January 5-6th, 2025 The Double Digit Storm

[Phr0z3n]

18z gfs also doesn’t transfer until West Virginia

[tpweather]

Okay folks I will be on here later for the late runs and lets hope things turn out well. I spent more time today looking at info then I have in years. Excitement probably one reason and again I still feel like this is a really nice storm for us locally and to what extent is still in progress but by Saturday morning I will probably throw out what I believe is going to happen and yes as with all storms surprises happen but again I never throw out something I don't believe in even if the models tell me a different story.

[tron777]

18z RDPS a little more north fwiw
IMG_1240.png

It held the upper level low structure longer with the transfer happening in WV
IMG_1241.png

Perfect! And that is the biggest concern I have for not getting the higher totals. We've got to see the primary SLP hold on long enough into WV to keep the upper low intact. Euro crapped out and did the transfer much, much earlier. Hopefully 18Z run will correct that issue.

[fyrfyter]

Wrap around snow is nice on the backend, but dang, there’s about 18 hours of ice in there. I still think CIncy gets a solid 5-6” of snow.

[tron777]

18z gfs also doesn’t transfer until West Virginia

I'll post the text data here for CVG. Awfully sleety! But we save face thanks to the backside snows. I'd love to see the GFS and RGEM 18Z runs bump south a tad but keep the strength.

Code: Select all

SUN 18Z 05-JAN  -4.2    -3.3    1023      74      97    0.13     558     540    
MON 00Z 06-JAN  -4.7    -2.1    1017      96      99    0.59     557     544    
MON 06Z 06-JAN  -4.4    -0.2    1011      96      99    0.72     553     545    
MON 12Z 06-JAN  -4.2     1.2    1006      95      60    0.25     544     540    
MON 18Z 06-JAN  -4.0    -7.9    1007      97      93    0.07     536     530    
TUE 00Z 07-JAN  -3.6    -9.7    1015      90      91    0.11     539     527   

[Phr0z3n]

I still not calling this a true transfer in the sense that it is developing a coastal low. Yes we have transfers over mountains all the time and when a stronger system that happens many times on the southeast coast we say yes it transfer the energy from the low on the west side of the mountains. This imo is just the system moving west to east and sure once it gets to the mountains it will lose some staying power unless we have that coastal low but in this case I believe the system just goes out to sea.

It’s a transfer of energy from one side of the H850 low to the other side. You can see it clearly on 850mb vorticity

[tron777]

I still not calling this a true transfer in the sense that it is developing a coastal low. Yes we have transfers over mountains all the time and when a stronger system that happens many times on the southeast coast we say yes it transfer the energy from the low on the west side of the mountains. This imo is just the system moving west to east and sure once it gets to the mountains it will lose some staying power unless we have that coastal low but in this case I believe the system just goes out to sea.

It’s a transfer of energy from one side of the H850 low to the other side. You can see it clearly on 850mb vorticity

Yes! It is clearly a transfer to a low that will move off the Coast. It won't turn the corner and be a typical Nor 'Easter.

[Phr0z3n]

H850 before the transfer

IMG_1243.png

H850 after the transfer

IMG_1244.png

[fyrfyter]

Here are the maps - snowfall includes the ice, so subtract about 10-11” for that

IMG_0917.jpeg

IMG_0918.jpeg

[tron777]

For CVG, we'll see more sleet versus frz rain IMO. I think the frz rain / ice storm threat will be south of the Metro. Our S counties like where Mark is in Grant, def still a concern there down into Central KY. Also for Matt in our SE counties. Same deal.

[tron777]

I-70 Crew.. for you guys, the stronger the storm the better. All snow for you folks IMO. For you guys it's more of a question of QPF. Do we get the GFS or Euro version of the storm in other words? My forecast confidence is probably the lowest for you guys.

[Phr0z3n]

I still not calling this a true transfer in the sense that it is developing a coastal low. Yes we have transfers over mountains all the time and when a stronger system that happens many times on the southeast coast we say yes it transfer the energy from the low on the west side of the mountains. This imo is just the system moving west to east and sure once it gets to the mountains it will lose some staying power unless we have that coastal low but in this case I believe the system just goes out to sea.

It’s a transfer of energy from one side of the H850 low to the other side. You can see it clearly on 850mb vorticity

Yes! It is clearly a transfer to a low that will move off the Coast. It won't turn the corner and be a typical Nor 'Easter.

Right. Trough is in the wrong place for that to happen. You need a broad neg tilted trough.

