Northern Ohio Obs/Discussion Part 2

[NEOH]

1 hour ago, dta1984 said:

It does seem they have dropped fairly rapidly the past few weeks.  I've only got a few left that still need to drop. 

Maybe first flakes late next week?  

Definitely an early fall clean-up this year. There's a pretty decent signal on the models for some cold/snow around Halloween... but I'll wait a few days before getting my hopes up. 

[NEOH]

CLE will finish October around +4 for the month. Two months in a row with a big positive temp departure. With today's rain October will likely be near normal precip wise. Looks like our first shot at a few flakes over the weekend. Trees are mostly bare outside of the oaks -- not sure if the dryness from mid-August on affected them but this is as early as I can remember in this area. 

[dta1984]

First accumulating snow of the season.  I've got 1" on my deck.  

[NEOH]

3 hours ago, dta1984 said:

First accumulating snow of the season.  I've got 1" on my deck.  

Well that was a surprise to see this morning. Measured 1.5". Elevation definitely helped. 

 

[dta1984]

I was a bit surprised the snow stuck around all day with the warm ground, sunshine and temps above freezing.  

Looks like tonight's event is mainly for northern areas, but will be interesting to see. 

[OHweather]

Holy crap winter came fast this year! Congrats on the "bonus" snow(?) yesterday morning. 

For tonight's event, it's sort of weird.  There's mid-level drying and sinking motion overnight, but instability is moderate to almost extreme with a fair amount of low-level moisture.  The flow doesn't move much for several hours overnight into early hours, is very well-aligned and under 30 knots so that does support an organized W-E band that doesn't move too much.  Despite the poor synoptic setup with large scale sinking motion and mid-level drying, there is moisture to 7-8k feet into early Sunday with lake to 850mb temp differentials of around 20C which does support moderate to heavy precip with any band (though, the inversion heights do fall short of some recent early season events with a warm lake and again, synoptically it's not a great setup).  There is some moisture from Lake Michigan feeding into any band too, especially during the first half of the event.  850mb temps dipping to -7C support accumulating snow if there's an organized band, especially above 1000 feet (though could see something stick at lower elevations under the heart of any band). 

Overall, I do think enough factors support a decent W-E band tonight and hi-res models also agree unanimously.  Given the marginal temperatures I hit the higher terrain hardest for accumulations, but again if the band sits over somewhere then a narrow corridor in the lower terrain can see a little more than shown.  If the band wiggles around I struggle seeing anyone getting over 2-3" in NE OH, however, the flow doesn't move too much so it may be somewhat persistent wherever it sets up which could allow for a bit more than I have drawn in here.  With a WSW wind over land, I favored the hi-res NAM and NMM for band placement as those models typically show less of a SW bias in their band location than the ARW and HRRR.  Into NW PA, with a decent WNW wind over the water I do think the band sags inland into at least Erie County and perhaps northern Crawford County.  If that occurs, then the added terrain and fetch there would support a few inches in the higher terrain, perhaps locally up to 6" given potential for rates over 1" per hour and 8-12 hours of fairly favorable conditions.  The inland penetration into NW PA is often over-forecasted, but with a good WNW wind over the lake I do think snow makes it at least somewhat inland. 

[OHweather]

Oof looks like the results in NE OH and NW PA were very disappointing...a little too warm. Probably more chances later in the week with all the cold air coming down though. 

[NEOH]

20 hours ago, OHweather said:

Oof looks like the results in NE OH and NW PA were very disappointing...a little too warm. Probably more chances later in the week with all the cold air coming down though. 

Good to see you drop in. I was checking the CLE NWS site and couldn't find any snow reports. The end of the week certainly looks interesting. It would be ideal to get a decent LES set-up while the lake is still warm. Some 40 degree temps already appearing in the western basin. 

 

[NEOH]

Still a long way out but the 12z runs were as good as they get around here in early November. 

 

[OHweather]

It seems that a brief period of light synoptic snow is fairly likely for most of northern Ohio Thursday afternoon.  It probably struggles to stick in most areas, but some hilly areas may see a slushy coating.

As for lake effect, the air coming down at the end of the week is much colder than the airmass we saw last weekend when accumulating snow was mostly confined to the highest terrain in SW NY, however, the fetch is short which adds different complications. 

