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OHweather

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  1. I'll take the over but not by much. That would be another 16" of snow to get there and we have a while left in winter. The lake should be wide open as you said so we'll see.
  2. The only good news is that after all this wind/wamrth/rain coming up the lake will be open when all this cold moves in starting at the end of the week. That won't last long so hopefully any accompanying lake effect doesn't go towards NY. I didn't have high hopes for this winter but it's been amazingly futile so far.
  3. Can't sugar coat the 8.4" CLE is sitting at so far. Pitiful
  4. Athens is running a bit ahead of CLE snowfall wise for the season with about 12", almost normal for the whole season. You guys will get lucky eventually
  5. Here's my attempt at contouring storm total accumulations from this past storm based on spotter reports and radar. CLE sent a PNS with storm total snowfall this evening which was very helpful and saved me some time. Used reports of about 7" in South Russel/Newbury from dta and NEOH and assumed LakeEffectOH got about 22 or 23" based on 20" as of early Tuesday and a few hours of moderate to heavy snow after, which helped me finesse the gradient some in NW Geauga County. The best event we've seen in NE Ohio in a while actually...too bad it was confined to the heart of the Snowbelt. Comparing my forecast to this...the southern cut off in many areas was a bit farther north than I anticipated by a few miles. That's not a huge bust but when you're on the short end of that stick it can be infuriating. Overall amounts were higher than I anticipated by a few inches in general with a few areas that were half a foot or more above my forecast. My 12"+ area over northern Geauga/far southern Lake had an implied range of 12-18", and that was still well too low on max amounts. The southern cut off was a few miles north of where I expected but other than that I wasn't too upset about my placement of the heavier snow in Ohio, but was again several inches too low across the board. In NW PA...just like in NE OH...I was a bit too far south with the southern cutoff in amounts, and needed to bring heavier amounts down to the lakeshore. Overall I (once again) fared worse in NW PA than in NE Ohio with the forecast. I mentioned in my long write up that I could see totals topping 20" locally in northern Geauga County if everything went well and bands were persistent...given the duration of the event...similar winds through the event...and favorable conditions for the entire event I probably should've pulled out some higher accums. Being a few miles off with placement on the southern edge is one thing, but being several inches too low across the board is annoying. These last two events have made me feel like a conservative forecaster (which I've never been known as)...ironically a few people tried telling me my 12"+ was "aggressive" before the event, but the lake got the last laugh over a lot of us forecasters as it sometimes does as my max amounts were almost a foot too low.
  6. Pretty nice MODIS imagery from earlier today showing decent banding starting to develop on the ice over the western basin this morning...
  7. It limited moisture and also pushed the convergence north from Cuyahoga County west which played a role in the band placement farther east. It is amazing that we had a record warm December yet the lake is freezing in mid-January. Kind of cruel actually
  8. I really think the ice over the western basin hurt a lot of Cuyahoga County. The bands have hit a wall there all event even as winds farther east turned WNW.
  9. The spotter 2N of Chardon reported a storm total of 26"!
  10. Two events in a row the NMM has done very well on
  11. Yeah, a trough is still expected to push through. The winds will probably back a little more ahead of it though and keep the bands confined to your north before they swing back south later tonight into early Tuesday. You'll again be on the fringe...my current guess is you'll get somewhere between 1 and 3" tonight into tomorrow, but it doesn't take a huge shift for you to get more. Based on some reports CLE sent out it looks like most of extreme NE Cuyahoga...southern Lake...and northern Geauga is at 8-12" total currently with some areas locally a bit higher. The snow will continue in a lot of those areas (especially southern Lake and northern Geauga) for quite some time so totals exceeding 18" locally wouldn't be surprising. Also a couple of impressive totals from Erie County PA where I'm sure some spots will get about 2 feet. Pretty good event overall, just wish it was more widespread for you guys. LakeEffectOH should've gotten a lot it looks like.
  12. I'm sorry but I don't think I can even concede scraps if I want to stay all snow Was planning on driving to Cleveland on Saturday so I'm not sure how much I want the storm to happen here, we'll see.