[tron777]

I still not calling this a true transfer in the sense that it is developing a coastal low. Yes we have transfers over mountains all the time and when a stronger system that happens many times on the southeast coast we say yes it transfer the energy from the low on the west side of the mountains. This imo is just the system moving west to east and sure once it gets to the mountains it will lose some staying power unless we have that coastal low but in this case I believe the system just goes out to sea.

It’s a transfer of energy from one side of the H850 low to the other side. You can see it clearly on 850mb vorticity

Yes! It is clearly a transfer to a low that will move off the Coast. It won't turn the corner and be a typical Nor 'Easter.

Right. Trough is in the wrong place for that to happen. You need a broad neg tilted trough.

Good thing the trough is neutral to positive or else we'd have a Lakes Cutter ourselves.

[Phr0z3n]

I still not calling this a true transfer in the sense that it is developing a coastal low. Yes we have transfers over mountains all the time and when a stronger system that happens many times on the southeast coast we say yes it transfer the energy from the low on the west side of the mountains. This imo is just the system moving west to east and sure once it gets to the mountains it will lose some staying power unless we have that coastal low but in this case I believe the system just goes out to sea.

It’s a transfer of energy from one side of the H850 low to the other side. You can see it clearly on 850mb vorticity

Yes! It is clearly a transfer to a low that will move off the Coast. It won't turn the corner and be a typical Nor 'Easter.

Right. Trough is in the wrong place for that to happen. You need a broad neg tilted trough.

Good thing the trough is neutral to positive or else we'd have a Lakes Cutter ourselves.

We see way too many of those lol

[tron777]

As of 4pm, the latest thinking from the boys:

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Bottom line up front: an impactful winter storm is expected for
the region Sunday into Monday, followed by an arctic outbreak
with daily average temperatures on the order of 15-20 degrees
below normal through much of next week.

The main item of interest for the long term period is going to
be the evolution of the system poised to impact the region
Sunday into Monday. We are starting to get within the range
where the breadth of the ensemble envelope is shrinking, albeit
still somewhat variable from run-to-run. This being said, the
prevailing message remains the same... parts of the region can
expect an impactful winter storm within the Sunday to Monday
time frame, with conditions and ptype amounts varying from
location to location.

Synoptically, by Saturday night, the expansive ern trof should
be pulling away from the OH Vly, with midlevel ridging building
E in its immediate wake. This midlevel ridge will nudge E into
the region by late Saturday night, but will gradually flatten as
the ejecting S/W into the central plains will move E quicker
than the departing ern trof will pull away. Although the
approaching trof will be positively-tilted, it will be subtly
deepening/strengthening into early Sunday, spreading large-scale
ascent (through isentropic lift) and moisture northeastward
into the mid MS/OH Vlys during the day.

Although the guidance from late Wednesday into Thursday /had/
shown a slightly stronger solution, the scales have tipped
subtly back in the other direction, particularly amongst the
GEPS and EPS suites. Ensemble probs for a sub-1000mb low have
decreased from runs 24-36 hours ago in the vicinity of KY/srn
IL/IN/OH by 06z Monday (to now focused more near the KY/TN state
line). Regardless, the /latest/ trend has been toward a
slightly more suppressed solution, which will undoubtedly
suggest the heaviest liquid-equiv pcpn and elevated warm layer
remaining a bit further S (to mainly near/S of the OH Rvr).
Certainly we don`t wish to windshield wiper the forecast, but
the trends are significant and somewhat uniform, even amongst
/some/ of the GEFS members. This, of course, has large
ramifications regarding pcpn amounts and ptype evolution,
especially as the elevated warm layer aloft (as seen in the H8
temp fields) may end up quite a bit further S than previously
expected. This may translate into more snow as the predominant
ptype, even near the OH Rvr. Nevertheless, for locales close to
and S of the OH Rvr, there is still some concern for some mixed
wintry pcpn, into Sunday evening/night, which complicates snow
amounts in these areas where a SN --> FZRA/IP --> SN evolution
could occur throughout the course of the main 24-hour time frame
of this event.

It seems likely, at this juncture, that some mixed (FZRA and/or
IP) wintry pcpn should still evolve for at least a period of
time late Sunday/night into early Monday across the srn third of
the ILN FA, with all snow favored further N (especially N of
the OH Rvr). Of course, the more mixed pcpn that occurs, the
lower the snow amounts would likely be in those spots. From a
liquid-equiv QPF perspective, ensemble guidance suggests medium
probabilities (~50%) of at least 1" near the OH Rvr, with high
probabilities (>70%) of at least 1" S of the OH Rvr. So
regardless of exact ptype that evolves, we are talking
*significant* amounts of wintry pcpn. This ensemble mean QPF
bullseye of around 1" (liquid-equiv) has also shifted S with
recent data, mirroring the same trend noted within the low
center clustering. Regardless, there will be extremely tight
ptype and amount gradients that set up squarely across srn parts
of the local area. From a planning perspective, right now, it
seems likely that FZRA (or IP) will occur for at least part of
the event for locales stretching from SE IN through the lower
Scioto Valley and points S of this axis. Further to the N,
between I-70 and the OH Rvr, significant amounts of snow (near
or greater than 6") are possible from Sunday afternoon through
Monday afternoon.