To re-hash the water temps NEOH posted, they're still fairly toasty in areas that we care about for a NW flow event, though the waters over western Lake Erie are into their yearly free-fall...

The airmass Thursday night into Friday features 500mb temps of -32 to -35C (even colder near BUF), a difference of 45C or so over central and eastern Lake Erie.  700mb temps will be -22 to -24C, a 35-38C difference, while even 850mb temps will be -11 to -12C, a 24-26C difference.  These values are all extreme.  The issue is fetch and how long any lake effect lasts.

The Cleveland sounding at its peek is perfectly fine, with extreme instability and EL heights over 15k feet, little shear, and moisture depth to almost 10k feet.  Unfortunately, this look only lasts a few hours with moisture depth and inversion heights falling quickly towards morning.

The Erie soundings are nuts, and last longer, well into Friday morning.  There is a bit more shear, but that seems to be partially due to the model trying to simulate an intense lake effect band off of Lake Huron that is messing with the wind fields.

With our short fetch events, some sort of synoptic lift and/or upstream lake connections seem to be mandatory for good snow...

The Lake Huron connection should go into extreme SW NY or NW PA (the NAM does swing it west after this image).  As usual with a NW flow, there will be some sort of Lake Superior/Michigan connection into the Cleveland area that can bring a narrow band or two of enhanced snow, especially in the hills.  This connection likely dies down early Friday as the ridge builds in, though the Lake Huron one may last through a good portion of the day Friday.

The models do swing a weak shortwave through late evening into the overnight Thursday night.  This would help for a few hours, though after this passes the ridging starts building in from the west and the environment becomes less conducive in NE Ohio (again though, downwind of Lake Huron will be conducive into a good chunk of Friday).

The above image is the NAM BUFKIT "overview" for Erie...the red contours are omega, greater than -15 is considered to be strong.  The fill is RH (height is on the right), the snow growth zone is the pink/yellow outlined area that is sitting from 4-10k feet Thursday night through Friday, the low-level wind direction is plotted by the dotted lines (direction in degrees on the left), and time is on the bottom (in Z time).  A busy image.  But, what it shows is a classic "cross hair" signature (strong lift in the snow growth zone) for about 12 hours late Thursday night into Friday, indicative of heavy snow potential, with the winds only shifting slowly...moisture depth doesn't really decrease until Friday evening.  It is really hard not to get warning criteria snowfall with this type of signature. 

My overall guess for NE Ohio is 1-3" for most areas (perhaps little to none right along the lake) from Lorain and Medina Counties points east, even as far south as Akron/Canton and Youngstown.  Short duration, short fetch events usually underwhelm, though with a NW flow many could see that light accumulation of snow.  If the upstream connection parks in the hills south or east of Cleveland for several hours late Thursday night into Friday morning someone could see locally several inches, but I think that's the exception and most see an inch or two.

For NW PA this seems like a very favorable setup, though whether or not the band slowly moves around or sits somewhere may determine how high the totals get.  I think a widespread 3-6" in interior NW PA (and extreme SW NY) is a decent bet, but locally up to or over a foot if the band off of Lake Huron is organized enough.  The lakeshore will see less, but under the Lake Huron band can accumulate decently.

Let's see how this trends over the next couple days...and probably more chances coming up with even colder air next week.  I'm in NE Ohio for a few days around Thanksgiving, let's not freeze the lake before then!

[NEOH]

Thanks for the forecast OHWeather. These early season LES events are always interesting with the extreme parameters. The wind direction/short duration will definitely be the limiting factors. 1-3" seems reasonable. The best wind direction for this area is in  280-300 range -- this direction includes a long fetch from the western basin. Next week looks interesting as well for a potential long duration LES event. The CMC has had this feature the past couple of runs.... now that would be something to see. 

 

[OHweather]

^That CMC depiction looks like some convective feedback, but it's pretty cool to imagine.  Definitely looks like some decent snow potential early next week, both with a wave moving by along the front Monday into Tuesday and with lake effect.  Winds likely have a decent northerly component for a time so it shouldn't all go into Buffalo.

