some sunshine today. High clouds are already coming in from the West ahead of this system and will continue to do so. Meanwhile, the first piece of energy is a weak 1006 MB low dropping down thru the CO front range while the main low for the Thurs night into Fri snow is a 996 MB low near Seattle, Washington. The first low will attempt to bring in some Gulf moisture but most of it will be to our south. The stronger low in Seattle is the main show and it will provide the frontogenic WAA snows to our north tonight into tomorrow (maybe a bit of that for I-70 folks). The main snow chance for the vast majority of us is on the backside of the stronger low as it takes on a bit of a negative tilt. When this occurs will determine the track and the dreaded dry slot which is a concern for those of us in the Cincy Metro and S of the river.

I maintain my call of 4-6"+ for S Mich, N IN, and N OH. 1-3" for our I-70 Posters in Dayton and Columbus. I think folks like Dave in Minster and Eric in Greenville could rack up 2-4". For the rest of us in the Cincy Metro and folks S and SE of Cincinnati, the dry slot may ruin our fun and I am going with an inch or less as a result of that. This is how I see things playing out based on meso analysis and model data from today. As a side note, there will be heavy lake effect snows in the favored snow belts throughout a good chunk of Saturday. Not that LES impacts AV Land too much though.

The Canadian, Euro, and the 12z HRRR all have 2 inches from about the river on North. More than 2 inches just north of the river. Honestly speaking, that's not bad. It would not take much for a slight southward adjustment to see the Cincy area in the higher totals. I'm by no means saying that will happen, but stranger things have happened. Having those models on your side is never a bad thing. We trust and respect those models. Even the GFS has 2 inches for the Cincinnati area. I'm my opinion, CB's forecast is not a bad forecast especially when looking at those particular models.

dce wrote: ↑Wed Jan 17, 2024 2:38 pm

tron777 wrote: ↑Wed Jan 17, 2024 1:47 pm SPC Meso Page this afternoon is showing a 1030 MB arctic high to our south which has provided the dry weather and some sunshine today. High clouds are already coming in from the West ahead of this system and will continue to do so. Meanwhile, the first piece of energy is a weak 1006 MB low dropping down thru the CO front range while the main low for the Thurs night into Fri snow is a 996 MB low near Seattle, Washington. The first low will attempt to bring in some Gulf moisture but most of it will be to our south. The stronger low in Seattle is the main show and it will provide the frontogenic WAA snows to our north tonight into tomorrow (maybe a bit of that for I-70 folks). The main snow chance for the vast majority of us is on the backside of the stronger low as it takes on a bit of a negative tilt. When this occurs will determine the track and the dreaded dry slot which is a concern for those of us in the Cincy Metro and S of the river.

I maintain my call of 4-6"+ for S Mich, N IN, and N OH. 1-3" for our I-70 Posters in Dayton and Columbus. I think folks like Dave in Minster and Eric in Greenville could rack up 2-4". For the rest of us in the Cincy Metro and folks S and SE of Cincinnati, the dry slot may ruin our fun and I am going with an inch or less as a result of that. This is how I see things playing out based on meso analysis and model data from today. As a side note, there will be heavy lake effect snows in the favored snow belts throughout a good chunk of Saturday. Not that LES impacts AV Land too much though.

The Canadian, Euro, and the 12z HRRR all have 2 inches from about the river on North. More than 2 inches just north of the river. Honestly speaking, that's not bad. It would not take much for a slight southward adjustment to see the Cincy area in the higher totals. I'm by no means saying that will happen, but stranger things have happened. Having those models on your side is never a bad thing. We trust and respect those models. Even the GFS has 2 inches for the Cincinnati area. I'm my opinion, CB's forecast is not a bad forecast especially when looking at those particular models.

I'd be thrilled with 2" honestly Doug, but that dreaded dry slot that has shown up literally on all of the models just has me spooked so I went lower with an inch as a result. The 18Z HRRR is coming in and thru 36 hours it is a tad further south then the 12Z run was at that time frame. But man... that dry slot is very close! Too close for comfort.