The evolution of the system into Monday morning also remains
somewhat uncertain as the system should generally have
transitioned to a subtle weakening state by this time, but
wraparound moisture on the backside of the departing low may
keep banded snow going for parts of the area into mid afternoon,
depending on the strength of the deformation axis. Either way,
the Monday morning commute is looking to be significantly
impacted by this winter storm region- wide, particularly near/S
of I-70.

At this point in time, general awareness and adequate planning
for a winter storm is the proper course of action. Details
regarding specific ptypes and amounts will become clearer in the
coming days. What is already clear, however, is the likelihood
that an arctic airmass will settle into the region next week,
with much below normal temperatures expected for the foreseeable
future in the OH Vly. Temperatures and wind chills may approach
or exceed critical (advisory) thresholds at times next week,
depending on evolution of cloud cover, winds, and potential for
fresh snowpack. It is, however, looking like the coldest stretch
of the winter thus far for us locally.

[tron777]

There she is! Low is still off the Coast. That's the energy that will help to create our storm.

https://www.star.nesdis.noaa.gov/goes/s ... &length=12 - Infrared

https://www.star.nesdis.noaa.gov/goes/s ... &length=12 - Visible so click on it soon before the sun sets.

https://www.star.nesdis.noaa.gov/goes/s ... &length=12 - Water vapor

[tron777]

WAVE3's call for the LOU area. They have me all snow and a foot plus! Whoa! That was not on my bingo card lol

Wave3.jpg

[Phr0z3n]

WAVE3's call for the LOU area. They have me all snow and a foot plus! Whoa! That was not on my bingo card lol


Wave3.jpg

That’s awesome. I hope it pans out that way!

[tron777]

WAVE3's call for the LOU area. They have me all snow and a foot plus! Whoa! That was not on my bingo card lol


Wave3.jpg

That’s awesome. I hope it pans out that way!

Oh me too! I don't have enough balls to go that high lol Another station out of LOU is 6-10"+ Even Chris Bailey, the guy out of Lexington keeps us all snow and the mixing to the south. I assume they are going with the Euro / CMC / RGEM blend.

[dce]

I-70 Crew.. for you guys, the stronger the storm the better. All snow for you folks IMO. For you guys it's more of a question of QPF. Do we get the GFS or Euro version of the storm in other words? My forecast confidence is probably the lowest for you guys.

That's exactly right. No ice up here. We can say that with about a 90%. The consistency of the GFS has been amazing. It hasn't waffled at all. It's either going to score a coup or it's going to bust badly. I think the truth will likely fall somewhere in the middle. If it buckles with the new data on the 00z run then we know what is going to happen. If the Nam and the American models hold, who knows? Cincinnati land looks to be golden on almost every model at the moment. It would be hard for you guys, at this point, to not see something significant.

[Phr0z3n]

WAVE3's call for the LOU area. They have me all snow and a foot plus! Whoa! That was not on my bingo card lol


Wave3.jpg

That’s awesome. I hope it pans out that way!

Oh me too! I don't have enough balls to go that high lol Another station out of LOU is 6-10"+ Even Chris Bailey, the guy out of Lexington keeps us all snow and the mixing to the south. I assume they are going with the Euro / CMC / RGEM blend.

Sounds like it! I wouldn’t make that call nether with nam north like that

[kywthrluvr]

WAVEs map seems to correspond pretty well with what the NWS in Louisville is saying in their AFD.

[tron777]

WAVE3's call for the LOU area. They have me all snow and a foot plus! Whoa! That was not on my bingo card lol


Wave3.jpg

That’s awesome. I hope it pans out that way!

Oh me too! I don't have enough balls to go that high lol Another station out of LOU is 6-10"+ Even Chris Bailey, the guy out of Lexington keeps us all snow and the mixing to the south. I assume they are going with the Euro / CMC / RGEM blend.

Sounds like it! I wouldn’t make that call nether with nam north like that

Yeah. The GFS has too much mixing too.

[tron777]

WAVEs map seems to correspond pretty well with what the NWS in Louisville is saying in their AFD.

For sure! It's going to be an interesting next 24 hours.

[Phr0z3n]

It’s going to be interesting what the 0z nam hi res has in store.