As for the event Thursday-Friday, some detailed thoughts...

First, the maps…the nice one I posted on my FB page:

I don’t have a nicer template that includes all of NW PA, but here’s a rough sketch:

 

And now an overly detailed analysis…

Synoptic rain / snow late Thursday morning/afternoon…

The back edge of a budding ana-frontal rain shield will mix with and change to snow across parts of central and northern Ohio on Thursday as colder air filters in.  This precip shield will be very progressive and only the back edge has a chance to briefly change to snow as the colder air catches it, so accumulations generally aren’t likely.  A few of the hills in north-central Ohio could see a coating on grassy and elevated surfaces.

The forecast soundings for CLE and ERI actually aren’t bad with some signs of lake enhancement early in the afternoon, but it’s warm.  There’s moderate lift co-located with the snow growth zone and a respectably deep layer of lake-induced instability, with northerly winds that will hit the terrain south and east of Cleveland, along with in NW PA and SW NY well.  The issue is boundary layer temperatures in the lower elevations will be in the mid to upper 30s, so despite 925mb temps of -1 to -2C in this time period accumulating snow won’t occur in the low elevations (and along the lake it may stay rain).  The hills south of Cleveland may see a dusting and there could be up to an inch in the highest hills of Geauga County (and perhaps a dusting as far west as the heights suburbs).  The higher elevations of NW PA could see a quick, wet inch of snow with up to 2” in the higher elevations of SW NY as there’s more terrain and the precip shield is better-developed by then.  Again, no daytime accumulations in the lower elevations.

Lake effect Thursday night through Friday…

As a very deep cold airmass moves over Lake Erie Thursday night into Friday extreme instability will develop with a generally northwest flow.  The airmass is fairly dry and ridging starts building in from the west Friday morning making this a short-duration window for lake effect (especially in Ohio), so any decent accumulations will depend on any synoptic moisture / lift and upstream lake connections.

There will be a few hour period in the evening behind the synoptic rain / snow when there’s little synoptic help and before any upstream connections establish.  There’s still moderate instability on the sounding and the winds in the lowest 5k feet are well-aligned, though the sounding is somewhat dry with a short fetch.  There will likely be snow showers in the early evening in this environment, especially in the higher terrain where there’s an orographic assist, but they won’t be organized and any initial accumulations won’t be especially good.

We do get a shot of synoptic help with a decent vort max that moves over the lake from late evening into the overnight, moving east into Friday morning.  This adds some upward motion over the entire lake and does bring a brief shot of synoptic moisture, especially to the eastern half or so of the lake (extreme NE OH points east).

CLE’s sounding improves as this vort moves overhead, with instability becoming extreme and moisture depth up to about 7k feet.  The flow is also moderate and fairly well aligned (a bit of shear but could be worse).  This may support a more widespread burst of snow with the vort max, along with locally heavy snow under any upstream connections that develop into NE Ohio.

Erie’s sounding has even deeper moisture and instability, along with little shear beneath 10k feet.  This would support lightning with any more intense snow bands and greater than 2” per hour snow rates…NW PA also has more terrain to work with than NE Ohio and has a stronger upstream connection to a close-by Lake Huron.

The Lake Huron connection may start fairly far west Friday evening as winds behind the developing wave of low pressure will be north, but should quickly swing into the eastern half of Erie County or even extreme SW Chautauqua County NY ahead of the vort max before going back into more of Erie County towards early Friday.  The classic NW flow connection from just east of Marquette to near Traverse City to Lake Erie likely goes into the eastern suburbs of Geauga County ahead of the vort max with a slightly W of NW wind (growing up in Solon that’s where that connection goes with a 305ish flow)…it may back west a bit into early Friday behind the vort as winds veer a little more.  There may be another connection from Lake Michigan west of Cleveland but is likely less organized.  These will be the connections to watch for the best accumulations…how stationary they are or aren’t will be important to how high the highest localized totals are…the Lake Huron one is most interesting as it’s obviously the closest connection and also has deeper synoptic moisture than the NE Ohio ones will.