  13. Looks like the amounts where the bands set up are pretty impressive, just a bit north of expected.
  14. If I'm doing my math right you're up to about 5" so far which is okay. The band is already lifting farther north, we'll see how far that next trough later tonight can push things back south.
  15. My only guess is the cold air inland kept the trough north. I can't ever remember bands staying so far north with 850mb winds turning almost due NW. It looks like only the southern fringes of my heavier amounts will struggle to hit the low end of my numbers but I'm really surprised things aren't farther south than last week's event.
  16. The bands are coming in from WNW to ESE and have been for several hours, but for some reason the southernmost band is coming in near Euclid towards Chesterland. The colder air over land must really be keeping the trough from pushing any farther south. Almost wonder if there's ice developing near the south shore of the western basin keeping the bands so far north. There should've been some good accums overnight where the bands happened to persist.
  17. I tend to agree with that WRT band placement. Winds over the lake turn pretty WNW to NW for a time and winds over land are pretty due W or close to it...not like Tuesday night where it was WNW over the lake and WSW to even SW over land. At this time I'm not planning on changing my forecast but we'll see how it works out The HRRR isn't my favorite model for LES, but it has a pretty good band across eastern Cuyahoga and Geauga tonight farther south than the NMM
  18. Here is what they look like off of WxBell: Unfortunately there aren't any great free links for them... http://www.tropicaltidbits.com/analysis/models/ TropicalTidbits has a decent regional view (click on "mesoscale" and then WRF-ARW or WRF-NMM) but it doesn't update that quickly. When I didn't have WeatherBell (which was for years) I used PSU's hi-res model site...the downfall here is there isn't a good zoomed in view http://mp1.met.psu.edu/~fxg1/ewallhires.html You can also get them off of NOAA's model site but the view is for the whole US so it's tough to see http://mag.ncep.noaa.gov/model-guidance-model-parameter.php?group=Model%20Guidance&model=HRW-ARW&area=CONUS&ps=area http://mag.ncep.noaa.gov/model-guidance-model-parameter.php?group=Model%20Guidance&model=HRW-NMMB&area=CONUS&ps=area At least you'll be within driving distance of the best snow if it does in fact stay to your north . Definitely a tough winter so far outside of a few small areas that have cashed in with each event.
  19. Looks like much like last week the NMM is north with the band (and has it close to last week's event) while the ARW has the heaviest along or a bit south of 322. Both models have a 1-1.5" QPF bullseye somewhere in Geauga County.
  20. Part 2: During the day Monday I expect the band to start lifting back northeast up the shoreline as high pressure noses in ahead of the next trough and backs winds a good bit. The band could very well disorganize for a few hours Monday morning behind the trough which is again, typical, but with continued extreme instability and a long fetch, I’d still expect moderate to heavy snow showers in the primary Snowbelt, perhaps favoring the higher terrain some…they just won’t be as organized. By Monday evening the models are really increasing convergence across Ashtabula and Erie Counties as temps start dropping again inland and high pressure continues to nose into the Ohio Valley, with another trough evident to the north starting to drop down. This suggests the band should start becoming more focused again by later Monday into Monday evening. Forecast soundings from Erie for Monday evening off both the 12km NAM and 4km NAM show continued high EL’s, good moisture, fairly well aligned winds and very strong lift in the DGZ. As convergence increases Monday evening and the band re-organizes I’d expect heavy snow rates of 1-2” per hour to resume. During the day Monday it takes until about mid-afternoon for the winds over the lake to go due west, so the snow showers may affect northeast Cuyahoga, central and northern Geauga, southern Ashtabula, and at least northern Crawford County into the early to mid-afternoon before activity becomes focused farther northeast. With due west winds over the lake by Monday evening with WSW or even SW winds over land, I’d have to suspect the band will end up fairly far northeast, into perhaps northern Ashtabula and certainly into Erie County. The potential for a well-organized, stable band Monday evening appears to be decent as one last good shortwave rotates in from the north late Monday night into Tuesday morning. This should bring another surface trough south across the lake late Monday night, increase mid-level moisture some and also provide some modest synoptic lift. Most models I looked at (NAM shown above) do show a nice lobe of mid-level moisture dropping south-southeast across the lake late Monday night into early Tuesday with the shortwave. This all suggests pretty good snow rates beneath any band Monday night into Tuesday morning. Forecast soundings from Erie overnight Monday night, while not as impressive as earlier in the event, are still good, with lake to 850mb and lake to 700mb temp differentials remaining near or better than 20C and 30C respectively suggesting extreme lake induced CAPE, along with equilibrium levels remaining near 10k feet…along with good moisture to about 8k feet and some moisture to about 13k feet, well aligned winds in the low levels