15Z SREF came back down to reality. Snowfall mean for CVG was 0.90" so almost an inch. An inch for HAO and in the 1-2" range for DAY and CMH. That is in line with my forecast to be honest.

tron777 wrote: ↑Wed Jan 17, 2024 2:41 pm

dce wrote: ↑Wed Jan 17, 2024 2:38 pm

tron777 wrote: ↑Wed Jan 17, 2024 1:47 pm SPC Meso Page this afternoon is showing a 1030 MB arctic high to our south which has provided the dry weather and some sunshine today. High clouds are already coming in from the West ahead of this system and will continue to do so. Meanwhile, the first piece of energy is a weak 1006 MB low dropping down thru the CO front range while the main low for the Thurs night into Fri snow is a 996 MB low near Seattle, Washington. The first low will attempt to bring in some Gulf moisture but most of it will be to our south. The stronger low in Seattle is the main show and it will provide the frontogenic WAA snows to our north tonight into tomorrow (maybe a bit of that for I-70 folks). The main snow chance for the vast majority of us is on the backside of the stronger low as it takes on a bit of a negative tilt. When this occurs will determine the track and the dreaded dry slot which is a concern for those of us in the Cincy Metro and S of the river.

I maintain my call of 4-6"+ for S Mich, N IN, and N OH. 1-3" for our I-70 Posters in Dayton and Columbus. I think folks like Dave in Minster and Eric in Greenville could rack up 2-4". For the rest of us in the Cincy Metro and folks S and SE of Cincinnati, the dry slot may ruin our fun and I am going with an inch or less as a result of that. This is how I see things playing out based on meso analysis and model data from today. As a side note, there will be heavy lake effect snows in the favored snow belts throughout a good chunk of Saturday. Not that LES impacts AV Land too much though.

The Canadian, Euro, and the 12z HRRR all have 2 inches from about the river on North. More than 2 inches just north of the river. Honestly speaking, that's not bad. It would not take much for a slight southward adjustment to see the Cincy area in the higher totals. I'm by no means saying that will happen, but stranger things have happened. Having those models on your side is never a bad thing. We trust and respect those models. Even the GFS has 2 inches for the Cincinnati area. I'm my opinion, CB's forecast is not a bad forecast especially when looking at those particular models.

I'd be thrilled with 2" honestly Doug, but that dreaded dry slot that has shown up literally on all of the models just has me spooked so I went lower with an inch as a result. The 18Z HRRR is coming in and thru 36 hours it is a tad further south then the 12Z run was at that time frame. But man... that dry slot is very close! Too close for comfort.

After the winter we've had and the snow drought we've had for several years now, all concerns are MORE than legitimate! . But in reality, I think Cincinnati is right on the fence. It literally could go either way. 2-3 inches is definitely not out of the question in the Cincinnati area. Again, I'm not saying that will happen, but taking all the emotion out of looking at the models, it is a real possibility. I definitely like my chances up here. I live 1 1/2 miles north of I-70. Climatology is on our side. We are way past due for a 2-4 inch storm. We will find out soon enough.

What are you thinking about the Maineville-Lebanon area. North of the dry slot or no?

What are you thinking about the Maineville-Lebanon area. North of the dry slot or no?

18z HRRR says I-70 has the lower totals…

18z Nam screws everyone lol

Trevor wrote: ↑Wed Jan 17, 2024 3:21 pm 18z HRRR says I-70 has the lower totals…

I declare that wrong!

mikeyp wrote: ↑Wed Jan 17, 2024 3:24 pm 18z Nam screws everyone lol

Indeed lol

Trevor wrote: ↑Wed Jan 17, 2024 3:27 pm

mikeyp wrote: ↑Wed Jan 17, 2024 3:24 pm 18z Nam screws everyone lol

Indeed lol

NAM goes all in on the Screw-Zone

When has the NAM been right lately...

mainevilleweather wrote: ↑Wed Jan 17, 2024 3:31 pm When has the NAM been right lately...