Ridging builds in quickly towards Friday morning and by 10 AM, the Cleveland sounding is pretty dry.  With a lake induced EL still over 10k feet and a well-aligned flow there may be some lingering light to moderate snow showers with any left-over band that’s drifting around the metro or Snowbelt south or east of Cleveland, but it likely won’t be organized or accumulate all that much more by this point.

Erie’s soundings still remain very impressive through the morning and half decent into the evening, so the Lake Huron connection (which may briefly drift into Ashtabula County around noon Friday before swinging back east) could still rip pretty well into Friday afternoon.  While the inversion heights and moisture finally start diminishing through the afternoon, there’s moderate instability and a reasonably well aligned flow through the evening, so as the winds go W and then SW Friday evening there may be one last flareup over NW PA that quickly lifts up the lakeshore but drops a little bit more snow as it goes.

Thoughts on band evolution and accumulation from the lake effect…

There’s likely an uptick late evening as the vort approaches over NE Ohio and NW PA.  Upstream connections will be important and eastern Erie County PA/Chautauqua County NY, along with eastern Cuyahoga/Geauga in Ohio (and perhaps a weak one southwest of Cleveland) may be hot spots.

As the vort moves through it brings a subtle surface trough that may bring a more general burst of snow from Lorain and Medina Counties points east given extreme instability and enough moisture after midnight.  With winds briefly going close to WNW ahead of it, it’s possible a more organized west-northwest to east-southeast oriented band briefly develops over Cuyahoga and Geauga Counties and then swings southwest into parts of Lorain, Medina and Summit Counties as the vort moves through and pushes the surface trough south.  This may coincide with the upstream connection into the east side of Cleveland.  The Lake Huron band will likely swing west into much more of Erie County PA as the vort passes overnight Thursday night into early Friday.

Behind the vort into Friday morning winds don’t move much for a few hours, so the lingering convergent band into the Secondary NE Ohio Snowbelt (parts of Lorain / Medina / Summit) may last into the morning in some form, and the upstream connection into the eastern suburbs also lasts into the early morning.  The big show will be the Lake Huron band in NW PA that should go straight into the morning.

Winds do go more northerly Friday morning as the flow turns anti-cyclonic.  This should end any substantial snow in the Cleveland area, though whatever is left of the bands that establish overnight may continue to drift west and produce snow showers that might drop very light amounts through Friday morning.  This likely brings the Lake Huron connection briefly into Ashtabula County (and it should still be moderate to heavy) before it slowly swings back east Friday afternoon and evening across NW PA and into SW NY as winds slowly back to the W and then SW.  As it swings east enough instability remains for it to drop a little more snow as it goes.

For daytime Thursday accums I’m assuming little to none except for the highest hills in northern Geauga that could see an inch…along with inland NW PA and SW NY that could see an inch or two above 1000 feet.

In NW PA I except any Lake Huron connection to have 1-2”+ per hour snow rates from late evening through Friday morning, a period of 12-15 hours.  With that said, it likely is gradually moving most of the time so areas may only be under it for a couple of hours at a time.  Outside of the connection, the soundings do support snow showers due to orographic lift for about the same period which will keep accums going, albeit at a slower pace, in the hills outside of the narrower heavy band.  Ratios will become high away from the lake as well which will help with accumulations.  There could be a quick dusting to 2” Friday afternoon or evening as the remnant band lifts back up the shore.  All in all I don’t see how a lot of the higher elevations in NW PA don’t see at least 4-8” of snow, with locally higher possible if the band is at all persistent in any area.  My gut says someone gets over 8”, perhaps a foot, but with the band perhaps not locking in it’s hard to explicitly forecast that.  Also went 2-4” into eastern Ashtabula where there’s some terrain and where the band may drift into for a time around noon Friday.

In NE Ohio I’m going with a general inch or so away from Lake Erie for the uptick that occurs when the vort max and trough push through.  The eastern suburbs into Geauga County I went 2-4”…the thought is with a possible WNW to ESE band developing for a time ahead of the vort max and a likely upstream connection that keeps a narrow band going into Friday morning, along with enough instability for 1” per hour rates under any focused bands, that over 2” is pretty likely.  If any banding is more persistent someone may get more than 4”, but I think that’s very localized.  The higher hills in northern Geauga may be a little northeast of the banding Thursday night into early Friday but will see some orographic lift snow showers anyways, and could see a light accumulation during the day Thursday, so over 2” seems likely there.