and good upward motion in the DGZ. Snow rates of 1 to at times 2” per hour should be attainable with that kind of profile in any well-organized band Monday night. As the trough drops south early Tuesday and starts turning the winds more NWrly over the lake while winds remain WSW or SW on land, convergence will become very strong over the Snowbelt from northern Lorain and Cuyahoga Counties points east Tuesday morning. This supports snow rates again maxing out at potentially 2-3” per hour briefly as the trough starts pushing south early Tuesday. NAM forecast profiles for CLE still look decent Tuesday morning…easily supportive of heavy snow rates given the expected strong convergence as the trough approaches and then pushes south. The trough could bring winds around to the NW enough to push the snow farther inland Tuesday morning than Monday morning…possibly getting into most of Lorain and parts of Medina/Summit/Portage for a time…before the high starts building back in and backing the winds again. Behind the trough inversions really crash on Tuesday and remain at 3-4k feet through the day. The activity should start shifting back northeast on Tuesday into the primary Snowbelt but will mainly be light by that point with just minimal additional accumulations. BUFKIT time-height profiles for CLE and ERI from the low-res NAM indicate high humidity (color fill) and good lift (red contours) in the DGZ (purple/white contours in the lower portions of the images) throughout the event…with clear bullseyes when convergence and hence banding could very well be maximized at each location. This suggests moderate to heavy snowfall in the bands through the event with many areas seeing multiple possible windows of banding. Snow ratios will probably be good due to good lift and humidity in the DGZ but not great due to the cold suppressing the height of the DGZ. As for specific amounts…expect 2-3” in the primary Snowbelt with the frontal snow through Sunday afternoon and an inch…locally a bit more elsewhere. I expect light accums Sunday evening before the band really organizes from eastern Cuyahoga County points east, especially in the higher terrain inland. Expect banding to flare up for several hours late Sunday night into Monday morning with little movement and heavy rates…think an additional 4-8” is quite possible where this banding sets up, possible near 322. NW PA will also see good snow in the orographic lift areas in this timeframe and will probably see a better band or two as well wherever upstream moisture from Lake Michigan makes it and possibly downwind of upstream bays over northern/western Lake Erie, which are often initiation points for bands. Think 5-9” in inland NW PA in this timeframe as it should snow just about all night with moderate to heavy snow for several hours after midnight. The banding should sag south briefly Monday morning and possibly drop an inch or two as far south/west as I-80. Expect the band to break up some Monday morning behind the trough and slowly push north through the day. Think maybe another 1-3” in NE Cuyahoga, Lake, northern/central Geauga, Ashtabula, Erie and northern Crawford in this timeframe, least near the lakeshore and most in the higher terrain. I'm expecting a better band to develop Monday evening near the lakeshore in Ashtabula into Erie County PA. The lakeshore in Erie County could get hit decently in this timeframe as well as winds on land really try to back. This band looks to have a several hour window of little movement and moderate to heavy snow and should produce another 4-8” where it sits Monday night, before pushing south early Tuesday. The band should persist for a couple hours or so as it pushes back southwest across northern/eastern Cuyahoga, southern Lake and Geauga and could produce a quick 2-4” or so as it goes…with lighter amounts possible again about as far south as I-80 Tuesday morning. Think another 1-2” in the primary Snowbelt (mainly in the higher terrain) from mid-Tuesday morning through Tuesday afternoon as the event winds down. Totaling things up, I get two areas where banding looks to be persistent for longest…parts of eastern Cuyahoga into northern/central Geauga…and also inland Erie County PA. Totaling things up in these areas am getting about 18-24” in parts of inland Erie County…with 12-18” in surrounding portions of Erie County, northern Crawford County and perhaps adjacent far eastern Ashtabula where there are some hills. Am also getting 10-20” in northern/possibly central Geauga County and far eastern Cuyahoga County along 322 and east of 271. Will call that 12”+ because I’m not sure they’ll get near the top end of the 10-20” range unless the band really sits in one area. There will be a couple of windows for banding along the western lakeshore west of Downtown although the banding looks more persistent farther east, so will bring moderate amounts into the western lakeshore, and put a little additional snow in for lake effect as far south/west as northern Lorain/northern Medina/northern Summit/northern Portage. The lakeshore in Lake County looks to see mainly transient banding and may struggle to see 6” or so over the course of the event. Will go a bit higher in NE Ashtabula as they could be under banding Monday night. Parts of Ashtabula may be in a bit of a whole between banding throughout the event as they often are but there will be plenty of window for snow…so I think inland Ashtabula can squeak out 8” or so over the course of 48 hours but the heaviest probably will be elsewhere.