It was correct about todays weather…

18z RGEM

ILN agrees with us. At mid-day West Chester had <1 inch Thursday and Thursday night and 1-2 Friday. Now it's little to no, less than an inch and less than an inch. Their graphics show the dry slot nosing into our area. On the optimistic side, the models didn't do well with weekend storm in the south. Maybe their miss on this one as well. Its not often that a move north or south would increase our totals

ILN has me at an inch or less which is my call for CVG. Can't argue with it. Wow... just saw the 18Z NAM and it is freaking brutal! AFD from the boys and as Wxnut said, they agree with the thinking portrayed by many of us on here.

.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
High and mid level clouds will continue to thicken and
overspread our CWA on Thursday. Model soundings do show quite a
bit of dry air in our region, with a gradual saturation
occurring from north to south throughout the day. While not an
overly robust signal, some snowfall may be observed during the
daytime as the lower troposphere continues to saturate. If any
snowfall were to occur, don`t see much in the way of
accumulation on Thursday given the drier air and lack of QPF on
hi-res models and the HREF.

Best chance for accumulating snowfall will begin to occur
Thursday night. There are two primary waves to monitor - a
southern wave will first impact our northern KY counties and
perhaps our lower Scioto Valley counties primarily. This will
lead to some light snow accumulations in the early overnight
hours Thursday, but the bulk of this wave appears to impact
locations south and east of our CWA. Have lowered snow amounts
from this particular wave given trends.

The second wave (and most impactful) will be from the primary
shortwave trough that pivots through the Midwest region. This
will lead to the best chance for accumulating snowfall across
our entire CWA, with better forcing and thus higher totals
expected for locations along/north of I-70. Given higher snow
ratios of around 16:1 to 18:1 overnight, along with sub-freezing
pavement temps, snowfall will be able to easily accumulate once
we start getting decent rates.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
There`s quite a bit to unpack through the course of the long term
period, with snow followed by cold followed by a warmup -- all in
the course of just a few days.

Light snow will likely be ongoing for most, if not all, of the ILN
FA at daybreak Friday, with the steadiest/heaviest activity focusing
north of the OH Rvr. This activity, associated with the S/W pivoting
to the ESE through the region, will spread through the ILN FA during
the morning hours, eventually decreasing in coverage and becoming
more showery in nature from W to E as we progress into the afternoon.

LL lapse rates will steepen through the day Friday as deep-layer CAA
evolves, with SCT to numerous snow showers during the afternoon
following the morning steady/light snow. This being said, moisture
availability/quality in the DGZ will become increasingly meager
later into the daytime as drier air filters in from the NW.
This should lead to an overall downtick in snow shower coverage
and intensity by early evening, even as a few flurries continue
through the overnight (especially within a fetch of
better/deeper moisture to the SE off Lake Michigan into WC OH).
The overall thinking for total snow remains largely unchanged,
but a few tweaks were made to lower snow totals in N KY and SE
IN (to around 1"), while forecasts of snow totals were increased
subtly from WC to central OH (to around 3") given latest
ensemble dataset trends. Certainly, given the anomalously-high
SLRs on the order of 15-20:1, an isolated 4" cannot be
completely ruled out, especially where repeated banding occurs
throughout the course of the event. But do think that most spots
end up in the 2"-3" range, with slightly less near/S of the OH
Rvr and slightly more favored near/N of I-70.

The bulk of the accumulating snow locally should be diminishing
by/around noontime, with the main story through the remainder of the
day being the /very/ cold air filtering back in from the W. Sfc
temps will be slowly falling through the day in SE IN, with CAA
allowing for temps to dip into the upper teens by mid afternoon
near/W of I-75. By early evening, temps will be falling area-wide
into the teens, eventually bottoming out around 5 degrees near/W of
I-75 to around 10 degrees from central OH through NE KY by daybreak
Saturday. This, combined with steady light NW sfc flow on the order
of 10-15kts, should lead to wind chill values below zero just about
everywhere, with the best chance for wind chill values near or less
than 10 degrees below zero to coincide with the coldest temps from
WC OH through the Tri-State.