The other interesting spot in NE Ohio is the “Secondary Snowbelt” as the remnant convergent band may sit in that area into Friday morning behind the vort max.  There isn’t a well-defined upstream connection into that area, I’m not confident they get any accumulation during the day Thursday, and ridging builds in fairly quickly so I’m not confident many areas get over 2” there, but a few may in the area I outlined.

[NEOH]

Good stuff OHWeather. 2-4" seems like a good call for this area. The wrf suite shows .4" - .5" of precip over Geauga county for the event (some of which is rain). 

[dta1984]

Thanks for stopping by Ohweather,   Good analysis!  Looking forward to tonight as well as next week!

[NEOH]

Temp down to 38 imby. Winds have gone northerly and you can already see a plume of lake enhancement precip heading toward CLE on radar.

Edit: Snow starting in Chagrin... a little earlier than I thought it would.  

[OHweather]

Looks like it's snowing pretty good away from the immediate lake, and the Chardon cam has covered the ground! Hoping for a flurry here in NW NJ tomorrow morning. 

[Chinook]

On Monday night (Tuesday 00z) the Euro and Canadian show a synoptic snow/ LES combo for Cleveland, and synoptic snow for other parts of Ohio. Yesterday's GFS run(s) had this also. It might be worth checking some model runs on this. Even if the synoptic snowfall doesn't materialize, the GFS says 850 temps will be down to -17C over Lake Erie. So this is massively cold considering October was some +3F above normal.

[dta1984]

I had a half inch when I left this morning.  There's 2-3" in Chardon.  

[NEOH]

7 minutes ago, dta1984 said:

I had a half inch when I left this morning.  There's 2-3" in Chardon.  

Same here. The LES was very localized it seems... focused up towards northern geauga and lake. On to next week. 

[OHweather]

That radar loop is very unfortunate for your area for sure 

[dta1984]

Looking over the snowfall reports, looks like the event was focused east of here...even some decent reports south.

Getting a nice flare up of a few bands.  Not sure if they will amount to too much. 

[NEOH]

23 minutes ago, dta1984 said:

Looking over the snowfall reports, looks like the event was focused east of here...even some decent reports south.

Getting a nice flare up of a few bands.  Not sure if they will amount to too much. 

I can't even find the snowfall reports on the CLE NWS site anymore. It was an unusual pattern to how the bands set-up. 

[dta1984]

17 minutes ago, NEOH said:

I can't even find the snowfall reports on the CLE NWS site anymore. It was an unusual pattern to how the bands set-up. 

https://www.weather.gov/source/crh/snowmap.html?zoom=8&lat=40.53&lon=-81.26&hr=12

The list is towards the bottom

[OHweather]

Here’s another link to the PNS. 

https://forecast.weather.gov/product.php?site=NWS&issuedby=CLE&product=PNS&format=CI&version=1&glossary=1

Some 2-4” reports down into Portage and Trumbull Counties even.  Hopefully the next event can spread the wealth some more! 

[OHweather]

I may or may not have time to post a more technical discussion tonight or tomorrow, but here's the map I posted on FB:

The thinking is 1-2" of synoptic snow near the lake and 2-4" inland, highest in the hills.  Temperatures marginal during the synoptic snow in the Cleveland area so hills should do better as they'll be colder and also have some orographic lift to enhance the snow.  Then the rest of the is lake effect.

Parameters are very good, with a prolonged period of extreme instability and much better moisture than the last event.  The flow is also fairly light and well aligned with decent synoptic support in a cyclonic flow under an upper-level trough.  The temperature profile is ideal for high ratios with the lake effect.  Question is band placement and persistence.

Winds swing NNE to NW late Monday night through Tuesday morning which should swing a Huron band from west of Cleveland east across the primary snowbelt, possibly getting into NW PA during the afternoon.  Outside of this band, favorable parameters should allow decent orographic lift snow showers to allow for continued slower accumulations, especially in the hills.  Both the NAM and RGEM show a vort max and surface trough dropping through late Tuesday afternoon or evening that may focus a more organized convergence band near Cleveland east into the snowbelt.  This band may linger through most of Tuesday night as ridging builds south of the lake and turns winds more SW over land, with the snow eventually lifting NE and weakening by Wednesday morning.  Any bands early Tuesday through Tuesday night can produce 1-2" per hour rates in their core and perhaps some thundersnow.