  21. What could be the largest lake effect snow event of the season in Northeastern Ohio is imminent as a lobe of the polar vortex brings the coldest air of winter thus far over the almost completely unfrozen waters of Lake Erie over the next couple of days. A cold front will move through NE Ohio and NW PA early to mid-afternoon on Sunday, with arctic air behind the front. This front will be passing through as a modest shot of positive vorticity advection (PVA) along with lift on the nose of a low to mid-level jet and in the left-exit quadrant of an upper level jet are all intersecting over the area as the front moves through. With forecast soundings showing nearly saturated profiles up to about 15K feet as the front goes through, certainly think this large scale lift will set off a general area of light snow late Sunday morning into the early afternoon across NE OH and NW PA. As the front moves through, forecast soundings show steep lapse rates and a little bit of CAPE into the snow growth zone (DGZ) which when combined with strong convergence/low level lift with the front itself will likely result in some snow squalls developing along the front: A forecast sounding for CLE off of the 0z 4km NAM as the front approaches shows the deep moisture (and weak lift in the mid-levels associated with the large scale lift discussed above, the white line is vertical motion, to the left is rising/upward motion), along with some CAPE to about 6k feet and through a good portion of the DGZ. This supports the notion of a general light snow for a couple or few hours with squalls along the front where low level lift will be maximized. In addition, there will already be some lake induced CAPE, so the squalls over the Snowbelt may pack a bit more of a punch along the front as the lake will add some additional instability. All in all, think the period of light snow and brief embedded squalls along the front will produce a general inch or so of snow for most of NE Ohio, with perhaps 2-3” in the primary Snowbelt in NE Ohio and NW PA where more instability will likely strengthen any snow squalls along the front. Ratios may be mediocre outside of any squalls which will likely limit over-performing potential with the synoptic snow. After the light amounts of synoptic snow, the attention will inevitably turn to lake effect snow as a very deep and cold upper low moves across the Great Lakes. There will likely be a period late Sunday afternoon and into the evening behind the frontal passage where lake effect takes some time to organize…which is fairly common…note how by 1AM Monday, the NAM is still just starting to develop better convergence across the Snowbelt. However, the above temperature/pressure pattern appears favorable for a strong, single band to eventually form from Cuyahoga County points east with NW to SE oriented isobars, a surface low pulling away to the east, some hints at a lake aggregate trough developing in the isobars, and another little trough evident in the isobars over southern Lower MI. Even if any bands struggle to consolidate some for a time Sunday evening, forecast soundings still suggest some decent moderate bursts of snow in the primary Snowbelt with W or WNW winds, moisture to 5k feet or so and equilibrium levels of near 11k feet. Forecast soundings from Erie are even gaudier with the instability Sunday evening with EQ levels near 13k feet and slightly warmer lake waters. I’d have to suspect that moderate to heavy orographic lift snows will occur in the higher terrain in inland Erie County and northern Crawford County Sunday evening even without a well-organized band due to the long fetch, extreme instability, pre-seeding and a fairly well-aligned flow. The NAM and Euro both agree on convergence really increasing across the Snowbelt after 1AM Sunday night into Monday morning as a trough drops southeast across Lake Erie while pressures rise over land and temps cool into the single digits inland. The trough dropping across the lake appears to be a result of another lobe rotating around the PV and moving across Lake Erie and northern OH/NW PA late Sunday night into Monday morning. This should provide some modest upward motion to enhance the lake effect further. In addition, this little lobe brings the coldest temps aloft, with 500mb temps bottoming out over the lake at near -40C early Monday morning. With lake to 850mb temp differentials of 22-24C…lake to 700mb differentials of 31-33C…and lake to 500mb differentials of 40-44C late Sunday night into Monday morning…along with some weak synoptic lift, a connection from Lake Michigan, and strong convergence over the Snowbelt, I have to expect a very focused and strong band to occur after midnight Sunday night into Monday morning as the trough approaches and pushes across the lake. Snow rates could briefly max out at 3” per hour under the band as the trough pushes into the lakeshore communities early Monday morning and maximizes convergence. A forecast sounding for CLE off of the 0z 4km NAM valid Monday morning as the trough is pushing through shows a deep layer of instability with high equilibrium levels and well-aligned winds. The DGZ is confined to the lowest 3-4k feet due to the very cold air, but the model shows the lowest 2-3k feet of the cloud layer being in the DGZ with the strongest upward motion also in the DGZ. So although the cold may keep ratios from getting to very high values such as 30-40:1, I think 20:1 is still very much doable Sunday night into Monday morning which will allow for relatively efficient accumulations. Forecast soundings for Erie are even more impressive, with equilibrium levels near 15k feet and around 1000 J/KG of lake induced CAPE…supportive of very heavy snow rates. As for band placement Sunday night into Monday morning…the NAM surface winds suggest it’ll be focused from extreme NE Cuyahoga east across southern Lake, northern Geauga, southern Ashtabula and into southern Erie/northern Crawford Counties. However, the isobar orientation as seen a few images up is a very close match to previous Cuyahoga County single band cases, and 850mb winds seen in the above image are in the 290-300 range over NE Ohio and the lake, which suggests winds over the lake should try to take on a pretty good northwesterly component and push the band inland a little bit. Everything suggests the band should sit 5-10 miles farther south than the band last Tuesday night sat. The 0z ARW has the band from near Avon east across most of northern and central Cuyahoga County east into Geauga County, with the heaviest just south of 322. The NMM is a bit farther north and takes the best band from Cleveland and Bratenahl ESE and is more centered right on 322. The winds backing some over land do give me pause on bringing the band too far south so I tend to think that the NMM is closer on band placement Sunday night into Monday morning as the trough approaches. Think there could be a 4-6 hour window from about 2AM-7AM (give or take an hour) where the band moves very little as the trough approaches, with the band swinging south into more of Cuyahoga and southern Geauga Counties *briefly* immediately behind the trough, before starting to slowly drift back north. There could be significant accumulations in that window where the band sits. In NW PA with a due west or WNW wind ahead of the trough, think the banding will stretch from northern Ashtabula east across inland Erie and northern Crawford for several hours, with snow rates of 1 to perhaps 2” per hour at times over the higher terrain given the very strong instability and lift with the trough. Could also see rates locally max out higher here too as the trough pushes inland and really enhances convergence for a time.
  22. I have you getting roughly 8" on the map I was sketching up earlier but with heavier amounts to your north and lighter just to your south, so I think you'll get more than this past event but still be too far south to jackpot. I'll post my map and a write up later tonight but it may be a while until I get around to it. Hopefully this isn't the "banner" event of the season for the Ohio snowbelt.
  23. Not a bad first forecast from CLE, although I'm personally more optimistic about parts of Cuyahoga getting warning criteria snow. I definitely think some areas will get 12-18" where the bands are more persistent.