The secondary snowbelt in southern Cuyahoga/northern Medina is odd...should get 2-4" of synoptic snow, another 1-3 or 2-4" through Tuesday AM as the Huron band swings east with orographic lift outside of it, and then not sure if the possible convergence band Tuesday evening/night sets up there or a little father north.  Either way they should get several inches and could get 8"+ if they get the convergence band later Tuesday/Tuesday night.

For eastern Cuyahoga and Geauga, thinking 2-4" of synoptic snow, another 2-4" or so through Tuesday AM, perhaps up to 6" if the Huron band is slow enough, and then likely at least several more inches where the convergence band sets up later Tuesday into Tuesday night.  Either way, I think that higher terrain gets widespread double digits with well over a foot if / where the convergence band develops and is persistent. 

Into NW PA, similar synoptic story, perhaps a tad more in the higher terrain, the Huron band may swing east into there and allow for beefier totals too, and even outside of that there will be some orographic lift.  Think widespread 8"+ is likely in the higher terrain in southern Erie and northern Crawford Counties..

Let it snow!

[vpbob21]

Great analysis OHweather, as always.

I mentioned in the main thread that I just find it hilarious that Ottawa/Sandusky/Seneca/Erie/Huron/Lorain/Medina counties are the missing link in an otherwise unbroken string of winter headlines that runs from Montana to Maine.  I guess I can't really blame them for not wanting to pull the trigger, knowing how bad our snow climo is around here.  I do think some of the counties left out of headlines will eventually be added, especially Lorain and Medina (perhaps even warnings there) and probably the inland counties of Huron, Sandusky and Seneca.  The lakeshore counties might be a little more borderline with the warm lake temps cutting into accumulations,  but at the least it looks like everyone should get on the scoreboard for the season.

 

 

[OHweather]

1 hour ago, vpbob21 said:

Great analysis OHweather, as always.

I mentioned in the main thread that I just find it hilarious that Ottawa/Sandusky/Seneca/Erie/Huron/Lorain/Medina counties are the missing link in an otherwise unbroken string of winter headlines that runs from Montana to Maine.  I guess I can't really blame them for not wanting to pull the trigger, knowing how bad our snow climo is around here.  I do think some of the counties left out of headlines will eventually be added, especially Lorain and Medina (perhaps even warnings there) and probably the inland counties of Huron, Sandusky and Seneca.  The lakeshore counties might be a little more borderline with the warm lake temps cutting into accumulations,  but at the least it looks like everyone should get on the scoreboard for the season.

 

 

Yeah, your area is unfortunate for snow lovers for a few reasons.  But, everyone should get something at least, which isn’t too bad for this early.  I do suspect advisories fill in for the rest of Ohio tomorrow due to the falling temperatures and icy roads along with the snow even if not everyone is hitting the advisory criteria.  My guess is near you right by the lake struggles to get 2” due to the warmth you mentioned but inland will do better. 

[NEOH]

Nice forecast OHWeather. Looks like everything is still on track... although it seems the 06z models have shifted a bit north but that is probably just noise at this point. Precip wise the average among the models seems to be .75" - 1". Hopefully we don't waste too much on liquid. Temp is down to 37 IMBY. 

[NEOH]

Currently 38 IMBY.  Tough getting temps to drop with the lake temps in the low 50's. At this point it looks like it will be early evening before we flip to snow. 

[dta1984]

7 minutes ago, NEOH said:

Currently 38 IMBY.  Tough getting temps to drop with the lake temps in the low 50's. At this point it looks like it will be early evening before we flip to snow. 

Heavier precip should help the temps drop.  Don't think any accumulating snow was supposed to start until this evening.  

Edit; just saw this in the discussion "

Slight concern that snow amounts will be
lower with the warmer air lingering into the evening across the
east. However for now we will not tweak them lower and remain
consistent with the previous forecast."