  24. There definitely are some similarities, especially Sunday night. At this point I'm feeling pretty good about a good band because of this, but location is obviously still up in the air. There isn't a ton of difference between a pattern favorable for a band slipping into a good portion of Cuyahoga and all of Geuaga and a setup similar to say Tuesday night of this past week so I don't want to go all in on a forecast of heavy snow for Cuyahoga and southern Geauga...but the winds do appear to be a little more favorable for it with this upcoming event than the past event. I certainly can't see any band setting up farther north than Tuesday night's band did. There appears to be at least a 12-24 hour window from Sunday evening through Monday evening where winds move very little with moderate to extreme instability and decent moisture so there could be some pretty big totals. Some models try to back the winds a bit on Monday which would shift the band north a little bit, while others don't move the winds a ton until early Tuesday...such as the Euro which drops a second trough across the lake Monday night and would extend the event. My one concern remains if the dry and cold air will limit snow ratios. The NAM and 4km NAM still show enough moisture to keep the bottom few thousand feet of the clouds in the DGZ, but the GFS remains drier with the low levels and would be dry enough to hurt snow ratios. That could honestly make the difference between a 1 to 2 foot event which I currently think is on the table for someone and a more run of the mill 4-8" event with the snow falling as a bunch of needles.
  25. In an effort to identify scenarios that support heavy, single banded lake effect snow into Cuyahoga County, I looked at several recent warning criteria lake effect snow events in Cuyahoga County that were caused by a single band of heavy snow (not multi-banded and/or orographic lift, or lake enhanced snow). The sample size is small but potentially useful. These events were off the top of my head as I’m quickly throwing this together, I’m sure I missed some events in the late 2000s. The following are surface maps from warning criteria, single banded events in Cuyahoga County that effected a fairly large portion of the county with heavy snow events. Surface maps are from the approximate time of maximum snow intensity: (the maps came out a bit fuzzy in the post, I linked to the WPC's surface map archives for the appropriate day for each event, those maps are less fuzzy) April 7th, 2007: Link to surface maps from this date for you to scroll through as you please: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=04/07/2007&selmap=2007040712&maptype=namussfc This was a part of a long duration, significant and out of season event. A heavy band of snow developed from the northwest portions of Cuyahoga County and set up east or slightly south of east towards the southeast portion of the county towards Solon and Chagrin Falls. Amounts from the band were in the 6-10″ range. The isobars over Lake Erie and Northeast Ohio are roughly oriented NW to SE, with a clear surface trough evident over central lower Michigan dropping south or southeast. There is a surface low over south-central Quebec and a surface high extending from western Manitoba south across the central Plains. April 8th, 2007: Link to maps from this date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=04/08/2007&selmap=2007040812&maptype=namussfc This was a part of the same event described above, just a day later. A band of heavy snow redeveloped on the evening of the 7th into the morning of the 8th, a few miles farther north than the previous night. The band set up from near downtown Cleveland east towards east-central Cuyahoga County, with heaviest amounts near or just south of the 322 corridor in eastern Cuyahoga County. Amounts with the band were up to a foot on the east side. The isobars are oriented a little more WNW to ESE, with a stronger surface low near the northern tip of Nova Scotia and the surface high slightly farther east extending from central Manitoba south across the Plains. A clear surface trough is evident across central lower Michigan. December 8th, 2010: Link to maps from this date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=12/08/2010&selmap=2010120821&maptype=namussfc Anyone who lived in Cleveland into December of 2010 should remember this event. A band of heavy snow developed across northern and eastern Cuyahoga County during the morning on December 8th and intensified during the afternoon while remaining nearly stationary. The heaviest snow affect the western lakeshore and downtown Cleveland (with over 10” of snow near downtown) and extended east into much of eastern Cuyahoga County, with even Solon receiving warning criteria snowfall. The band shifted south and weakened during the evening of the 8th. This came at the end of a significant, multi-day lake effect event. The isobars are roughly oriented northwest to southeast, with a clear trough near or just north of Lake Erie. There is a surface low located east of Hudson Bay and a surface high extended from near the Ontario/Manitoba border south across the Mississippi Valley. A nose of higher pressure extends east across the Ohio Valley as well. January 2nd, 2012: Link to maps from this date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=01/02/2012&selmap=2012010212&maptype=namussfc This occurred at the beginning of a warning criteria (but not incredibly notable) lake effect event for the primary Northeast Ohio Snowbelt. A snow band developed across the eastern lakeshore in Lake and Ashtabula Counties overnight on the 1st into the 2nd and shifted into eastern Cuyahoga County on the morning of the 2nd and persisted for a few hours, before shifting south and dissipating. Warning criteria snow occurred during a 12 hour period during the daylight hours on the 2nd in portions of east-central Cuyahoga County. This is a marginal case. The isobars are oriented roughly northwest to southeast, with a surface low located southeast of Hudson Bay. High pressure extended from central Manitoba south-southwest towards central Texas. A surface trough is evident over northern lower MI and central Lake Huron and is analyzed as a cold front on this map. January 22nd, 2013: Link to maps from this date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=01/22/2013&selmap=2013012218&maptype=namussfc This was a part of a fairly decent multi-day event in the primary Snowbelt mainly east of Cleveland. A single band of snow developed across northern and eastern Cuyahoga County late in the evening on the 21st and persisted into the morning on the 22nd, before shifting south and weakening by late morning on the 22nd. The heaviest snow occurred from the lakeshore in Cleveland east towards the eastern suburbs such as Lyndhurst and Mayfield. Amounts from the band were over 6″. The isobars are roughly oriented northwest to southeast, with a clear surface trough analyzed as a stationary front extending across northern Michigan and Lake Huron. A smaller surface trough is analyzed in southeast Michigan but has a minimal impression on the pressure field. A surface low is located off the New England coast, with high pressure extending from North Dakota south-southeast towards Illinois and Arkansas. A nose of higher pressure extends east through the Ohio Valley. October 24th, 2013: Maps from the date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=10/24/2013&selmap=2013102412&maptype=namussfc This was one of the most significant October lake effect snow events that Northeast Ohio has seen in recent memory. A snow band developed in the evening of the 23rd, initially across northern and eastern Cuyahoga County east into Geauga County, before shifting north into Lake, northern Geauga, and Ashtabula Counties for a few hours. The band settled back south into northeastern Cuyahoga County early in the morning on the 24th and was persistent through most of the afternoon from over or just north of downtown Cleveland east towards Mayfield, at times getting as far south as Beachwood, but generally a little farther north. Snowfall amounts of near 8” occurred in Mayfield Heights. If this occurred when it was colder, snowfall totals of 1 to 2 feet very well could’ve occurred on a fairly widespread basis. The band shifted south and weakened during the evening on the 24th. The isobars were generally oriented WNW to ESE…however, a very well-defined trough moving across the lake had a strong impression on the pressure field downwind of the trough in Northeast Ohio. A low was located east of Hudson Bay with a high extending from southeast Alberta towards Kansas. A small area of higher pressure extended east through the Ohio Valley. November 14th, 2014: Maps from the date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=11/14/2014&selmap=2014111412&maptype=namussfc This was a part of a multi-day event focused from northern Lorain County points east. A strong band of heavy snow developed along the eastern shoreline from Lake County up through Erie County PA on the 13th, with some areas receiving over a foot of snow during the day on the 13th. That first single band swung southwest during the evening and produced a quick couple inches or more of snow as it went as far west as parts of central Lorain County, before the band broke up and multi-bands took over for a time. A single band re-organized early in the morning on the 14th from northern Lorain County east across a large portion of Cuyahoga County and southern Geauga County and persisted for several hours, before becoming more diffuse in the evening on the 14th. The second band allowed portions of eastern Cuyahoga County to reach the 24 hour warning criteria of 8” or more of snow. The isobars were oriented northwest to southeast, with a modest surface trough evident from central Lake Huron points west. A surface low was located well off the New England coast, with a surface high across the eastern Plains. Higher pressures extended east through a good portion of the Ohio Valley. November 20-21st, 2014: Maps from the data: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=11/21/2014&selmap=2014112106&maptype=namussfc This event came at the end of a multi-day event that dropped feet of snow on western New York south of Buffalo. A well-established single band pushed southwest across the lake late in the afternoon and into the evening on the 20th and swung through Cuyahoga County fairly quickly, before stabilizing for several hours from northwestern Lorain County east-southeast into southwestern Cuyahoga County, just south of the airport. Snow totals of up to 6” occurred in parts of southwestern Cuyahoga County. The band quickly broke up on the morning of the 21st as high pressure moved in lowering inversion heights and as winds turned more northwesterly. The isobars when the band stabilized across parts of Cuyahoga County were oriented NW to SE, with a clear trough near the south shore of Lake Erie and another one farther northwest across central lower Michigan and Lake Huron. A surface low was located north of Maine and a surface high stretched from Iowa to Kentucky. November 27th, 2014: Maps from this date: http://www.wpc.ncep.noaa.gov/archives/web_pages/sfc/sfc_archive_maps.php?arcdate=11/28/2014&selmap=2014112800&maptype=namussfc This was a short duration, high intensity event. The event started early in the morning on the 27th as a surface low moved up the East Coast and swung the winds around from NE to NW. Multi-banded lake effect with some Lake Huron connection developed into the west side early in the morning and quickly swung east across the Cleveland metro into the primary Snowbelt and dissipated by late morning. 1-2” of snowfall fell in parts of the metro with this portion of the event. The snow essentially ended for several hours before a surface trough dropped across the lake during the evening and produced a single band of heavy snow into northern Lorain, southern and eastern Cuyahoga, far northern Summit, southern Geauga and northern Portage Counties for a few hours, before the trough shifted south causing the band to shift south and break up. Snowfall rates of 3” per hour were observed at CLE and some areas received 6” of snowfall in under 3 hours, making this a warning criteria snowfall. A surface low during the time of the band was located northeast of Nova Scotia, with a surface high extending from Iowa to Mississippi. A surface trough was located over Lake Erie when the band occurred. Isobars were located north to south north of the trough and NW to SE south of the trough. Summary: Every event featured isobars oriented a pretty true NW to SE. A couple of events had isobars slightly more westerly than northerly, but were generally oriented NW to SE or very close to it. Every event featured lower pressure somewhere to the east or northeast, with an inverted trough extending back towards the Great Lakes. Most of the events that locked a band in for more than a few hours also had high pressure extending east from the central US into the Ohio Valley…events like 11/27/14 and 1/2/12 that were more marginal and didn’t feature a well-organized band for more than a few hours didn’t have higher pressure nosing into the Ohio Valley as well as the other events did. Every event had at least a subtle surface trough over Lake Erie or not far to the north. It seems that for a single band of lake effect snow to produce warning criteria snow into a good portion of Cuyahoga County, a few things are needed (other than the obvious proper moisture/instability for a strong lake response): -Low pressure to the east or northeast with an inverted trough extending towards the Great Lakes. The inverted trough doesn’t seem to be required as a couple of good events didn’t have it, but most events do have a feature like that. -At least a subtle surface trough over the lake or just to the north of the lake. An inverted trough extending west from a surface low to our east or northeast can serve this purpose. -Isobars oriented northwest to southeast. More WNW to ESE isobars may still clip the extreme NE corner of the county but would likely miss a majority of the county. -High pressure nosing into the Ohio Valley appears to make it more likely for bands to lock into place for more than a brief period of time. -High pressure placement to our west doesn’t seem extremely important, as long as the high is centered to the west somewhere with preferably some higher pressure extending east into the Ohio Valley. Shortfalls: Obviously this is a small sample size off the top of my head. There is the possibility that other seemingly favorable environments with similar pressure patterns didn’t produce, so this doesn’t scratch the false alarm rate of using isobaric patterns to predict if a single band of lake effect snow will occur in Cuyahoga County or not. Only warning criteria events were used…shorter duration events that only produced advisory snowfall were not explored as again, this sample was off the top of my head. More obviously goes into lake effect forecasting than the isobaric pattern, however, all 9 events featured very similar patterns so I believe this information can still be useful.
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